Immune Dysfunction and Coinfection with Human Immunodeficiency Virus and Schistosoma japonicum in Yi People

OBJECTIVE: To explore the association between infections with HIV and Schistosoma japonicum, and to determine the influences of the HIV-S. japonicum coinfections on the immune system of Yi people. METHODS: A block design study was conducted in a Yi county in southwestern China, one of the endemic areas of both HIV/AIDS and S. japonicum in China. All participants were screened for HIV antibodies and S. japonicum antibodies (SjAb) and were classified into four groups: HIV(+)/S. japonicum(−), HIV(−)/S. japonicum (+), HIV(+)/S. japonicum(+), and HIV(−)/S. japonicum(−). RESULTS: There were significant differences among the four groups in both CD4(+) T lymphocytes and CD8(+) T lymphocytes, but no significant difference in CD3(+) T lymphocytes. Both the CD4(+) T lymphocyte counts and the ratio of CD4(+)/CD8(+) were lower in HIV-infected people compared with those uninfected. People infected with S. japonicum had increased CD4(+) T lymphocyte counts but reduced CD8(+) T lymphocyte counts. Similarly, the ratio of CD4(+)/CD8(+) was higher in S. japonicum-infected people compared with those uninfected. People coinfected with HIV and S. japonicum had lower CD4(+) T lymphocyte counts, lower ratio of CD4(+)/CD8(+), and higher CD8(+) T lymphocyte counts compared with those infected with HIV only or S. japonicum only. People infected with HIV only and those coinfected with HIV and S. japonicum had a higher level of IFN-γ compared with people with no infection. There were no significant differences between people infected with HIV only and with S. japonicum only in the levels of IFN-γ and IL-10. CONCLUSIONS: People coinfected with HIV and S. japonicum might have a suppressed immune function because of a decrease in CD4(+) T lymphocyte counts, a lowered ratio of CD4(+)/CD8(+), and an increase in CD8(+) T lymphocyte counts. Coinfection with HIV and S. japonicum would alter the level of IFN-γ in plasma.