AIMS/HYPOTHESIS:
Diabetes mellitus is one of the most common endocrine disorders in dogs and is commonly proposed to be of autoimmune origin. Although the clinical presentation of human type 1 diabetes (T1D) and canine diabetes are similar, the aetiologies may differ. The aim of this study was to investigate if autoimmune aetiology resembling human T1D is as prevalent in dogs as previously reported.
METHODS:
Sera from 121 diabetic dogs representing 40 different breeds were tested for islet cell antibodies (ICA) and GAD65 autoantibodies (GADA) and compared with sera from 133 healthy dogs. ICA was detected by indirect immunofluorescence using both canine and human frozen sections. GADA was detected by in vitro transcription and translation (ITT) of human and canine GAD65, followed by immune precipitation. Sections of pancreata from five diabetic dogs and two control dogs were examined histopathologically including immunostaining for insulin, glucagon, somatostatin and pancreas polypeptide.
RESULTS:
None of the canine sera analysed tested positive for ICA on sections of frozen canine or human ICA pancreas. However, serum from one diabetic dog was weakly positive in the canine GADA assay and serum from one healthy dog was weakly positive in the human GADA assay. Histopathology showed marked degenerative changes in endocrine islets, including vacuolisation and variable loss of immune-staining for insulin. No sign of inflammation was noted.
CONCLUSIONS/INTERPRETATIONS:
Contrary to previous observations, based on results from tests for humoral autoreactivity towards islet proteins using four different assays, and histopathological examinations, we do not find any support for an islet autoimmune aetiology in canine diabetes mellitus.
Autoimmune polyendocrine syndrome type 1 (APS-1) is a multiorgan autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. Chronic mucocutaneous candidiasis, hypoparathyroidism and adrenal failure are hallmarks of the disease. The critical mechanisms causing chronic mucocutaneous candidiasis in APS-1 patients have not been identified although autoantibodies to cytokines are implicated in the pathogenesis. To investigate whether the Th reactivity to Candida albicans (C. albicans) and other stimuli was altered, we isolated PBMC from APS-1 patients and matched healthy controls. The Th17 pathway was upregulated in response to C. albicans in APS-1 patients, whereas the IL-22 secretion was reduced. Autoantibodies against IL-22, IL-17A and IL-17F were detected in sera from APS-1 patients by immunoprecipitation. In addition, Aire-deficient (Aire(0/0) ) mice were much more susceptible than Aire(+/+) mice to mucosal candidiasis and C. albicans-induced Th17- and Th1-cell responses were increased in Aire(0/0) mice. Thus an excessive IL-17A reactivity towards C. albicans was observed in APS-1 patients and Aire(0/0) mice.
Mutations of the gene encoding four-and-a-half LIM domain 1 (FHL1) are the causative factor of several X-linked hereditary myopathies that are collectively termed FHL1-related myopathies. These disorders are characterized by severe muscle dysfunction and damage. Here, we have shown that patients with idiopathic inflammatory myopathies (IIMs) develop autoimmunity to FHL1, which is a muscle-specific protein. Anti-FHL1 autoantibodies were detected in 25% of IIM patients, while patients with other autoimmune diseases or muscular dystrophies were largely anti-FHL1 negative. Anti-FHL1 reactivity was predictive for muscle atrophy, dysphagia, pronounced muscle fiber damage, and vasculitis. FHL1 showed an altered expression pattern, with focal accumulation in the muscle fibers of autoantibody-positive patients compared with a homogeneous expression in anti-FHL1-negative patients and healthy controls. We determined that FHL1 is a target of the cytotoxic protease granzyme B, indicating that the generation of FHL1 fragments may initiate FHL1 autoimmunity. Moreover, immunization of myositis-prone mice with FHL1 aggravated muscle weakness and increased mortality, suggesting a direct link between anti-FHL1 responses and muscle damage. Together, our findings provide evidence that FHL1 may be involved in the pathogenesis not only of genetic FHL1-related myopathies but also of autoimmune IIM. Importantly, these results indicate that anti-FHL1 autoantibodies in peripheral blood have promising potential as a biomarker to identify a subset of severe IIM.
BACKGROUND: Autoimmune polyendocrine syndrome type 1 (APS-1) is a multiorgan autoimmune disorder caused by mutations in AIRE, the autoimmune regulator gene. Though recent studies concerning AIRE deficiency have begun to elucidate the molecular pathogenesis of organ-specific autoimmunity in patients with APS-1, the autoantigen responsible for hypoparathyroidism, a hallmark of APS-1 and its most common autoimmune endocrinopathy, has not yet been identified. METHODS: We performed immunoscreening of a human parathyroid complementary DNA library, using serum samples from patients with APS-1 and hypoparathyroidism, to identify patients with reactivity to the NACHT leucine-rich-repeat protein 5 (NALP5). Subsequently, serum samples from 87 patients with APS-1 and 293 controls, including patients with other autoimmune disorders, were used to determine the frequency and specificity of autoantibodies against NALP5. In addition, the expression of NALP5 was investigated in various tissues. RESULTS: NALP5-specific autoantibodies were detected in 49% of the patients with APS-1 and hypoparathyroidism but were absent in all patients with APS-1 but without hypoparathyroidism, in all patients with other autoimmune endocrine disorders, and in all healthy controls. NALP5 was predominantly expressed in the cytoplasm of parathyroid chief cells. CONCLUSIONS: NALP5 appears to be a tissue-specific autoantigen involved in hypoparathyroidism in patients with APS-1. Autoantibodies against NALP5 appear to be highly specific and may be diagnostic for this prominent component of APS-1.
Patients with autoimmune polyendocrine syndrome type 1 (APS-1) suffer from multiple organ-specific autoimmunity with autoantibodies against target tissue-specific autoantigens. Endocrine and nonendocrine organs such as skin, hair follicles, and liver are targeted by the immune system. Despite sporadic observations of pulmonary symptoms among APS-1 patients, an autoimmune mechanism for pulmonary involvement has not been elucidated. We report here on a subset of APS-1 patients with respiratory symptoms. Eight patients with pulmonary involvement were identified. Severe airway obstruction was found in 4 patients, leading to death in 2. Immunoscreening of a cDNA library using serum samples from a patient with APS-1 and obstructive respiratory symptoms identified a putative potassium channel regulator (KCNRG) as a pulmonary autoantigen. Reactivity to recombinant KCNRG was assessed in 110 APS-1 patients by using immunoprecipitation. Autoantibodies to KCNRG were present in 7 of the 8 patients with respiratory symptoms, but in only 1 of 102 APS-1 patients without respiratory symptoms. Expression of KCNRG messenger RNA and protein was found to be predominantly restricted to the epithelial cells of terminal bronchioles. Autoantibodies to KCNRG, a protein mainly expressed in bronchial epithelium, are strongly associated with pulmonary involvement in APS-1. These findings may facilitate the recognition, diagnosis, characterization, and understanding of the pulmonary manifestations of APS-1.
