Platelets and neutrophils from healthy term neonates exhibit increased levels of immunoglobulins.
Immune-mediated thrombocytopenia and neutropenia are not uncommon problems in the newborn period. Such cytopenias have been associated with increased levels of IgG, IgM, or both, in the serum, documented by indirect assay, and/or on the cell surface, documented by direct assay, and decreased cell survival. However, interpretation of measurement of platelet- or neutrophil-associated antibodies is problematic due to the lack of data from healthy neonates. In this study, both direct and indirect neutrophil- and platelet-associated IgG and IgM were measured in cord samples from 44 healthy, term neonates. These infants had increased amounts of direct platelet-associated IgG and direct neutrophil-associated IgM and IgG compared with adult controls. Serum samples from these healthy newborns manifested a significantly decreased level of IgM binding to target platelets compared with serum from healthy adult controls. There was not a significant difference in direct platelet-associated IgM, or indirect Ig to neutrophils or platelets. Complete blood counts drawn at 24 h of age were within normal limits in 34/35 infants studied. Moreover, there was not a statistical difference in platelet or neutrophil Ig studies between the newborns of multiparous and primigravida mothers. The physiologic consequences of the increased amounts of these Ig to the survival and function of platelets and neutrophils in neonates is unclear. However, these values must be considered for proper interpretation of platelet and neutrophil Ig measurements in newborns with cytopenias.
Silliman
C C
CC
Department of Research, Bonfils Memorial Blood Center, Denver, Colorado, USA.
Cusack
N A
NA
Swanson
N J
NJ
Ghaffarifar
S
S
Ambruso
D R
DR
D000328:Adult; D001792:Blood Platelets / Q000276:immunology*; D016022:Case-Control Studies; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D007231:Infant, Newborn / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*; D012016:Reference Values
D007074:Immunoglobulin G; D007075:Immunoglobulin M