Antibodies to Ro/SS-A and La/SS-B in systemic lupus erythematosus and other autoimmune disorders.

AIM: 1. To study the presence of anti-Ro/SS-A, anti-La/SS-B, anti-Sm and anti-nRNP in diagnosed antinuclear factor (ANF) positive systemic lupus erythematosus (SLE) cases and their association with various organ involvement. 2. To study autoantibodies in other autoimmune disorders. MATERIAL AND METHODS: A total of 4050 suspected cases of autoimmune disorders referred for serological work up were evaluated for ANF by indirect immunofluorescence technique, anti-dsDNA by PHA, autoantibodies to Ro-SS-A and La/SS-B by ELISA and rheumatoid factor was tested by latex agglutination using commercial kits. RESULTS: Out of 4050 patients 19.5% were ANF positive and 5% were anti-dsDNA positive. Out of these 50 diagnosed ANF positive cases of SLE, an incidence of anti-dsDNA 54%, anti-Sm 25.9%, anti-nRNP 29.6%, anti-Ro/SS-A 10% and anti-La/SS-B was 22% was observed. In rheumatoid arthritis, 17.4% positivity of anti-Ro/SS-A and 39.1% positivity for anti-La/SS-B was observed. In SLE with renal involvement, joint complaints and skin or malar rash were seen in 66%, 56% and 46%, respectively. CONCLUSION: Determining anti-Ro/SS-A and anti-La/SS-B antibody could be important in evaluating patients with suspected connective tissue disorders, who usually show diverse clinical presentations like skin, kidney and joint manifestations. The most prominent feature in anti-Ro/SS-A and anti-La/SS-B positive patients was skin involvement and sicca complex in 60% of SLE patients.