A clinicopathologic analysis of AIDS-related cryptosporidiosis

Objective: To characterize the histology of AIDS-associated cryptosporidios is and identify features that explain the clinical variability. Design: A retrospective analysis of HIV-positive individuals with cryptospo ridiosis who underwent endoscopy at the Johns Hopkins Hospital between 1985 and 1996. Methods: The histologic features (intensity of Cryptosporidium infection, i nflammation, mucosal damage, copathogens) of gastrointestinal biopsies from 37 HIV-positive individuals with cryptosporidiosis were systematically gra ded. These histologic features were correlated with the severity of the dia rrheal illness obtained from a patient chart review. Results: Histologic features associated with Cryptosporidium infection incl ude a neutrophilic infiltrate in the stomach, villus blunting in the duoden um, cryptitis and epithelial apoptosis in the colon, and reactive epithelia l changes in the stomach and duodenum. The nature and intensity of the infl ammatory response varied widely; however, duodenal biopsies from a subset o f patients (37%) revealed marked acute inflammation that was associated wit h concomitant cytomegalovirus infection. Although duodenal infection was co mmon (93% of individuals), infection of other sites was variable (gastric c ryptosporidiosis in 40% and colonic cryptosporidiosis in 74%). Widespread i nfection of the intestinal tract, which included both the large and small i ntestine, was associated with the most severe diarrheal illness. Conclusions: Cryptosporidium infection produces histologic evidence of gast rointestinal mucosal injury. The inflammatory response to the infection is variable, and may be modified by copathogens such as cytomegalovirus. The c linical manifestations are influenced, in part, by the anatomic distributio n of the infection, with extensive infections involving both small and larg e intestines producing the most severe illness. (C) 1998 Lippincott William s & Wilkins.