Plasma Concentrations and Role of Macrophage Inflammatory Protein–1α during Chronic Schistosoma mansoni Infection in Humans

Chemokines play an important role during granulomatous inflammation in murine models of Schistosoma mansoni infection. Here, the expression and possible roles of chemokines during human S. mansoni infection were examined. Compared with uninfected individuals, infected patients had elevated plasma concentrations of macrophage inflammatory protein (MIP)–1α, RANTES (regulated on activation, normally T cell–expressed and secreted), and eotaxin. Concentrations of macrophage-derived chemokine, eotaxin-2, monocyte chemotactic protein–1, growth-related oncogene, and interleukin-8 were similar between the 2 groups. When subjects were grouped according to disease severity, individuals with a plasma MIP-1α concentration >400 pM had a 10-times greater risk of having the more severe hepatosplenic form of disease. In the in vitro granuloma reaction, greater concentrations of MIP-1α were produced by cells of patients with hepatosplenic disease than cells of patients with intestinal disease. Pretreatment with a chemokine receptor antagonist attenuated the enhanced in vitro reaction seen with cells derived from patients with hepatosplenic disease. MIP-1α may not only mark a subset of patients with a greater risk of having more severe disease but also play a relevant pathophysiological role in human schistosomiasis