Anti-IgE autoantibodies in systemic sclerosis (scleroderma).

An enzyme immunoassay was used to determine the prevalence of anti-IgE auto-antibodies in 66 patients with systemic sclerosis (scleroderma) stratified according to extent and duration of disease. Serum IgG anti-IgE antibodies were detected in 14 (21%) patients and IgM anti-IgE antibodies in nine (14%) patients. The overall prevalence of IgG or IgM isotypes was 21/66, (32%). Anti-IgE autoantibodies were not found in six patients with undifferentiated connective tissue disease or two patients with eosinophilic fasciitis. Attempts to demonstrate histamine release from basophils in vitro by using serum samples containing high titre anti-IgE antibody were unsuccessful. By multivariate analysis the presence of anti-IgE antibody was not associated with duration of systemic sclerosis; extent of scleroderma; specific visceral features, including heart, lung, renal, and gastrointestinal involvement; or mortality.