Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a life-saving treatment for many malignant hematologic diseases. Its curative potential is due to both high-dose chemotherapy and the graft-versus-host disease (GvHD) process, in which the donor's T cells recognize the recipient's tissue as foreign. However, GvHD is a potentially fatal complication that significantly affects both survival and quality of life. GvHD can be acute or chronic, and one of the main target organs involved in acute GvHD is the intestine, with a high rate of treatment failure and mortality. We expect to identify a set of biomarkers, both clinical and experimental, that will enable the stratification of patients based on prognosis and response to treatment in intestinal GvHD. The ultimate goal of the study is to integrate clinical, transplant, and biomarker data into a robust predictive algorithm. This tool will enable personalized therapeutic approaches based on early biomarkers, improving prognostic accuracy for patient outcomes and optimizing therapeutic strategies.

Inclusion Criteria:

• Patients aged ≥ 12 years
• Indication for allogeneic HSCT
• Obtaining informed consent

Exclusion Criteria:

• None

The study population will be constituted through the consecutive enrollment of adult and pediatric patients with hematological diseases treated with allogeneic hematopoietic cell transplantation.