Clinical significance of antibodies to histones in systemic lupus erythematosus.

IgG antibodies to whole histones and to individual histones H1, H2A+H4, H2B and H3 were measured by enzyme linked immunosorbent assay in serum samples from 46 untreated patients with systemic lupus erythematosus (SLE) who had undergone renal biopsy. Patients with the WHO Class IV lupus nephritis had significantly higher levels of antibodies to histones (except H1) than those with milder forms of nephritis. Among antibodies to individual histones, the levels of antibodies to H2B histones best correlated with the renal histologic and the clinical activity of disease (rs = 0.759, rs = 0.577, p less than 0.001, respectively).