Outcome predictors for thiopurine maintenance therapy in patients with Crohn's disease

Abstract

[한글]

[영문]Little is known about the predictive factors for clinical relapse in patients with Crohn’s disease receiving thiopurine therapy for maintenance of remission. The aim of this study was to investigate factors predictive of clinical relapse in these patients receiving thiopurine therapy for maintenance of remission. A total of 82 patients with CD, who received their first course of azathioprine or 6-mercaptopurine treatment at Severance Hospital from June 1996 to July 2007 were recruited. The indications of thiopurine therapy were as follows; steroid dependency in 60 cases (73.2%), draining fistula in 13 cases (15.9%), and maintenance of remission after surgery in 9 cases (11.0%). During the follow-up period of 25.5±16.6 months (range, 4.3?83.8 months), 19 patients (23.1%) discontinued medications due to significant adverse effects. Finally, 45 patients, who continually received thiopurine for maintaining medically or surgically induced remission were enrolled. After adjustment of maintenance dose, patients in remission were followed at 2-3 months interval. Relapse was defined as a Crohn’s disease activity index (CDAI) > 150. Patiens who achieved remission were followed for clinical relapse. Male to female ratio was 1.5:1 and the mean age was 26.3±7.1 year. The cumulative relapse rate was 18.0% at 1 year and 49.2% at 3 year. At multivariate Cox regression analysis, young age (<30 year) at thiopurine therapy and increased C-reactive protein level (>0.5 mg/mL) at the time of remission achievement were found to be independent predictors for relapse (hazard ratio 13.055, 95% confidence interval 1.447-117.792, P = 0.022 and hazard ratio 8.233, 95% confidence interval 1.448-46.801, P = 0.017, respectively). The results of this study suggest that thiopurine was efficacious for maintaining remission in Korean CD patients, although full dose was not administered in many cases due to leukopenia. Young age (<30 year) and increased C-reactive protein level at remission were independent predictors of relapse in patients with CD receiving thiopurines for maintenance of remission. These high risk groups warrant more close observation and might require early introduction of biologics.