# On the Correlation Between Gastrointestinal Symptoms and Sites for Endoscopic Biopsies to Diagnose Graft-Versus-Host Disease

## TL;DR

This study shows that gastrointestinal symptoms strongly correlate with biopsy results for diagnosing GVHD, suggesting targeted endoscopic approaches can be effective and cost-efficient.

## Contribution

The study demonstrates that flexible sigmoidoscopy is a cost-effective alternative for diagnosing lower GI GVHD without compromising diagnostic yield.

## Key findings

- 89.5% of patients with upper GI symptoms had positive upper GI biopsies, and 100% with lower GI symptoms had positive lower GI biopsies.
- Rectosigmoid biopsies showed perfect correlation with GVHD diagnosis compared to other colon sites, suggesting flexible sigmoidoscopy is sufficient for LGI symptoms.

## Abstract

Gastrointestinal graft-versus-host disease (GI-GVHD) is a serious complication of hematopoietic stem cell transplantation, with diagnosis reliant on results of endoscopic biopsy. Optimal endoscopic approaches based on symptoms remain unclear.

We conducted a retrospective cohort study of 75 adult hematopoietic stem cell transplantation recipients with GVHD and GI symptoms undergoing endoscopic biopsy at Montefiore Medical Center (2015–2023). We assessed correlations between presenting upper (UGI) or lower GI (LGI) symptoms and biopsy-proven GVHD. Statistical analyses included χ2 tests, phi coefficients, and logistic regression adjusting for demographic confounders. A subgroup analysis compared the diagnostic yield of flexible sigmoidoscopy vs full colonoscopy.

Biopsy positivity strongly correlated with symptom location: 89.5% of patients with UGI symptoms had positive upper GI biopsies, and 100% with LGI symptoms had positive lower GI biopsies. χ2 tests showed significant associations between symptoms and biopsy positivity (P < 0.001), with phi coefficients indicating strong correlations (r = 0.79 UGI; r = 0.82 LGI). Logistic regression confirmed symptom location as an independent predictor of biopsy results. Among 37 patients undergoing full colonoscopy, rectosigmoid biopsies showed perfect correlation with a diagnosis of GVHD (r = 1.0, P < 0.001) when compared with other anatomic colon biopsy sites, suggesting flexible sigmoidoscopy is a cost-effective alternative for LGI symptoms.

Symptom-guided endoscopic evaluation in GI-GVHD yields high diagnostic accuracy. Flexible sigmoidoscopy with targeted biopsies should be considered for patients with LGI symptoms because it may reduce procedural burden and health care costs without compromising diagnostic yield. These findings support symptom-directed, anatomically targeted approaches to improve patient care and resource utilization.