The clinical application of an ELISA technique for the detection of antihistone antibodies.

A rapid reproducible technique for measuring antihistone antibodies is described in which unfractioned nuclear histones covalently bonded to plastic discs are employed in an ELISA system. All 20 patients with drug induced lupus erythematosus had antihistone antibodies, usually at high titer. In contrast, 22% of 18 asymptomatic patients with drug induced antinuclear antibodies (ANA), 15% of 20 patients with seropositive RA and 42% of 60 patients with systemic lupus erythematosus (SLE) had detectable antihistone antibodies. High titers of antihistone antibodies were not seen in drug induced ANA or RA. This assay differentiates between patients with drug induced lupus and drug induced ANA (p less than 0.01) and drug induced lupus erythematosus and SLE (p less than 0.01). In patients with SLE antihistone antibodies had no association with disease activity.