Interleukin‐1 alpha genotype and outcome of unrelated donor haematopoietic stem cell transplantation for chronic myeloid leukaemia

Summary Interleukin‐1 alpha (IL‐1α) is a pro‐inflammatory cytokine that is implicated in the initiation/maintenance of graft‐versus‐host disease (GVHD) and the immune response to infection. A cytosine (C) to thymine (T) transition at position −889 is believed to influence gene transcription. A previous single institution study showed that the presence of at least one IL1A T allele in the donor was associated with improved survival after unrelated donor haematopoietic stem cell transplant and lower transplant‐related mortality if the donor and recipient each possessed the IL1A T allele. The present study sought to confirm these results in a larger homogeneous population. Thus the study population included 426 patients older than 18 years with chronic myeloid leukaemia (CML), transplanted in first chronic phase and receiving a total body irradiation and cyclophosphamide preparative regimen. Donor recipient pairs were categorised into four groups according to the presence or absence of an IL1A T allele in the donor and recipient. There were no significant differences in patient, donor and transplant characteristics between the groups. We did not observe an association with IL‐1α genotype in donor and/or recipient and transplant‐outcome. These data suggest that the outcome of unrelated donor transplant for CML is not influenced by IL‐1α genotype.