Duodenal ultrastructure in patients with chronic renal failure with a comment on the incidence of Campylobacter pylori infection.

This study was aimed at identifying ultrastructural abnormalities that may be present in the duodenum of patients with chronic renal failure who were undergoing hemodialysis and that may have an effect on the normal absorptive function of the duodenum. Duodenal biopsy specimens from ten patients and four controls were examined. Light microscopy showed gastric metaplasia in eight patients and in none of the controls. The main electron microscopic findings were related to the metaplastic changes, with abundant mucous globules and abnormal microvilli being seen in the affected columnar cells. Prominent lysosomes and wide intercellular spaces were seen in some areas. Goblet and enterochromaffin cells appeared to be normal. Some of the reported abnormal duodenal absorptive functions may be related to the ultrastructural abnormalities seen in the microvilli and the apical parts of the columnar cells. Because of the known association between gastric metaplasia and colonization of the duodenum with Campylobacter pylori, we looked for these organisms in our cases. Light microscopy demonstrated these bacteria in only one of the eight duodenal biopsy specimens with gastric metaplasia. Particles, probably representing degenerated bacteria, were seen by electron microscopy in most of the examined specimens, however, suggesting that the duodenum of these patients remains hostile to the growth of these organisms.