Effects of immunosuppressive therapy on murine Leishmania infantum visceral leishmaniosis

We evaluated the effect of immunosuppressive therapy on the course of infec tion, the spleen cell immunophenotype and cytokine production during murine Leishmania infantum visceral leishmaniosis (VL), Rousseau et al, [1] recen tly reported that prolonged administration of dexamethasone induces limited reactivation of chronic murine visceral leishmaniosis, with no clear Th1-T h2 cytokine patterns. We found that another glucocorticoid, hydrocortisone acetate, had similar effects during acute visceral leishmaniosis, i.e. an i ncrease in parasite burden in the spleen, but not the liver, of infected mi ce. A significant increase in parasite burden in both the liver and the spl een was only achieved when mice were treated with combined dexamethasone pentoxifylline immunotherapy; increases in parasite burden were never assoc iated,vith a specific spleen cell immunophenotype or a Th1-Th2 cytokine sec retion profile.