Antibody to signal recognition particle in polymyositis.
Using immunoprecipitation, we identified 13 patients with antibodies to the signal recognition particle (SRP) from a collection of sera representing 265 polymyositis/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.
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City.
I N
IN
Targoff
A E
AE
Johnson
F W
FW
Miller
D000328:Adult; D000906:Antibodies / Q000032:analysis*; D003882:Dermatomyositis / Q000097:blood / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000097:blood / Q000276:immunology*; D021382:Protein Sorting Signals / Q000276:immunology*
D000906:Antibodies; D021382:Protein Sorting Signals