BACKGROUND: We have previously shown that vaccination with DNA encoding the encephalitogenic peptide myelin oligodendrocyte glycoprotein (MOG)(91-108) (pMOG) suppresses MOG(91-108)-induced rat Experimental Autoimmune Encephalomyelitis (EAE), a model for human Multiple Sclerosis (MS). The suppressive effect of pMOG is dependent on inclusion of CpG DNA in the plasmid backbone and is associated with early induction of Interferon (IFN)-beta. PRINCIPAL FINDINGS: In this study we examined the mechanisms underlying pMOG-induced protection. We found that in the DNA vaccinated cohort proinflammatory Interleukin (IL)-17 and IL-21 responses were dramatically reduced compared to in the control group, but that the expression of Foxp3 and Tumor Growth Factor (TGF)-beta1, which are associated with regulatory T cells, was not enhanced. Moreover, genes associated with Type I IFNs were upregulated. To delineate the role of IFN-beta in the protective mechanism we employed short interfering RNA (siRNA) to IFN-beta in the DNA vaccine. SiRNA to IFN-beta completely abrogated the protective effects of the vaccine, demonstrating that a local early elaboration of IFN-beta is important for EAE protection. IL-17 responses comparable to those in control rats developed in rats injected with the IFN-beta-silencing DNA vaccine. CONCLUSIONS: We herein demonstrate that DNA vaccination protects from proinflammatory Th17 cell responses during induction of EAE. The mechanism involves IFN-beta as IL-17 responses are rescued by silencing of IFN-beta during DNA vaccination.
Primary sclerosing cholangitis (PSC) is an enigmatic disorder with a suggested autoimmune basis. A variety of autoantigens have been suggested but no specific or highly directed epitope has been identified. To address this issue, we constructed a cDNA library from normal human choledochus and screened expressing clones with serum from a patient with PSC and inflammatory bowel disease (IBD). Based on this screening, glutathione S-transferase theta 1 (GSTT1) was identified as a potential autoantigenic target. To study the specificity of GSTT1, we determined immunoreactivity using a panel of 58 patients with PSC, with and without IBD, 57 patients with IBD, 31 patients with Hashimoto's thyroiditis, 30 patients with primary biliary cirrhosis (PBC), 20 patients with insulin dependent diabetes mellitus, 22 patients with autoimmune polyendocrine syndrome type 1, 10 patients with systemic lupus erythematosus (SLE), 20 patients with Sjogren's syndrome, 12 patients with autoimmune pancreatitis, 28 patients with Addison's disease, 27 patients with Grave's disease, 17 with myasthenia gravis, and 118 healthy controls. Reactivity against GSTT1 was found with PSC and IBD as well as some patients with other autoimmune pathology, indicating that this population of antibodies is neither specific nor a sensitive serologic marker for PSC, but the frequency was clearly higher in autoimmune patients than controls. GSTT1-antibodies have been described in persons with GSTT1-null genotype and are suggested to develop as an alloimmune response to blood transfusions from GSTT1-positive donors or pregnancies with GSTT1-positive children. Therefore, two IBD patients with and 15 PSC patients without GSTT1-antibodies were genotyped for GSTT1 to investigate if the presence of GSTT1-antibodies was associated with the GSTT1-null genotype and possibly caused by an alloimmune response. Both IBD patients and three of the PSC patients were of the GSTT1-null genotype. We note that the frequency of GSTT1-antibodies in this study is more than 100-fold higher than the frequency described earlier in patients with autoimmune diseases. We also observe an increased frequency of GSTT1-antibodies in patients with autoimmune diseases compared to healthy controls. This increased frequency can be explained by an autoimmune phenotype which increases susceptibility to such autoantibodies, or by a high frequency of the GSTT1-null genotype in autoimmune disease.
BACKGROUND: A number of autoantibodies have been reported in inflammatory bowel disease (IBD). The aim of this study was to investigate to what extent sera from patients with IBD contain autoantibodies directed against normal human gastrointestinal mucosa. METHODS: Samples of sera from 50 patients with IBD and 50 healthy subjects were used for immunostaining of normal and affected human gastrointestinal tissues. RESULTS: Eighty-four percent of the sera from IBD patients showed immunoreactivity against goblet cells in the appendix compared with 8% of the sera from healthy subjects. Goblet cell reactivity of IBD patient sera varied between regions in the gastrointestinal tract. Sera from healthy subjects only reacted with goblet cells in the appendix. In the colon and the appendix, goblet cell reactivity of IBD sera was generally weak at the base of the crypts and gradually increased toward the lumen. Three IBD sera samples reacted with gastrin cells in the antrum. In colon biopsies from patients with ulcerative colitis, immunoreactivity against the remaining goblet cells showed an inverse correlation with inflammatory activity. CONCLUSIONS: These findings suggest that immunoreactivity against goblet cells may be of central importance in the pathogenesis of IBD. Identification of goblet cell antigens could lead to a better understanding of IBD and provide a new diagnostic tool.
OBJECTIVES: Primary adrenocortical insufficiency is mostly caused by an autoimmune destruction of the adrenal cortex. The disease may appear isolated or as a part of an autoimmune polyendocrine syndrome (APS). APS1 is a rare hereditary disorder with a broad spectrum of clinical manifestations. In APS2, primary adrenocortical insufficiency is often combined with autoimmune thyroid disease and/or type 1 diabetes. We analysed mortality and cancer incidence in primary adrenocortical insufficiency patients during 40 years. Data were compared with the general Swedish population. DESIGN AND PATIENTS: A population based cohort study including all patients with autoimmune primary adrenocortical insufficiency (3299) admitted to Swedish hospitals 1964-2004. MEASUREMENTS: Mortality risk was calculated as the standardized mortality ratio (SMR) and cancer incidence as the standardized incidence ratio (SIR). RESULTS: A more than 2-fold increased mortality risk was observed in both women (SMR 2.9, 95% CI 2.7-3.0) and men (SMR 2.5, 95% CI 2.3-2.7). Highest risks were observed in patients diagnosed in childhood. SMR was higher in APS1 patients (SMR 4.6, 95% CI 3.5-6.0) compared with patients with APS2 (SMR 2.1, 95% CI 1.9-2.4). Cancer incidence was increased (SIR 1.3, 95% CI 1.2-1.5). When tumours observed during the first year of follow-up were excluded, only the cancer risk among APS1 patients remained increased. Cause-specific cancer incidence analysis revealed significantly higher incidences of oral cancer, nonmelanoma skin cancer, and male genital system cancer among patients. Breast cancer incidence was lower than in the general population. CONCLUSIONS: Our study shows a reduced life expectancy and altered cancer incidence pattern in patients with autoimmune primary adrenocortical insufficiency.
Autoimmune polyendocrine syndrome type 1 (APS1) is a rare autosomal recessive disorder caused by mutations in the autoimmune regulator (AIRE) gene. High titer autoantibodies (Aabs) toward intracellular enzymes are a hallmark for APS1 and serve as diagnostic markers and predictors for disease manifestations. In this study, we aimed to identify pituitary autoantigens in patients with APS1. A pituitary cDNA expression library was screened with APS1 sera and a tudor domain containing protein 6 (TDRD6) cDNA clone was isolated. Positive immunoreactivity against in vitro translated TDRD6 fragments was shown in 42/86 (49%) APS1 patients but not in patients with other autoimmune diseases or in healthy controls. By using immunohistochemistry, sera from 3/6 APS1 patients with growth hormone (GH) deficiency showed immunostaining of a small number of guinea pig anterior pituitary cells, and 40-50% of these cells were GH-positive. No such immunostaining was seen with sera from healthy controls. The APS1 Aab-positive, GH-negative cells may represent a novel subpopulation of anterior pituitary cells. In addition, 4/6 patient sera showed staining of a fiber-plexus in the pituitary intermediate lobe recognizing enzymes of monoamine and GABA synthesis. Thus, we have identified TDRD6 as a major autoantigen in APS1 patients and shown that several sera from GH-deficient patients stain specific cell populations and nerves in the pituitary gland.
