Fecal Calprotectin as a Biomarker of Crohn's Disease in Patients With Short Disease Durations: A Prospective, Single-Center, Cross-Sectional Study.

Fecal calprotectin (FC) is a Crohn's disease (CD) biomarker, although the impact of disease duration on its accuracy remains unclear. This study was aimed at investigating the effects of CD disease duration on FC. In this prospective, single-center, cross-sectional study, we performed 113 endoscopies and biomarker measurements. Endoscopy results were assessed using the simple endoscopic score for Crohn's disease (SES-CD), with an SES-CD ≤ 2 defined as endoscopic remission (ER). Cohort 1 was divided into short-term and long-term disease groups. The associations of the SES-CD with C-reactive protein and FC were analyzed. The correlation coefficient of FC and the SES-CD was 0.670 for all cases. In Cohort 1, the correlation coefficient of FC and the SES-CD was > 0.670 for all subgroups of the short-term disease group (≤ 20 years). The correlation coefficient of FC and CD was < 0.670 for all subgroups of the long-term disease group (> 20 years). In Cohort 2, the correlation coefficients were > 0.670 (0.808) for the 0-4-year disease group and < 0.670 for the 5-14- and 15-40-year disease groups. The receiver-operating characteristic analysis performed to predict ER of all cases resulted in an area under the curve (AUC) of 0.8443, with large AUCs of 0.907, 0.816, and 0.770 observed for the 0-4-, 5-14-, and 15-40-year disease groups, respectively. FC was affected by CD duration, and it may be a useful biomarker of CD, especially in patients with a short disease duration.