1. ¹Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2. ²Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
3. ³Cancer Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea

Correspondence: Professor HH Koo, Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710, Korea. E-mail: hhkoo@smc.samsung.co.kr

Received 28 December 2006; Revised 2 February 2007; Accepted 5 February 2007; Published online 5 March 2007.

Abstract

We retrospectively reviewed the engraftment kinetics following unrelated cord blood transplantation (CBT) in association with the post-thaw colony-forming units-granulocyte/macrophage (CFU-GM) number along with the numbers of total nucleated cells (TNC), CD34⁺ cells and CD3⁺ cells. A total of 71 cord blood units prepared for 53 patients (double-unit CBT in 18 patients) were evaluated. Either the number of infused CFU-GM or CD34⁺ cells was significantly lower in patients who failed to achieve engraftment (P=0.028 and 0.005, respectively). Post-thaw CFU-GM, TNC and CD34⁺ cells correlated with the speed of neutrophil engraftment (P=0.004, 0.037 and 0.004, respectively), whereas only CFU-GM showed a significant correlation with platelet engraftment (r=-0.385, P=0.024). In double-unit transplants, the number of CFU-GM was the only significant factor predicting engraftment of the predominating unit (P=0.006). We conclude that the post-thaw CFU-GM number is a reliable predictor of rapid engraftment after CBT as well as of the predominating unit in double-unit transplants. Thus, it would be important to perform post-thaw CFU-GM assay on cryopreserved aliquots from several candidate cord blood units in advance before CBT to avoid selecting the unit that might possess a low clonogenic potential.