Studies of esophageal epithelial cell proliferation in patients with reflux esophagitis.

Accelerated cell turnover has been held responsible for the basal zone thickening of the esophageal squamous mucosa of patients with reflux esophagitis. We have studied the in vitro proliferative activity of the basal zone in suction biopsy specimens obtained from normal subjects, from patients with medically treated esophagitis, and from patients who had previously undergone anterior fundoplication. In patients with severe esophagitis, the basal zone showed a significantly elevated [3H]thymidine labeling index in contrast to that of mild esophagitis patients and that of normal subjects. When esophagitis was associated with mucosal lesions at endoscopy, the labeling index was higher than that seen in esophagitis patients without endoscopic abnormalities. Significantly increased thymidine labeling was found only in patients with the most severe changes of papillary length or basal layer thickening. We therefore conclude that there is an increased basal zone uptake of [3H]thymidine in severe esophagitis which suggests increased cell turnover as the mechanism for basal zone hyperplasia. Present techniques for measuring mucosal uptake of [3H]thymidine, however, do not permit the distinction of mild degrees of esophagitis from normal epithelium.