Perianal Involvement in Crohn`s Disease: Are There Always Two Sides to Every Coin?

BACKGROUND: Crohn's disease (CD) is complicated with perianal disease in 21-23% of patients. Presence of perianal disease has been associated with a disabling course of CD and dreadful impact on quality of life. We aim to identify if perianal disease has negative implication on CD remission rates, after one-year infliximab therapy course.

METHODS: Cohort, retrospective, single center study, including consecutive CD patients on Infliximab perfusion. Patients were followed one year, since the beginning of biological therapy. Co-variables were chosen bearing in mind clinical relevance and literature evidence. We split our outcome variable into clinical remission; analytical remission; endoscopic remission and deep remission (including all three mentioned before). The correlation towards the outcome variable was assessed with univariate and multivariate analysis, and a survival assessment, using SPSS – P value < 0.05 was considered statistically significant.

RESULTS: We assessed 74 patients with CD, of whom 41 (55,4%) were female, with a mean age of 36 years old, all Caucasian. From our cohort, 36.5% of the patients presented perianal disease at diagnosis. After one year of treatment course, we documented 31.5% of deep remission, 47.2% endoscopic remissions, 55.4% analytical remission and 70.3% of clinical remission. Sixty-six patients (89.2%) presented any type of initial response to the treatment, from whom, 20 presented disease relapses (clinical or/and analytical or/and endoscopic). Patients with perianal disease, on the first year of Infliximab therapy, have a higher probability of disease relapse, displaying statistically significant difference on Kaplan-Meyer curves (Breslow P-value 0.043). Several variables had statistical significance towards the outcomes on the univariate analysis (age at diagnosis; disease behavior at diagnosis; smoking; hospital admission; days of hospital stay; corticoid cycle; biological naïve patients; blood infliximab levels; calprotectin, protein c reactive, erythrocyte sedimentation rate levels before and after one year of follow up). Adjusting for confoundment, patients with perianal disease have an odd 7.6 times higher of achieving endoscopic remission (P-value 0.038) and 17 times higher of achieving clinical remission (P-value 0.019) with infliximab therapy.

CONCLUSION(S): In CD patients on infliximab therapy, perianal disease involvement is associated with higher endoscopic, analytical and clinical remission rates, after one year follow up. However, they are more prone to disease relapse, in the first year of biological therapeutic.