Autoantibodies in sera from patients with L-tryptophan-associated eosinophilia-myalgia syndrome. Demonstration of unique antigen-antibody specificities

Abstract

The purpose of this study was to determine whether specific autoantibodies could be identified that are associated with eosinophilia-myalgia syndrome (EMS). Sera from 44 patients with EMS were tested by indirect immunofluorescence, immunodiffusion against calf thymus extract, and immunoprecipitation from HeLa cell extract. Antinuclear antibodies were detected in the sera of 24/39 patients with EMS (61.5%) by indirect immunofluorescence against HEp-2 cells. Seven patients (16%) were demonstrated to have specific autoantibodies by immunoprecipitation in which at least two shared patterns were noted. In three sera immunoprecipitation identified a similar 63-kDa band (Ab-1). An additional four sera shared a pattern of bands consisting of a strong 110-kDa protein and a weak 95-kDa protein (Ab-2). Absorption of HeLa extract with a strongly positive Ab-2 serum confirmed that the four patients shared the same antibody. In conclusion, the detection of these autoantibodies provides evidence of autoimmunity in EMS, and may distinguish this syndrome from clinically related conditions.