Changes in small intestinal structure and function in HIV-infected patients with chronic diarrhoea.

Human immunodeficiency virus (HIV) is often combined with unexplainable diarrhoea and weight loss. This study was designed to see if changes in the intestinal mucosal structure could explain the malabsorption found in HIV-infected patients with diarrhoea. Twenty acquired immunodeficiency system (AIDS) patients, 19 men and 1 woman, CD4 < 0.01, with severe weight loss and with non-infectious chronic diarrhoea, were evaluated using a new intestinal function test (D-xylose breath test). Fifteen of the subjects were examined with an upper intestinal endoscopy with biopsy specimens taken from the duodenal mucosa. The function test showed that the D-xylose uptake was markedly decreased to the same extent as for patients with coeliac disease (breath index AIDS patients 9.4 (4.3-14.4), coeliac patients 15.6 (7.6-23.6), reference level 2.5 (2.4-2.9), urine excretion AIDS patients 20% (13-26), coeliac patients 22% (14-24), reference level 37% (32-42)). The severe malabsorption could not be explained by the slight mucosal changes occasionally seen by light microscopy with small mucosal inflammation and almost normal villi. However, electron microscopy showed enterocytes with signs of hypofunction and degeneration correlating better to the intestinal malabsorption found in patients with advanced HIV infection and chronic diarrhoea.