This study has the aim to analyze intestinal expression of cellular stress molecules in patients with intestinal GVHD. Patients with colitis and patients without intestinal inflammation will serve as controls.

Acute graft-versus-host disease (GVHD) is a major cause of morbidity and mortality in patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). Acute GVHD results from a complex multi-step crosstalk between extensive epithelial tissue damage in the patient and activation of the allo-reactive immune system transferred with the donor graft. The conditioning treatment prior to allo-HCT creates an inflamed microenvironment with high concentrations of pathogen-associated and danger-associated molecular patterns (PAMPs and DAMPs) as well as pro-inflammatory cytokines. This inflammation is perpetuated by activation of myeloid immune cells and recruitment of allo-reactive T cells to the intestine. Enterocytes are subjected to cellular stress and undergo apoptosis. As a result, patients can develop high-voluminous diarrhea, dehydration, intestinal bleeding, hypalbuminemia, and generalized infections.

In this study, the investigators aim to analyze the expression of molecules related to different types of cellular stress in the intestine of patients with acute GVHD. The hypothesis is that some stress-related markers would be upregulated during GVHD. The results will be valuable to study the role of cellular stress reactions during acute GVHD pathogenesis or as potential biomarkers for disease activity.

Inclusion Criteria:

Age >18 years intestinal biopsy depending on cohort: healthy intestinal tissue, colitis or GVHD

This study will recruit adults at least 18 years of age, who underwent intestinal biopsy and either had (i) non-inflamed intestinal tissue, (ii) colitis, (iii) graft-versus-host disease.