Baseline C-reactive protein is associated with disease progression in patients with Crohnʼs disease

Abstract

Elevated C-reactive protein (CRP), a marker of inflammation, is known to correlate with Crohn's disease (CD) activity1,2 and to be a predictor of disease relapse in CD.3,4 However, in patients with moderate or severe CD it is not known whether CRP is associated with disease progression. This post hoc analysis evaluated the association of baseline (BL) CRP and change in CDAI over time in patients with moderate (CDAI>220 to ≤300) to severe (CDAI>300) CD who were randomized to the placebo group in the CHARM trial5 (N=238). Patients received open-label adalimumab (ADA) induction (week 0: 80mg; week 2: 40mg) followed by blinded weekly placebo treatment from weeks 4-56, with switch to open-label ADA allowed after week 12 for disease flare. This analysis grouped patients by CD severity and BL CRP (severe, high: CDAI>300, CRP≥10mg/L; severe, low: CDAI>300, CRP<10mg/L; moderate, high: CDAI≤300, CRP≥10mg/L; moderate, low: CDAI≤300, CRP<10mg/L). Mean CDAI scores at each visit from weeks 4-56 were calculated for each subgroup, using last observation carried forward (after week 4) to handle dropouts or switch to ADA. Mean CDAI decreased from BL in all subgroups after ADA induction (Week 4, Table). By week 56, the mean CDAI in all subgroups had increased compared with week 4, and was greater in patients who had higher CRP versus lower CRP at BL (244 vs 223, 306 vs 260, for moderate and severe groups, respectively). In patients with moderate CD and high CRP, week 12 and week 56 CDAI approached that of patients with severe CD and low CRP, despite BL differences in CDAI of over 90 points (week 12: 235 vs 243; week 56: 244 vs 260). ORs (95% Confidence Intervals) ORs (95% Confidence Intervals) This post hoc analysis of disease activity and CRP demonstrates that an elevated BL CRP in patients with moderate or severe CD is associated with higher disease scores after one year. Disease activity over time in patients with moderate CD and higher CRP behaved similarly to that of patients with severe CD and lower CRP.