Urinary Calprotectin Is Not a Reliable Surrogate of Fecal Calprotectin Levels in Adults and Children with Crohn’s Disease
摘要
Fecal calprotectin (FCAL) is an established biomarker for monitoring intestinal inflammation in inflammatory bowel disease. However, fecal sampling can be socially unacceptable and inconvenient. Urinary calprotectin (UCAL) could potentially be a suitable surrogate marker of FCAL.
MethodsLevels of FCAL and UCAL and C-reactive protein (CRP) were measured in samples from two different cohorts; a) in adults with active Crohn’s disease (CD) receiving induction treatment with adalimumab and b) children with CD during early food re-introduction after successful treatment with exclusive enteral nutrition (EEN). In each cohort, participants were categorized based on their FCAL trajectories. Adults were classified as responders if FCAL decreased ≥ 50% after 12 weeks of treatment; otherwise, they were classified as non-responders. In children, a FCAL baseline rise > 100% during three weeks of food reintroduction, after EEN, was classified as having an FCAL increase. Children were classified as FCAL-stable if FCAL remained < 300 mg/kg throughout food reintroduction. FCAL, UCAL and CRP were also measured in healthy adults.
ResultsA total of 364 paired stool and urine samples, and 100 blood samples were utilized from adults and children with CD. Changes in UCAL did not parallel changes in FCAL, neither in adults who were classed as FCAL responders after 12-weeks treatment with biologics, nor in pediatric patients who demonstrated an increase in FCAL, following completion of EEN and return to normal diet. UCAL did not correlate with either FCAL or CRP.
ConclusionsUrinary calprotectin is not a useful biomarker of systemic or gut inflammation in patients with CD.