Malabsorption and wasting in AIDS patients with microsporidia and pathogen-negative diarrhea

Objective: To define the clinical syndrome, nutritional status and malabsorptive status in patients with HIV and chronic diarrhea and either microsporidia or no identified pathogen. Patients: HIV-positive patients from an urban, hospital-based infectious disease clinic with chronic diarrhea who had undergone exhaustive gastrointestinal and stool studies for enteric pathogens and were found to have either microsporidia or no pathogen. Methods: Patients were evaluated for clinical history, physical, body composition, nutritional and malabsorptive studies including D-xylose, Schilling test, determinations of 24 h stool fat, weight and nitrogen, and 24 h urea nitrogen. Results: Ten patients with microsporidia were studied, four of whom were infected with Septata intestinalis, six with Enterocytozoon bieneusi; nine patients had no identified pathogen. Patients in both groups were comparable in stage of HIV disease, and demonstrated abnormal nutritional status and malabsorptive parameters. Patients with no pathogen had significantly longer duration of symptoms prior to presentation; however, patients with microsporidia had significantly greater malabsorption of fat, D-xylose, vitamin B-12, and significantly lower serum levels of zinc. Nutritional status and malabsorption were similarly depressed in patients infected with either species of microsporidia. Conclusion: HIV-infected patients with chronic diarrhea associated with either microsporidial infection or with no identified pathogen had abnormal parameters of absorption and malnutrition, and those infected with microsporidia demonstrated more severe malabsorption.