Comparison of Immunofluorescence and Chemiluminescence Methods for ANA Detection

Introduction: The large number and variety of autoantibodies can be seen against nuclear and cytoplasm antigens in rheumatic diseases. The selective and sensitive method for detection of these autoantibodies is immunofluorescent technique. In this technique lower titration of 1/100 considered to be negative and higher titers are positive. The second method for detection of autoantibodies is chemiluminescence, the results of which are reported as positive or negative. The aim of this study was to compare the two methods. Methods and materials In this study, sera from 87 patients referred to Razi Pathobiology laboratory for ANA testing was used. ANA-IFA of patient samples using the kit Euroimmun in according to manufacturer's protocol. Criteria for patients selection was ANA-IFA titer higher than 1/100. For these patients ANA-CLIA test was done using kit DiaSorin with LIAISON automated analyzer. Results 10 patients were male and 77 were female of the 87 samples. In ANAIFA method, 7/28 % of patient has had titre 1/100, 2/17% titre 1/320, 4/26% titre 1/1000, 4/18% titre 1/1000, 3.3% titre 1/10000 and 6% were negative. In ANA-CLIA method 33/3% and of patients have been positive and the others were negative. Discussion In this study the data was shown that there are false positive results in chemiluminescence method in comparison to immunofluroscent method. So it is better FANA test is requested by physicians.

ANA, Chemiluminescence, Immunoflurescent, Rheumatic Diseases