Macroscopic, Histologic and Clinical Assessment of Acute GVHD of the Upper Gastrointestinal Tract within 6 Weeks after Allogeneic Hematopoietic Cell Transplantation

Effect of GVHD on the gut and intestinal microflora

Graft-versus-host disease (GVHD) is one of the most important cause of death in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). The gastrointestinal tract is one of the most common sites affected by GVHD. However, there is no gold standard clinical practice for diagnosing gastrointestinal GVHD (GI-GVHD), and it is mainly diagnosed by the patient's clinical symptoms and related histological changes. Additionally, GI-GVHD causes intestinal immune system disorders, damages intestinal epithelial tissue such as intestinal epithelial cells((IEC), goblet, Paneth, and intestinal stem cells, and disrupts the intestinal epithelium's physical and chemical mucosal barriers. The use of antibiotics and diet alterations significantly reduces intestinal microbial diversity, further reducing bacterial metabolites such as short-chain fatty acids and indole, aggravating infection, and GI-GVHD. gut microbe diversity can be restored by fecal microbiota transplantation (FMT) to treat refractory GI-GVHD. This review article focuses on the clinical diagnosis of GI-GVHD and the effect of GVHD on intestinal flora and its metabolites.

Histological diagnosis of acute graft-versus-host disease in different sites of the upper gastrointestinal tract with correlation to endoscopic findings

Graft-versus-host disease (GvHD) involving the intestine is a threat to patients after allogeneic hematopoietic stem cell transplantation (alloHSCT). We evaluated biopsies from different sites of the upper gastrointestinal tract (GIT) of 97 patients after alloHSCT. Forty-six patients with clinical symptoms consistent with upper GI GvHD revealed histological features of GvHD in the esophagus, stomach, and/or duodenum. Biopsies of the duodenum and esophagus were significantly more sensitive for signs of GvHD than those of the gastric antrum or corpus. The histological features of GvHD were significantly correlated with the endoscopic findings of ulcers, erosion, atrophy, and white plaques; however, the sensitivity and specificity of the latter were low. In univariate analysis, overall mortality was significantly associated with histological GvHD signs in all four sites. Nonrelapse mortality was associated with histologic GvHD features in the antrum only. Regarding GvHD diagnosis, biopsies of the upper gastrointestinal tract should include the duodenum and/or esophagus.