Volume 96, Issue 6
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



More than 2 billion people are infected with parasites globally, and the majority have coinfections. Intestinal protozoa and helminths induce polarizing CD4 T-helper cell 1 (Th1) mediated cytokine responses within the host. Such immune polarization may inhibit the ability of the host to mount an adequate immune response for pathogen clearance to concurrent pathogens. The current study evaluated the plasma cytokine profile in and coinfected children compared with - and -only infected children. Fecal samples and blood samples were collected from asymptomatic 3-year-old children living in the district of Quininde, Ecuador. Stool samples that tested positive for -only, only, or and coinfections were confirmed by quantitative real-time polymerase chain reaction. Plasma samples from the study subjects were used to quantitate cytokines. A total of 39 patients were evaluated. Children with coinfection had a significant decrease in Th1 cytokine production, interleukin 2 (IL-2) ( < 0.05), IL-12 ( < 0.05), and tumor necrosis factor alpha ( < 0.05) compared with -only infected children. Coinfected children had an increase in IL-10/interferon gamma (IFN-γ) ratio compared with uninfected ( < 0.05) and alone ( < 0.05). The increased IL-10/IFN-γ ratio in the setting of decreased Th1 cytokine response indicates Th2 polarization in the coinfected group. Reduced Th1 cytokines in children coinfected with and may impair the host's ability to eradicate infection leading to chronic giardiasis.


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  • Received : 17 Jul 2016
  • Accepted : 18 Jan 2017

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