PRIMARY ACUTE SIMIAN IMMUNODEFICIENCY VIRUS-INFECTION OF INTESTINAL LYMPHOID-TISSUE IS ASSOCIATED WITH GASTROINTESTINAL DYSFUNCTION

Human immunodeficiency virus (HIV)-associated intestinal abnormalities can occur before immunodeficiency or infection with opportunistic ent eropathogens. Rhesus macaques infected with simian immunodeficiency vi rus (SIV) develop an AIDS-like illness that frequently includes entero pathy. The development of enteropathy and its association with SIV inf ection in the intestinal tract was examined. By 1 week after infection , SIV-infected macrophages and T lymphocytes were detected in gut-asso ciated lymphoid tissue. In contrast to findings in the asymptomatic st age, SIV-infected macrophages were numerous in primary and terminal st ages of infection. An acute enteropathy syndrome was observed in the p rimary acute stage of infection. Functional abnormalities of absorptiv e epithelium, indicated by D-xylose malabsorption and decreased sucras e activity, occurred before the onset of diarrhea or opportunistic ent eric infections. These findings indicate that macrophages and T cells in the intestinal tract are early targets of SIV infection and may pla y a critical role in the development of SIV-associated intestinal dysf unction.