Comparing acute and chronic human cutaneous leishmaniasis caused by Leishmania major and Leishmania tropica focusing on arginase activity.

Abstract

Cutaneous leishmaniasis (CL) in Iran is mainly caused by Leishmania major (L. major) and L. tropica. Arginase mediated L-arginine metabolism is an important issue in Leishmania parasite propagation. Arginase activity in human CL due to L. major and L. tropica have not been studied up to now. We aimed to compare the clinical and laboratory aspects of acute and chronic CL, focussing on arginase activity. In this case-control study, 30 patients with acute CL (duration ≤ 1 year), 13 patients with chronic CL (duration ≥ 2 year) and 11 healthy controls were recruited. Arginase activity was measured in skin biopsies of lesions, peripheral blood polymorphonuclear cells (PMNs), peripheral blood mononuclear cells (PBMCs) and plasma by standard methods. The median of arginase activity in the acute lesions was higher than in chronic samples and significantly higher than in healthy controls (P = 0.008). PMNs of both acute and chronic patients showed higher levels of arginase activity as compared to the levels in PBMCs and plasma. The median of arginase activity in the PMNs of patients with chronic CL was higher than that of patients with acute CL and significantly higher than that of the healthy controls (P = 0.010). The level of arginase activity in lesions of patients with acute and chronic CL was higher than the skin of healthy controls. The highest level of arginase activity was observed in PMNs from patients with chronic CL. This suggests that the high level of arginase activity in PMNs of patients with chronic CL may contribute to the chronicity.