Histone reactivity of drug-induced antinuclear antibodies. A comparison of symptomatic and asymptomatic patients.

Anti-histone antibodies were measured in a group of patients with drug-induced lupus erythematosus and in asymptomatic patients with drug-induced antinuclear antibodies (DANA). Anti-histone antibodies were found in the majority of drug-induced lupus patients. DANA patients had lower titers of ANA and no detectable anti-histone activity. Longitudinal studies of the drug-induced lupus patients showed a gradual fall in the ANA and anti-histone titers. Our data suggest that the immune response in the drug-induced lupus patients is similar to but more intense than that seen in the DANA patients. Possible factors altering the immune response in these 2 groups are discussed.