A multicenter, retrospective, observational study of the clinical outcomes and risk factors for relapse of ulcerative colitis at 1 year after leukocytapheresis

BACKGROUND: Extracorporeal leukocytapheresis (LCAP) is effective for inducing remission of ulcerative colitis (UC). This retrospective observational study aimed to evaluate the clinical outcome at 1 year and identify risk factors for relapse of UC after LCAP. METHODS: Patients with active UC treated with LCAP between 2010 and 2012 were enrolled from 54 medical facilities in Japan. Clinical data evaluated at 1 year after the last LCAP session included the incidence of relapse, 1-year cumulative relapse-free rate, risk factors for relapse, and history of re-induction treatment following relapse. Relapse was defined by the addition of treatment to induce remission. The primary endpoint was the 1-year cumulative relapse-free rate. Secondary endpoints were risk factors for relapse and outcomes of re-induction treatment after relapse. RESULTS: For 314 patients, the 1-year cumulative relapse-free rate was 63.6%. Following LCAP, a Lichtiger clinical activity index (CAI) of 3 or 4 and high leukocyte count (cut-off value: 7790/mm(3)) were associated with a greater risk of relapse. Intensive LCAP (≥4 sessions within the first 2 weeks) was associated with favorable long-term outcomes in corticosteroid-refractory patients. The response rate was 85.1% among 30 patients who required re-treatment with LCAP. CONCLUSIONS: The majority of patients (>60%) with UC treated with LCAP achieved clinical remission within 1 year and remained relapse-free. A higher Lichtiger CAI and leukocyte count following LCAP were risk factors for relapse. Re-induction therapy with LCAP was effective for relapse of UC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00535-017-1356-8) contains supplementary material, which is available to authorized users.