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Background and Aims:

The diagnostic and prognostic properties of anti-integrin alpha v beta 6 immunoglobulin G (IgG) autoantibodies in ulcerative colitis (UC) are poorly understood. We aimed to assess the diagnostic performance of anti-integrin alpha v beta 6 autoantibodies and examine their association with disease outcomes.

Methods:

Serum samples from a Swedish inception cohort of patients with suspected inflammatory bowel disease (IBD, n = 473) were analyzed using an in-house fluorescence enzyme immunoassay based on EliA technology. Findings were validated in a Norwegian population-based inception cohort (n = 570). Diagnostic performance was assessed by calculating the area under the curve (AUC) with 95% confidence intervals and determining sensitivity and specificity. Reclassification was evaluated using the net reclassification index.

Results:

In the discovery cohort, patients with UC, IBD-unclassified, or colonic Crohn's disease exhibited higher median autoantibody levels compared to symptomatic and healthy controls. In the validation cohort, the autoantibody demonstrated 79% sensitivity and 94% specificity for UC vs symptomatic controls at a cut-off of 400 UA/l. Its diagnostic performance (AUC = 0.92, 95% CI, 0.89-0.95) was superior to hs-CRP (AUC = 0.65, 95% CI, 0.60-0.70, P < .001) and faecal calprotectin (fcalpro) (AUC = 0.88, 95% CI, 0.84-0.92, P = .09). Combining the autoantibody with fcalpro further improved diagnostic accuracy (AUC = 0.97, 95% CI, 0.95-0.98) and patient reclassification (P < .001). Autoantibody positivity was associated with a severe phenotype of UC, characterised by increased inflammatory activity and higher IL-17A and granzyme B levels. Higher autoantibody levels were linked to an aggressive disease course, remaining stable in aggressive UC but decreasing in indolent disease (P = .003).

Conclusions:

Anti-integrin alpha v beta 6 is a reliable diagnostic and prognostic marker for UC, with potential clinical implementation.

Background and purpose

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by progressively destructive polyarthritis. Key autoimmune features include the presence of autoantibodies. The purpose of this review is to discuss the diagnostic and prognostic properties of rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA), based on current use in Sweden. Furthermore, we discuss their relation to disease outcomes and their importance for management of patients with RA.

Principal findings

Based on current cut-offs, ACPA has a higher specificity for RA than RF, and testing for ACPA alone is recommended when investigating patients with clinically suspect RA. The diagnostic utility of RF may improve with adjusted reference range/upper limit of normal.

RF and ACPA both predict rapid radiographic progression, severe extra-articular manifestations and mortality, whereas other outcomes, such as osteoporosis, pain and disability are not as clearly related to seropositivity. RF/ACPA positive patients respond better to some targeted therapies, in particular rituximab, compared to seronegative RA patients. Recent studies indicate that treatment of ACPA-positive arthralgia with abatacept may delay and perhaps sometimes even prevent development of arthritis. Available evidence does not support an added value of repeated RF or ACPA testing.

Conclusions

Testing for ACPA in patients with arthralgia or suspected early RA, and for ACPA and RF at RA diagnosis, provides useful diagnostic and prognostic information, which has implications for follow-up and treatment. Repeated testing for ACPA and RF is not recommended. Potential future developments include treatment of ACPA-positive individuals for prevention of arthritis.

OBJECTIVES: In SLE, anti-dsDNA can co-occur with autoantibodies against other chromatin components, like histones and nucleosomes. These antibodies induce type-1 interferon production, a hallmark of SLE. We measured antinuclear antibody (ANA) sub-specificities and investigated their associations to inflammatory biomarkers including interferon-regulated chemokines.

METHODS: We included 93 Sudanese and 480 Swedish SLE patients and matched controls (N = 104 + 192). Autoantibodies targeting ANA-subspecificites: dsDNA, Sm, Sm/U1RNPcomplex, U1RNP, SSA/Ro52, SSA/Ro60, SSB/La, ribosomal P, PCNA and histones were quantified in all subjects, anti-nucleosome only in the Swedish patients, with a bead-based multiplex immunoassay. Levels of 72 plasma biomarkers were determined with Proximity Extension Assay technique or ELISA.

