Rapidly reversible depression of delayed hypersensitivity in two children with visceral leishmaniasis.

Two cases of visceral leishmaniasis in children are described. In both "in vitro" lymphocyte response to mitogens and allogeneic cells was initially markedly depressed, but returned to normal within a few days after six days of treatment with N-methylglucamine antimonate; in one the candidin skin test reverted from negative to positive after treatment and in the other a circulating serum factor was found which strongly inhibited phytohemagglutinin--and mixed--responsiveness of normal lymphocytes, but disappeared after therapy.