INTESTINAL INFLAMMATION, ILEAL STRUCTURE AND FUNCTION IN HIV

Objectives: This study examines small intestinal absorption-permeabili ty, intestinal inflammation and ileal structure and function in HIV-po sitive male homosexuals. Methods: Thirty HIV-seropositive male homosex uals at various stages of disease underwent intestinal absorption-perm eability and (111)indium leukocyte studies (for quantification of inte stinal inflammation). Twenty-six men with AIDS had a dual radioisotopi c ileal function test (whole body retention of tauro 23-[Se-75]-selena 25-homocholic acid and (58)cobalt-labelled cyanocobalamine), and 17 u nderwent ileocolonoscopy with terminal ileal biopsy. Results: Well, HI V-infected, subjects had normal intestinal absorption-permeability, bu t both functions were impaired upon the development of AIDS. The media n faecal excretion of (111)indium in well patients (0.66%) did not dif fer significantly (P > 0.5) from controls (0.46%), but subjects with A IDS who were well or who had diarrhoea had significant (P < 0.005) int estinal inflammation (1.33% and 2.18%, respectively). The median 7-day retention of tauro 23-[Se-75]-selena 25-homocholic acid in well patie nts with AIDS (38.9%) did not differ significantly (P > 0.2) from cont rols (39.3%), whereas the absorption of (58)cobalt-labelled cyanocobal amine was significantly (P < 0.05) lower than controls (32.1% and 59.4 %). Patients with AIDS-diarrhoea had significant (P < 0.001) malabsorp tion of both the bile acid (7.7%) and vitamin B-12 (8.9%) which was mo re severe than in Crohn's ileitis (14.2% and 30.3%, respectively). Mor phometric analyses of ileal biopsies were unremarkable in AIDS. Conclu sions: These studies demonstrate a low-grade enteropathy in patients w ith AIDS, severe ileal malabsorption in patients with AIDS diarrhoea a nd relatively minor ileal morphologic changes. Malabsorption of bile a cids may play a pathogenic role in patients with AIDS and diarrhoea.