Human Umbilical Cord Blood CD34-Positive Cells as Predictors of the Incidence and Short-Term Outcome of Neonatal Hypoxic-Ischemic Encephalopathy: A Pilot Study

BACKGROUND AND PURPOSE Neonatal hypoxic-ischemic encephalopathy (HIE) is one of the leading causes of neurological handicap in developing countries. Human umbilical cord blood (hUCB) CD34-positive (CD34⁺) stem cells exhibit the potential for neural repair. We tested the hypothesis that hUCB CD34⁺ stem cells and other cell types [leukocytes and nucleated red blood cells (NRBCs)] that are up-regulated during the acute stage of perinatal asphyxia (PA) could play a role in the early prediction of the occurrence, severity, and mortality of HIE. METHODS This case-control pilot study investigated consecutive neonates exposed to PA. The hUCB CD34⁺ cell count in mononuclear layers was assayed using a flow cytometer. Twenty full-term neonates with PA and 25 healthy neonates were enrolled in the study. RESULTS The absolute CD34⁺ cell count (p=0.02) and the relative CD34⁺ cell count (CD34⁺%) (p<0.001) in hUCB were higher in the HIE patients (n=20) than the healthy controls. The hUCB absolute CD34⁺ cell count (p=0.04), CD34⁺% (p<0.01), and Hobel risk scores (p=0.04) were higher in patients with moderate-to-severe HIE (n=9) than in those with mild HIE (n=11). The absolute CD34⁺ cell count was strongly correlated with CD34⁺% (p<0.001), Hobel risk score (p=0.04), total leukocyte count (TLC) (p<0.001), and NRBC count (p=0.01). CD34⁺% was correlated with TLC (p=0.02). CONCLUSIONS hUCB CD34⁺ cells can be used to predict the occurrence, severity, and mortality of neonatal HIE after PA.