RESUMEN
Having established previously that prematurity in The Gambia is associated with impaired maternofetal transfer of some specific antibodies, we investigated the influence of low birthweight and prematurity on placental transfer of IgG subclasses in 180 Gambian mothers and their newborn babies. A physician-blinded, cross-sectional study of 180 mother-baby pairs was carried out in the labour ward of Bansang Hospital, The Gambia. Paired maternal and cord serum samples were collected from mothers and their newborns. Serum IgG subclass levels were measured by laser nephelometry. Placental transfer of all IgG subclasses was significantly reduced in preterm newborns compared with term newborns (p < 0.01). In low birthweight (LBW) babies, the transfer of IgG1 (p = 0.03) and IgG2 (p < 0.01) subclasses, but not IgG3 and IgG4, was significantly reduced. In preterm neonates with an adequate birthweight and term neonates with a low birthweight, all IgG subclasses were transferred with reduced efficiency, but IgG1 and IgG2 subclasses were transferred with significantly less efficiency than IgG3 and IgG4. These results confirm that prematurity and low birthweight are associated with impaired placental transfer of IgG1 and IgG2 subclasses in this Gambian population. This impairment might explain the susceptibility of these newborns to certain polysaccharide-encapsulated organisms.
Asunto(s)
Inmunoglobulina G/sangre , Recién Nacido de Bajo Peso/sangre , Recien Nacido Prematuro/sangre , Intercambio Materno-Fetal/inmunología , Adolescente , Adulto , Estudios Transversales , Femenino , Sangre Fetal/inmunología , Gambia , Humanos , Inmunoglobulina G/inmunología , Recién Nacido de Bajo Peso/inmunología , Recién Nacido , Recien Nacido Prematuro/inmunología , Masculino , Persona de Mediana Edad , EmbarazoRESUMEN
OBJECTIVE: To determine the influence of prematurity and low birthweight (LBW) on transplacental antibody transfer. METHOD: In a physician-blinded, cross-sectional study of 213 mother--baby pairs in the labour ward of Bansang Hospital, The Gambia, paired maternal and cord serum samples were tested for specific IgG antibody titres for measles virus (MeV), herpes simplex virus type 1 (HSV1), respiratory syncytial virus (RSV), varicella-zoster virus (VZV), tetanus toxoid (TT) and diphtheria toxoid (DT) antigens using enzyme linked immunosorbent assay (ELISA). RESULTS: Prematurity was significantly associated with reduced placental antibody transfer for MeV, HSV1, TT, DT, RSV and VZV. Maternal antibody transfer for MeV, HSV1, TT, DT, RSV and VZV was significantly lower in neonates with LBW than in babies with adequate birthweight (ABW). CONCLUSION: Materno--foetal transfer of antibodies is impaired in prematurity and LBW babies in this Gambian population. Reduction in antibody transfer may further predispose these already vulnerable neonates to bacteria and viral infections. Therefore, alternative vaccination strategies, including earlier vaccination schedules, are needed to provide better protection to these young infants.
Asunto(s)
Anticuerpos Antivirales/sangre , Inmunidad Materno-Adquirida , Recién Nacido de Bajo Peso/inmunología , Recien Nacido Prematuro/inmunología , Población Rural , Adulto , Estudios Transversales , Difteria/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Gambia , Humanos , Recién Nacido , Paridad , Tétanos/inmunologíaRESUMEN
The influence of gestational age, the neonate's birthweight, and maternal age, weight, height and parity on transplacental antibody transfer was assessed in 141 mothers from Sri Lanka and their neonates. Paired blood samples were collected from the mothers and the umbilical cords of the newborns. The sera separated from these samples were categorized as: preterm but adequate birthweight (< 37 weeks' gestation and birthweight > or = 2500 g); term but low birthweight (> or = 37 weeks' gestation and birthweight < 2500 g); or term and adequate birthweight (> or = 37 weeks' gestation and birthweight > or = 2500 g). Neonatal and maternal sera were assessed, in ELISA, for specific IgG antibodies against measles virus (MeV), herpes simplex virus type-1 (HSV1), respiratory syncytial virus (RSV), varicella-zoster virus (VZV), tetanus toxoid (TT), diphtheria toxoid (DT), and Streptococcus pneumoniae (Pn) and Haemophilus influenzae type-b (Hib) capsular antigens. Placental antibody transfer to certain antibody specificities was significantly lower in preterm neonates than term neonates. Thus the ratios between geometric mean cord antibody levels and geometric mean maternal antibody levels (the antibody-transfer ratios) were lower in preterm sera than term sera, for MeV (1.51 v. 2.03; P = 0.03), HSV1 (1.29 v. 1.76; P = 0.04), VZV (0.96 v. 2.50; P = 0.01), TT (1.13 v. 1.33; P = 0.04), DT (1.03 v. 2.39; P = 0.02), Pn (0.68 v. 0.98; P = 0.01) and Hib (0.58 v. 0.98; P = 0.00). Geometric mean levels of antibody to MeV, VZV, TT, DT and Pn were also significantly lower in preterm neonates than term. Compared with the values for 'adequate-birthweight' sera, low birthweight was independently associated with significantly lower levels of antibody transfer, for MeV (with antibody-transfer ratios of 1.51 v. 2.03; P = 0.02), VZV (0.99 v. 2.50; P = 0.03), TT (1.01 v. 1.33; P = 0.04) and DT (1.16 v. 2.39; P = 0.04) and significantly lower levels of antibodies to MeV, HSV1, VZV, TT, DT and Pn in the neonates. Maternal age, weight, height and parity had no independent influence on placental IgG transfer for antibodies to any of the pathogens investigated. These results demonstrate that prematurity and low birthweight may influence the level of maternally acquired immunity in Sri Lankan neonates.