RESUMO
The contribution of interferon-gamma (IFN-gamma) to immunity from amebiasis was assessed in a three-year prospective study of children 2-5 years of age in an urban slum of Dhaka, Bangladesh. IFN-gamma produced by peripheral blood mononuclear cells stimulated with soluble amebic antigen was measured upon enrollment. Thirty-one of the 209 enrolled children had Entamoeba histolytica-associated diarrhea. Children who produced higher than the median level of IFN-gamma (median = 580 pg/mL) had longer survival without E. histolytica diarrhea/dysentery (log rank test P = 0.03) and a reduction in the risk of E. histolytica diarrhea/dysentery by more than half (Cox proportional hazard regression = 0.45, P = 0.04). When adjusted for stunting, the association between IFN-gamma and the time to the first episode of E. histolytica-associated diarrhea remained marginally significant (Cox proportional hazard regression = 0.49, P = 0.07). We conclude that production of IFN-gamma is linked to nutritional status and predicts future susceptibility to symptomatic amebiasis.
Assuntos
Entamoeba histolytica/imunologia , Entamebíase/imunologia , Interferon gama/biossíntese , Leucócitos Mononucleares/imunologia , Desnutrição/imunologia , Animais , Antropometria , Bangladesh , Pré-Escolar , Estudos de Coortes , Diarreia/sangue , Diarreia/imunologia , Diarreia/parasitologia , Entamebíase/sangue , Entamebíase/parasitologia , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Feminino , Humanos , Interferon gama/sangue , Interferon gama/imunologia , Interleucina-5/biossíntese , Interleucina-5/imunologia , Estimativa de Kaplan-Meier , Masculino , Desnutrição/sangue , Áreas de Pobreza , Modelos de Riscos Proporcionais , Estudos Prospectivos , População UrbanaRESUMO
The last year has seen new approaches to the diagnosis, treatment, and prevention of protozoal infections of the gastrointestinal tract. Some of the news is not good: new foodborne and swimming pool outbreaks of cyclosporiasis and cryptosporidiosis, respectively, occurred in North America; paromomycin was shown to be ineffective treatment for cryptosporidiosis; and these parasitic diseases continued to have a worldwide impact on human health. On the bright side, there were important advances in the understanding of the pathogenesis of cryptosporidiosis and the diagnosis of amebiasis and giardiasis, and some new leads on the treatment of cryptosporidiosis and refractory giardiasis. Finally, evidence was found of acquired mucosal immunity to amebiasis in Bangladeshi children, offering a guide for the development of an amebiasis vaccine. This review is not intended to be comprehensive, but contains a variety of articles that the authors hope will be of interest to the reader.
