BACKGROUND AND OBJECTIVES: Whilst cord blood (CB) contains a significant number of haematopoietic stem and progenitor cells suitable for bone marrow transplantation, levels of these cells are very low in the adult circulation. In previous studies, we demonstrated that stem and progenitor cells are present in neonatal blood (NB) and reported the first sibling transplant using a combination of CB and NB for a @entity1 with @entity5357 major. However, our preliminary data showed that the number of @entity2280 + cells decreased rapidly in the peripheral blood of neonates soon after birth. To further investigate the mechanism of the change of stem and progenitor cells in NB, we measured the steady-state levels of @entity2280 + cells, early progenitor subsets and the expression of adhesion molecules, in term and preterm neonates. MATERIALS AND METHODS: NB was collected serially from @entity1 at 2, 4, 6, 8, 24 and 48 h after birth and was analysed by three-colour flow cytometry. RESULTS: Our results demonstrated that the number of @entity2280 + cells rapidly decreased in term NB, particularly during the first 2-6 h of life, by 29.2 +/- 5.55% (P = 0.0003) in absolute counts/ml. A decrease was observed in all subsets of @entity2280 + cells studied, including the @entity1116 +, @entity8282 +, @entity1196 + and @entity5690 + populations. In contrast, the @entity2280 + cell number increased in preterm @entity1 in the first 8 h of life, before starting to decrease. Significant inverse correlations were observed between gestational age and levels of @entity2280 + cells (P = 0.0065, 4-h collection time-point). CONCLUSION: Our study suggests that changes in the levels of @entity2280 + stem and progenitor cells in NB might be triggered by parturition and affected by the gestational age. Our findings confirmed that if targeted as a supplementary source of stem and progenitor cells to CB for transplantation, NB should be collected as soon as possible after birth.

Haematopoietic stem and progenitor cells in XXXX term and preterm neonatal blood.

@entity1 :: ('9606', 'Species') :: ['patient', 'infants'] @entity5690 :: ('3676', 'Gene') :: ['CD49d'] @entity8282 :: ('7037', 'Gene') :: ['CD71'] @entity1196 :: ('6402', 'Gene') :: ['CD62L'] @entity5357 :: ('MESH:D012497', 'Disease') :: ['beta-thalassaemia'] @entity2280 :: ('947', 'Gene') :: ['CD34'] @entity1116 :: ('945', 'Gene') :: ['CD33']
@entity1 :: (9606,Species) :: ['human']
