Study of Effect of Nitrosamine Stress in Progression of Leprosy

Objective: In several countries, including India, leprosy is an older disease & till now continues to be an important health issue. Leprosy is a chronic granulomatous disease, the contributing agent for this is mycobacterium leprae. Nitric oxide (NO) plays a significant role in immunity to fight against bacteria. But increased NO can harm host tissue by causing altered structure of thiol-containing compounds, which is a significant event that influences the pathogenesis of leprosy. Considering this, the study was planned to determine the type of relationship between NO, nitrothiols, and thiols as disease advances.

Methods: 50 newly diagnosed leprosy patients & 50 healthy controls were included in the study. In the leprosy group,16 were Paucibacillary (PB), and 34 were Multibacillary (MB) type, leprosy patients.

Results: Serum NO and serum nitrothiol significantly increased (p<0.01) in leprosy patients than controls. Further, Serum NO and serum nitrothiol significantly increased (p<0.01) in MB leprosy patients than PB leprosy patients. On the other hand, we found a significantly decreased (p<0.01) level of total thiols in leprosy patients compared with controls. Serum thiols significantly decreased (p<0.01) in MB leprosy patients than PB leprosy patients. Among Both leprosy patients, the negative correlation of NO with thiol and nitrothiol with thiols was observed.

Conclusion: Thus, in leprosy, increased nitric oxide causes modification of thiol groups of proteins and impaired their activity which may be responsible for the severity of disease; hence therapy aimed to reduce nitrosative modification of proteins leprosy.