A ROLE FOR APOPTOSIS IN THE PATHOGENESIS OF AIDS-RELATED IDIOPATHIC ESOPHAGEAL ULCERS

Lack of understanding of the mechanism of tissue destruction associate d with idiopathic esophageal ulcers (IEUs) poses a diagnostic and ther apeutic dilemma for the clinician. The possible role of apoptosis in I EUs, as suggested by endoscopic and histologic observations, was inves tigated by examination of archival tissues for apoptosis-related DNA f ragmentation using in situ nick end labeling (TUNEL). High levels of a poptosis were observed in mucosal cells immediately adjacent to IEUs. Apoptotic cells were virtually absent in normal control tissues, while the edges and bases of lesions and sloughed-off tissues in IEUs in hu man immunodeficiency virus (HIV)-infected patients showed elevated lev els of apoptotic cell death. However, tissue samples from patients wit h esophageal ulcerations of known etiology showed no apoptosis of muco sal cells. These data support a role for apoptosis in the pathogenesis of IEUs and suggest a mechanism involving HIV-associated bystander ki lling of uninfected mucosal cells.