FK506-Binding Protein 5 mRNA Levels in Ileal Mucosa Are Associated with Pouchitis in Patients with Ulcerative Colitis.

Background: Although the pathogenesis of pouchitis is incompletely understood, steroid and FK506 therapy are significantly associated with pouchitis. These medical treatments are regulated by the FK506-binding protein (FKBP) 4 and FKBP5 genes.

Aim: This study aimed to evaluate the relationship between pouchitis and FKBP4 and FKBP5 mRNA expression in ileal mucosa at the time of colectomy.

Methods: Ileal mucosa specimens were collected from 71 patients who underwent ileal pouch-anal anastomosis for ulcerative colitis. FKBP4 and FKBP5 mRNA expression was evaluated. The relationship between mRNA expression and clinicopathological factors, including developed pouchitis, was investigated.

Results: Of these 71 patients, 25 (35.2 %) patients developed pouchitis in a mean duration of 20.2 months (range 0-68 months). FKBP4 mRNA levels in patients who received an immunomodulator were significantly higher than those in untreated patients (0.167 ± 0.060 vs 0.131 ± 0.065, p = 0.009). However, FKBP5 mRNA levels in patients who received a three-stage operation were significantly lower than those in the other patients (1.97 ± 1.15 vs 2.70 ± 1.12, p = 0.02). A total dose of prednisolone >9.4 g (HR 2.84, p = 0.02) before colectomy and FKBP5 mRNA level higher than the median (HR 4.49, p = 0.01) were identified as factors related to pouchitis.

Conclusions: FKBP5 mRNA levels in ileal mucosa at the time of colectomy are significantly associated with pouchitis and may be a predictive factor for developing pouchitis.