Current status of paediatric umbilical cord blood transplantation in Korea

• Published in: Bone marrow transplantation (Basingstoke) Vol. 43; no. S1; p. S12
• Main Authors: Yoo, K.H, Sung, K.W, Koo, H.H, Chung, N.G, Cho, B, Kim, H.K, Kang, H.J, Shin, H.Y, Ahn, H.S, Back, H.J, Han, D.K, Kook, H, Hwang, T.J, Lim, Y.J, Lee, Y.H, Ha, J.O, Lim, H.J, Seo, J.J, Park, S.K, Jung, H.J, Park, J.E, Lim, Y.T, Yoo, E.S.Y, Ryu, K.H, Lee, S.H, Park, H.J, Park, B.K
• Format: Journal Article
• Language: English
• Published: Nature Publishing Group 01.03.2009
• Subjects: Acute leukemia; Care and treatment; Complications and side effects; Cytomegalovirus infections; Fetal blood; Patient outcomes; Risk factors; Transplantation; South Korea
• ISSN: 0268-3369

We report the clinical results of 236 pediatric cord blood transplantations (CBT) performed from 1998 until 2006 in Korea. The most frequent primary disease was acute leukemia (n=173) and the majority of patients (91.9%) were seropositive for cytomegalovirus (CMV). The median NC and CD34+ cell dose were 4.82 x [10.sup.7]/kg and 1.99 x [10.sup.5]/kg, respectively. The median time to neutrophil recovery (>0.5 x [10.sup.9]/L) was 18 d and that of platelet recovery was 45 d. The probability of neurtophil recovery by d 60 was 90.7%. Grade 2-4 and grade 3-4 acute graft-versus-host disease (GVHD) were developed in 40.5% and 14.4%, respectively. Fifty-three of the 155 evaluable patients (34.2%) developed chronic GVHD. Ninety-nine patients (42.0%) developed CMV infection, of whom 45 patients (19.1%) developed CMV disease. The 5-y overall survival was 47.6% with a median followup of 35 mo (range, 1-138). Factors that favorably affected survival were non-TBI-based conditioning (P=0.0029), in vivo T-cell depletion (P=0.0035), first transplant (P=0.01), complete donor chimerism (CC) at 1 mo (P=0.04), absence of grade 3-4 acute GVHD (P=0.0476), and no CMV disease (P=0.003), among which non-TBI-based conditioning regimen (P=0.004), first transplant (P=0.002), CC at 1 mo (P<0.0005), and no CMV disease (P=0.001) were also significant by multivariate analysis. In acute leukemia, not advanced disease status (CR1/CR2; P<0.00005), higher CD34+ cell dose (≥2 x [10.sup.5]/kg; P=0.07), non-TBI-based conditioning regimen (P=0.0009), in vivo T-cell depletion (P=0.01), CMV seronegative recipients (P=0.1), CC at 1 mo (P=0.02), absence of grade 3-4 acute GVHD (P=0.068), absence of chronic GVHD (P=0.1), and no CMV disease (P=0.0055) were the factors favorably affect survival. However, pre-transplant disease status was the only independent prognostic variable by multivariate analysis (P=0.007). When we compared two-unit CBT group (n=64) with single-unit CBT group, such variables as time to engraftment, incidence of GVHD, and survival rates were not statistically different, while two-unit group was heavier (P <0.0005) and older (P <0.0005). In conclusion, we strongly recommend timely CBT when appropriate marrow donor is not available. Thorough surveillance of CMV infection may be especially important in Korea where the CMV seroprevalence exceeds 90%. Two-unit CBT seems to be a reasonable option for older or heavier children although no survival advantage over single-unit CBT was shown in this study.