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Phenotypic Differences in Leucocyte Populations among Healthy Preterm and Full‐Term Newborns
Author(s) -
Quinello C.,
SilveiraLessa A. L.,
Ceccon M. E. J. R.,
Cianciarullo M. A.,
CarneiroSampaio M.,
Palmeira P.
Publication year - 2014
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/sji.12183
Subject(s) - immunology , cord blood , immune system , flow cytometry , medicine , myeloid , myeloid cells , phenotype , umbilical cord , biology , genetics , gene
The immune system of neonates has been considered functionally immature, and due to their high susceptibility to infections, the aim of this study was to analyse the phenotypic differences in leucocyte populations in healthy preterm and full‐term newborns. We evaluated the absolute numbers and frequencies of dendritic cells ( DC s) and DC subsets, monocytes and T and B lymphocytes and subsets in the cord blood of healthy moderate and very preterm ( G roup 1), late preterm ( G roup 2) and full‐term ( G roup 3) newborns and in healthy adults, as controls, by flow cytometry. The analyses revealed statistically higher absolute cell numbers in neonates compared with adults due to the characteristic leucocytosis of neonates. We observed a lower frequency of CD 80 + myeloid and plasmacytoid DC s in Group 1 and reduced expression of TLR ‐4 on myeloid DC s in all neonates compared with adults. TLR ‐2 + monocytes were reduced in Group 1 compared with Groups 2 and 3, and TLR ‐4 + monocytes were reduced in Groups 1 and 2 compared with Group 3. The frequencies and numbers of naïve CD 4 + T and CD 19 + B cells were higher in the three groups of neonates compared with adults, while CD 4 + effector and effector memory T cells and CD 19 + memory B cells were elevated in adults compared with neonates, as expected. Our study provides reference values for leucocytes in cord blood from term and preterm newborns, which may facilitate the identification of immunological deficiencies in protection against extracellular pathogens.