Soluble Interleukin-7 receptor levels and risk of acute graft-versus-disease after allogeneic haematopoietic stem cell transplantation

Abstract Interleukin-7 is a cytokine essential for T cell homeostasis. IL-7 binds to cellular IL-7 receptors in competition with a soluble form of the receptor (sIL-7Rα). We hypothesized that altered sIL-7Rα levels may cause adverse outcomes in patients undergoing HSCT. In parallel, we investigated the impact of the IL-7Rα SNP rs6897932, which has been associated with release of IL-7R. The sIL-7Rα levels decreased during HSCT (from 114 ng/ml before to 48 ng/ml at day + 14 ( P P  = 0.026). Furthermore, donor carriage of the rs6897932 T allele was associated with reduced sIL-7Rα levels, increased risk of grades II–IV aGVHD (OR = 2.4, P  = 0.055) and increased transplant-related mortality (CC = 4.5%, CT = 21.4% and TT = 27.3%, P  = 0.0037). In conclusion, this study suggests an impact of sIL-7Rα levels and rs6897932 donor genotype on alloreactivity and outcome after HSCT.