title: Hepatitis B-specific T helper cell responses in uninfected infants born to HBsAg+/HBeAg- mothers.
abstract: Vertically transmitted hepatitis B virus (HBV) usually causes chronic infection. While combined active-passive immunoprophylaxis in neonates of hepatitis B surface antigen-positive (HBsAg(+)) mothers at birth prevents vertical transmission, it is not yet clear whether neonates encounter the virus or its products in the absence of hepatitis B e antigen (HBeAg). This study was undertaken to investigate HBV antigen-specific T-cell responses in vaccinated neonates of HBsAg(+)/HBeAg(-) mothers. Blood was collected from 46 HBsAg(+) mothers and their neonates (subjects) as well as 24 age-matched controls. All neonates of HBsAg(+) mothers received appropriate immunoprophylaxis, and HBsAg and hepatitis B surface antibody (anti-HBs) antibody titers were determined after completion of the vaccination course. Peripheral blood mononuclear cells (PBMCs) from infants at birth, 1 and 6 months of age were stimulated with recombinant HBsAg, hepatitis B core antigen (HBcAg) and mitogen, and interferon (IFN)-γ concentrations were determined by ELISA. HBsAg-induced production of IL-2, IL-5, IL-6 and IL-10 was assessed using a cytometric bead array kit on cells from 6-month-old neonates post-vaccination. All neonates were HBsAg(-) and responded to vaccination. Increased IFN-γ production following HBcAg stimulation was seen in 30.4% of neonates born to HBsAg(+)/HBeAg(-) mothers. Subjects demonstrated significantly higher IL-2 production post-HBsAg stimulation, whereas IL-5, IL-6 and IL-10 cytokine responses were not significantly different. Almost one-third of uninfected neonates developed viral antigen-induced IFN-γ production, suggesting that they had been exposed to virions or viral derivatives. This encounter, however, did not impair their T-cell responses to vaccination.
authors.affiliation: Second Department of Pediatrics, Allergy Research Center, University of Athens, Athens, Greece. lemonica.koumbi@gmail.com
authors.forename: Lemonica
authors.initials: L
authors.lastname: Koumbi
authors.forename: Antonio
authors.initials: A
authors.lastname: Bertoletti
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Anastasiadou
authors.forename: Maria
authors.initials: M
authors.lastname: Machaira
authors.forename: Winnie
authors.initials: W
authors.lastname: Goh
authors.forename: Nikolaos G
authors.initials: NG
authors.lastname: Papadopoulos
authors.forename: Dimitris A
authors.initials: DA
authors.lastname: Kafetzis
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Papaevangelou
mesh_terms: D016022:Case-Control Studies; D005260:Female; D006509:Hepatitis B / Q000097:blood / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000276:immunology*; D006513:Hepatitis B e Antigens / Q000097:blood / Q000276:immunology*; D006801:Humans; D007231:Infant, Newborn / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis; D011247:Pregnancy; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D007371:Interferon-gamma