Partial conditioning regimen for stable mixed chemerism after unrelated cord blood transplantation in adult patients with severe aplastic anemia / 中华器官移植杂志

ABSTRACT

Objective To study and observe the engraftment of donor cells from unrelated cord blood into adult patients with severe aplastic anemia (SAA) and the outcome of allo-CBSCT. Methods Six patients received cord blood provided by Guangzhou Cord Blood Bank, for three of which one unit of cord blood was given in a procedure, whereas for other 3 patients, 2 units of cord blood were infused at the same time in a transplant protocol. In all 9 units of umbilical cord blood (UCB) infused, UCB units contained 1.6 ～ 10.7 nucleated cells/kg body weight of the recipient after thawing. The patients were conditioned with decreased dosage of immunosuppressive agents of CTX (60?mg/kg) and ALG (120?mg/kg). The engraftment state of the donor cells into recipients was confirmed by microsatellite DNA fingerprinting and fluorescent quantitative PCR analysis. Results Engrafted evidence has been found in 5 patients by molecular biology analyses showing donor-recipient mixed chimerism post transplant which was stable and persistent. After a median follow-up of 21 months (range 7～50), 4 patients were alive and disease free. One patient died of severe infection in the 3rd month from transplant, though the evidence of engraftment was obvious. Another patient also died in the early stage posttransplant of serious aspergillus infection without the engrafted proof.Conclusion Durable donor-recipient stable mixed chimerism can be achieved by unrelated UCBT in patients with SAA. Umbilical cord blood could be employed as a source of hematopoietic stem cell for adult transplantation.