Fecal Calprotectin as a biomarker for early diagnosis and prediction of steroid response in Acute Gastrointestinal Graft versus Host Disease

Background: Acute gastrointestinal graft-versus-host disease (GI-GVHD) is a complication of allogeneic hematopoietic stem cell transplantation (HSCT) that requires early diagnosis.Fecal calprotectin (FC) is a biomarker of intestinal inflammation.We studied the role of FC in differentiating GI-GVHD from other diarrhea.Methods: We prospectively studied allogeneic HSCT recipients between 2017 and 2020.FC levels were measured pre-transplant, on post-transplant day 14, on day 1 of diarrhea, and post-steroid treatment (day 3-7 of steroid treatment).Results: We studied 116 patients with median age 14.5 (5-29) years; 84 were male (72.4%).Fifty-seven patients (49.1%) developed diarrhea post-HSCT, 34 (59.7%)patients had GI-GVHD, and 23 patients (40.3%) developed other diarrheal illnesses.FC level on day1 of diarrhea among GI-GVHD patients (n=33) was higher (63 μg/g [Q1-Q3:25.6-358.5])compared to other diarrhea (27.5 μg/g [21.1-60.4],p=0.045).FC cut-off > 53.7 μg/g had sensitivity (78.6%) and specificity (57.9%) with area under the receiver operating characteristic curve of 0.67 to predict GI-GVHD on day 1 of diarrhea.FC levels in steroid non-responders (n=7) were higher (311.5 μg/g [40.5-1,291.5])than responders (n=11) (31.2 μg/g [20.8-137.2]μg/g); p=0.03.Haplomatch, severe GI-GVHD, and coexisting skin GVHD were significant predictors of poor treatment response.Conclusion: A higher FC value on day 1 of diarrhea aids in the diagnosis of acute GI-GVHD and predicts poor response to treatment.