THE PATHOGENIC 16 6-IDIOTYPE IN PATIENTS WITH SILICA ASSOCIATED SYSTEMIC LUPUS-ERYTHEMATOSUS (SLE) AND URANIUM MINERS WITH INCREASED RISK FOR DEVELOPMENT OF SLE/

Objective, To investigate the prevalence of the 16/6 idiotype (16/6 Id ), a major cross reactive idiotype of anti-DNA antibodies involved in the pathogenesis of experimental lupus, in subjects with an exogenous risk for the development of systemic lupus erythematosus (SLE), Method s. The titer of 16/6 Id was determined by ELISA in sera of uranium min ers exposed to heavy quartz dust: 15 developed definite and 12 probabl e SLE, 34 had clinical symptoms, and 27 had only serological signs (me dium to high titer anti-dsDNA antibodies) of possible connective tissu e disease (CTD) development. Results, The prevalence of 16/6 Id was hi gher in all groups compared to healthy blood donors, It was 18.5% in m iners with SLE (definite and probable) and 22.2-26.5% in miners with c linical and/or serological signs for developing CTD. All 16/6 Id posit ive miners were positive for anti-dsDNA antibodies and other autoantib odies associated with CTD. The prevalence of 16/6 Id in anti-dsDNA pos itive miners correlated slightly with CTD/SLE symptoms: 55.6% in patie nts with SLE, 47.4% in miners with possible CTD/SLE, and 22.2% in mine rs without CTD symptoms, Further, at short term followup, disease prog ressed in 2 miners of the 16/6 Id positive, but not in 16/6 Id negativ e miners. Conclusion, The detection of 16/6 Id in miners exposed to qu artz dust may indicate a higher risk for development of SLE, warrantin g further studies of the role of 16/6 Id in the development of SLE in a cohort with the same sex, ethnicity, geographic region, and occupati on.