DUODENAL INTRAEPITHELIAL AND LAMINA PROPRIA T-LYMPHOCYTES IN HUMAN IMMUNODEFICIENCY VIRUS-INFECTED PATIENTS WITH AND WITHOUT DIARRHEA

Background: Diarrhoea is an important problem in human immunodeficienc y virus (HIV)-infected patients. Intestinal pathologic conditions may arise from changes in local immunocyte populations. The aims of our st udy were to establish the histologic features of the duodenal mucosa o f HIV-infected patients and to determine a) the phenotype of small-int estinal-intraepithelial (IELs) and lamina propria (LPLs)-lymphocytes; b) their degree of activation and differentiation within the lamina pr opria; and c) their relation to the presence of diarrhoea. Methods: Di stal duodenal biopsy specimens were obtained prospectively from 29 HIV -infected patients-11 patients with diarrhoea (group 1) and 18 patient s without diarrhoea (group 2)-and from 42 patients who had neither any risk factor for HIV nor diarrhoea (group 3). Histopathologic and immu nohistochemical studies were combined with flow cytometric analysis, a fter separation of the mucosal intraepithelial compartment from the la mina propria. Results: The median number of IELs and the percentage of gamma delta IELs were both unchanged in HIV-infected patients as comp ared with controls. In HIV-infected patients LP CD4 cells were decreas ed, and LP CD8 cells increased. No significant difference was found in the expression of CD25 or CD27 within the LP CD8 populations of HIV-i nfected patients in groups 1 and 2. Conclusions: These findings sugges t that the occurrence of diarrhoea in HIV-infected patients is unrelat ed to IEL and LPL phenotype.