Prognostic Significance of Interleukin-7 Receptor-α Gene Polymorphisms in Allogeneic Stem-Cell Transplantation: A Confirmatory Study

Background. Interleukin-7 (IL-7) is a hematopoietic cytokine essential for T-cell development in the thymus and for the maintenance of peripheral T cells. A previous study of single nucleotide polymorphisms in the exons of IL-7 receptor α-chain (IL-7Rα) in a Danish cohort of patients undergoing allogeneic stem-cell transplantation (SCT) identified donor genotype GG at rs1494555 as a risk factor for treatment-related mortality (TRM) after SCT. Methods. In this validation study, 116 British and French SCT patients and their donors were investigated by sequence-specific primer polymerase chain reaction. Results. Both donor rs1494555GG genotype and the tightly coupled rs1494558TT genotype were significantly associated with grade 3 to 4 acute graft versus host disease. Although both genotypes tended to be associated with increased TRM, this did not translate into altered overall survival. Conclusion. The present data indicate that the IL-7 pathway is associated with alloreactivity in SCT, which is in line with the previously observed association between IL-7Rα single nucleotide polymorphisms and TRM.