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

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