Background: Patients with Crohn's disease (CD) are often comorbid with perianal lesions (especially in Asian countries). Perianal lesions in CD are generally characterized by pathological complications and a high incidence of relapse. The long-term efficacy of adalimumab (ADA) on CD, especially with perianal lesions, is still unclear. We retrospectively analysed Japanese CD cases with perianal lesions to evaluate the efficacy of ADA treatment.
Methods: We enrolled 83 CD patients who underwent scheduled maintenance treatment using ADA from 2010 to 2015 in the Coloproctology Centre at Takano Hospital, Japan. The long-term effectiveness of ADA on CD with perianal lesions and the prognostic factors for relapse were analysed. Relapse was defined using a IOIBD score of ≥2, CRP >0.3 mg/dl or occurrence of a new pathological lesion.
Results: There were 56 male (67%) and 27 female (33%) patients with a mean age of 33.3 years at the first administration. The mean duration of disease was 8.8 years and the mean follow-up period was 40 months. The number of patients who experienced prior infliximab was 26 (31%) and 58 (68%) patients experienced anal lesions.
Clinical remission was achieved in 76 patients (91%) using ADA induction treatment. Persistence rate of ADA treatment during a 6 year follow-up period was greater than 80% (See Figure).
Multivariate analysis revealed that complications due to perianal lesions (OR=4.58, 95% CI: 1.01–20.7, p<0.05) and prior surgical treatment for perianal lesions (OR=46.6, 95% CI: 3.79–573, p<0.01) are significant independent risk factors for relapse.
Clinical improvement of perianal lesions was achieved in 50 patients (86%) within 8 weeks and clinical remission of perianal lesions was achieved in 28 patients (48%) within 20 weeks. Furthermore, patient history of antibiotic use (OR=0.12, 95% CI: 0.022–0.697, p<0.05) and surgical treatment for perianal lesions (OR=0.03, 95% CI: 0.005–0.172, p<0.0001) were significant risk factors for relapse. Moreover, the relapse-free survival curve analysis (p<0.01, Kaplan-Meier) also revealed that prior surgical treatment for perianal lesions was a risk factor for the relapse of perianal lesions.
Conclusions: ADA treatment showed high and long-term efficacy on CD with perianal lesions in this retrospective study. Moreover, surgical treatment for perianal lesions may be a poor prognosistic factor for disease progression.