Influence of helminth infections on the clinical course of and immune response to Leishmania braziliensis cutaneous leishmaniasis

Background. Helminth infections influence the clinical outcome of and immune response to certain immune-mediated diseases. Methods. We conducted a cohort study of 120 patients to examine the role that intestinal helminth infection plays in the clinical course of and immune response to cutaneous leishmaniasis (CL) treated with pentavalent antimony. Results. Patients coinfected with Leishmania braziliensis and helminths took longer to heal (relative hazard for healing, 0.47 [95% confidence interval, 0.26-0.85]; P = .01) than patients with CL without helminths, with 70% of coinfected patients being cured at 90 days, compared with 92% of helminth-free patients. Coinfected patients had an immune response shifted toward the T helper 2 type, with increased total immunoglobulin E levels (P < .06) and a tendency toward increased interleukin-5 levels, compared with helminth-free patients with CL. Conclusions. Helminths influence both the clinical outcome and the immune response of patients with CL. These results may have clinical implications for the care of patients with CL caused by Leishmania braziliensis, because screening for and treatment of helminths may improve responses to treatment and possibly reduce the risk of progression to mucosal disease.