[Analysis of Related Factors for Graft Failure in Umbilical Cord Blood Transplantation for Hematological Diseases].

OBJECTIVE

To investigate the early influencing factors of primary graft failure (PGF) following umbilical cord blood transplantation (UCBT).

METHODS

A retrospective analysis was conducted on the clinical data of 40 patients who underwent UCBT and developed PGF at the First Affiliated Hospital of the University of Science and Technology of China from June 1, 2017 to July 30, 2024. Additionally, 139 patients with successful transplantation during the same period were selected as a control group. Donor chimerism was assessed on day 7, 14, 21, and 30 post-transplantation, and lymphocyte subsets were examined on day 30 post-transplantation.

RESULTS

There were no significant differences between the two groups in baseline characteristics such as disease types, sex, age, and HLA matching status (all P>0.05). The number of infused CD34+ cells in the graft failure group was lower than that in the graft success group (P<0.05), and the donor chimerism at each detection time point was significantly lower than that in the graft success group (P<0.001). When the chimerism was lower than 32.6% on day 7 post-transplantation, the sensitivity and specificity for predicting graft failure were 0.825 and 0.884, respectively. The median proportion of CD3+CD4+CD8- T cells in lymphocytes in the graft failure group was 12.4% (3.3%-29.8%), which was significantly lower than that in the graft success group ［19.9% (4.4%-56.8%)］ (P=0.001).

CONCLUSION

The chimerism on day 7 post-UCBT is a potential indicator for predicting graft failure. A lower number of CD34+ cells in the umbilical cord blood stem cells used for transplantation and a lower level of CD3+CD4+CD8- T cells in the early stage after transplantation may be related to graft failure.