Kiss LS et al. – The data suggest that high–sensitivity (hs)–C–reactive protein (CRP) positivity at diagnosis is associated with disease location and behavior, and in patients who are hs–CRP positive at diagnosis, is an accurate marker of disease activity and a predictor of short– and medium–term clinical flare–ups during follow–up.

• In all, 260 well-characterized, unrelated, consecutive CD patients (male/female: 120/140; duration: 7.0 ± 6.1 years), with a complete clinical follow-up, were included.
• Hs-CRP, clinical activity according to the Harvey-Bradshaw Index, and clinical data (disease phenotype according to the Montreal Classification, extraintestinal manifestations, smoking habits, medical therapy, and surgical events) were prospectively collected between January 1, 2008 and June 1, 2010.
• Medical records prior to the prospective follow-up period were analyzed retrospectively.

• In all, 32.3% of CD patients had normal hs-CRP at diagnosis.
• Elevated hs-CRP at diagnosis was associated with disease location (P = 0.002), noninflammatory disease behavior (P = 0.058), and a subsequent need for later azathioprine/biological therapy (P < 0.001 and P = 0.024), respectively.
• The accuracy of hs-CRP for identifying patients with active disease during prospective follow-up was good (area under the curve [AUC]: 0.82, cutoff: 10.7 mg/L).
• AUC was better in patients with an elevated hs-CRP at diagnosis (AUC: 0.92, cutoff: 10.3 mg/L).
• In Kaplan-Meier and Cox-regression analyses, hs-CRP was an independent predictor of 3- (P = 0.007) or 12-month (P = 0.001) clinical relapses for patients in remission who had elevated hs-CRP at diagnosis.
• In addition, perianal involvement (P = 0.01) was associated with the 12-month relapse frequency.