RESULTS: Among Sudanese patients, the investigated antibodies significantly associated with 9/72 biomarkers. Anti-histone antibodies showed the strongest positive correlations with MCP-3 and S100A12 as well as with interferon I-inducible factors MCP-1 and CXCL10. Anti-dsDNA antibodies associated with CXCL10 and S100A12, but in multivariate analyses, unlike anti-histone, associations lost significance.Among Swedish patients, MCP-1, CXCL10, SA100A12 also demonstrated stronger associations to anti-histone and anti-nucleosome antibodies, compared with anti-dsDNA and other ANA sub-specificities. In multiple regression models, anti-histone/nucleosome retained the strongest associations. When excluding anti-histone or anti-nucleosome positive patients, the associations between MCP-1/CXCL10 and anti-dsDNA were lost. In contrast, when excluding anti-dsDNA positive patients, associations with anti-histone and anti-nucleosome remained significant.

CONCLUSION: In two cohorts of different ethnical origin, autoantibodies targeting chromatin correlate stronger with IFN-induced inflammatory biomarkers than anti-dsDNA or other ANA sub-specificities. Our results suggest that anti-histone/nucleosome autoantibodies may be main drivers of type-1 interferon activity in SLE.

Patients with rheumatoid arthritis (RA) have altered levels of exhaled nitric oxide (NO) compared with healthy controls. Here, we investigated whether the clinical features of and immunological factors in RA pathogenesis could be linked to the NO lung dynamics in early disease. A total of 44 patients with early RA and anti-citrullinated peptide antibodies (ACPAs), specified as cyclic citrullinated peptide 2 (CCP2), were included. Their exhaled NO levels were measured, and the alveolar concentration, the airway compartment diffusing capacity and the airway wall concentration of NO were estimated using the Högman–Meriläinen algorithm. The disease activity was measured using the Disease Activity Score for 28 joints. Serum samples were analysed for anti-CCP2, rheumatoid factor, free secretory component, secretory component containing ACPAs, antibodies against Porphyromonas gingivalis (Rgp) and total levels of IgA, IgA1 and IgA2. Significant negative correlations were found between the airway wall concentration of NO and the number of swollen joints (Rho −0.48, p = 0.004), between the airway wall concentration of NO and IgA rheumatoid factor (Rho −0.41, p = 0.017), between the alveolar concentration and free secretory component (Rho −0.35, p = 0.023) and between the alveolar concentration and C-reactive protein (Rho −0.36, p = 0.016), but none were found for anti-CCP2, IgM rheumatoid factor or the anti-Rgp levels. In conclusion, altered NO levels, particularly its production in the airway walls, may have a role in the pathogenesis of ACPA-positive RA.

Objectives: To investigate how individual rheumatoid arthritis (RA) autoantibodies associate with individual signs and symptoms at the time of RA diagnosis.

Methods: IgA, IgG, IgM rheumatoid factor (RF), antibodies against cyclic citrullinated peptide version 2 (anti-CCP2) and 16 individual antibodies against citrullinated protein (ACPA) reactivities were analysed centrally in baseline sera from 1600 patients with RA classified according to the 1987 American College of Rheumatology (ACR) criteria. These results were related to C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), number of swollen and tender joints (SJC and TJC), 28-joint disease activity scores (DAS28 and DAS28CRP), global disease activity evaluated by the patients and Health Assessment Questionnaire, all obtained at baseline.

Results: Individually, all autoantibodies except immunoglobulin G (IgG) RF associated with low SJC and TJC and with high ESR. In IgM RF-negative patients, ACPA associated strictly with low number of swollen and tender joints. This association persisted in multiple regression and stratified analyses where IgM and IgA RF instead associated with inflammation expressed as ESR. Among subjects without any ACPA peptide reactivity, there was no association between RF isotypes and ESR. The effect of RF on ESR increased with the number of ACPA reactivities, especially for IgM RF. In patients fulfilling the 1987 ACR criteria without taking RF into account, associations between IgM RF and high ESR, as well as between ACPA and low joint counts, remained.

Conclusion: Whereas ACPA associate with low counts of affected joints in early RA, RF associates with elevated measures of systemic inflammation in an ACPA-dependent manner. This latter finding corroborates in vitro models of ACPA and RF in immune complex-induced inflammation. These phenotypic associations are independent of classification criteria.

