Influence of obstetric factors on the yield of mononuclear cells, CD34+cell count and volume of placental/umbilical cord blood

Abstract

Placental/umbilical cord blood (CB) has been used increasingly not only for transplantations, but also in the field of life science research. However, little information is available on the biological characteristics of CB units collected in rural areas because no medical facilities are affiliated with CB banks. Little attention has been paid to the collection of CB units in rural areas compared to CB collected in metropolitan areas. CB is a precious source for life science research due to the recent low birth rate in Japan. Therefore, to efficiently utilize CB units, the purpose of the present study was to investigate the optimum obstetric factors associated with a higher yield of mononuclear/CD34(+) cells per CB unit. CB units were collected at a single hospital (Hirosaki National Hospital). A total of 126 CB units from 105 vaginal deliveries and 21 cesarean section deliveries were available for cell separation within 24 h. Mononuclear low-density (LD) cells were separated using Ficoll-Paque and then processed for CD34(+) cell enrichment using magnetic cell sorting. Associations between the maternal/neonatal factors and the yield of LD/CD34(+) cells were analyzed. Despite the larger net weight of CB collected from cesarean section deliveries, the total number of LD cells collected from vaginal deliveries was significantly higher than that collected from cesarean section deliveries. The total number of LD cells per CB unit from primigravidae was significantly higher compared with that collected from from multigravidae. CB units from vaginal deliveries of primigravidae may be more favorable because they contain a higher yield of mononuclear cells.