Lymphocytic hypophysitis (LyH) is a rare inflammatory disease, considered to be autoimmune. LyH has mainly been reported in females and in relation to pregnancy or the post-partum period. We describe a 73-yr-old woman and a 63-yr-old male who were evaluated at our clinic because of pituitary hormone deficits. Both patients had pituitary masses suggestive of a pituitary adenoma on magnetic resonance imaging (MRI). Transsphenoidal pituitary surgery was performed and histopathological examinations revealed LyH in both cases. Clinical, laboratory, radiological and the histopathological findings in these two patients are discussed in detail. In addition, we report on a 79-yr-old man with partial hypopituitarism and empty sella. Screening of a human pituitary cDNA library with his serum revealed autoantibodies against secretogranin II. This is a protein commonly present in human gonadotrophs, thyreotrophs and corticotrophs. Since the patient selectively showed the corresponding pituitary insufficiencies, we speculate on an autoimmune background. Further studies may ascertain the importance of secretogranin II autoantibodies as markers for LyH.
OBJECTIVE: The cause of empty sella syndrome (ESS) remains largely unknown. We measured eleven organ-specific autoantibodies in serum in order to evaluate possible autoimmune components in ESS. PATIENTS: Thirty patients with ESS and 50 healthy blood donors participated in the study. MEASUREMENTS: Detection of pituitary autoantibodies was performed by immunoblotting with human pituitary cytosol as antigen. Thyroid peroxidase (TPO) and TSH receptor (TRAK) autoantibodies were analysed by radioimmunoassay. The remaining eight autoantibodies were detected by in vitro transcription and translation of the autoantigens and immunoprecipitation. RESULTS: The majority of the ESS patients (18/30) exhibited no immunoreactivity at all. None of the remaining 12 ESS patients reacted against more than one autoantigen. No immunoreactivity was found more frequently among ESS patients than healthy blood donors. Pituitary autoantibodies were not correlated to the ESS patients' pituitary function or sellar size, although the results indicated a tendency of increased autoimmunity in patients with hypopituitarism and normal sella size respectively. CONCLUSION: Detection of autoantibodies is a valuable tool in the diagnostic work-up of autoimmune diseases. By analysing a large number of organ-specific autoantibodies we found no evidence of ESS being associated with any specific autoimmune disease. The pathogenesis of ESS is believed to be heterogeneous and our findings suggest autoimmune components to be of minor importance. In some selective cases, ESS in combination with hypopituitarism may be the result of an autoimmune disease in the pituitary gland but this needs further investigation.
ContextConventional glucocorticoid replacement therapy in patients with Addison's disease (AD) is unphysiological with possible adverse effects on mortality, morbidity and quality of life. The diurnal cortisol profile can likely be restored by continuous subcutaneous hydrocortisone infusion (CSHI). ObjectiveThe aim of this study was to compare circadian hormone rhythms and insulin sensitivity in conventional thrice-daily regimen of glucocorticoid replacement therapy with CSHI treatment in patients with AD. Design and settingAn open, randomized, two-period, 12-week crossover multicentre trial in Norway and Sweden. PatientsTen Norwegian patients were admitted for 24-h sampling of hormone profiles. Fifteen Swedish patients underwent euglycaemic-hyperinsulinaemic clamp. InterventionThrice-daily regimen of oral hydrocortisone (OHC) and CSHI treatment. Main outcome measureWe measured the circadian rhythm of cortisol, adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin-like growth factor-1, (IGF-1), IGF-binding protein-3 (IGFBP-3), glucose, insulin and triglycerides during OHC and CSHI treatment. Euglycaemic-hyperinsulinaemic clamp was used to assess insulin sensitivity. ResultsContinuous subcutaneous hydrocortisone infusion provided a more physiological circadian cortisol curve including a late-night cortisol surge. ACTH levels showed a near normal circadian variation for CSHI. CSHI prevented a continuous decrease in glucose during the night. No difference in insulin sensitivity was observed between the two treatment arms. ConclusionContinuous subcutaneous hydrocortisone infusion replacement re-established a circadian cortisol rhythm and normalized the ACTH levels. Patients with CSHI replacement had a more stable night-time glucose level compared with OHC without compromising insulin sensitivity. Thus, restoring night-time cortisol levels might be advantageous for patients with AD.
Context: There are no published data on drug prescription in patients with Addison's disease ( AD). Objective: Our objective was to describe the drug prescription patterns in Swedish AD patients before and after diagnosis compared with population controls. Design and Setting: We conducted a population-based cohort study in Sweden. Patients: Through the Swedish National Patient Register and the Swedish Prescribed Drug Register, we identified 1305 patients with both a diagnosis of AD and on combination treatment with hydrocortisone/cortisone acetate and fludrocortisone. Direct evidence of the AD diagnosis from patient charts was not available. We identified 11 996 matched controls by the Register of Population. Main Outcome Measure: We determined the ratio of observed to expected number of patients treated with prescribed drugs. Results: Overall, Swedish AD patients received more prescribed drugs than controls, and 59.3% of the AD patients had medications indicating concomitant autoimmune disease. Interestingly, both before and after the diagnosis of AD, patients used more gastrointestinal medications, antianemic preparations, lipid-modifying agents, antibiotics for systemic use, hypnotics and sedatives, and drugs for obstructive airway disease (all P values < .05). Notably, an increased prescription of several antihypertensive drugs and high-ceiling diuretics was observed after the diagnosis of AD. Conclusion: Gastrointestinal symptoms and anemia, especially in conjunction with autoimmune disorders, should alert the physician about the possibility of AD. The higher use of drugs for cardiovascular disorders after diagnosis in patients with AD raises concerns about the replacement therapy.
Context: Autoimmune Addison's disease(AAD) tends to affect young and middle-aged women. It is not known whether the existence of undiagnosed or diagnosed AAD influences the outcome of pregnancy. Objective: The aim of the study was to compare the number of children and pregnancy outcomes in individuals with AAD and controls. Design and Setting: We conducted a population-based historical cohort study in Sweden. Patients: Through the Swedish National Patient Register and the Total Population Register, we identified 1,188 women with AAD and 11,879 age-matched controls who delivered infants between 1973 and 2006. Main Outcome Measures: We measured parity and pregnancy outcome. Results: Adjusted odds ratios (ORs) for infants born to mothers with deliveries 3 yr or less before the diagnosis of AAD were 2.40 [95% confidence interval (Cl), 1.27-4.53] for preterm birth (<= 37 wk), 3.50 (95% Cl, 1.83-6.67) for low birth weight (<2500 g), and 1.74 (95% Cl, 1.02-2.96) for cesarean section. Compared to controls, women who gave birth after their AAD diagnosis were at increased risk of both cesarean delivery (adjusted OR, 2.35; 95% Cl, 1.68-3.27) and preterm delivery (adjusted OR, 2.61; 95% Cl, 1.69-4.05). Stratifying by isolated AAD and concomitant type 1 diabetes and/or autoimmune thyroid disease in the mother did not essentially influence these risks. There were no differences in risks of congenital malformations or infant death. Women with AAD had a reduced overall parity compared to controls (P < 0.001). Conclusion: Clinically undiagnosed and diagnosed AAD both entail increased risks of unfavorable pregnancy outcomes. AAD also influences the number of childbirths.
