Gustavo Steibel

Hematologic and immunophenotypic characterization of human umbilical cord blood

In this work, cord blood cells from 30 healthy term newborns were analyzed for complete blood counts with an automated cytometer and, in part of the sample, for surface molecules in cord blood monocytes, lymphocytes and CD34+ cells by two-color flow cytometry. Hematological parameters were as follows: WBC = 12.85 (5.24–15.10) ×109/l; platelets = 304.33 (156.00–469.00) × 109/l; Hb = 14.45 (11.90–17.82) g/dl; RBC = 3.99 (3.14–5.12) × 1012/l; MCV 107.25 (99.60–115.00) fl; reticulocytes = 157.80 (101.00–124.00) × 109/l or 3.99 (2.45–6.01)%; erythroblasts = 0.88 (0.15–2.58) per 100 WBC or 6.63 (2.86–16.80) × 109/l. The mononuclear population, as evaluated by flow cytometry, was composed of 22.9 ± 7.2% monocytes and 77.05 ± 7.24% lymphocytes, among which 46.59 ± 15.62% were T lymphocytes (43.94 ± 16.94% CD3+/CD4+ and 13.45 ± 7.46% CD3+/CD8+). CD34+ cells were on average 0.54 ± 0.24% of the mononuclear fraction. CD11c, CD49e and HLA-DR were found mainly on monocytes, and CD31 and CD62L occurred in similar levels on monocytes and lymphocytes. CD117+ cells were less than 5% of these populations. Among CD34+ cells, CD31 and HLA-DR were the molecules with higher frequencies (79.7 ± 19.9 and 65.7 ± 23.0%, respectively), followed by CD62L (41.8 ± 31.9%) and CD117 (20.1 ± 15.8%). The presence of CD11c and CD49e on CD34+ cells was low (below 10%). The results stress the phenotypic heterogeneity of cord blood CD34+ cells, and the different behavior of the cells when manipulated in vitro in different degrees of isolation.