[Experimental research on effects of different T cell ratios of graft to receptor on severity of GVHD after allo-stem cell transplantation].

BACKGROUND &

OBJECTIVE

Allogeneic stem cell transplantation has achieved great progress in hematology, and provided possibility to cure malignant hematological diseases. Graft-versus-host disease (GVHD) is a significant complication after transplantation with a mortality of over 30%. In clinical practice we noticed that the successful implantation and the severity of GVHD were associated with T cell ratio of graft to receptor after pretreatment. This study was to set up rat allo-stem cell transplantation model, and explore effects of different T cell ratios of graft to receptor on severity of GVHD.

METHODS

SD rats were selected as receptor, and pretreated with total body irradiation (TBI), and cyclophosphamide (CTX). WISTAR rats were used as donors, their bone marrow cells were collected as graft. Receptors were transfused with different ratios of T cells (1:1, 2:1, and 4:1). Life-span, clinical and pathologic GVHD scores were observed.

RESULTS

When T cell ratios of graft to receptor were 1:1, 2:1, and 4:1, life-spans of receptors were (16.7+/-1.3) d, (16.8+/-1.5) d, and (15.0+/-1.7) d, respectively; clinical GVHD scores of receptors were 2.4+/-0.6, 3.3+/-1.2, and 5.3+/-1.4, respectively. Life-span, and clinical and pathologic GVHD scores of receptors transfused with T cells of 1:1 and 2:1 were significantly different from those of receptors transfused with T cells of 4:1(P<0.05).

CONCLUSION

When T cell ratio of graft to receptor was 1:1, or 2:1, the GVHD was comparatively mild; when this ratio reached to 4:1, the GVHD was aggravated.