Acute graft-versus-host disease is more prevalent and severe in the lower than the upper gastrointestinal tract.

It is unclear whether acute gastrointestinal (GI) graft-versus-host disease (GVHD) affects all segments of the GI tract equally. Up to 45% patients reported showed discrepancy in involvement between upper GI (UGI) and lower GI (LGI) tract. We compared the prevalence and the severity of acute GVHD in UGI and LGI tract on histologic examination. A cohort of 110 cases of simultaneous UGI and LGI biopsies from 105 allogeneic hematopoietic stem cell transplantation recipients with clinically confirmed GI GVHD were reviewed retrospectively. The χ(2) test and 1-way analysis of variance test were used for statistical analysis. Most (75%) of the cases had GVHD involvement in both UGI and LGI tracts, whereas UGI-only GVHD was found in 6% and LGI-only GVHD in 19%. GVHD prevalence was the lowest in stomach (61%) and significantly increased toward duodenum/jejunum (81%; P = .0019). The LGI tract showed similar GVHD prevalence (P = .3648); the highest was in the sigmoid colon (97%). The histologic grade was lowest in the stomach (mean ± SD, 1.6 ± 0.8) and was similar across all UGI segments (P = .0883). The histologic grade in LGI significantly increased (P = .0265) from the terminal ileum (2.0 ± 1.3) to the rectum (2.9 ± 1.0). Overall, both the prevalence and the histologic grade of GVHD in LGI were significantly higher than those of UGI (P < .0001 for both). Our results show that acute GVHD had a higher prevalence and was more severe in the LGI than in UGI tract. A small subset of patients had only UGI involvement.