Objectives: The results of studies of bone mineral density (BMD) in Addison's disease (AD) are inconsistent. There are no published data on hip fracture risk in patients with AD. In this study we compare hip fracture risk in adults with and without AD. Design: A population-based cohort study. Methods: Through the Swedish National Patient Register and the Total Population Register, we identified 3,219 patients without prior hip fracture who were diagnosed with AD at the age of ≥30 years during the period 1964-2006, and 31,557 age- and sex-matched controls. Time to hip fracture was measured. Results: We observed 221 hip fractures (6.9%) in patients with AD and 846 (2.7%) in the controls. Patients with AD had a higher risk of hip fracture (hazard ratio (HR) = 1.8; 95% confidence interval (CI), 1.6-2.1; p < 0.001). This risk increase was independent of sex and age at or calendar period of diagnosis. Risk estimates did not change with adjustment for type 1 diabetes, autoimmune thyroid disease, rheumatoid arthritis or coeliac disease. Women diagnosed with AD ≤50 years old had the highest risk of hip fracture (HR = 2.7; 95% CI, 1.6-4.5). We found a positive association between hip fracture and undiagnosed AD (odds ratio (OR) = 2.4; 95% CI, 2.1- 3.0) with the highest risk estimates in the last year before AD diagnosis (OR = 2.8; 95% CI, 1.8-4.2). Conclusion: Both clinically undiagnosed and diagnosed AD were associated with hip fractures, with the highest relative risk seen in women diagnosed with AD ≤50 years of age.
Background
The diagnosis of malignant melanoma currently relies on clinical inspection of the skin surface and on the histopathological status of the excised tumor. The serum marker S100B is used for prognostic estimates at later stages of the disease, but analyses are marred by false positives and inadequate sensitivity in predicting relapsing disorder.
Objectives
To investigate SOX10 as a potential biomarker for melanoma and vitiligo.
Methods
In this study we have applied proximity ligation assay (PLA) to detect the transcription factor SOX10 as a possible serum marker for melanoma. We studied a cohort of 110 melanoma patients. We further investigated a second cohort of 85 patients with vitiligo, which is a disease that also affects melanocytes.
Results
The specificity of the SOX10 assay in serum was high, with only 1% of healthy blood donors being positive. In contrast, elevated serum SOX10 was found with high frequency among vitiligo and melanoma patients. In patients with metastases, lack of SOX10 detection was associated with treatment benefit. In two responding patients, a change from SOX10 positivity to undetectable levels was seen before the response was evident clinically.
Conclusions
We show for the first time that SOX10 represents a promising new serum melanoma marker for detection of early stage disease, complementing the established S100B marker. Our findings imply that SOX10 can be used to monitor responses to treatment and to assess if the treatment is of benefit at stages earlier than what is possible radiologically.
OBJECTIVE: Immunoglobulin G (IgG) antibodies to the steroidogenic enzymes 21-hydroxylase (21OH) and side-chain cleavage enzyme (SCC) are important diagnostic markers for autoimmune Addison's disease and autoimmune polyendocrine syndromes (APS) types I and II. The characterization of autoantibody (IgG) subclasses may reveal information on how tIssue destruction takes place; therefore, IgG subtypes of anti-21OH and anti-SCC antibodies from sera of patients with Addison's disease, APS I and APS II were determined using recombinant 21OH and SCC. METHODS: SCC(51-521) and his-SCC(51-521) were expressed by pET-scc in the Escherichia coli strain BL21 Star (DE3) and inclusion bodies were purified. Full-length, human 21OH fused to an N-terminal 6x histidine affinity tag was expressed in insect cells by using the baculovirus expression system bac-to-bac. Western blots were used to investigate the IgG subtype(s) of the autoantibodies against 21OH and SCC in patients and healthy blood donors. RESULTS: All anti-SCC positive sera (n=10) contained autoantibodies of the IgG1 subclass, while four out of ten also contained IgG3. All anti-21OH positive sera (n=16) had autoantibodies exclusively against IgG1. Sera from 20 healthy subjects did not show any reactivity against 21OH or SCC. CONCLUSIONS: The finding of a predominating IgG1 response against 21OH and SCC may suggest that T helper (Th) cells of the Th1 subclass are involved in destruction of the adrenal cortex in patients with autoimmune Addison's disease.
Patients with autoimmune polyendocrine syndrome type 1 (APS-1) frequently have autoantibodies directed against the aromatic amino acid hydroxylases tryptophan hydroxylase (TPH) and tyrosine hydroxylase (TH). We aimed to characterize these autoantibodies with regard to their antigenic determinants, their influence on enzymatic activity and their clinical associations. In particular, we wanted to compare autoantibodies against the two different isoforms of TPH, which display different tissue distribution. Using sera from 48 Scandinavian APS-1 patients we identified 36 patients (75%) with antibodies against one or more of these three enzymes. Antibodies against TPH1, but not TPH2, were associated with malabsorption in the whole Scandinavian cohort, while TH antibodies were associated with dental enamel hypoplasia in Norwegian patients. Subsequent experiments with selected patient sera indicated that while the C-terminal domain was the immunodominant part of TPH1, the epitopes of TPH2 and TH were mainly located in the N-terminal regulatory domains. We also identified a TPH1 specific epitope involved in antibody mediated inhibition of enzyme activity, a finding that provides new insight into the enzymatic mechanisms of the aromatic amino acid hydroxylases and knowledge about structural determinants of enzyme autoantigens. In conclusion, TPH1,TPH2 and TH all have unique antigenic properties in spite of their structural similarity.
Autoimmune polyendocrine syndrome type I (APS I) is a rare hereditary condition considered a model disease for organ specific autoimmunity. A wide range of autoantibodies targeting antigens present in the affected organs have been identified. Autoantibodies against aromatic l-amino acid decarboxylase (AADC) are present in about 50% of APS I patients. In order to increase our understanding of autoantibody specificity in APS I, the aim of the present study was to localize target regions on AADC recognized by sera from APS I patients. Using several complementing strategies, we have shown that autoantibodies against AADC mainly recognize conformational epitopes. The major antigenic determinants were detected N-terminally to amino acid residue 237. Replacement of amino acids 227–230 (ERDK) with alanine residues reduced the reactivity towards AADC by >80% in all patient sera tested, suggesting that amino acids 227–230 are an important part of an immunodominant epitope.
Dogs can spontaneously develop complex systemic autoimmune disorders, with similarities to human autoimmune disease. Autoantibodies directed at self-antigens are a key feature of these autoimmune diseases. Here we report the identification of interleukin enhancer-binding factors 2 and 3 (ILF2 and ILF3) as autoantigens in canine immune-mediated rheumatic disease. The ILF2 autoantibodies were discovered in a small, selected canine cohort through the use of human protein arrays; a method not previously described in dogs. Subsequently, ILF3 autoantibodies were also identified in the same cohort. The results were validated with an independent method in a larger cohort of dogs. ILF2 and ILF3 autoantibodies were found exclusively, and at a high frequency, in dogs that showed a speckled pattern of antinuclear antibodies on immunofluorescence. ILF2 and ILF3 autoantibodies were also found at low frequency in human patients with SLE and Sjogren's syndrome. These autoantibodies have the potential to be used as diagnostic biomarkers for canine, and possibly also human, autoimmune disease.
