Intestinal acute graft-versus-host disease (i-aGvHD) is a serious complication during the first 100 days after allogeneic hematopoietic stem cell transplantation (HSCT). Diagnosis of i-aGvHD is based on clinical symptoms and CT imaging but endoscopic evaluation with histologic and microbiologic examination of the biopsied tissue is necessary to confirm the diagnosis. There is a paucity of data on the efficacy of magnetic resonance enterography(MRE) detecting i-aGvHD. Francesca Maccionifrom Sapienza University, Rome, Italy, on behalf of her colleagues presented results of their retrospective analysis investigating the clinical significance of MRE in i-aGvHD diagnosis during an oral abstract session at the 44 thAnnual Meeting of the European Society for Blood and Marrow Transplantation (EBMT), Lisbon, Portugal, on Wednesday 21 March 2018.
Thirty-five patients (age = 9-69 years) who had suspected i-aGvHD and had a MRE exam between 2015-2017 were included in the analysis. 1.5 Tesla scanner (Siemens, MagnetomAvanto) with 16-channels phased-array coils was used to perform the test.
To accurately assess the severity of i-aGvHD, a score system for all intestinal segments (from stomach to rectum) was implemented based on the following factors:
- Inflammation-activity: mural T2 signal (oedema), mesenteric T2 signal (oedema), gadolinium wall enhancement on T1 (vascularity), DWI signal (inflammation)
- Morphologic parameters: maximum wall thickness, increased number and/or size of local mesenteric lymph nodes, comb sign (mesenteric vessels dilation), presence of peritoneal effusion 1
Key findings:
- 21 patients had histologically confirmed i-aGvHD
- Observed MRE parameters:
- Stratified mucosal wall enhancement after gadolinium injection: 90% of patients
- Parietal enhancement was associated with high-grade oedema of mesenteric fat tissue and comb sign: 76% of patients
- Mesenteric lymph nodes were not shown: 52.4% of patients
- Free intra-peritoneal fluid: 57.2% of patients
- Most commonly involved intestinal segments:
- distal ileum (85.7%)
- mean ileum (66.6%)
- proximal ileum (57.1%)
- ascending colon and sigmoid equally (38%)
- Significant association was found between clinical stage of i-aGVHD and mural T2 signal, number of involved intestinal segments, wall thickness, T1 enhancement, and peritoneal effusion, P< 0.001
Francesca Maccioni concluded her talk by highlighting that MRE is efficient in terms of diagnosis of i-aGvHD. She further added that “this technic should be considered to replace invasive methods like endoscopic biopsy.”