The CD28 IVS3 + 17 T/C polymorphism and the GVHD occurrence in Tunisian patients receiving an HLA-identical sibling HSCs transplant.

Graft-versus-host disease (GVHD) is a potentially serious complication ofallogeneic hematopoietic stem cell transplantation (HSCT). Graft-contaminating T cells (donor T cells) arecrucial for the development ofGVHD since they are able to react against the recipient's antigens. In this study we aim toevaluatethepotentialassociation between the IVS3 + 17 T/C gene variation in the CD28 molecule, a T cells costimulatory factor, and the GVHD occurrence in a Tunisian group of recipients of allo-HSCTs. Results show that there is an association between the presence of this polymorphism and the occurrence of grades II-IV acute GVHD (OR: 2.470, I.C: 1.027-5.938, p = 0.043). As for the chronic GVHD, it seems that the studied gene variation has no impact on the occurrence of this complication, which appeared likely to be affected by the HSCT graft source (PBSC: peripheral blood stem cells) (OR: 5.141, I.C: 1.590-16.620, p = 0.006). Based on these data, we believe that the CD28 IVS3 + 17 T/C polymorphism is a significant factor in the pathogenesis of acute GVHD.