Erythrocyte superoxide dismutase, catalase activities and hydrogen peroxide induced lipid peroxidation in leprosy.

OBJECTIVES: To assess erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities and hydrogen peroxide induced lipid peroxidation in leprosy. DESIGN: One hundred leprosy patients and 50 normal healthy controls were studied for the parameters. The data was analysed by grouping the patients into Ridley-Jopling (RJ) types [Tuberculoid leprosy (TT, n = 22), Borderline tuberculoid leprosy (BT, n = 28), Borderline leprosy (BB, n = 13), Borderline lepromatous leprosy (BL, n = 16) and Lepromatous leprosy (LL, n = 21)] and into different levels of Bacteriological Index (BI) [bacteriologically negative (n = 32), BI = 0.1-1 (n = 22), BI = 1.1-2 (n = 16), BI = 2.1-3 (n = 14), BI = 3.1-4 (n = 10) and BI = 4.1-6 (n = 06)]. RESULTS: The induced peroxidation was significantly high and the enzyme activities were significantly low in leprosy (total patients) as compared to controls. A progressive increase in peroxidation was detected along the leprosy spectrum from TT to LL and the increase was significant in BB, BL and LL groups as compared to controls. Induced peroxidation in LL group as compared to TT, BT and BB and in the BL group as compared to TT and BT were significantly different. A concomitant progressive decline in enzyme activity was detected along the leprosy spectrum from TT to LL. The SOD activity in BB, BL and LL and the CAT activity in BL and LL were significantly low as compared to controls. SOD activity in BB, BL and LL groups as compared to TT and in the LL group as compared to BT were significantly different. A progressive trend of increasing peroxidation and decreasing SOD and CAT activity were also detected along the leprosy groups with advancing level of BI. Induced peroxidation and SOD activity were significantly different in bacteriologically positive groups as compared to controls and in the BI levels 1.1-2, 2.1-3, 3.1-4 and 4.1-6 as compared to bacteriologically negative group. The peroxidation was significantly different in BI levels 2.1-3, 3.1-4 and 4.1-6 as compared to BI level 0.1-1. The CAT activity was significantly different in BI levels 2.1-3, 3.1-4 and 4.1-6 as compared to controls. CONCLUSION: The study findings suggest oxidative stressful state associated with reduced antioxidant defence potential in erythrocytes of leprosy patients. The study implicates association of erythrocyte oxidative stress with bacterial load and type of leprosy.

Expression of inducible nitric oxide synthase and nitrotyrosine in borderline leprosy lesions.

BACKGROUND: In the response to T-helper cell (Th1)-type cytokines and interactions with pathogens, high levels of nitric oxide (NO) are produced by activated macrophages expressing the inducible NO synthase (iNOS). The role and importance of reactive nitrogen intermediates (RNIs) such as NO and peroxynitrite in the host response to diseases caused by intracellular pathogens such as Mycobacterium leprae and M. tuberculosis is unclear. OBJECTIVES: The aim of this study was to investigate the presence of local production of NO and peroxynitrite in borderline leprosy by using antibodies against iNOS and the product of peroxynitrite, nitrotyrosine (NT). METHODS: We detected the presence of iNOS and NT in skin biopsies from borderline leprosy patients, with and without reversal reaction (RR), by immunohistochemistry (n = 26). RESULTS: In general, the granulomas from borderline leprosy lesions with and without RR showed high and specific expression of iNOS and NT. Moreover, strong immunoreactivity to iNOS and NT was observed in granulomas surrounding and infiltrating dermal nerves. The expression of iNOS and NT was also strong in keratinocytes, fibroblasts and endothelial cells in close relation to the granulomatous reaction. In contrast, normal human skin showed no expression of iNOS and NT in these cells. CONCLUSIONS: We conclude that iNOS and NT are expressed in granulomas from borderline leprosy patients with and without RR and propose that RNIs might be involved in the nerve damage following RR in leprosy.

Adenosine deaminase activity in leprosy.

Serum adenosine deaminase (ADA) was studied in 60 patients of different types of leprosy and 50 healthy control subjects. ADA levels in patients with tuberculoid (50.50 +/- 5.22 U/L), borderline (41.14 +/- 3.89 U/L) and lepromatous leprosy (30.10 +/- .03 U/L) were higher than that in controls (17.84 +/- 2.78 U/L), thus correlating with the immunological status of patients. Patients with lepra reaction showed decreased ADA levels and higher grade of lepromin test positivity was associated with increased ADA activity.

Gamma-glutamyl transpeptidase in leprosy.

Activity of the enzyme-gamma-glutamyl transpeptidase (GGTP) was measured in sera of 20 patients each of paucibacillary and multibacillary leprosy and 20 healthy controls. None of the subjects had any systemic or hepatic disease and none had taken any hepatotoxic or antileprotic drugs in the past 3 months. Mean values in the paucibacillary group (38.62 +/- 1.99 U/L) and in the multibacillary group (59.04 +/- 3.13 U/L) were significantly higher compared to that in controls (32.04 +/- 0.66 U/L). Mean value in the multibacillary group was also significantly higher compared to that in the paucibacillary group.

Lymphocyte arginase activity in leprosy--a preliminary report.

Arginase activity was estimated in serum and lymphocytes of 22 healthy controls and 50 untreated leprosy patients across the spectrum. The patients included 21 lepromatous/borderline lepromatous (LL/BL); 20 borderline borderline/borderline tuberculoid (BB/BT) and 9 tuberculoid (TT) cases. Mean serum arginase levels were 1.51 +/- 0.43, 1.41 +/- 0.43, 1.24 +/- 0.43 and 1.10 +/- 0.026 mu moles/min/ml in LL/BL, BB/BT and TT patients and healthy controls respectively. The lymphocyte arginase activity showed a similar increasing trend from TT to LL/BL. The mean lymphocyte arginase levels were 0.87 +/- 0.31 mu moles/min/10(6) cells in healthy controls and 1.81 +/- 0.40, 2.54 +/- 0.60 and 5.48 +/- 0.56 mu moles/min/10(6) cells in TT, BB/BT and LL/BL patients respectively. The increasing trend specially in lymphocyte arginase levels across the spectrum of leprosy correlated with the degree of impairment in the protective cell mediated immune response and also the extent of disease. The role of these pathophysiological alterations in relation to defect in immune response calls for investigation.

Adenosine deaminase activity in leprosy (a preliminary study).

Adenosine deaminase (ADA) activity was studied in 25 patients having different types of leprosy and 25 healthy volunteer as control. There was definite rise of ADA activity in BL (72.9 +/- 6.85), LL (56.7 +/- 3.35) and BT (39.1 +/- 8.28) which was statistically significant when compared to ADA activity in healthy control (9.7 +/- 0.53).