Aims: Personalised medicine in chronic complex diseases such as rheumatoid arthritis (RA) is within reach but requires international multi-stakeholder collaboration. We exemplify how national implementations of the General Data Protection Regulation (GDPR) have introduced administrative delays and created disincentives for data sharing and collaborative research. Methods: Our Danish/Swedish/Norwegian research collaboration (the 3-year NordForsk-funded "NORA" project) aims to develop a personalised medicine approach for the management of RA, built on the exploitation of unique existing data sources: longitudinal data from clinical rheumatology registries, research cohorts, nationwide health care registries, and biobank material from >20 sample collections. Data and results are shared and accessed remotely by collaborators at secure servers. New biomarker assays and patient-centric implementations of the results are to be explored, validated, and disseminated to patients and health care via the development of digital tools. Results: Following the advice of legal experts at the involved academic or public institutions and private companies, GDPR compliance resulted in >20 legal documents to govern the collaboration (consortium-, joint controller-, research collaboration-, data sharing-, and a series of unique two-way data processing-, and material transfer agreements). Lack of agreed-upon templates, policies, procedures, and a shortage of legal resources have caused considerable delays. Thus, our research consortium has spent more time ensuring GDPR compliance than on actual research activities. Conclusions: The current interpretation and implementation of the legal premises (rather than the GDPR per se) for research collaborations caused unnecessary barriers and delays. Our experiences call for Nordic trust-based code-of-conduct-like framework agreements, and for harmonisation of procedures and templates, lest the Nordic advantage in research be lost.

Background: Anti-nuclear antibodies (ANA) assessed by immunofluorescence (IF) microscopy are associated with systemic autoimmune rheumatic diseases (SARD) and can be detected years before onset of clinical symptoms. Recent data indicate dysregulation of the immune system with increased levels of proinflammatory cytokines, including type I interferons (IFN), in ANA-positive versus ANA-negative individuals. Herein, the aims were to investigate IF-ANA, ANA fine specificities, and IFN-α protein levels in relation to self-reported symptoms, as well as clinical signs, of SARD in a large group of healthy blood donors (HBD).

Methods: Sera from 825 HBD (48.8% females) were included. IF-ANA was assessed, using HEp-2 cells, according to the routine at the accredited laboratory of Clinical Immunology, Linköping University Hospital. All samples were analyzed for IgG-ANA fine specificities using addressable laser bead assay (ALBIA) at the same laboratory. IFN-α was determined using ELISA. Antibody-positive individuals, and their sex- and age-matched antibody-negative controls, were asked to fill a questionnaire regarding symptoms associated with SARD.

Results: In total, 130 HBD (15.8%) were positive with IF-ANA and/or ALBIA. Anti-U1RNP was significantly more common among women. Generally, self-reported symptoms correlated poorly with IF-ANA and/or ALBIA results. Two females with high levels of Ro60/SSA, Ro52/SSA and IFN-α reported mild sicca symptoms and were diagnosed with Sjögren’s disease after clinical evaluation.

Conclusion: A considerable proportion of apparently HBD are autoantibody positive, but without clear association to self-reported symptoms. Nevertheless, the combination of autoantibodies, relevant symptoms and high IFN-α levels identified the small proportion of individuals with SARD in the study population.

Scleritis is a severe and painful ophthalmic disorder, in which a pathogenic role for collagen-directed autoimmunity was repeatedly suggested. We evaluated the presence of sclera-specific antibodies in a large cohort of patients with non-infectious scleritis. Therefore, we prospectively collected serum samples from 121 patients with non-infectious scleritis in a multicenter cohort study in the Netherlands. In addition, healthy (n = 39) and uveitis controls (n = 48) were included. Serum samples were tested for anti-native human type II collagen antibodies using a validated enzyme-linked immunosorbent assay (ELISA). Further, sclera-specific antibodies were determined using indirect immunofluorescence (IIF) on primate retinal/scleral cryosections. Lastly, human leukocyte antigen (HLA) typing was performed in 111 patients with scleritis. Anti-type II collagen antibodies were found in 13% of scleritis patients, in 10% of healthy controls and in 11% of uveitis controls (p = 0.91). A specific reaction to scleral nerve tissue on IIF was observed in 33% of patients with scleritis, which was higher than in healthy controls (11%; p = 0.01), but similar to uveitis controls (25%; p = 0.36). Reactivity to the scleral nerve tissue was significantly associated with earlier onset of scleritis (48 versus 56 years; p < 0.001), bilateral involvement (65% versus 42%; p = 0.01), and less frequent development of scleral necrosis (5% versus 22%; p = 0.02). HLA-B27 was found to be twice as prevalent in patients with scleritis (15.3%) compared to a healthy population (7.2%). In conclusion, scleral nerve autoantibody reactivity was more common in scleritis and uveitis patients in contrast to healthy controls. Further research is needed to characterize these scleral-nerve directed antibodies and assess their clinical value.

