A comparative study of the ELISA and IF methods for detection of Antinuclear antibodies characteristic of connective tissue diseases

Dr.C. Revathy; Dr.G. Sucilathangam; Dr.V.P.Amudha; Dr.G. Velvizhi

Volume : V, Issue : IX, September - 2016

A comparative study of the ELISA and IF methods for detection of Antinuclear antibodies characteristic of connective tissue diseases

Dr. C. Revathy, Dr. G. Sucilathangam, Dr. V. P. Amudha, Dr. G. Velvizhi

Abstract :

Anti–nuclear antibody (ANA) testing is widely used as a screening test in autoimmune diseases. The most commonly used method for ANA testing is ANA immunofluorescence assay (ANA–IFA). This study compared the diagnostic performance of Enzyme linked immunosorbent assay (ELISA) with IFA for the detection of ANA.321 samples were from patients with clinical suspicion of autoimmune diseases. Of the 321 test samples, IFA was positive in 53 (16.5%), negative in 268 (83.5 %) cases. ELISA was positive in 47 ( 14.6 %), negative in 274 (85.4%) cases. 44 (13.7%) samples were positive by both methods. 266 (82.9%) samples tested negative by both. 9 (2.8%) samples were IFA positive but ELISA negative. 3 samples (1%) were ELISA positive but IFA negative. Comp� with the gold standard IFA, the sensitivity of ELISA was 83% and the specificity was 98.8%. ANA by ELISA is less sensitive than IFA using the HEp 2 substrate.