Increased soluble Fas-ligand in sera of bone marrow transplant recipients with acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) is a major complication following allogeneic bone marrow transplantation (BMT). Recently, accumulating evidence indicates that the Fas/Fas ligand (FasL) system is implicated in the pathogenesis of aGVHD in murine models, We determined the serum levels of soluble Fast (sFasL) in BMT recipients using an enzyme-linked immunosorbent assay. The serum sFasL was suppressed during the period of myelosuppression following the preparative regimen and subsequently increased with hematopoietic reconstitution after BMT, In patients with aGVHD, the serum sFasL level was significantly higher than in those without aGVHD, In the mixed lymphocyte reaction assay, sFasL in the supernatants was increased with a significant correlation to the level of H-3-thymidine uptake. Our findings suggest that the Fas/FasL system is activated by allogeneic stimulation and may have close correlation to the development of aGVHD in human BMT.