Context: NACHT leucine-rich-repeat protein 5 (NALP5)/maternal antigen that embryo requires (MATER) is an autoantigen in hypoparathyroidism associated with autoimmune polyendocrine syndrome type 1 (APS1) but is also expressed in the ovary. Mater is an autoantigen in experimental autoimmune oophoritis. Objectives: The objectives of the study were to determine the frequency of NALP5/MATER autoantibodies (NALP5/MATER-Ab) in women with premature ovarian insufficiency (POI) and in patients with autoimmune Addison's disease (AAD) and to evaluate whether inhibin chains are a target for autoantibodies in POI. Methods: Autoantibodies against NALP5/MATER and inhibin chains-alpha and -beta A were determined by radiobinding assays in 172 patients with AAD without clinical signs of gonadal insufficiency, 41 women with both AAD and autoimmune POI [steroidogenic cell autoimmune POI (SCA-POI)], 119 women with idiopathic POI, 19 patients with APS1, and 211 healthy control subjects. Results: NALP5/MATER-Ab were detected in 11 of 19 (58%) sera from APS1 patients, 12 of 172 (7%) AAD sera, 5 of 41 (12%) SCA-POI sera, 0 of 119 idiopathic POI sera and 1 of 211 healthy control sera (P < .001). None of 160 POI sera, including 41 sera from women with SCA-POI and 119 women with idiopathic POI, and none of 211 healthy control sera were positive for inhibin chain-alpha/beta A autoantibodies. Conclusions: NALP5/MATER-Ab are associated with hypoparathyroidism in APS1 but are present also in patients with AAD and in women with SCA-POI without hypoparathyroidism. Inhibin chains do not appear to be likely candidate targets of autoantibodies in human POI.
Objective To assess autoimmune regulator (AIRE) gene mutations, class II HLA haplotypes, and organ- or non-organ-specific autoantibodies in patients with chronic hypoparathyroidism (CH) without associated Addison's disease (AD) or chronic candidiasis (CC). Patients and Measurements Twenty-four patients who had CH without AD or CC were included in the study. AIRE gene mutations in all 14 exons were studied using PCR in 24 patients, 105 healthy controls and 15 first-degree relatives of CH patients with AIRE mutations. Human leucocyte antigens (HLA) were determined for all 24 patients and 105 healthy controls. Autoantibodies to a range of antigens including NACHT leucine-rich-repeat protein-5 (NALP5) and interferon omega (IFN omega) were tested in all 24 patients. Results AIRE gene mutations were found in 6 of 24 (25%) patients, all females, and this was significantly higher (P < 0.001) compared with AIRE mutations found in healthy controls (2/105). Three patients (12.5%) had homozygous AIRE mutations characteristic of Autoimmune-Poly-Endocrinopathy-Candidiasis-Ectodermal-Dystrophy and all three were also positive for IFN omega-autoantibodies. Three patients (12.5%) had heterozygous AIRE mutations; two of these were novel mutations. One of the patients with heterozygous AIRE mutations was positive for both NACHT leucine-rich-repeat protein 5 and IFN omega autoantibodies. Heterozygous AIRE mutations were found in 10 of 15 first-degree relatives of CH patients with AIRE mutations, although none was affected by CH. Class II HLA haplotypes were not statistically different in patients with CH compared to healthy controls. Conclusions Analysis of AIRE gene mutations together with serum autoantibody profile should be helpful in the assessment of patients with CH, in particular young women with associated autoimmune diseases.
The mechanisms behind destruction of the adrenal glands in autoimmune Addison's disease remain unclear. Autoantibodies against steroid 21-hydroxylase, an intracellular key enzyme of the adrenal cortex, are found in >90% of patients, but these autoantibodies are not thought to mediate the disease. In this article, we demonstrate highly frequent 21-hydroxylase-specific T cells detectable in 20 patients with Addison's disease. Using overlapping 18-aa peptides spanning the full length of 21-hydroxylase, we identified immunodominant CD8(+) and CD4(+) T cell responses in a large proportion of Addison's patients both ex vivo and after in vitro culture of PBLs <= 20 y after diagnosis. In a large proportion of patients, CD8(+) and CD4(+) 21-hydroxylase-specific T cells were very abundant and detectable in ex vivo assays. HLA class I tetramer guided isolation of 21-hydroxylase-specific CD8(+) T cells showed their ability to lyse 21-hydroxylase-positive target cells, consistent with a potential mechanism for disease pathogenesis. These data indicate that strong CTL responses to 21-hydroxylase often occur in vivo, and that reactive CTLs have substantial proliferative and cytolytic potential. These results have implications for earlier diagnosis of adrenal failure and ultimately a potential target for therapeutic intervention and induction of immunity against adrenal cortex cancer.
Systemic sclerosis (SSc) or scleroderma is a rare, autoimmune, multi-factorial disease characterized by early microvascular alterations, inflammation, and fibrosis. Chickens from the UCD-200 line develop a hereditary SSc-like disease, showing all the hallmarks of the human disorder, which makes this line a promising model to study genetic factors underlying the disease. A backcross was generated between UCD-200 chickens and its wild ancestor - the red jungle fowl and a genome-scan was performed to identify loci affecting early (21days of age) and late (175days of age) ischemic lesions of the comb. A significant difference in frequency of disease was observed between sexes in the BC population, where the homogametic males were more affected than females, and there was evidence for a protective W chromosome effect. Three suggestive disease predisposing loci were mapped to chromosomes 2, 12 and 14. Three orthologues of genes implicated in human SSc are located in the QTL region on chromosome 2, TGFRB1, EXOC2-IRF4 and COL1A2, as well as CCR8, which is more generally related to immune function. IGFBP3 is also located within the QTL on chromosome 2 and earlier studies have showed increased IGFBP3 serum levels in SSc patients. To our knowledge, this study is the first to reveal a potential genetic association between IGFBP3 and SSc. Another gene with an immunological function, SOCS1, is located in the QTL region on chromosome 14. These results illustrate the usefulness of the UCD-200 chicken as a model of human SSc and motivate further in-depth functional studies of the implicated candidate genes.
Objectives: Earlier research has suggested a positive association between Addison's disease (AD) and celiac disease (CD). We have here investigated the risk of AD in individuals with CD from a general population cohort. Methods: Through the Swedish national registers we identified 14,366 individuals with a diagnosis of CD (1964-2003) and 70,095 reference individuals matched for age, sex, calendar year, and county of residence. We used Cox regression to estimate hazard ratios (HRs) for subsequent AD. Analyses were restricted to individuals with more than 1 yr of follow-up and without AD prior to study entry or within 1 yr after study entry. Conditional logistic regression estimated the odds ratio for CD in individuals with prior AD. Results: There was a statistically significantly positive association between CD and subsequent AD [HR = 11.4; 95% confidence interval (CI) = 4.4 -29.6]. This risk increase was seen in both children and adults and did not change with adjustment for diabetes mellitus or socioeconomic status. When we restricted reference individuals to inpatients, the adjusted HR for AD was 4.6 (95% CI = 1.9 -11.4). Individuals with prior AD were at increased risk of CD (odds ratio = 8.6; 95% CI = 3.4 -21.8). Conclusions: This study found a highly increased risk of AD in individuals with CD. This relationship was independent of temporal sequence. We therefore recommend that individuals with AD should be screened for CD. We also suggest an increased awareness of AD in individuals with CD.
