Impaired Gut Epithelial Tight Junction Expression in Hemodialysis Patients Complicated with Intradialytic Hypotension

BACKGROUND: There is accumulating evidence pointing to uremia-induced impairment of the intestinal epithelial barrier structure in advanced chronic kidney disease (CKD) and hemodialysis (HD) patients. In this study, the impact of intradialytic hypotension on intestinal barrier integrity is being explored. METHODS: Immunohistochemical staining was used to detect the expression of 4 types of tight junction (TJ) proteins such as occludin, zonula occludens-1 (ZO-1), claudin-1, and claudin-4, in colonic samples of a group of patients receiving segmental colectomy. Five patients with nondialysis CKD (group 2), 5 HD patients with intradialytic hypotension (group 3), and 5 non-CKD subjects (group 1) were examined. RESULTS: Both patients' groups 2 and 3 demonstrated significantly reduced expression of occludin as compared to group 1 (p < 0.05 and p < 0.01, resp.). Except for claudin-4, expression of all markers of TJ proteins was significantly reduced in patients' group 3 as compared to control (p < 0.01). In addition, decreased expressions of claudin-1 and ZO-1 were also more pronounced in group 3 when compared to group 2. CONCLUSIONS: This study extends the earlier finding by demonstrating that dialysis-related hypotension caused even marked depletion of the key protein constituents of the epithelial TJ.