Isoniazid acetylatlon rate and development of antinuclear antibodies upon isoniazid treatment

Abstract

Abstract A large proportion of tuberculous patients on isoniazid develop antinuclear antibodies, and an occasional one may also develop overt systemic lupus erythematosus. To determine if the development of antinuclear antibodies in such patients is related to the rate of acetylation of the drug, which is determined phenotypically, we studied both isoniazid acetylation rate and serum antinuclear antibodies in tuberculous patients who had been on isoniazid. Of 153 such patients studied, 78 were phenotypically slow and 75 were phenotypically fast isoniazid acetylators. Antinuclear antibodies to whole nuclei, nucleoprotein, soluble nucleoprotein and isoniazid‐altered soluble nucleoprotein were detected by complement fixation tests more frequently in slow than in fast acetylators but this difference was not statistically significant. They also occurred more frequently in females than in males. Antinuclear antibodies that develop after prolonged isoniazid intake may be elicited by in vivo alteration of nucleoprotein by isoniazid and modestly influenced in their frequency by sex and by the pharmacogenetics of isoniazid.