Background Methotrexate monotherapy is recommended as a maintenance therapy for Crohn's disease (CD). However, long-term follow-up data are scarce. Objectives We aimed to examine the effectiveness and tolerability of methotrexate monotherapy in 94 CD patients from three inflammatory bowel disease Clinics in Korea. Design This was a multicenter retrospective observational study. Methods Patients with active CD treated with methotrexate monotherapy were included. Clinical characteristics, laboratory indicators, endoscopy indices were evaluated at baseline, 6, 12, and 24 months. Independent factors associated with long-term clinical and endoscopic outcomes were determined. Results Methotrexate was administered orally (70.2%) or parenterally (29.8%). The mean methotrexate induction dose was 15.3 ± 0.4 mg/week, and the mean duration of therapy was 26.2 months. Of 76 patients who were treated for >6 months, the clinical remission rates were 76.3%, 74.6%, and 80.0% at 6, 12, and 24 months, respectively, by per-protocol analysis. The mean CRP levels were 7.5 ± 1.3, 5.3 ± 1.2, 3.8 ± 0.7, and 2.6 ± 0.5 mg/L at 0, 6, 12, and 24 months, respectively. Of 31 patients who underwent follow-up endoscopy after 27.5 months, the endoscopic remission rate was 38.7%. Baseline hemoglobin level <10 g/dL was a significant independent factor negatively associated with clinical remission at 6 [odds ratio (OR): 0.023, 95% confidence interval (CI): 0.003-0.206, p = 0.001] and 12 (OR: 0.079, 95% CI: 0.009-0.699, p = 0.023) months. Parenteral administration was a significant independent factor positively associated with clinical remission (OR: 11.231, 95% CI: 1.027-122.811, p = 0.047) and endoscopic remission (hazard ratio: 4.711, 95% CI: 1.398-15.874, p = 0.012) at 12 months. Conclusions Methotrexate monotherapy was effective and tolerable as a maintenance therapy in CD patients.

中文翻译：

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克罗恩病患者甲氨蝶呤单一疗法的有效性和耐受性：一项多中心观察研究。

背景 甲氨蝶呤单一疗法被推荐作为克罗恩病 (CD) 的维持疗法。然而，长期随访数据却很少。目的 我们旨在检查韩国三个炎症性肠病诊所的 94 名克罗恩病患者接受甲氨蝶呤单药治疗的有效性和耐受性。设计 这是一项多中心回顾性观察研究。方法 纳入接受甲氨蝶呤单药治疗的活动性 CD 患者。在基线、6、12和24个月时评估临床特征、实验室指标、内镜检查指标。确定了与长期临床和内窥镜结果相关的独立因素。结果 甲氨蝶呤采用口服给药（70.2%）或胃肠外给药（29.8%）。平均甲氨蝶呤诱导剂量为 15.3 ± 0.4 mg/周，平均治疗持续时间为 26.2 个月。根据方案分析，76 名治疗时间 > 6 个月的患者中，6、12 和 24 个月时的临床缓解率分别为 76.3%、74.6% 和 80.0%。0、6、12 和 24 个月时的平均 CRP 水平分别为 7.5 ± 1.3、5.3 ± 1.2、3.8 ± 0.7 和 2.6 ± 0.5 mg/L。27.5个月后接受内镜随访的31名患者中，内镜缓解率为38.7%。基线血红蛋白水平 <10 g/dL 是与临床缓解呈负相关的重要独立因素，分别为 6 [比值比 (OR)：0.023，95% 置信区间 (CI)：0.003-0.206，p = 0.001] 和 12（OR： 0.079, 95% CI: 0.009-0.699, p = 0.023) 个月。胃肠外给药是与临床缓解（OR：11.231，95% CI：1.027-122.811，p = 0.047）和内镜缓解（风险比：4.711，95% CI：1.398-15.874，p = 0.012）呈正相关的显着独立因素12个月大时。结论 甲氨蝶呤单药治疗作为 CD 患者的维持治疗是有效且可耐受的。