Background: A higher risk of both advanced adenoma and carcinoma occurs in the sigmoid colon of patients with diverticular disease, for which bacterial carcinogens have been claimed to play a role.
Aim: To assess epithelial cell proliferation in colonic mucosa of diverticular disease patients before and after rifaximin treatment.
Methods: Twelve consecutive patients with a new endoscopic diagnosis of left-sided diverticular disease and 12 matched controls were enrolled. Epithelial cell proliferation in the sigmoid mucosa was assessed by using proliferating cell nuclear antigen. The proliferating cell nuclear antigen index of the whole crypt and of the upper third was separately evaluated before and after 10-day rifaximin (400 mg b.d.) therapy.
Results: Proliferating cell nuclear antigen index in the upper third of the crypt was significantly higher in the diverticular patients (median: 25, range: 14-32) as compared with controls (median: 15, range: 5-20) (P = 0.038), and it was not reverted by rifaximin therapy. No difference of the proliferating cell nuclear antigen index of the whole crypt was detected between cases (median: 27, range: 23-44) and controls (median: 25, range: 18-42) (P = 0.6).
Conclusions: Our data showed an upward shifting of cellular proliferation in the sigmoid mucosa of patients with diverticular disease. Because of rifaximin failure in reversing this alteration, factors other than the bacterial load should probably be investigated.