Intestinal protein leakage in the acquired immunodeficiency syndrome

Body wasting, protein catabolism, and hypoalbuminemia are complicating features of the acquired immunodeficiency syndrome (AIDS). Given their multifactorial causes, the contributing role of intestinal protein loss has not yet been fully elucidated. To quantify enteric protein leakage, determination of fecal alpha 1-antitrypsin (AAT) excretion has been established as an accurate and reliable endogenous marker. We estimated AAT concentration by standard immune nephelometry in duplicate random stool samples of 49 patients with AIDS, and we compared it to that of 43 patients with chronic inflammatory bowel disease and to 34 healthy controls. When compared with healthy persons, patients with AIDS had increased fecal AAT excretion regardless of current opportunistic intestinal infections and fecal AAT excretion similar to that of patients with quiescent chronic inflammatory bowel disease. The ratio of fecal and serum AAT concentration was not different between AIDS patients and healthy controls, although it was consistently increased in those with chronic inflammatory bowel disease. Significant intestinal protein leakage occurs in patients with AIDS, probably due to primary impairment of gut permeability. Enteric protein loss may be an important feature of human immunodeficiency virus-associated enteropathy with altered mucosal barrier function.