Role of Defibrotide in the Prevention of Murine Model Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation

Abstract

Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Vascular endothelial cells are entirely exposed and damaged during the pathogenesis of acute GVHD. Defibrotide is a mixture of single-stranded oligonucleotides that has several pharmacological effects that contribute to its endothelial protective properties. B10.BR mice were conditioned followed by the infusion of donor C57BL/6J T-cell depleted (TCD) bone marrow cells with or without splenocytes. Animals were either treated with defibrotide or appropriate controls daily for the first week and then three times per week thereafter. Allogeneic defibrotide-treated recipients demonstrated significantly better survival with reduced clinical GVHD. Significantly reduced organ pathology in the gut was associated with significantly decreased T-cell infiltration in the ileum and colon on day +28. Serum cytokine analysis revealed significantly reduced level of TNF and IL-6 at day +7 and TNF at day +28 in allogeneic defibrotide treated recipients. Significantly reduced levels of ICAM-1, Angiopoietin-2 in serum and reduced VCAM-1 and HCAM in the ileum and colon of allogeneic defibrotide-treated recipients were observed. Improved survival was seen in the GVL model (C3H.SW into C57BL/6J mice with C1498-luc). Defibrotide treatment through its anti-inflammatory and endothelial-protective effects reduces the severity of acute GVHD, while not impairing GVL activity.