Authors : Sadhna Sodani, Sadhna Sodani, Ranjana Hawaldar, Ranjana Hawaldar
DOI : 10.18231/2394-5478.2018.0082
Volume : 5
Issue : 3
Year : 0
Page No : 393-397
Introduction: Autoimmune diseases (AID) are a manifestation of a self damaging immune response of the body to its own antigen. In any suspected AID, the first test to be done is ANA detection by indirect immunofluoresence using HeP 2 cells due to its sensitivity. A positive ANA test is further evaluated by performing immunoblot test to detect specific antigens causing autoimmunity. The present study was undertaken to study the prevalence of antinuclear antibodies in patient population of Central Madhya Pradesh as well as to study the prevalence of disease specific antigens.
Materials and Methods: A total of 650 patients of all ages and both sexes coming to our diagnostic centre between January to June 2018 for ANA testing were included in the study. Serum ANA was determined by indirect immunofluorescence (IIFA) using Hep 2 cell lines (Euroimmun, Germany). A positive result by IIFA was further tested by immunoblot method (Euroimmun, Germany) when requested by the clinician.
Result: Out of 650 patients ANA screen was positive in 280 (43.08%) patients and negative in 209(32.15%) patients. ANA blot was requested in 161 patients (57.5%) of the total 280 ANA screen positive patients. Out of the 161 patients, 69 had a positive Immunoblot test for one or more antigens. Total 53.69% patients were positive by both ANA screen and immunoblot test. The total coincidence rate was 44.5% between ANA screen and ANA blot test with a positive coincidence rate of 81.6% and negative coincidence rate of 79.1%.
Conclusion: ANA IIF is considered to be the gold standard screening test for detecting autoantibodies and ANA blot is done as a confirmatory test to detect specific autoantibodies against antigens causing autoimmunity. The combination of ANA IIF and ANA blot is an effective method to diagnose autoimmune diseases. If used alone, a possibility of missing a diagnosis is high and so a combinbation of these two tests is of great benefit to both the clinicians as well as laboratorians.
Keywords: ANA, IIF, ANA blot, AID.