Antinuclear Antibody Induced by Procainamide

Abstract

Sixteen patients were followed prospectively for the possible development of the lupus syndrome while being treated for cardiac arrhythmias with conventional doses of procainamide hydrochloride. In eight antinuclear antibody developed. Two of the eight had positive slide reactions with nucleoprotein-coated latex particles. In one of these two rheumatoid factor (anti-IgG) activity in low titer also developed. Another two of the eight showed symptoms consistent with the lupus syndrome. The high percentage of patients in this study in whom antinuclear antibody developed suggests that the lupus response appearing in patients treated with procainamide is not restricted to the small proportion of the population that may have a genetic predisposition to idiopathic lupus erythematosus.