Common features of T cell reactivity in persistent helminth infections: lymphatic filariasis and schistosomiasis

This review highlights striking similarities in the down-regulated inflamma tory responses that are observed in chronic infectious diseases. It is clea r that peripheral mononuclear cells show poor antigen-specific T cell proli feration in lymphatic filariasis as well as schistosomiasis. With respect t o cytokines both Th1- and Th2-type products are down-regulated during chron ic infection. Drug treatment restores responsiveness in both diseases indic ating a link between infection and immune suppression. Interestingly, immun ological responses in subjects carrying recent infections are characterized by strong proliferation to parasite antigen and IFN-gamma production. Thes e heightened responses are gradually down-regulated with increased length o f exposure to infection. (C) 1999 Elsevier Science B.V. All rights reserved .