Investigation of anti-neutrophil cytoplasmic antibody presence with indirect immunofluorescence and enzyme-linked immunosorbent assay

Abstract

Anti-neutrophil cytoplasmic antibodies (ANCA) are a family of autoantibodies that react with proteins expressed mainly in cytoplasmic granules of polymorphonuclear neutrophil granulocytes (PMNs). The ANCA test is used to diagnose small vessel vasculitis and to monitor inflammatory activity. ANCA was initially detected using indirect immunofluorescence (IIF), which allowed differentiation of different patterns, such as p-ANCA (perinuclear) and c-ANCA (cytoplasmic). It is now common to detect antibodies by immunochemical assays using purified proteins, such as Enzyme-Linked Immunosorbent Assay (ELISA). In our study, we evaluated ANCA test results studied with IIF and ELISA methods and recorded patient diagnoses in the system. Serum samples of 4524 patients who were thought to have autoimmunity in their etiology were evaluated for ANCA presence. In accordance with the recommendation of the manufacturer (Euroimmun AG, Lübeck, Germany), serum IFA technique was evaluated for the presence of p-ANCA, c-ANCA. ELISA test (Alegria, Orgentec) was used to detect antibodies against MPO and PR3. The number of ANCA IIF positive patients was 525(11.6%). When we look at the distribution of ANCAs, 275(52.5%) formalin sensitive pANCA, 95 (18%) formalin resistant pANCA, 60 formalin sensitive cANCA(11.5%), 95(18%) formalin resistant cANCA. 18 (3.4%) of ANCA IIFA positives had PR3 antigen and 22 (4.1%) had significant antibody elevation against MPO antigen., ANCA IIF positive samples, according to the diagnosis of information registered in the operating system, consist of 424 (80.8%) autoimmune and inflammatory diseases according to disease groups, 36 (6.9%) malignancies, 18 (3.4%) infectious diseases, 47 (8.9%) are other diseases which are not included in these groups. ANCA is a determinant for many diseases, especially vasculitis. ANCA, which we found in a large number of different disease groups, was found to be an indicator that should be used in the diagnosis and follow-up of many autoimmune and inflammatory diseases.