Neonatal antibody titers against varicella-zoster virus in relation to gestational age, birth weight, and maternal titer.
OBJECTIVE
Varicella-zoster virus (VZV) can cause severe disease in premature neonates. The fetus receives protective maternal VZV-immunoglobulin G (IgG) mainly in the third trimester of pregnancy. Therefore, premature neonates are considered at risk for VZV infection. Administration of varicella-zoster immunoglobulin (VZIG) within 96 hours after exposure effectively prevents severe illness in susceptible patients. The objectives of this study were to define the major determinants of the neonatal VZV-IgG titer and to determine the half-life of transplacentally acquired VZV-IgG. Guidelines provided by the Centers for Disease Control and Prevention for the use of VZIG in (premature) neonates were evaluated.


METHODS
VZV-IgG titers were measured in sera of 221 neonates and 43 mothers using a quantitative enzyme-linked immunosorbent assay. In 27 neonates, VZV-IgG titers were followed for up to 14 weeks.


RESULTS
In a linear regression model, the maternal antibody titer was the major determinant of the neonatal titer (beta = 0.89); gestational age was only of minor importance (beta = 0.18). The median half-life of VZV-IgG in neonates was 25.5 days (range: 14.6-76.0 days). In the first weeks of life, major fluctuations of the VZV-IgG titer occurred in >50% of the neonates. The predictive value of Centers for Disease Control and Prevention guidelines for identification of neonates who should receive VZIG in case of exposure to VZV was poor: positive and negative predictive values were 0.80 and 0.43, respectively.


CONCLUSIONS
The neonatal VZV-IgG titer is predominantly predicted by the maternal VZV-IgG titer, whereas birth weight and gestational age are much less predictive than previously reported.
van Der Zwet
Wil C
WC
Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, the Netherlands. w.zwet@vumc.nl
Vandenbroucke-Grauls
Christina M J E
CM
van Elburg
Ruurd M
RM
Cranendonk
Anneke
A
Zaaijer
Hans L
HL
D000914:Antibodies, Viral / Q000097:blood*; D001722:Birth Order; D005865:Gestational Age; D017408:Guidelines as Topic; D006207:Half-Life; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000276:immunology*; D016014:Linear Models; D011237:Predictive Value of Tests
D000914:Antibodies, Viral; D007074:Immunoglobulin G