Pathophysiology of HIV-associated diarrhea

Malabsorption Syndromes

Malabsorption syndrome refers to the small intestines' inability to absorb certain nutrients and fluids. There are several common associated disorders, which may present with subtle and/or overt symptoms. With subtle symptoms, it is difficult to determine the cause, making diagnosis difficult or even inaccurate. Malabsorption can originate from an immune response, an inflammatory process, or alternation of the small intestines by surgical methods. This article reviews common malabsorption disease processes of the small bowel and the resulting pathophysiology. Diagnostic studies, treatment, and prognosis of various conditions within the malabsorption disease state are discussed.

Human immunodeficiency virus-associated gastrointestinal disease: common endoscopic biopsy diagnoses

THE GASTROINTESTINAL (GI) TRACT IS A MAJOR SITE OF DISEASE IN HIV INFECTION: almost half of HIV-infected patients present with GI symptoms, and almost all patients develop GI complications. GI symptoms such as anorexia, weight loss, dysphagia, odynophagia, abdominal pain, and diarrhea are frequent and usually nonspecific among these patients. Endoscopy is the diagnostic test of choice for most HIV-associated GI diseases, as endoscopic and histopathologic evaluation can render diagnoses in patients with non-specific symptoms. In the past three decades, studies have elucidated a variety of HIV-associated inflammatory, infectious, and neoplastic GI diseases, often with specific predilection for various sites. HIV-associated esophageal disease, for example, commonly includes candidiasis, cytomegalovirus (CMV) and herpes simplex virus (HSV) infection, Kaposi's sarcoma (KS), and idiopathic ulceration. Gastric disease, though less common than esophageal disease, frequently involves CMV, Mycobacterium avium-intracellulare (MAI), and neoplasia (KS, lymphoma). Small bowel biopsies and intestinal aspirates from HIV-infected patients often show HIV enteropathy, MAI, protozoa (Giardia, Isospora, Cryptosporidia, amebae, Microsporidia), and helminths (Strongyloides stercoralis). Colorectal biopsies demonstrate viral (CMV, HSV), bacterial (Clostridia, Salmonella, Shigella, Campylobacter), fungal (cryptococcosis, histoplasmosis), and neoplastic (KS, lymphoma) processes. Herein, we review HIV-associated GI pathology, with emphasis on common endoscopic biopsy diagnoses.

Management of protease inhibitor-associated diarrhea

Diarrhea is a common and often inadequately treated complication in patients with human immunodeficiency virus infection. Diarrhea has a significant impact on quality of life (QOL) and can contribute to malnutrition, weight loss, immunosuppression, and mortality. In addition, diarrhea may have a significant impact on compliance with antiretroviral therapy; however, this impact has not been adequately assessed. Medications, including protease inhibitors (PIs), are recognized as a common cause of diarrhea. Treatment of PI-associated diarrhea is largely nonspecific; most of the available literature is published only in abstract form and is based primarily on retrospective and survey data. Agents for which some efficacy has been shown for treatment of PI-associated diarrhea include oat bran, psyllium, loperamide, calcium carbonate, SP-303, and pancrelipase. Practitioners and patients need to work together to determine which treatment modality is appropriate based on efficacy, cost, and lifestyle. Management of diarrhea is crucial to improving QOL, controlling weight loss, and enhancing overall efficacy of antiretroviral therapy.

HIV and diarrhea in the era of HAART: 1998 New York State hospitalizations

BACKGROUND

This study reflects an attempt to identify the causes of diarrheal illness in hospitalized HIV patients in light of therapeutic advancements in HIV management.

METHODS

The study identifies the various etiologies associated with diarrhea among HIV patients hospitalized in New York State in 1998. Data for this study were extracted from the New York State Department of Health Statewide Planning and Research Cooperative System. Pathogens recognized to cause diarrhea in persons with HIV and general codes identifying diarrhea were examined by using the principal and all secondary diagnoses based on the International Classification of Diseases 9th Revision Clinical Modification codes.

RESULTS

Based on the Statewide Planning and Research Cooperative System data set, more than 15,000 patients with HIV were hospitalized in 1998. Among the HIV patients hospitalized, 2.8% were admitted with a diarrheal diagnosis. The following diagnoses occurred the most frequently among HIV patients hospitalized with a diarrheal illness: Clostridium difficile (51.3%), other protozoal diseases (18.1%), and other organisms, not elsewhere specified (11.7%).

CONCLUSIONS

In the era of highly active antiretroviral therapy, diarrhea is still an occurring symptom in HIV patients. Despite the relatively small percentage of hospitalizations attributed to diarrhea, clinicians must remember that even "mild" to "moderate" diarrhea can have a debilitating impact among persons with the symptom.