Endoscopic and Histological Findings Are Predicted by Fecal Calprotectin in Acute Intestinal Graft-Versus-Host-Disease.

Background: Gastrointestinal graft-versus-host-disease (GI-GVHD) is a major cause of nonrelapse mortality after hematopoietic stem cell transplantation (HSCT) necessitating endoscopic examinations and biopsies for diagnosis. Fecal calprotectin (CPT) has been widely used in gastrointestinal inflammation, but comprehensive data in GI-GVHD are lacking.

Aims: We aimed to identify an association of CPT with endoscopic findings, mucosal damage and symptoms for diagnosing and monitoring acute GI-GVHD.

Methods: Symptoms were prospectively evaluated in 110 consecutive HSCT recipients by standardized questionnaires and Bristol Stool Scale (BSS). CPT was assayed by ELISA. Symptom assessment and CPT were performed weekly and with onset of first symptoms. GVHD was diagnosed according to the Glucksberg criteria and by endoscopic biopsies. Patients with GI-GVHD received standard high-dose corticosteroid therapy and follow-up CPT, and symptom evaluation was performed after 28 days. Patients not responding to steroid treatment were re-evaluated by colonoscopy.

Results: GI-GVHD was diagnosed in 40 patients. Twelve patients with GI symptoms and CMV colitis and 24 patients with isolated skin GVHD were included as control subjects. CPT was significantly higher in GI-GVHD compared to skin GVHD and CMV colitis. Endoscopic findings, histological grading, abdominal cramps, diarrhea, urgency and BSS correlated with CPT. At follow-up, CPT correlated with abdominal cramps, diarrhea, urgency and BSS. In steroid refractory patients, CPT level was still significantly associated with severity of mucosal damage.

Conclusion: CPT predicts endoscopic and histological findings in GI-GVHD and correlates with lower GI symptoms. It enables to discriminate GVHD from CMV colitis and to monitor therapeutic success.