Question

The clinical outcome of leishmaniasis (CL, MCL or VL) is due to many factors including which Leishmania species is involved and the type of host response generated. If the patient develops visceral leishmaniasis (VL), what can be predicted in terms of the predominant immune response?

Select one:

a. No T cell response

b. Th2

c. Th1

d. Mixed Th1 & Th17

e. Mixed Th1 & Th2

Answer 1

Option D-Mixed Th1 & Th17.

Visceral leishmaniasis is the most severe form of leishmaniasis ,Caused by parasite leishmania Donovani.

On Infection with L.Donovani---Antigen presentng Cell(Dendritic cells) are activated,which Secreates Interleukins like IL-12,IL-23&TGF-Beta.

This Causes Differentiation of Native CD4+Tcells----Th1 cells and Th17 cells.

Th1 cells and Th17 cells---Produces IFN-Gamma,TNF(Tumor Necrosis Factor)--- activates infected macrophages &monocytes to produce Reactive Oxygen species and reactive nitrogen Species---This can kill Intracellular Parasites

The Dendritic cell may also causes differentiation of Native CD8 T cells to Cytotoxic T cells----Which releases Granzymes and perforins and Kills Parasites