Cytogenetic study of tuberculosis patients before and after tuberculostatic drug treatment

Cytogenetic analyses were carried out in lymphocytes of 15 untreated tuberculosis (tb) patients and 15 other tb patients who had received combined tuberculostatic chemotherapy HRZ (isoniazid+rifampicin+pyrazinamide) for 2 months. The frequency of chromosomal aberrations and sister-chromatid exchanges (SCEs) did not show any statistically significant differences in the patients before treatment and after exposure to combined HRZ therapy as compared to controls (p > 0.05). However, we observed that the mitotic index was significantly decreased in both groups (p < 0.05). Based on the results of the present study, we believe there is no indication for a chromosome damaging effect of HRZ and their metabolites in human lymphocytes in vivo after treatment of tuberculosis patients with optimum doses.