Evaluation of Anti-Nuclear antibody test results in clinical practice

Objective: Aim of this study is to evaluate anti-nuclear antibody (ANA) test results obtained between 2009 and 2011. Methods: Of a totally 5068 cases tested for ANA by indirect immunofluorescence method (IIFA), randomly chosen 982 ANA-positive cases were reviewed in terms of gender, level and pattern of fluorescence, anti-dsDNA (anti-double stranded DNA) and anti-extractable nuclear antigen (ENA) profile. Anti-dsDNA levels and anti-ENA profiles were determined by enzyme linked immune assay (ELISA) and immune-blotting (IB), respectively. Results: Sex distribution of ANA positive patients was determined as 756 (77%) females and 226 (23%) males. Fifty per cent of the cases were from rheumatology department, 20% from gastroenterology and 30% from other units. Fluorescence levels were considered borderline or weak positive in 62.6% of the samples. The most frequent patterns were homogeneous (23%), speckled (22%), homogeneous-speckled (15.5%) and nucleolar (13.5%). Anti-dsDNA were studied in 759 ANA positive patients and 66 (8.7%) samples were found positive, being 44 of them (68.8%) with homogeneous pattern and the rest with speckled, nucleolar, nuclear dots, centromeric or midbody patterns. Totally 131 (31.6%) of 414 samples studied for anti-ENA profile were found positive. The first four frequent profiles were SSA (34.4%), SSA-SSB (16.8%), Scl70 (16%) and Sm/RNP (9.2%). Conclusion: Our results are similar with the current related literature. It is known that autoantibodies can be detectable before clinical symptoms being apparent, especially in SLE. Therefore, borderline or weak fluorescence levels should also be reported and the patients having them should be followed-up carefully. J Microbiol Infect Dis 2015;5(2): 63-6