In this study the investigators evaluate the outcomes of six steroid-refractory GVHD patients with gastrointestinal signs of GVHD that were treated with teduglutide.

Preliminary studies have showed that Glucagon-like peptide 2 (GLP-2) has regenerative and protective effects on the gastrointestinal tract after bowel injury. It induces positive effects in the GI tract like nutrient uptake, mucosal growth, protection from inflammation, etc. One of the target organs from GVHD is the GI tract, and since patients suffering from GI-GVHD experience intestinal disorders like loss of mucosal epithelial integrity, diarrhea accompanied by strong abdominal pain that can lead to food inanition, the investigators therefore aimed to examine the outcome of patients suffering from SR-GI-GVHD that are treated with the GLP-2 analogue, Teduglutide. The investigators will determine the outcome of each patient by monitoring the gastrointestinal signs like diarrhea frequency, intestinal absorption measured by serum-albumin concentrations and GI histology, specifically the number of Paneth cells before and during teduglutide treatment.

Inclusion Criteria:

• Patients with signs of acute SR-GI-GVHD
• Age ≥ 18 years
• Peripheral blood and stool samples available before and during treatment
• Written informed consent
• Ability to understand the nature of the study and the study related procedures and to comply with them

Exclusion Criteria:

• Age ≤ 18 years
• Lack of informed consent