Correlation of interferon-γ production by peripheral blood mononuclear cells with childhood malnutrition and susceptibility to amebiasis

The contribution of interferon-gamma (IFN-gamma) to immunity from amebiasis was assessed in a three-year prospective study of children 2-5 years of age in an urban slum of Dhaka, Bangladesh. IFN-gamma produced by peripheral blood mononuclear cells stimulated with soluble amebic antigen was measured upon enrollment. Thirty-one of the 209 enrolled children had Entamoeba histolytica-associated diarrhea. Children who produced higher than the median level of IFN-gamma (median = 580 pg/mL) had longer survival without E. histolytica diarrhea/dysentery (log rank test P = 0.03) and a reduction in the risk of E. histolytica diarrhea/dysentery by more than half (Cox proportional hazard regression = 0.45, P = 0.04). When adjusted for stunting, the association between IFN-gamma and the time to the first episode of E. histolytica-associated diarrhea remained marginally significant (Cox proportional hazard regression = 0.49, P = 0.07). We conclude that production of IFN-gamma is linked to nutritional status and predicts future susceptibility to symptomatic amebiasis.