Analysis of granzyme B activity as a surrogate marker of Leishmaniaspecific cell-mediated cytotoxicity in zoonotic cutaneous leishmaniasis

The purpose of this study was to analyze Leishmania-specific cell-mediated cytotoxicity in individuals with active or healed zoonotic cutaneous leishmaniasis (ZCL). The 51Cr-release assay revealed a significant cyto-toxicity against L. major–infected autologous macrophages in individuals with active or healed ZCL. As a surrogate marker of cytotoxic response, a test based on the measure of granzyme B activity in parasite-stimulated peripheral blood mononuclear cells was optimized and evaluated in 88 individuals. Increased granzyme B activity was found in 62.5 % of patients with active ZCL and in only 30 % of individuals with healed ZCL. In both groups, granzyme B activity was significantly higher than in healthy, leishmanin skin test–negative control subjects (). These data provide additional evidence that Leishmania-specific cell-P!.05 mediated cytotoxicity is part of the acquired immune response developed against the parasite. Its role in resistance to reinfection should be evaluated. The leishmaniases constitute a heterogeneous group of diseases that affect millions of people and are caused by various Leishmania species [1]. The diseases range from asymptomatic infections to self-limiting cutane-ous lesions or fatal visceral forms. During their lif