Circulating T helper 1 (Th1) cell- and Th2 cell-associated cytokines in Indian patients with visceral leishmaniasis.
Academic Article
Overview
abstract
Sera from 61 Indian patients with visceral leishmaniasis caused by infection with Leishmania donovani were tested for the presence of T helper 1 (Th1) cell-(interferon-gamma [IFN-gamma]) and Th2 cell-associated cytokines (interleukin-4 [IL-4] and IL-10). The IFN-gamma activity was detected in 53%. IL-4 in 84%, and IL-10 in 56% of patient samples. Sera from 10 healthy Indian controls showed detectable IFN-gamma in 90%. IL-4 in 10%, and IL-10 in 20%; corresponding percentages for sera from eight healthy American controls were 100%, 12%, and 0%, respectively. Quantitative data for the 61 patients compared with the 10 Indian controls indicated comparable mean levels of IFN-gamma, but three- and 13-fold increases in IL-10 and IL-4, respectively. Undetectable IFN-gamma activity, observed in 47% of patients, was associated with the presence IL-4 alone or in combination with IL-10 but not with IL-10 alone. In patients who had failed prior therapy (n = 29) compared with previously untreated patients (n = 32). IFN-gamma levels were 67% lower and IL-4 levels were two-fold higher, IL-10 activity was comparable. These results using peripheral blood support the presence of a suppressive Th2 cell-associated immune response in symptomatic Indian kala-azar and point to a possible role for IL-4.