Correlation Between Serum and Fecal Biomarkers and Patient-Reported Outcomes in Patients with Crohn's Disease and Ulcerative Colitis.

Background: Patient-reported outcomes (PROs), such as the short CD activity index (sCDAI) and partial Mayo Score (PMS), are used to define clinical remission in IBD, but may not represent the true degree of inflammation and endoscopy is invasive. Non-invasive testing options include c-reactive protein (CRP) and fecal calprotectin (FCP). Aim: The aim of this study was to assess the degree of correlation of non-invasive biomarkers with PROs and the impact other clinical variables can have on their levels. Methods: We reviewed data collected from the prospective cohort, Study of a Prospective Adult Research Cohort with IBD (SPARC-IBD), comprised of over 3000 patients from 17 tertiary referral centers. Demographic and clinical variables were analyzed by disease type, disease severity was based on PROs, and baseline CRP and FCP were measured. For comparative analysis, we performed Fisher's exact test and Welch's t test, where p < 0.05 was significant. Results: 1547 patients were included; 63% had CD, 56% were female, with an average disease duration of 13.6 years. CRP and FCP were associated with symptom severity in inflammatory CD. CRP was useful to differentiate symptoms across different disease locations in CD, whereas FCP was associated with symptom severity in Crohn's colitis only. For UC, FCP was able to distinguish symptom severity better in distal UC, whereas in extensive or pancolitis, it was useful only to distinguish severe symptoms from other categories of symptom severity. Conclusion: PROs correlate with CRP and FCP; however, disease location and phenotype impact their ability to distinguish symptom severity. [ABSTRACT FROM AUTHOR]