Detection of HIV-1 RNA/DNA and CD4 mRNA in feces and urine from chronic HIV-1 infected subjects with and without anti-retroviral therapy

Gut-Associated Lymphoid Tissues (GALT) are very important in HIV pathogenesis. GALT is the largest single immunologic organ in the body, containing a large amount of lymphocytes. Contrast to the blood and other organized lymphoid tissues, which contain abundance of naive resting T cells, a majority of the CD4+ T cells that reside in GALT are CCR5 positive, activated memory CD4 T cells which are the preferred target cells for HIV/SIV infection [1-3]. HIV infects GALT at a very early stage of infection regardless of the route of infection and active HIV/SIV replication in GALT is present throughout the entire course of infection, which leads to GALT acting as a major viral reservoir and results in mucosal barrier dysfunction and bacterial translocation that contributes to generalized systemic immune activation and disease progression[2-6].CD4+ T cells in the gut are rapidly infected and depleted soon after infection[3,7] and CD4+ T cell repopulation of the gut is prevented throughout infection[4]. We hypothesize that during HIV-1 infection, HIV-1 free virus and infected/uninfected CD4+ T cells constantly shed from GALT into the intestinal lumen and are discharged with feces. Therefore, the amount of HIV-1 and CD4+ T cells contained in the feces could reveal the degree of pathogenesis in GALT. Detection of HIV-1 has been reported in fecal specimens from drug na？ve HIV-1 infected individuals in the acute phase of infection [8-10]. There is no information on HIV-1 detection in the feces of chronically infected subjects, especially in subjects undergoing antiretroviral drug therapy (ART). Monitoring the dynamic change of CD4+ T cells in GALT of infected individuals is very important to evaluate disease progression. However, due to the anatomic location of GALT, invasive and expensive biopsy is the only current method to monitor CD4+ T cell loss in GALT. In contrast, feces could be an easily accessible, non-invasive and inexpensive specimen to assess CD4+ T cell depletion