POS0773 AUTOANTIBODIES IN A MULTI-INSTITUTIONAL INDIAN COHORT (INSPIRE) OF SLE PATIENTS: PREVALENCE, CLUSTER ANALYSIS AND PHENOTYPE ASSOCIATION

Abstract

Background Systemic Lupus Erythematosus (SLE) is characterized by an array of autoantibodies. Different autoantibodies have been associated with different clinical features like anti-dsDNA antibodies with nephritis and anti-phospholipid antibodies with pregnancy loss. However, the prevalence of autoantibodies has been variable across different ethnic groups. Data on the Indian population is limited. Objectives To assess the prevalence of different autoantibodies in a multi-institutional cohort (INSPIRE) of Indian SLE patients and to test their association with various clinical features using cluster analysis. Methods The patients (n=1053) enrolled in a multi-institutional cohort of Indian patients (Indian SLE inception cohort for Research [INSPIRE]) were included.1 Antibodies were assayed using Immunoline (Euroimmune, Germany) 17 antigen kit. Anti-phospholipid antibodies (IgG and IgM anti-cardiolipin antibodies (ACLs), IgG anti-Beta 2 GpI antibodies) were measured using ELISA (Euroimmune). Lupus anticoagulant was available in a subset of patients. The prevalence data for autoantibodies were analyzed using an intensity of only ++ and above on Immunoline assay as significant. Univariate analysis by Chi-square test was done to identify associations between individual autoantibodies and their clusters with clinical manifestations. Results The clinical features were fever in 702, alopecia in 813, oral ulcers in 628, acute cutaneous lupus (ACLE) in 520, proteinuria in 400, pleural effusion in 181, thrombocytopenia in 250 and autoimmune hemolytic anemia in 137 patients. The prevalence of various autoantibodies by ELISA was anti-dsDNA antibodies in 70.2% (551/784), IgG Anti- beta-2 GpI in 4.47% (42/938), IgG ACL in 6.14% (61/992) and IgM ACL in 7.1% (54/760). Lupus anticoagulant was present in 13.9% (112/ 805). By Immunoline assay, the prevalence for anti-Ro 52, anti-Ro 60, anti-La and anti-Ribosomal P was 28.49%, 33.14%, 10.07% and 24.03% respectively.