Relationship between interleukin-5 production and variations in eosinophilcounts during HIV infection in West Africa: Influence of Mycobacterium tuberculosis infection

Eosinophils are important effecters of the non-specific immune response and we studied whether perturbations in the production of the type 2 cytokine, interleukin-5 (IL-5), could account for the variations in eosinophil count s observed in human immunodeficiency virus (HIV) infection. HIV-infected pa tients without helminthiasis were investigated in a cross-sectional study i n West Africa. Eosinophil counts were significantly higher in CDC-B patient s than in controls, but were dramatically decreased at the CDC-C stage. Pho rbol 12-myristate 13-acetate (PMA) + ionomycin-induced IL-5 production by p eripheral blood mononuclear cells (PBMC) was decreased from the A stage of the disease, and significant correlations were observed between IL-5 produc tion and eosinophil counts in tuberculosis (TB)-negative HIV-1-positive, TB -positive HIV-1 positive and TB-positive HIV-negative patient groups. Never theless, the production of IL-5 was not decreased in HIV-positive patients with TB, in contrast to HIV-positive patients without TB presenting with th e same ranges of CD4(+) counts. Our data suggest that, during HIV infection , the impairment in IL-5 production is one of the factors associated with t he 'paradoxal' eosinopenia observed in tropical areas, but that IL-5 produc tion during active TB is compensated by cellular subsets, yet to be identif ied.