Enteroscopy with a confocal laser endomicroscope detects early changes related to acute gastrointestinal graft-versus-host disease in the jejunum – A prospective study involving 23 consecutive patients after hematopoietic stem cell transplantation

Introduction: Graft-versus-host disease (GvHD) is a major cause of morbidity and mortality in patients after allogeneic hematopoietic stem cell transplantation (HSCT). Confocal laser endomicroscopy (CLE) provides in-vivo histology of gastrointestinal pathology and has recently been investigated for diagnosing acute GvHD of the colon.

Aims and Methods: This prospective study aimed to evaluate GvHD-associated changes in the upper GI tract (including the proximal jejunum) by CLE. Consecutive patients with clinical suspect of acute gastrointestinal GvHD after HSCT underwent upper GI enteroscopy with an endoscope-based confocal laser endomicroscope. Findings on white light endoscopy and endomicroscopy were compared to the histological evaluation of segmental biopsies (reference standard).

Results: 23 patients (13 male, 10 female, median age 46 years) were studied. At histology, 8/23 patients suffered from acute gastrointestinal GvHD, mostly involving the jejunum (7/8 GvHD cases). Findings on white light endoscopy varied from mild erythema up to massive ulceration. Endomicroscopic findings included a higher density of intramucosal vessels, cellular infiltrates and leakage of contrast agent as typical signs of inflammation up to complete loss of normal tissue structure. For diagnosing GvHD, sensitivity and specificity were 38% and 53% for white light endoscopy and 88% and 86% for CLE. During follow-up, two patients in whom acute GvHD was initially restricted to the jejunum showed also involvement of other gastrointestinal sites including the stomach and the colon.

Conclusions: In this prospective trial, confocal laser endomicroscopy showed an excellent diagnostic accuracy for predicting the histological diagnosis of acute graft-versus-host disease in the upper gastrointestinal tract. The jejunum was involved in almost all GvHD-positive cases. Upper gastrointestinal endomicroscopy also involving the jejunum could be a valuable option for early detection of acute GvHD in order to minimize invasive procedures and speed up diagnostic workflow in patients after hematopoietic stem cell transplantation, ClinicalTrials.gov identifier: NCT01583712.