Histopathologic evaluation of gastrointestinal graft-versus-host disease: Opportunities for improvement based on a...

Graft-versus-host disease (GVHD) is a common and serious complication of allogeneic hematopoietic stem cell transplantation, with the gastrointestinal (GI) tract being a major target. Histologic diagnosis of GI GVHD remains challenging due to overlapping features with other conditions and variability in guideline adoption.

To assess current diagnostic practices, histologic thresholds, and guideline utilization among practicing pathologists evaluating GI GVHD.

A 30-question, anonymous, web-based survey was distributed to GI pathologists worldwide. The survey explored diagnostic strategies, threshold criteria for apoptosis, use of grading systems, ancillary testing practices, and satisfaction with existing guidelines.

Of the 200 pathologists contacted, 80 responded (40 % response rate), with 69 actively evaluating GI GVHD. Most respondents (92.8 %) practiced in academic settings, and 81.2 % had completed GI pathology fellowships. A majority (73.9 %) reported no standardized diagnostic criteria within their practice groups. Among those using guidelines, the NIH criteria were most commonly applied. There was substantial variability in the threshold for apoptosis, ranging from the presence of any apoptotic body to higher thresholds. Only 42 % of respondents routinely graded GI GVHD, primarily using the Lerner system. CMV immunostaining was frequently employed, and mycophenolate toxicity was commonly considered in the differential diagnosis.

The survey highlights marked heterogeneity in the histologic evaluation of GI GVHD among pathologists. These findings underscore the need for more standardized, evidence-based diagnostic criteria and enhanced consensus on grading practices.