Immunoassays distinguishing between HNL/NGAL released in urine from kidney epithelial cells and neutrophils
2012 (English)In: Clinica Chimica Acta, ISSN 0009-8981, E-ISSN 1873-3492, Vol. 413, no 19-20, 1661-1667 p.Article in journal (Refereed) Published
Background: The distinction between monomeric human neutrophil lipocalin/neutrophil gelatinase-associated lipocalin (HNL/NGAL), secreted by injured kidney tubular cells, and dimeric HNL/NGAL, released by activated neutrophils, is important to accurately diagnose acute kidney injury (AKI).
Methods: 132 urine samples from 44 intensive care unit (ICU) patients and five urine samples from non-ICU patients with urinary tract infections (UTIs) were analyzed by two monoclonal enzyme-linked immunosorbent assays (ELISA-1 and ELISA-2). The presence of monomeric and/or dimeric HNL/NGAL in each sample was visualized by Western blotting.
Results: The ELISA-1 detected both monomeric and dimeric HNL/NGAL whereas the ELISA-2 almost exclusively detected dimeric HNL/NGAL with an area under the receiver-operating characteristics curve (AuROC) of 0.90. The ELISA-1/ELISA-2 ratio detected the monomeric form with an AuROC of 0.92. In 32 AKI patients, dimer-specific EUSA-2 levels decreased pre-AKI whereas the monomer-specific ELISA-1/ELISA-2 ratio gradually increased beyond AKI diagnosis. High EUSA-2 levels and/or low ELISA-1/ELISA-2 ratios detected a predominance of dimeric HNL/NGAL in urine from the patients with tills.
Conclusions: In combination, our two ELISAs distinguish monomeric HNL/NGAL, produced by the kidney epithelium, from dimeric HNL/NGAL, released by neutrophils during AKI development, as well as reduce the confounding effect of neutrophil involvement when bacteriuria is present.
Place, publisher, year, edition, pages
2012. Vol. 413, no 19-20, 1661-1667 p.
Acute kidney injury, AKIN, Biomarker, HNL, NGAL, RIFLE
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-181994DOI: 10.1016/j.cca.2012.05.010ISI: 000307924000043OAI: oai:DiVA.org:uu-181994DiVA: diva2:559466