definition of autoimmune responses in polymyositis
Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(2)
Patents
Grants
Pathways
Clinical trials
Publication
Journal: American Journal of Medicine
April/4/1990
Abstract
OBJECTIVE
Anti-PL-12 antibody is directed at the enzyme alanyl-tRNA synthetase (ARS). Studies have clearly associated anti-Jo-1, also directed at an aminoacyl-tRNA synthetase (histidyl-tRNA synthetase), with a subgroup of myositis marked by a high frequency of interstitial lung disease (ILD) and arthritis. A similar syndrome has been reported in patients with antibodies to PL-12, but few patients have been studied. We describe the clinical manifestations in a new series of patients with antibody to PL-12.
METHODS
Sera from patients with polymyositis and sera found to contain anticytoplasmic antibodies were screened for antibody to PL-12 by testing for inhibition of ARS enzymatic activity by serum, and by immunoprecipitation.
RESULTS
Nine sera inhibited ARS. These nine plus two additional sera with anticytoplasmic antibodies immunoprecipitated an identical pattern of tRNAs and a polypeptide of 110 kd. Of the 10 patients that could be evaluated, eight had some evidence of myositis, including six that satisfied the criteria for myositis. Three of these six, all with dermatomyositis, had severe muscle involvement. Eight of the 10 patients had radiographic evidence of pulmonary fibrosis, and seven of the eight had clinical pulmonary impairment, including four with clinically severe ILD. Joint manifestations were found in five patients, and arthritis was the only clinical problem in one patient.
CONCLUSIONS
We conclude that anti-PL-12, like anti-Jo-1 and anti-PL-7, was frequently associated with the "Jo-1 syndrome" of myositis with ILD. ILD was a major clinical problem in this group of patients.
Publication
Journal: Arthritis and rheumatism
February/6/1995
Abstract
OBJECTIVE
To determine the biochemical structure and antigenic components of Mi-2 autoantigen, the target of autoantibodies in 15-20% of dermatomyositis patients.
METHODS
Immunoprecipitation from 35S-labeled HeLa cell extract, immunoblotting, and purification from bovine thymus by immunoaffinity chromatography.
RESULTS
All 46 sera that had anti-Mi-2 autoantibodies demonstrated by immunodiffusion immunoprecipitated a major protein of approximately 240 kd. Additional proteins of 200, 150, 72, 65, 63, 50, and 34 kd appeared to be part of the antigen. Fractions of purified bovine Mi-2 with antigenic activity showed high molecular weight bands comparable with immunoprecipitated HeLa Mi-2. Twenty-four of 47 anti-Mi-2 positive sera reacted with the 240-kd protein by immunoblot against anti-Mi-2 immunoprecipitates.
CONCLUSIONS
Mi-2 antigen consists of multiple proteins, of which the 240-kd protein appears to be the major reactive component.