Systemic Cytokine Profiles in Strongyloides stercoralisInfection and Alterations following Treatment

ABSTRACTStrongyloides stercoralisis a soil-transmitted helminth organism that infects ∼50 to 100 million people worldwide. Despite its widespread prevalence, very little is known about the immune response that characterizes human S. stercoralisinfection. To study the systemic cytokine profile characteristic of Strongyloidesinfection, we measured the circulating levels of a large panel of pro- and anti-inflammatory cytokines in asymptomatic, infected individuals (n= 32) and compared them to those in uninfected, controls (n= 24). Infected individuals exhibited significantly lower circulating levels of proinflammatory cytokines (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], and interleukin-1β [IL-1β]) and significantly higher levels of anti-inflammatory cytokines (IL-4, IL-5, IL-9, IL-10, IL-13, IL-27, IL-37, and transforming growth factor β [TGF-β]). Moreover, treatment of Strongyloidesinfection resulted in a significant reversal of the cytokine profile, with increased levels of proinflammatory (IFN-γ, TNF-α, IL-2, IL-17A, IL-17F, IL-22, IL-23, and IL-1β) and decreased levels of anti-inflammatory (IL-4, IL-5, IL-9, IL-10, IL-13, IL-27, IL-37, and TGF-β) cytokines following treatment. Thus, S. stercoralisinfection is characterized by alterations in the levels of systemic cytokines, reflecting major alterations in the underlying immune response to this chronic helminth infection.