Primary Objective

In this study, we aim to comprehensively investigate the effects of donor CH in the setting of unrelated donor/recipients couples in alloHSCT. Screening for CH and optionally validation of the mutations will be performed by next-generation sequencing (NGS).

Clonal haematopoiesis is defined by the expansion of a hematopoietic stem cell that has acquired a somatic mutation. It occurs in at least 10% of the healthy population over 60 years. The frequency of mutations increases with age and often affects epigenetic transcription regulators. To differentiate between clonal haematopoiesis and idiopathic or clonal cytopenia of unknown significance, the term "clonal haematopoiesis with undetermined potential" (CHIP) has been proposed as the diagnostic category. CHIP is characterized by the absence of definitive morphological evidence of haematological neoplasia and the presence of a somatic mutation. CHIP is associated with an increased risk of haematological, cardiovascular, and coronary artery disease deaths, leading to increased mortality in affected individuals in affected cohorts.

The analysis of the effects of CHIP present in the donor, on the outcome of the transplantation of a patient is medically relevant and still insufficiently characterized. Publications indicate clinical effects of CHIP in the donor on the risk of Graft-versus-Host Disease and the risk of relapse. Published data is not sufficient to provide a complete picture of the potential risks and benefits of CHIP in the donor. Therefore, the proposed study aims to deepen the understanding of the effects of CHIP in the context of allograft transplantation. The focus of this study is on the constellation of unrelated donor/recipient pairs. With this study, we want to accurately characterize risks and benefits of CHIP in donors, on the outcome of transplantation for patients.