Cell surface markers and circulating cytokines in graft versus host disease

Graft versus host disease (GVHD) remains the major obstacle to the widespread application of allogeneic bone marrow transplantation (BMT) despite improvement in drug prophylaxis. T cells in the donor bone marrow recognize and react against host alloantigens and thereby initiate GVHD, but the precise mechanisms by which host tissues are damaged remain unclear. In the current study, we determined the cytokine secretion, cell population distribution, and cell surface markers expression by ELISA and flow cytometer, to understand further the pathophysiology of GVHD. Our results demonstrated that there was no significant change in the cell ratio of B-and T- lymphocytes, and helper/suppressor cells during GVHD development when compared to the condition before transplantation. Furthermore, the percentage of natural killer cells, the interleukin-2 receptor (IL-2R) or the HLA-DR antigen on both CD4 and CD8 positive cells presented no significant difference between pre-transplantation and during GVHD. The serum cytokine secretion of IL-1, TNF-alpha, IL-2, ICAM-1, endothelin, TGF-beta showed no difference before BMT and during GVHD. However, when patients in the developing of GVHD, there was significant difference in the serum levels of soluble IL-2R (slL-2R), epidermal growth factor (EGF), and platelet derived growth factor (PDGF). In addition, with patients who develop GVHD, the mixed lymphocyte reaction also presented a significant difference. This study indicated that some serum cytokines such as sIL-2R, growth factors, and the mixed lymphocyte reaction may be used as parameters for the early detection of the development of GVHD.