BACKGROUND: Trigger finger, or stenosing tendovaginitis, is one of the most common causes of hand disability, where a finger or thumb painfully snaps and locks due to a tendon-sheath size mismatch at the A1 pulley. The exact aetiology of trigger finger is unknown, though it is associated with factors like diabetes, rheumatic disease and carpal tunnel syndrome. The main purpose of this prospective study was to explore clinical characteristics and comorbidities in a cohort of 139 patients who underwent surgery for trigger finger and find factors of importance for the outcome 1 year postoperatively.

METHODS: Pain, range of motion, hand function evaluated by the Disabilities of the Arm Shoulder and Hand questionnaire as well as Quinnell grade of triggering were examined preoperatively. Symptom duration, working status, medical history and comorbidities at baseline were also noted. Further, range of motion was evaluated 3 months after surgery, pain and hand function were evaluated 3 and 12 months after surgery. An outcome scale with three levels was defined. The development of any new comorbidities was monitored during an extended postoperative observation period, with a mean duration of 70 months (range: 56-88 months).

RESULTS: Poor outcome was strongly associated with younger age (P = 0.0009), a high level of preoperative pain in the operated hand (P = 0.0027), psoriatic arthritis (P = 0.021) and atopic disease (P = 0.028; odds ratio [OR]: 3.87, 95% confidence interval [CI]: 1.15-13.04). A low range of motion preoperatively did not affect the outcome. Carpal tunnel syndrome was the most common comorbidity but did not affect the outcome. A good preoperative range of motion, good hand function and less pain were associated with better outcomes.

CONCLUSION: Younger age, a high level of preoperative pain, psoriatic arthritis and atopic disease were factors associated with a worse outcome of trigger finger surgery. Pain and disability decreased 3 months postoperatively and continued to decrease between 3 and 12 months.

Objectives: Emerging evidence demonstrates that aPS-PT associate with thrombotic events. Genetic predisposition, including HLA-DRB1 alleles, is known to contribute to the occurrence of conventional aPL [anti-beta(2)glycoprotein-I (anti-beta(2)GPI) and aCL]. We investigated associations between aPS-PT and HLA-DRB1* alleles and thrombosis in SLE. Conventional aPL were included for comparison.

Methods: We included 341 consecutive SLE patients, with information on general cardiovascular risk factors, including blood lipids, LA and thrombotic events. aPS/PT, anti-beta(2)GPI and aCL of IgA/G/M isotypes and LA were quantified.

Results: aPS/PT antibodies associated positively with HLA-DRB1*13 [odds ratio (OR) 2.7, P = 0.002], whereas anti-beta(2)GPI and aCL antibodies associated primarily with HLA-DRB1*04 (OR 2.5, P = 0.0005). These associations remained after adjustment for age, gender and other HLA-DRB1* alleles. HLA-DRB1*13, but not DRB1*04, remained as an independent risk factor for thrombosis and APS after adjustment for aPL and cardiovascular risk factors. The association between DRB1*13 and thrombosis was mediated by aPS-PT positivity. HLA-DRB1*03, on the other hand, associated negatively with thrombotic events as well as all aPL using both uni- and multivariate analyses. HLA-DRB1*03 had a thrombo-protective effect in aPL-positive patients. Additionally, HLA-DRB1*03 was associated with a favourable lipid profile regarding high-density lipoprotein and triglycerides.

Conclusions: HLA-DRB1*13 confers risk for both aPS-PT and thrombotic events in lupus. The association between HLA-DRB1*13 and thrombosis is largely, but not totally, mediated through aPS-PT. HLA-DRB1*03 was negatively associated with aPL and positively with favourable lipid levels. Thus, HLA-DRB1*03 seems to identify a subgroup of SLE patients with reduced vascular risk.