Relationship between mucosal healing by tacrolimus and relapse of refractory ulcerative colitis: a retrospective study

Background Tacrolimus (TAC) is a powerful remission-inducing drug for refractory ulcerative colitis (UC). However, it is unclear whether mucosal healing (MH) influences relapse after completion of TAC.We investigated whether MH is related to relapse after TAC. Patients: Among 109 patients treated with TAC, 86 patients achieved clinical remission and 55 of them underwent colonoscopy at the end of TAC. These 55 patients were investigated. Methods Patients with MH at the end of TAC were classified into the MH group ( n = 41), while patients without MH were classified into the non-MH group ( n = 14). These groups were compared with respect to 1) clinical characteristics before treatment, 2) clinical characteristics on completion of treatment, and 3) the relapse rate and adverse events rates. This is a retrospective study conducted at a single institution. Results 1) There was a significant difference in baseline age between the two groups before TAC therapy, but there were no significant differences in other clinical characteristics. The NMH group was younger (MH group: 48.1 (23–79) years, NMH group: 36.3 (18–58) years, P = 0.007). Endoscopic scores showed significant differences between the 2 groups at the end of TAC. There were also significant differences in the steroid-free rate after 24 weeks (MH group: 85.3%, NMH group 50%, P = 0.012). There was no significant difference in the relapse rate between the 2 groups at 100 days after remission, but a significant difference was noted at 300 days (17% vs. 43%), 500 days (17% vs. 75%), and 1000 days (17% vs. 81%) (all P < 0.05). Conclusions TAC is effective for refractory ulcerative colitis. However, even if clinical remission is achieved, relapse is frequent when colonoscopy shows that MH has not been achieved. It is important to evaluate the mucosal response by colonoscopy on completion of TAC.