Background: It has been suggested that celiac disease is associated with thyroid disease. Earlier studies, however, have been predominately cross-sectional and have often lacked controls. There is hence a need for further research. In this study, we estimated the risk of thyroid disease in individuals with celiac disease from a general population cohort. Methods: A total of 14,021 individuals with celiac disease (1964-2003) and a matched reference population of 68,068 individuals were identified through the Swedish national registers. Cox regression estimated the risk of thyroid disease in subjects with celiac disease. Analyses were restricted to individuals with a follow-up of more than 1 yr and with no thyroid disease before study entry or within 1 yr after study entry. Conditional logistic regression estimated the odds ratio for subsequent celiac disease in individuals with thyroid disease. Results: Celiac disease was positively associated with hypothyroidism [hazard ratio (HR) = 4.4; 95% confidence interval (CI) = 3.4-5.6; P < 0.001], thyroiditis (HR = 3.6; 95% CI = 1.9-6.7; P < 0.001) and hyperthyroidism (HR = 2.9; 95% CI = 2.0-4.2; P < 0.001). The highest risk estimates were found in children (hypothyroidism, HR = 6.0 and 95% CI = 3.4-10.6; thyroiditis, HR = 4.7 and 95% CI = 2.1-10.5; hyperthyroidism, HR = 4.8 and 95% CI = 2.5-9.4). In post hoc analyses, where the reference population was restricted to inpatients, the adjusted HR was 3.4 for hypothyroidism (95% CI = 2.7-4.4; P < 0.001), 3.3 for thyroiditis(95% CI = 1.5-7.7; P < 0.001), and 3.1 for hyperthyroidism (95% CI = 2.0-4.8; P < 0.001). Conclusion: Celiac disease is associated with thyroid disease, and these associations were seen regardless of temporal sequence. This indicates shared etiology and that these individuals are more susceptible to autoimmune disease.
BackgroundAutoimmune disease is one of the leading causes of morbidity and mortality worldwide. In Addison's disease, the adrenal glands are targeted by destructive autoimmunity. Despite being the most common cause of primary adrenal failure, little is known about its aetiology. MethodsTo understand the genetic background of Addison's disease, we utilized the extensively characterized patients of the Swedish Addison Registry. We developed an extended exome capture array comprising a selected set of 1853 genes and their potential regulatory elements, for the purpose of sequencing 479 patients with Addison's disease and 1394 controls. ResultsWe identified BACH2 (rs62408233-A, OR = 2.01 (1.71-2.37), P = 1.66 x 10(-15), MAF 0.46/0.29 in cases/controls) as a novel gene associated with Addison's disease development. We also confirmed the previously known associations with the HLA complex. ConclusionWhilst BACH2 has been previously reported to associate with organ-specific autoimmune diseases co-inherited with Addison's disease, we have identified BACH2 as a major risk locus in Addison's disease, independent of concomitant autoimmune diseases. Our results may enable future research towards preventive disease treatment.
Context: Autoimmune polyendocrine syndrome type 1 (APS1) is a monogenic disorder that features autoimmune Addison disease as a major component. Although APS1 accounts for only a small fraction of all patients with Addison disease, early identification of these individuals is vital to prevent the potentially lethal complications of APS1.
Objective: To determine whether available serological and genetic markers are valuable screening tools for the identification of APS1 among patients diagnosed with Addison disease.
Design: We systematically screened 677 patients with Addison disease enrolled in the Swedish Addison Registry for autoantibodies against interleukin-22 and interferon-α4. Autoantibody-positive patients were investigated for clinical manifestations of APS1, additional APS1-specific autoantibodies, and DNA sequence and copy number variations of AIRE.
Results: In total, 17 patients (2.5%) displayed autoantibodies against interleukin-22 and/or interferon-α4, of which nine were known APS1 cases. Four patients previously undiagnosed with APS1 fulfilled clinical, genetic, and serological criteria. Hence, we identified four patients with undiagnosed APS1 with this screening procedure.
Conclusion: We propose that patients with Addison disease should be routinely screened for cytokine autoantibodies. Clinical or serological support for APS1 should warrant DNA sequencing and copy number analysis of AIRE to enable early diagnosis and prevention of lethal complications.
Background: Canine diabetes mellitus (DM) is a common endocrinopathy with an unclear etiology. For a better understanding of the underlying mechanisms, there is a need for comprehensive epidermiologic studies. Earlier studies have shown that the risk of disease is higher in certain dog breeds. Hypothesis: Incidence, age of onset, survival and sex proportion of DM vary by breed. Animals: Data from a cohort of 182,087 insured dogs aged 5-12 years accounting for 652,898 dog-years at risk were studied retrospectively. Methods: Incidence rates by sex, breed, and geography were calculated with exact denominators. Age-specific incidence and survival after 1st DM claim were computed with Cox's regression and Kaplan-Meier survival function. Multivariable survival analysis was performed for the outcome diagnosis of DM with age, sex, and geography tested as fixed effects, previous endocrine or pancreatic diseases tested as time-dependent covariates, and breed tested as a random effect. Results: The mean age at 1st insurance claim for the 860 DM dogs (72% females) was 8.6 years. The incidence of DM was 13 cases per 10,000 dog-years at risk. Australian Terriers, Samoyeds, Swedish Elkhounds, and Swedish Lapphunds were found to have the highest incidence. The proportion of females with DM varied significantly among breeds. Swedish Elkhounds, Beagles, Norwegian Elkhounds, and Border Collies that developed DM were almost exclusively females. The multivariable model showed that breed, previous hyperadrenocorticism, and female sex were risk factors for developing DM. Median survival time was 57 days after 1st claim. Excluding the 223 dogs that died within I day, the median survival time was 2 years after 1st claim of DM. Conclusion: The significant breed-specific sex and age differences shown in this study indicate that genetic variation could make breeds more or less susceptible to different types of DM.
Background: Female Elkhounds are shown to be at increased risk for diabetes mellitus, and occurrence of diabetes during pregnancy has been described in several cases. Hypothesis: Onset of diabetes mellitus in Elkhounds is associated with diestrus. Animals: Sixty-three Elkhounds with diabetes mellitus and 26 healthy controls. Methods: Medical records from 63 Elkhounds with diabetes were reviewed and owners were contacted for follow-up information. Blood samples from the day of diagnosis were available for 26 dogs. Glucose, fructosamine, C-peptide, growth hormone (GH), insulin-like growth factor-1, progesterone, and glutamate decarboxylase isoform 65-autoantibodies were analyzed and compared with 26 healthy dogs. Logistic models were used to evaluate the association of clinical variables with the probability of diabetes and with permanent diabetes mellitus after ovariohysterectomy (OHE). Results: All dogs in the study were intact females and 7 dogs (11%) were pregnant at diagnosis. The 1st clinical signs of diabetes mellitus occurred at a median of 30 days (interquartile range [IQR], 3-45) after estrus, and diagnosis was made at a median of 46 days (IQR, 27-62) after estrus. Diabetes was associated with higher concentrations of GH and lower concentrations of progesterone compared with controls matched for time after estrus. Forty-six percent of dogs that underwent OHE recovered from diabetes with a lower probability of remission in dogs with higher glucose concentrations (odds ratio [OR], 1.2; P = .03) at diagnosis and longer time (weeks) from diagnosis to surgery (OR, 1.5; P = .05). Conclusions: Diabetes mellitus in Elkhounds develops mainly during diestrus and pregnancy. Immediate OHE improves the prognosis for remission of diabetes.
