[715] ERADICATION OF HELMINTH INFECTIONS DECREASES CHRONIC IMMUNE ACTIVATION OF THE HOST: RELEVANCE TO THE AIDS EPIDEMIC IN DEVELOPING COUNTRIES

1st International AIDS Society Conference on HIV Pathogenesis and Treatment

Buenos Aires, Argentina - July 8-11, 2001

[TITLE:] ERADICATION OF HELMINTH INFECTIONS DECREASES CHRONIC IMMUNE ACTIVATION OF THE HOST: RELEVANCE TO THE AIDS EPIDEMIC IN DEVELOPING COUNTRIES

[AUTHOR(S):] Weisman, Z; Kalinkovich, A; Zlotnikov, S; Stein, M; Leng, Q; Borkow, G; Bentwich, Z
Hebrew University Hadassah Medical School, Rehovot, Israel

IAS Conf HIV Pathog Treat 2001 Jul 8-11;1st: Abstract No. 715

[ABSTRACT:] Hypothesis: Chronic immune activation by helminthic infections make the host more susceptible to HIV and Tuberculosis, and less able to cope with them.

Objectives: Study the immune effects of helminth infection and the changes confered by their eradication.

Methods: Four groups of HIV negative Ethiopian immigrants (ETH)- 111 newly arrived with helminths, 42 adjusted and free of helminths> 5 years, 30 newly arrived before and after helminth eradication and 19 newly arrived who did not receive antihelminthic treatment, and 45 non ETH controls were studied. Lymphocyte subsets,activation markers, cytokine profile, and cellular response by cell proliferation and skin delayed hypersensitivity to recall antigens, was determined in all participants of the study.

Results: High eosinophilia and IgE blood levels, with decreased CD4⁺ and increased CD8⁺ cells, increased proportion of activated T-cells (HLA-DR, Ki67,DR38 and CTLA-4),decreased proportion of naive T cells, increased secretion of Th2 cytokines (IL4 and IL-5) and significantly impaired cellular and skin test response, characterized helminth infected participants. In contrast, the immune profile of ETH free of helminths for 1-5 years, was clearly reverting towards that observed in the non-Ethiopian Israeli controls (n=31), though the changes in recovery of cellular response and some of the TH2 dominant profile were slower to change back.

Conclusions: 1)Helminth infections alone and distinctive from other environmental factors, influence significantly the host immune system and this can be reversed within a reasonably short time after helminth eradication. 2) The chronic immune activation and decreased cellular immune response associated with helminth infection, act together to undermine host immunity. 3) These results support the notion that effective eradication of helminthic infection may be of prime importance in the fight against AIDS and Tuberculosis in developing countries.

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