Chromosomal aberration, micronucleus and Comet assays on peripheral blood lymphocytes of leprosy patients undergoing multidrug treatment

To evaluate the genetic damage in leprosy patients, we carried out the alkaline Comet assay and chromosomal aberration (CA) and micronucleus (MN) tests in peripheral blood lymphocytes of 50 leprosy patients receiving multidrug treatment (MDT) and 50 healthy individuals. The Comet assay showed statistically higher mean values for length to width ratios of DNA mass (P < 0.01) and for mean frequencies of tailed cells (P < 0.001) in cells of leprosy patients than in those of controls. Similarly, the mean frequencies of micronucleated cells (per 1000 cytochalasin B-induced binucleated cells) were significantly greater (P < 0.001) in leprosy patients (19.92 +/- 2.564) than in controls (1.6 +/- 0.231). A statistically significant 10-fold increase in the frequency of CAs (11.16 +/- 0.411) was observed in leprosy patients compared with controls (1.28 +/- 0.242). In multiple regression analyses, when patients and controls were considered together, disease factor alone significantly influenced the genotoxicity markers. In the control group, age and alcohol consumption significantly influenced MN and length to width ratios and CA frequency, respectively. However, in MDT-treated leprosy patients none of the other confounding factors (sex, age, smoking and alcohol drinking) significantly affected the extent of genetic damage.