Gomes, Regis Bernardo Brandim. “Documento produzido em parceria ou por autor vinculado à Fiocruz, mas não consta à informação no documento”.Conselho Nacional de Desenvolvimento Científico e Tecnológico—CNPq (grant 20.1145/95-2 to I.K.F.D.M.S.), World Health Organization (grant M8/181/4/C.256 to C.H.N.C.), Pediatric Scientist Development Program (NICHD grant K12-HD00850 to J.E.E.), and the National Institutes of Health.Levels of the serum opsonin mannan-binding lectin (MBL) were directly correlated with the probability of developing visceral leishmaniasis. Monocytes infected with MBL-opsonized Leishmania chagasi promastigotes secreted higher levels of tumor necrosis factor alpha and interleukin-6 than cells infected with nonopsonized parasites. Our findings indicate that MBL can modulate the clinical outcome of infection with L. chagasi and the function of infected macrophages.