Fifty-one dogs (27 diabetic dogs, four that had recovered from diabetes and 20 healthy control dogs) were given 0.5 or 1.0 mg glucagon intravenously. Blood samples were taken before the injection and 10 and 20 minutes after it. Samples were analysed to determine C-peptide, insulin and glucose concentrations, and one sample from each dog was analysed for fructosamine. The median (interquartile range) concentrations of C-peptide in the samples taken at 10 minutes were 0.5 (0.3 to 0.8) nmol/l in the control dogs, 0.1 (0 to 0.2) nmol/l in the diabetic dogs, and 0.3 (0.2 to 0.4) nmol/l in the dogs that had recovered from diabetes. Seven of the 51 dogs showed mild adverse reactions after the injection of glucagon.
Background: 21-Hydroxylase autoantibodies (21OHAb) are markers of an adrenal autoimmune process that identifies individuals with autoimmune Addison's disease (AAD). Quality and inter-laboratory agreement of various 21OHAb tests are incompletely known. The objective of the study was to determine inter-laboratory concordance for 21OHAb determinations. Methods: Sixty-nine sera from 51 patients with AAD and 51 sera from 51 healthy subjects were blindly coded by a randomization center and distributed to 14 laboratories that determined 21OHAb, either by an "in-house" assay (n=9) using in vitro-translated S-35-21OH or luciferase-labeled 21OH or a commercial kit with I-125-21OH (n=5). Main outcome measures were diagnostic accuracy of each participating laboratory and inter-laboratory agreement of 21OHAb assays. Results: Intra-assay coefficient of variation ranged from 2.6% to 5.3% for laboratories using the commercial kit and from 5.1% to 23% for laboratories using "in-house" assays. Diagnostic accuracy, expressed as area under ROC curve (AUC), varied from 0.625 to 0.947 with the commercial kit and from 0.562 to 0.978 with "in-house" methods. Cohen's. of inter-rater agreement was 0.603 among all 14 laboratories, 0.691 among "in-house" laboratories, and 0.502 among commercial kit users. Optimized cutoff levels, calculated on the basis of AUCs, increased the diagnostic accuracy of every laboratory (AUC >0.9 for 11/14 laboratories) and increased the Cohen's. of inter-rater agreement. Discrepancies in quantitation of 21OHAb levels among different laboratories increased with increasing autoantibody levels. Conclusions: The quality of 21OHAb analytical procedures is mainly influenced by selection of cutoff value and correct handling of assay materials. A standardization program is needed to identify common standard sera and common measuring units.
Patients with autoimmune polyglandular syndrome type I (APS1) often display high titers of autoantibodies (autoAbs) directed against aromatic L-amino acid decarboxylase (AADC), tyrosine hydroxylase (TH), tryptophan hydroxylase (TPH), and glutamic acid decarboxylase (GAD). Neurological symptoms, including stiff-man syndrome and cerebellar ataxia, can occur in subjects with high levels of GAD autoAbs, particularly when patient sera can immunohistochemically stain gamma-aminobutyric acid (GABA) neurons. However, it was not known if APS1 sera can also stain major monoamine systems in the brain. Therefore, in this work we applied sera from 17 APS1 patients known to contain autoAbs against AADC, TH, TPH, and/or GAD to rat brain sections and processed the sections according to the sensitive immunohistochemical tyramide signal amplification method. We found that autoAbs in sera from 11 patients were able to stain AADC-containing dopaminergic, serotonergic, and noradrenergic as well as AADC only (D-group) neurons and fibers in the rat brain, in several cases with a remarkably high quality and sensitivity (dilution up to 1:1,000,000); and, since they are human antibodies, they offer a good opportunity for performing multiple-labeling experiments using antibodies from other species. Six APS1 sera also stained GABAergic neuronal circuitries. Similar results were obtained in the mouse and primate brain. Our data demonstrate that many APS1 sera can immunostain the major monoamine and GABA systems in the brain. Only in a few cases, however, there was evidence that these autoAbs can be associated with neurological manifestations in APS1 patients, as, e.g., shown in previous studies in stiff-man syndrome.
The Dark brown (DB) mutation in chickens reduces expression of black eumelanin and enhances expression of red pheomelanin, but only in certain parts of the plumage. Here, we present genetic evidence that an 8.3-kb deletion upstream of the SOX10 transcription start site is the causal mutation underlying the DB phenotype. The SOX10 transcription factor has a well-established role in melanocyte biology and is essential for melanocyte migration and survival. Previous studies have demonstrated that the mouse homolog of a highly conserved element within the deleted region is a SOX10 enhancer. The mechanism of action of this mutation remains to be established, but one possible scenario is that the deletion leads to reduced SOX10 expression which in turn down-regulates expression of key enzymes in pigment synthesis such as tyrosinase. Lower tyrosinase activity leads to a shift toward a more pheomelanistic (reddish) plumage color, which is the characteristic feature of the DB phenotype.
Autoimmune polyglandular syndrome type I (APS I) is an autosomal recessive disorder characterized by a combination of autoimmune manifestations affecting endocrine and non-endocrine organs. APS I usually presents in childhood. The three most common manifestations are chronic mucocutaneous candidiasis, hypoparathyroidism and Addison's disease. At least two of these must be present to fulfill the diagnostic criteria of this syndrome. The spectrum of other associated diseases includes gonadal insufficiency, alopecia, vitiligo and chronic active hepatitis. APS I is caused by a mutation in the AIRE-gene (autoimmune regulator) located on chromosome 21. Analysis of specific autoantibodies against intracellular enzymes, particularly enzymes in the synthesis of steroids and neurotransmittors, can be used in the diagnosis of APS I and to predict different manifestations of the disease.
In autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, hypoparathyroidism (HP) is the most common endocrine component. It occurs in most (but not all) patients. Determinants of its occurrence are unknown, and there is no proof for its autoimmune nature. Recently, the Ca(2+)-sensing receptor (CaSR) was reported to be an autoantigen in HP. With our group of 90 patients, we aimed at identifying the determinants and pathomechanism of HP. For the determinants, we evaluated gender and the HLA class II. For the pathomechanism, we searched for parathyroid autoantibodies, including antibodies against CaSR and PTH. Also, we studied whether AIRE is expressed in the human parathyroid, because its absence could be a pathogenetic factor. We found a clear gender linkage with lower and later incidence in males. Of the 14 patients who had escaped HP, 13 were males. This was associated with adrenal failure, which was the first or only endocrinopathy in 47% of males vs. 7% of females. In contrast, we found no linkage to the HLA class II. By immunofluorescence, 19% of the patients had antibodies to parathyroid epithelia. By immunoblotting, these recognized several parathyroid proteins. No antibodies were observed against the CaSR or PTH. By RT-PCR, AIRE mRNA was not found in the parathyroid.
