Fecal calprotectin measurement as a biomarker of severe disease phenotype in celiac disease and non-celiac enteropathies

Background: Fecal calprotectin (FC) is a non-invasive biomarker of gut inflammation, but its role in celiac disease (CD) and non-celiac enteropathies (NCEs) is undefined. Aims: To retrospectively evaluate FC in patients with CD and NCEs as a tool for assessing disease activity and predicting long-term outcomes. Methods: Patients with uncomplicated and complicated CD, and NCEs with data on FC, evaluated at our center between June-2008 and December-2023, were enrolled. The relationship between elevated FC (>50 mg/kg) and disease activity was statistically analysed and Cox regression adjusted for age and sex was used to compare development of complications and mortality in patients with elevated and normal FC. Results: 177 patients (109F, mean age at diagnosis 39±20 years, 132 CD, 17 complicated CD, 28 NCEs) were enrolled. 55 patients had elevated FC, which was associated with lack of clinical and histological response to therapy (both p < 0.001). During a median follow-up of 103 months (IQR 54–176), 22 patients developed complications (15.4 %) and 21 died (11.9 %). Elevated FC was significantly more common in complicated CD (70.6 %) and NCEs (67.9 %) than in uncomplicated CD (18.2 %), p < 0.001. Elevated FC was independently predictive of developing complications (HR 4.8,95 %CI 1.4–17.7, p = 0.01) and mortality (HR 4.8,95 %CI 1.6–14.3, p < 0.01). Conclusion: FC is a promising non-invasive biomarker for assessing disease severity and long-term outcomes in CD and NCEs.