Can Presumptive Anthelminthic Treatment Delay the Progression of HIV in ART-naïve Patients in Rural Africa?

Overview

This study focuses on one of the major health issues of Sub-Saharan Africa: multi-parasitism and co-infections. In particular this study aims to elucidate the interaction of helminths with HIV. There is good reason to suspect a detrimental effect of helminth infection on the course of HIV infection. We hypothesize, that treatment of helminths in HIV- and helminth co-infected individuals leads to a reduction of HIV viral load. With a lower HIV RNA level one would expect a slower decline of CD4 cells and hence also a slower progression of the disease. Ideally this would lead to a prolongation of the chronic phase of HIV infection and to a delay in the time when anti-retroviral treatment needs to be started.

\* Background: On the basis of immunological considerations and in vitro trials on co-infections there is strong reason to suspect a detrimental effect of helminth infection on the course of HIV. The immunological answer very efficiently evoked by helminth infection is aimed at hijacking and suppressing the immune system in order to suit the requirements of the specific helminth. This permits helminths to cause chronic infection, often persisting over years and allowing some infecting worms to grow to several centimetres of length within their host. However, this immune modulation also affects non-related antigens (for example HIV) which would actually require a different line of immunological action. Some clinical trials have been able to confirm this detrimental effect of helminths on HIV infection, while other trials failed to do so. A recent Cochrane review on clinical trials with HIV and helminth co-infection found an overall slight reduction of HIV viral load if helminth infection was treated. However there was no measurable effect on CD4 count or clinical staging of HIV. This might be explained by the fact that these trials were very heterogeneous in their set-up and were run for too short a time (max 6 months) to allow sufficient answers to these questions. According to mathematical models, even a relatively modest reduction of HIV RNA by 0.5 log could delay the need to start combined antiretroviral therapy by about 3.5 years and potentially prolong the symptom-free phase of HIV-infection by nearly 1 year. On a population scale this could lead to substantial savings with regard to drug and clinical costs and on an individual level to an invaluable gain in drug-free and ideally also symptom-free life years. * Objective: To assess the impact of presumptive anthelminthic treatment on HIV progression in patients infected with HIV in a rural setting with presumed high prevalence of helminth infection. * Methods: Randomised open-label trial of presumptive triple anthelminthic treatment in HIV positive patients not yet requiring anti-retroviral treatment.