Antibody to signal recognition particle in polymyositis

Authors

  • Ira N. Targoff MD,

    Corresponding author
    1. Department of Medicine, University of Oklahoma Health Sciences Center, the Veterans Administration Medical Center of Oklahoma City, and the Oklahoma Medical Research Foundation, Oklahoma City
    2. The National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland.
    • Arthritis/ Immunology Section, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104
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  • Arthur E. Johnson PhD,

    Professor of Chemistry
    1. the Department of Chemistry and Biochemistry, University of Oklahoma, Norman
    2. The National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland.
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  • Frederick W. Miller Md, Phd

    Senior Staff Fellow
    1. The National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland.
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Abstract

Using immunoprecipitation, we identified 13 patients with antibodies to the signal recognition particle (SRP) from a collection of sera representing 265 poly-myositis/dermatomyositis (PM/DM) patients. Antibody reactivity with SRP was confirmed by enzyme-linked immunosorbent assay and immunoprecipitation with isolated dog pancreas SRP. The antibody was present in the serum of 4% of PM/DM patients, and 18% of PM/ DM patients with anticytoplasmic antibodies other than anti-Jo-1, but not in patients with other conditions who had anticytoplasmic antibodies. Anti-SRP was associated with classic adult PM, and some of these cases were unusually severe and/or of rapid onset; it was not found in patients with overlap syndromes or with DM involvement. Unlike patients with antibodies to aminoacyl-transfer RNA synthetases, patients with anti-SRP had a low frequency of pulmonary fibrosis, as well as of arthritis and Raynaud's phenomenon. Anti-SRP antibodies may serve as a marker for a second, distinct subgroup of adult PM.

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