title: The impact of HLA matching on unrelated donor hematopoietic stem cell transplantation in Korean children.
abstract: BACKGROUND
  The impact of HLA matching on outcomes of unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) varies in different racial or ethnic groups. Since little is known about the impact of such matching on URD HSCT in Korean children, we analyzed this issue.
  
  
  METHODS
  We analyzed the outcomes of 142 patients who underwent URD HSCT at 4 Korean medical centers. All patient donor pairs were fully typed for HLA-A, -B, -C, and -DR alleles.
  
  
  RESULTS
  At a median follow-up of 22 months, 3-year survival rates for patients with 8, 7, and ≤6 matched alleles were 88.4%, 70.7%, and 53.6%, respectively. A single mismatch (Mm) at HLA-B or -C was associated with lower survival compared with that associated with 8 matched alleles. No significant differences were observed between single-allele and single-antigen Mms with respect to survival rate or acute graft-versus-host disease (aGVHD) incidence rates. HLA disparity had a greater impact on the survival of patients with high-risk malignancy than of those with low-risk malignancy. Among pairs with a single Mm, only locus A showed a significant association and higher risk of grade III-IV aGVHD compared to those in patients with 8 matched alleles.
  
  
  CONCLUSIONS
  Disparity in HLA class I, regardless of antigen or allele Mm, adversely affected both survival and grade III-IV aGVHD development. An increased number of HLA Mms was associated with a higher risk of post-transplantation complications. Further investigations using larger cohorts are required to confirm the effects of HLA mismatching on URD HSCT patient outcomes.
authors: Department of Pediatrics, University of Ulsan College of Medicine, Asan Medical Center Children's Hospital, Seoul, Korea.
authors: Meerim
authors: M
authors: Park
authors: Kyung Nam
authors: KN
authors: Koh
authors: Bo Eun
authors: BE
authors: Kim
authors: Ho Joon
authors: HJ
authors: Im
authors: Kyung Duk
authors: KD
authors: Park
authors: Hyoung Jin
authors: HJ
authors: Kang
authors: Hee Young
authors: HY
authors: Shin
authors: Hyo Seop
authors: HS
authors: Ahn
authors: Keon Hee
authors: KH
authors: Yoo
authors: Ki Woong
authors: KW
authors: Sung
authors: Hong Hoe
authors: HH
authors: Koo
authors: Hyeon Jin
authors: HJ
authors: Park
authors: Byung-Kiu
authors: BK
authors: Park
authors: Jong Jin
authors: JJ
authors: Seo