title: Eosinophil activity in Schistosoma mansoni infections in vivo and in vitro in relation to plasma cytokine profile pre- and posttreatment with praziquantel.
abstract: Eosinophil activity in vivo and in vitro was studied in relation to infection intensities and plasma cytokine profiles of 51 Schistosoma mansoni-infected Ugandan fishermen before treatment and 24 h and 3 weeks posttreatment. Blood eosinophil numbers significantly declined 24 h posttreatment, but significant eosinophilia had developed by 3 weeks posttreatment. Cellular eosinophil cationic protein (ECP) content increased significantly during the transient eosinopenia but was significantly reduced 3 weeks later. No similar reduction in cellular eosinophil protein X (EPX) content was seen. Before treatment, S. mansoni infection intensity was positively correlated with 24-h boosts in plasma interleukin-5 (IL-5) and IL-6 levels, which were in turn negatively correlated with the posttreatment fall in eosinophil numbers. Significant correlations were observed between pretreatment infection intensities and plasma IL-10 and eotaxin levels. Treatment induced significant fluctuations in plasma IL-5, IL-6, IL-10, tumor necrosis factor alpha (TNF-alpha), and eotaxin levels. Optimal relative release of ECP and EPX in vitro was detected in S. mansoni soluble egg antigen-stimulated cultures during transient eosinopenia. Our data suggest that blood eosinophils are activated during S. mansoni infection and that treatment induces a burst in released antigens, causing increased production of IL-5, IL-6, IL-10, and eotaxin; a drop in TNF-alpha levels; and a transient sequestration of eosinophils, which leaves fewer degranulated eosinophils in the circulation 24 h posttreatment, followed by the development of eosinophilia 3 weeks later. During these events, it appears that preferential release of ECP occurs in vivo. Moreover, it is possible that infection intensity-dependent levels of plasma IL-10 may be involved in the prevention of treatment-induced anaphylactic reactions.
authors: DBL, Institute for Health Research and Development, Jaegersborg Alle 1 D, 2720 Charlottenlund, Denmark. cmreimert@dblnet.dk
authors: Claus M
authors: CM
authors: Reimert
authors: Colin M
authors: CM
authors: Fitzsimmons
authors: Sarah
authors: S
authors: Joseph
authors: Joseph K
authors: JK
authors: Mwatha
authors: Frances M
authors: FM
authors: Jones
authors: Gachuhi
authors: G
authors: Kimani
authors: Karl F
authors: KF
authors: Hoffmann
authors: Mark
authors: M
authors: Booth
authors: Narcis B
authors: NB
authors: Kabatereine
authors: David W
authors: DW
authors: Dunne
authors: Birgitte J
authors: BJ
authors: Vennervald