Comparison between systemic and intralesional meglumine antimoniate therapy in a primary health care unit.

Cutaneous leishmaniasis (CL) is not a life-threatening condition. However, its treatment can cause serious adverse effects and may sometimes lead to death. Recently, safer local treatments have been included among therapies acceptable to New World CL cases, but the use of intralesional meglumine antimoniate (IL-MA) is recommended to be performed in reference centers, for patients with single cutaneous lesions <3 cm in diameter at any location except the head and periarticular regions; the volume of injected MA should not exceed 5 mL. In this study we compared two groups of patients with CL treated with MA in a primary health care unit in Brazil. Patients were treated with systemic MA (n = 76) or IL-MA (n = 30). In the IL-MA group, 93% of patients had one or more of the following lesion characteristics: two or more lesions, lesions >3 cm in diameter, lesions located in the head or in periarticular regions, or had been administered IL-MA volumes >5 mL. Patients responded well (68.4% and 66.7% for the MA and IL-MA groups, respectively). When a second cycle of treatment was necessary, the responses were 72.4% and 90%, respectively. There were no significant differences between groups. In the IL-MA group, 43% had mild to moderate adverse effects, without needing treatment discontinuation. Results suggest that the treatment of CL lesions with IL-MA is simple, efficient, and safe.

Are Neutrophil Extracellular Traps Playing a Role in the Parasite Control in Active American Tegumentary Leishmaniasis Lesions?

Neutrophil extracellular traps (NETs) have been described as a network of extracellular fibers composed by DNA, histones and various proteins/enzymes. Studies have demonstrated that NETs could be responsible for the trapping and elimination of a variety of infectious agents. In order to verify the presence of NETs in American tegumentary leishmaniasis (ATL) and their relationship with the presence of amastigotes we evaluated active cutaneous lesions of 35 patients before treatment by the detection of parasites, neutrophils (neutrophil elastase) and histones through immunohistochemistry and confocal immunofluorescence. Intact neutrophils could be detected in all ATL lesions. NETs were present in 27 patients (median 1.1; range from 0.1 to 23.5/mm2) with lesion duration ranging from one to seven months. NETs were in close proximity with neutrophils (r = 0.586; p = 0.0001) and amastigotes (r = 0.710; p = 0.0001). Two patterns of NET formation were detected: small homogeneously distributed networks observed in all lesions; and large structures that could be visualized at a lower magnification in lesions presenting at least 20% of neutrophils. Lesions presenting the larger NET formation showed high parasite detection. A correlation between NET size and the number of intact amastigotes was observed (p=0.02). As we detected an association between NET and amastigotes, our results suggest that neutrophil migration and NET formation could be stimulated and maintained by stimuli derived from the parasite burden/parasite antigen in the extracellular environment. The observation of areas containing only antigens not intermingled with NETs (elastase and histone) suggests that the involvement of these structures in the control of parasite burden is a dynamic process in which the formation of NETs is exhausted with the destruction of the parasites. Since NETs were also associated with granulomas, this trapping would favor the activity of macrophages in order to control the parasite burden.