Isoniazid induction of antinuclear antibodies. A prospective study

We prospectively studied 102 patients admitted to the Chest Service with tuberculosis. Four patients (4%) had antinuclear antibodies before therapy and 22 patients (21.6%) developed antinuclear antibodies after treatment. None developed lupus erythematosus cells or signs or symptoms of systemic lupus erythematosus. Age and race were not related to the induction of antinuclear antibodies. The percent of positive sera was similar during and after 3 months of treatment, with higher titers after 3 months of therapy. Although patients were treated with various antituberculosis drugs, isoniazid alone or in combination with other drugs induced antinuclear antibodies.