Immunoregulatory and proinflammatory cytokine production in visceral and cutaneous leishmaniasis

Visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) are the major parasitic diseases in which the immune system is implicated in pathogenesis. The in vitro production of interleukin (IL)-2, IL-4, IL-6, IL-8, tumor necrosis factor-alpha (TNF alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF), spontaneously and in response to stimulation of peripheral blood mononuclear cells with anti-CD3, phytohemagglutinin, and lipopolysaccharide, was investigated to determine their importance in VL and CL. Highly enhanced production of IL-4, IL-6, IL-8, and TNF alpha was seen in VL. However, enhanced production of IL-4 and TNF alpha but almost normal production of IL-6 and IL-8 was seen in CL. The highly increased IL-4 production was the most characteristic and common feature of both VL and CL. Of interest, highly deficient GM-CSF production may be implicated in abnormalities in synthesis of hematopoietic lineage of cells in these diseases.