Association of HLA-A, -B and -DRB1 genotype with birthweight and CD34+ cell content: analysis of Korean newborns and their cord blood.

Birthweight and the hematopoietic progenitor cell content in cord blood affect and reflect fetal development, and MHC has been reported to play an important role in intrauterine growth. In this study, we assessed HLA-A, -B and -DRB1 polymorphisms, birthweight and cord blood CD34(+) cell content in 1628 full-term healthy neonates to identify the HLA alleles that are associated with fetal growth in Koreans. HLA-A*31, B*47, B*51, DRB1*04 showed positive association and HLA-A*03, A*24, A*30, B*07, B*52, B*58, DRB1*03 showed negative association with birthweight and/or CD34(+) cell content; additionally, there was a greater association in homozygotes than heterozygotes revealed in the trend analysis of birthweight centile with candidate allele zygosity (A*24, P= 0.018; DRB1*04, P= 0.047). Among these alleles, HLA-A*24 and DRB1*03 showed significant negative association with birthweight and/or CD34(+) cell content after Bonferroni correction, suggesting a significant association of these alleles with fetal growth in late pregnancy (A*24, P= 0.002, P(c) = 0.026; DRB1*03, P < 0.001, P(c) < 0.001). Various populations should be analyzed to identify different or consistent factors among ethnicities. Furthermore, a larger scale study that includes pre-terms will aid in the comprehensive understanding of these associations.