Relationship of serum antihistone antibody level to the patient's age.

Abstract

The serum antihistone antibody (AHA) positivity of patients with various autoimmune diseases was compared with their positive reaction for antinuclear factor, rheumatoid factor, lupus erythematosus factor, cryoglobulin, immunocomplex, C-reactive protein, total protein, gamma globulin, IgG and IgM. In non-drug-induced SLE cases the predictive value of the AHA test was not higher than that of the other tests. It was striking that in 42% of patients with non-autoimmune disease aged over 70 the AHA test was positive. Elevated IgM values were recorded in about 70% of positive AHA samples.