OBJECTIVETo study the relationship between pretransplantation host thymic recent output function and prognosis in HLA-matched sibling bone marrow transplantation (MSD-BMT) and determine whether pretransplantation host thymic recent output function can act as a marker for predication of prognosis after HSCT.

METHODST-cell receptor excision circle (TREC) in DNA of pretransplantation peripheral blood mononuclear cells from 64 patients underwent MSD-BMT was detected by real-time quantitative PCR. The content of TREC in 70 normal donors was detected as well. All clinical data of patients after HSCT were collected and studied. Survival rates of patients after HSCT were estimated with Log-rank test. Univariate and multivariate analysis of prognostic factors were carried out by COX's proportional hazard regression model.

RESULTSThe mean value of TREC in normal donors was (3351 +/- 3711) copies/10(5) cells. There was an inverse correlation between TREC and age in the donor groups. Before transplantation, all patients were detected TREC, with a mean TREC number of (180 +/-332) copies/10(5) cells being significantly lower than that of normal donors. The results of univariate analysis showed that the counts of pre-HSCT TREC were closely, correlated with long term survival and chronic graft versus host disease (cGVHD) (P < 0.05) and with CMV infection (P = 0.084) but not with acute graft versus host disease (aGVHD). The results of multivariate analysis showed the same thing as that of univariate analysis.

CONCLUSIONPretransplantation host thymic recent output function is closely correlated with prognosis in MSD-BMT and can be a factor for predicting the outcome of HSCT.