Co-infection with subclinical HIV and Wuchereria bancrofti, and the role of malaria and hookworms, in adult Tanzanians: infection intensities, CD4/CD8 counts and cytokine responses.

The association between HIV and Wuchereria bancrofti, and the role of malaria and hookworms, were analysed by comparing three groups of individuals with: (1) HIV (HIV+; n=16); (2) W. bancrofti (circulating filarial antigen (CFA)+; n=25); and (3) HIV and W. bancrofti (HIV+/CFA+; n=18). A slightly higher HIV load and lower CD4% was observed in the HIV+/CFA+ group compared with the HIV+ group, and a slightly higher W. bancrofti CFA intensity was observed in the CFA+ group compared with the HIV+/CFA+ group, but none of these differences were statistically significant. Specific and non-specific IL-4, IL-10, IFNgamma and TNF levels were measured. Only specific IL-4 was significantly higher in the CFA+ group compared with the HIV+/CFA+ group. Thus, there was no clear evidence for an interaction between HIV and W. bancrofti infection. A multiple linear regression model showed that the presence of CFA was strongly positively associated with specific TNF response and, similarly, that HIV-positive individuals had higher TNF responses than HIV-negative individuals. Interestingly, the CD4% and CD4/CD8 ratio were higher in HIV-positive individuals with hookworms than in those without hookworm co-infection. Malaria was not associated with any of the other infections, or with CD4/CD8 counts or cytokine responses.