SENSITIVITY AND SPECIFICITY OF ANTI-JO-1 ANTIBODIES IN AUTOIMMUNE-DISEASES WITH MYOSITIS

Objective. To determine the sensitivity and specificity of anti-Jo-1 i n systemic sclerosis (SSc) patients with and without myositis. Methods . Immunoblots on HeLa nuclei were used to screen sera from 554 consecu tive connective tissue disease patients. Those who had 45-55-kd bands, all patients with polymyositis/dermatomyositis (PM/DM), and a random selection of SSc, Raynaud's disease, systemic lupus erythematosus, and rheumatoid arthritis patients were also studied by anti-Jo-1 enzyme-l inked immunosorbent assay and by immunoblots on rabbit pooled aminoacy l-transfer RNA synthetase. Results. Anti-Jo-1 was present only in 8 of the 40 PM/DM patients. Conclusion. Anti-Jo-1 is specific for PM/DM.