Antibodies to histones in patients with various connective tissue diseases

Abstract

It is well known that anti-histone antibodies (AHA) are generated frequently in Caucasian populations receiving certain drugs. In Japanese patients, however, drug-induced lupus or autoantibodies are very rare, so that the study of AHA has not received much attention. Therefore, the precise prevalence of AHA in Japanese patients remains unknown. AHA in patients with various connective tissue diseases were detected by an ELISA method that employed purified histones as the antigen. The patients included 140 with systemic lupus erythematosus (SLE), 45 with rheumatoid arthritis (RA), 34 with mixed connective tissue disease (MCTD), 30 with polymyositis (PM)/dermatomyositis (DM), and 30 with progressive systemic sclerosis (PSS). The positivity rate of serum for total histone was 35.7% in SLE, 8.9% in RA, 17.6% in MCTD, 16.7% in PM/DM, and 30.0% in PSS. Both SLE and PSS showed significantly higher positivity rates than RA (p<0.005, and p<0.05) respectively. In the analysis of each subfraction, it was noted that the positivity rate was relatively higher for H 1 and H 2 B in SLE patients and for H 3 and H 4 in PSS patients. Furthermore, the positivity rate in PSS patients was higher than the previously reported rate for Caucasians. Among SLE patients, the positivity rate was particularly high for H 1, and significantly higher than that for MCTD (p<0.01). In contrast, the positivity rate was lower for RA and PM/DM patients than for patients with other diseases. On the basis of the mode of reaction for individual sera, patients with SLE, MCTD or PSS generally reacted with various subfractions, whereas those with RA or PM/DM reacted mostly with a single subfraction.