Phenotypic Immaturity of T and B Lymphocytes in Cord Blood of Full-Term Normal Neonates

Abstract

We examined mononuclear cell subsets in cord blood of normal newborns by surface marker analysis. The percentages of T lymphocytes (E-rosetting and T3⁺ cells) were lower in cord blood than in peripheral blood (PB) from adults, while the percentage and absolute number of T6⁺ cells were higher in cord blood. As the sum of T4⁺ and T8⁺ cells exceeded the values of E-rosetting lymphocytes in cord blood, we suggest that immature lymphocytes with the phenotype of ‘common’ thymocytes (T6⁺, T4⁺, T8⁺) are present in cord blood of full-term newborns. Higher percentage and absolute number of B lymphocytes were detected in cord blood. More than 50% of B cells in cord blood formed rosettes with mouse erythrocytes, a surface marker of functional immaturity. Finally, cells bearing receptors for IgG-Fc fragments or C3 and expressing Ia-like and Ml antigens were uniformly increased in cord blood, suggesting higher percentages of cells of the monocytic lineage.

Phenotypic characterization of immature lymphoid cells in human umbilical cord blood

“…A number of authors has reported on the distribution of T lymphocyte differentiation antigens on cord blood leucocytes (3)(4)(5)(6)(7)(8)(9)20,21). Our finding of lower numbers of CD-2+ cells in cord blood is in agreement with these studies.…”

“…There has been some controversy over the detection of CD-I positive lymphocytes in cord blood. In three reports, significant numbers (10-8, 14-2, and 24% of leucocytes) of CD-I + cells were found (7)(8)(9), and the authors cited these findings as indicating the presence of immature T cells in the neonatal circulation. Four other studies, however, documented lower (0-7-2-0%) numbers of these cells (2,6,20,22), a range more consistent with the present observations.…”

The development of anti-HLA antibodies in multiply transfused preterm infants.

“…B lymphocytes in cord blood of normal full term neonates are functionally immature having a reduced capacity to secrete immunoglobulins. 6 At birth there is a linear relationship between log IgG and gestational age, most of the IgG being transferred transplacentally.7 Immunoglobulin synthesis in neonates is mostly of the IgM class, but cord IgM may be undetectable especially in babies less than 32 weeks' gestation.7 A previous study of multiply transfused infants failed to detect red cell antibodies in 53 infants and leucocyte antibodies in 13 infants. 8 Febrile reactions to blood transfusions have been documented in infants beyond the neonatal period,' and an 18 day old infant who produced alloanti-E antibodies has been reported.…”

Flow cytometric analysis of lymphocyte subpopulations in infants with congenital heart disease

“…The T4/T8 ratio did not differ significantly between CHD patients (3.36 i-2.0) and our retrospective infant controls (2.95 f 0.8, p = 0.29). Two reports (16,19) found %CD1+ to be substantially higher in cord blood samples (3.8% i-4.3 and 14.2% i-8.4). A single reported study of cord blood identified an unexpectedly large number of cells staining with the CD38 Mab (18), similar to our patients with CHD.…”

“…Similarly, 17 hospitalized but clinically stable nontransfused infants under 6 months of age studied previously using a slightly modified but comparable whole blood methodology (15) had nearly indistinguishable phenotypes with regard to the markers evaluated. In Table 4, the mean percentages derived from the present study are compared with our previous study and with unweighted averages for the same or similar markers drawn from currently published studies of infants peripheral and cord blood (16)(17)(18)(19)(20)(21)(22)(23). The average percentages for CD4 + and CD8 + are in very close agreement, although the range reported in the literature is quite large.…”