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, OMIM 240300) is a rare autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene on chromosome 21q22.3. This monogenic disease provides an interesting model for studies of other common and more complex autoimmune diseases. The most common components of APECED are chronic mucocutaneous candidiasis, hypoparathyroidism, and Addison’s disease, but several other endocrine deficiencies and ectodermal dystrophies also occur and the phenotype varies widely. The AIRE genotype also varies; 42 different mutations have been reported so far. To understand the complexity of the phenotype, we studied the AIRE and human leukocyte antigen (HLA) class II genotypes in a series of patients with APECED. The only association between the phenotype and the AIRE genotype was the higher prevalence of candidiasis in the patients with the most common mutation, R257X, than in those with other mutations. Addison’s disease was associated with HLA-DRB1*03 (P = 0.021), alopecia with HLA-DRB1*04- DQB1*0302 (P < 0.001), whereas type 1 diabetes correlated negatively with HLA-DRB1*15-DQB1*0602 (P = 0.036). The same HLA associations have previously been established for non-APECED patients. We conclude that mutation of AIRE per se has little influence on the APECED phenotype, whereas, in contrast to earlier reports, HLA class II is a significant determinant.
In the autosomal recessively inherited autoimmune polyendocrine syndrome type I (APS I) patients have autoantibodies directed against several endocrine and nonendocrine organs. Alopecia areata is present in about one-third of the patients and usually in the more severe forms, alopecia universalis or totalis. Sera from 39 patients with APS I, diluted 1:150, were used in indirect immunofluorescence staining of cryo-sections from normal human scalp. Two hair follicle staining patterns were observed. A cytoplasmic staining of the differentiating matrix, cuticle, and cortex keratinocytes in the anagen hair follicle was seen in five (13%) APS I sera. All these five patients had alopecia totalis, representing 63% of the eight patients with alopecia totalis (p < 0.0001). Furthermore, four (10%) of the APS I sera stained the nuclei of the melanocytes in the hair follicle. Two of these patients had vitiligo. None of 20 healthy control sera stained the keratinocyte cells or the melanocyte nuclei. These data show that many patients with APS I have high-titer autoantibodies directed against the anagen matrix, cuticle, and cortex keratinocytes and a melanocyte nuclear antigen, and also that the hair follicle keratinocyte staining is associated with alopecia, especially alopecia totalis. This study emphasizes the role of the differentiating anagen keratinocytes as an important structure in the autoimmune etiology of alopecia, both in APS I and at least in a subgroup of patients with alopecia areata unrelated to APS I.
Sex-linked barring, a common plumage colour found in chickens, is characterized by black and white barred feathers. Previous studies have indicated that the white bands are caused by an absence of melanocytes in the feather follicle during the growth of this region. Here we show that Sex-linked barring is controlled by the CDKN2A/B locus, which encodes the INK4b and ARF transcripts. We identified two non-coding mutations in CDKN2A that showed near complete association with the phenotype. Also identified were two missense mutations at highly conserved sites, V9D and R10C, and every bird tested with a confirmed Sex-linked barring phenotype carried one of these missense mutations. Further work is required to determine if one of these or a combined effect of two or more CDKN2A mutations is causing Sex-linked barring. This novel finding provides the first evidence that the tumour suppressor locus CDKN2A/B can affect pigmentation phenotypes and sheds new light on the functional significance of this gene.
Primary adrenal insufficiency (PAI), or Addison's disease, is a rare, potentially deadly, but treatable disease. Most cases of PAI are caused by autoimmune destruction of the adrenal cortex. Consequently, patients with PAI are at higher risk of developing other autoimmune diseases. The diagnosis of PAI is often delayed by many months, and most patients present with symptoms of acute adrenal insufficiency. Because PAI is rare, even medical specialists in this therapeutic area rarely manage more than a few patients. Currently, the procedures for diagnosis, treatment and follow-up of this rare disease vary greatly within Europe. The common autoimmune form of PAI is characterized by the presence of 21-hydroxylase autoantibodies; other causes should be sought if no autoantibodies are detected. Acute adrenal crisis is a life-threatening condition that requires immediate treatment. Standard replacement therapy consists of multiple daily doses of hydrocortisone or cortisone acetate combined with fludrocortisone. Annual follow-up by an endocrinologist is recommended with the focus on optimization of replacement therapy and detection of new autoimmune diseases. Patient education to enable self-adjustment of dosages of replacement therapy and crisis prevention is particularly important in this disease. The authors of this document have collaborated within an EU project (Euadrenal) to study the pathogenesis, describe the natural course and improve the treatment for Addison's disease. Based on a synthesis of this research, the available literature, and the views and experiences of the consortium's investigators and key experts, we now attempt to provide a European Expert Consensus Statement for diagnosis, treatment and follow-up.
Autoimmune polyendocrine syndrome type I (APS-I) is a monogenic model disease of autoimmunity. Its hallmarks are chronic mucocutaneous candidosis, hypoparathyroidism and adrenal insufficiency, but many other autoimmune disease components occur less frequently. The first components usually appear in childhood, but may be delayed to adolescence or early adult life. There is enormous variation in presentation and phenotype, which makes the diagnosis difficult. Antibodies against interferon-omega and -alpha have recently been shown to be sensitive and relatively specific markers for APS-I, and mutational analysis of the autoimmune regulator gene gives the diagnosis in >95% of cases. The treatment and follow-up of patients is demanding and requires the collaboration of specialists of several fields. However, the literature is especially sparse regarding information on treatment and follow-up; hence, we present here a comprehensive overview on clinical characteristics, treatment and follow-up based on personal experience and published studies.
Autoimmune polyendocrine syndrome type I (APS I) is an inherited recessive disorder with a progressive immunological destruction of many tissues including the adrenal cortex, the parathyroid glands, and the gonads. APS I is caused by mutations in the AIRE gene (autoimmune regulator), expressed in cells of the thymus and spleen, suggesting a role in central and peripheral tolerance. Aire(-/-) mice replicate the autoimmune features of APS I patients with the presence of multiple autoantibodies and lymphocytic infiltrates in various tissues, but young mice appear clinically healthy. We here report the investigation of 15- to 24-month-old Aire(-/-) mice. We did not observe any endocrinological abnormalities, nor did sera from these mice recognize known APS I autoantigens. Interestingly, however, there was a high frequency of marginal zone B-cell lymphoma in Aire(-/-) mice and liver infiltrates of B cells, suggesting chronic antigen exposure and exaggerated activation. Furthermore, increased numbers of monocytes in blood were identified as well as augmented numbers of metallophilic macrophages in the spleen. We propose that Aire, in addition to its function in the thymus, also has a peripheral regulatory role by controlling the development of antigen-presenting cells (APCs) and marginal zone B-cell activation.
Patients with autoimmune polyendocrine syndrome type I (APS I)suffer from endocrine and non-endocrine disorders due to mutations in the autoimmune regulator gene (AIRE). Mouse Aire is expressed both in thymic medullary epithelial cells and in peripheral antigen-presenting cells, suggesting a role in both central and peripheral tolerance. We here report that Aire(-/-) dendritic cells (DC) activate naive T cells more efficiently than do Aire(+/+) DC. Expression array analyses of Aire(-/-) DC revealed differential regulation of 68 transcripts, among which, the vascular cell adhesion molecule-1 (VCAM-1) transcript was up-regulated in Aire(-/-) DC. Concurrently, the expression of the VCAM-1 protein was up-regulated on both Aire(-/-) DC and monocytes from APS I patients. Blocking the interaction of VCAM-1 prevented enhanced Aire(-/-) DC stimulation of T cell hybridomas. We determined an increased number of DC in spleen and lymph nodes and of monocytes in the blood from Aire(-/-) mice, and an increased number of blood monocytes in APS I patients. Our findings imply a role for Aire in peripheral DC regulation of T cell activation, and suggest that Aire participates in peripheral tolerance.