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A Marker for a Subset of Polymyositis with Interstitial Pulmonary Fibrosis SHUNJI YOSHIDA, MASASHI AKIZUKI, TSUNEYO MIMORI, HAJIME YAMAGATA, SHINICHI INADA, and MITSUO HOMMAThe clinical significance of antibodies to the Jo-1 antigen in connective tissue diseases was studied. Clinical diagnoses of I1 patients who had anti-Jo-1 antibody were: polymyositis 8, dermatomyositis 1, and overlap syndrome 2 (polymyositis-systemic lupus erythematosus 1, polymyositis-scleroderma 1). All the patients who had anti-Jo-1 antibody showed interstitial pulmonary fibrosis, and in 2 patients antiJo-1 antibodies were detected before the appearance of lung disease.Identification of antinuclear antibodies with defined specificities has diagnostic and prognostic value in connective tissue diseases (1-3). Recent studies reveal the presence of several precipitating antibody systems in polymyositis-dermatomyositis (PM-DM) in which immunologic abnormalities were previously considered to be infrequent (4-8). However, the results from several laboratories indicate that these serologic reactions have considerable heterogeneity, and their mutual relationships and clinical significance remain to be clarified (8).We have reported two distinct precipitating

Objective. To elucidate the profile and clinical significance of autoantibodies to small nuclear and small cytoplasmic ribonucleoproteins in Japanese patients with polymyositis and dermatomyositis (PMBM).Methods. Radioimmunoprecipitation assays were performed with sera from 91 patients with various inflammatory muscle diseases and from 254 control patients with other rheumatic diseases. Patients with PWDM were categorized according to autoantibody specificities, and clinical comparisons were made.Results. Antibodies to aminoacyl transfer RNA (tRNA) synthetases and the signal recognition particle (SRP) were found to be specific for PM/DM. PWDM

Anti-Ku (p70/p80) autoantibodies in patients with scleroderma-polymyositis overlap syndrome recognize a 70-kDa/80-kDa protein heterodimer which binds to terminal regions of double-stranded DNA. In the present study, we isolated full-length cDNAs that encode the 80-kDa Ku subunit.

We identified an autoantibody that reacts with calpastatin [an inhibitor protein of the calcium-dependent neutral protease calpain (EC 3.4.22.17)]. In early immunoblot studies, sera from patients with rheumatoid arthritis (RA) recognized unidentified 60-, 45-, and 75-kDa proteins in HeLa cell extracts.