Inflammatory cytokines IFN-γ, IL-4, IL-13 and TNF-α alterations in schistosomiasis: a meta-analysis

Cytokines play an important role in the immunological pathogenesis of schistosomiasis. Schistosomiasis would be associated with an imbalance in inflammatory cytokines that leads to a decrease of T helper (Th) 1 and an increase of Th2 cytokine secretion. Corresponding data so far have been inconsistent, so we performed a meta-analysis to assess whether cytokine alterations were risk factors for schistosomiasis progression. We searched MEDLINE, EMBASE, and CNKI databases for literatures including abstracts, reviews, and reference lists. Our studies included assessment of cytokine concentrations in vivo plasma or serum and secretion of cytokines in vitro by peripheral blood leukocytes from schistosomiasis patients or infected individuals with schistosome. The prototypic Th1 and Th2 cytokines IFN-γ and interleukin (IL)-4 were assessed as well as IL-13 and tumor necrosis factor-alpha (TNF-α). The results implied that an increase occurs in TNF-α and IL-4 with schistosomiasis progression.