C-reactive protein, an indicator for maintained response or remission to infliximab in patients with Crohn's disease: a post-hoc analysis from ACCENT I

Background Secondary loss of response to anti-TNF-alpha therapy is observed in Crohn's disease patients. Aim Serum C-reactive protein (CRP) levels at baseline and after infliximab induction therapy at week 14 were assessed as predictors for maintained response or remission through 54 weeks of treatment in patients with Crohn's disease who responded to induction therapy. Methods ACCENT I was a multicenter, randomised, placebo-controlled study. Patients who received infliximab induction (weeks 0, 2 and 6) and maintenance (5 or 10 mg/kg every 8 weeks beginning at week 14) therapy were considered. Patients in clinical response or remission to induction therapy at week 14 (n = 212 or n = 138 respectively) were analysed. Associations between CRP levels (cut-off points 0.5-3.0 mg/dL), baseline disease variables and maintained clinical response or remission during maintenance therapy were assessed. Results A significant association was observed between baseline CRP levels and maintained remission. Forty-five percent of patients with baseline CRP = 0.7 mg/dL vs. 22.0% with CRP < 0.7 mg/dL maintained remission (P = 0.012). CRP normalisation during infliximab treatment (decrease from 0.5 mg/dL at baseline to < 0.5 mg/dL at week 14) resulted in higher probability of maintained response (P < 0.001) or remission (P = 0.052). At week 14 low CRP levels were associated with maintained response (56.6% of patients with CRP < 0.5 mg/dL vs. 37.2% with higher CRP, P = 0.005). No optimal predictive CRP cut-off point was observed. Conclusions High baseline CRP levels increased the likelihood of maintained remission. Normalised CRP levels at week 14 increased the likelihood of maintained response or remission during 1 year of infliximab maintenance therapy (Clinical trial: NCT00207662).