title: Developmental changes in adhesion molecule expressions in umbilical cord blood CD34 hematopoietic progenitor and stem cells.
abstract: OBJECTIVE
  The purpose of this study was to determine whether expressions of the cell adhesion molecules LFA-1 (CD11a), VLA-4 (CD49d), and L -selectin (CD62L ) on CD34(+) stem and progenitor cells in umbilical cord blood change during gestation.
  
  
  METHODS
  In a prospective observational study 3-color fluorescence-activated cell sorting was used to assess the levels of expression of CD11a, CD49d, and CD62L on CD34(+) cells in fresh cord blood samples collected at delivery between 22 and 42 weeks' gestation.
  
  
  RESULTS
  The relative number of CD34(+) cells decreased as gestational age increased (r = -0.71; P<.001). Conversely, we found significant increases in cell adhesion molecule expression by CD34(+) cells during gestation (LFA-1, r = 0.47; P =.001; VLA-4, r = 0.33, P =.031; L -selectin, r = 0.61; P<.001). Comparisons between grouped samples from early preterm (22-32 weeks' gestation), late preterm (33-37 weeks' gestation), and term (38-42 weeks' gestation) infants confirmed this correlation and revealed that the major increases occurred between early and late preterm gestation.
  
  
  CONCLUSIONS
  These results suggest a role for cell adhesion molecule expression in the process of migration and homing of circulating stem cells to the fetal bone marrow toward the end of pregnancy. The findings may have implications for the use of preterm cord blood for hematopoietic stem cell transplantation and also for prenatal gene therapy.
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital, King's College Hospital, London, United Kingdom.
authors.forename: D V
authors.initials: DV
authors.lastname: Surbek
authors.forename: C
authors.initials: C
authors.lastname: Steinmann
authors.forename: M
authors.initials: M
authors.lastname: Bürk
authors.forename: S
authors.initials: S
authors.lastname: Hahn
authors.forename: A
authors.initials: A
authors.lastname: Tichelli
authors.forename: W
authors.initials: W
authors.lastname: Holzgreve
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000032:analysis*; D015815:Cell Adhesion Molecules / Q000097:blood*; D002452:Cell Count; D005314:Embryonic and Fetal Development; D005260:Female; D005312:Fetal Blood; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies
chemical_list: D018952:Antigens, CD34; D015815:Cell Adhesion Molecules