Antigen-specific Immune Response to Hepatitis B Virus in Utero
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ClinicalTrials.gov Identifier: NCT00845403
Recruitment Status : Unknown
Verified January 2014 by Obstetrics & Gynaecology, National University Hospital, Singapore. Recruitment status was: Recruiting
First Posted : February 18, 2009
Last Update Posted : January 13, 2014
National University Hospital, Singapore
Information provided by (Responsible Party):
Obstetrics & Gynaecology, National University Hospital, Singapore
This study aims to gain an understanding of the key components of the immune response to hepatitis B present in cord blood of HBV infected mothers.
Condition or disease
Despite the development of an effective preventive HBV vaccine, the spread of HBV virus continue, particularly in Asia, where the majority of HBV infection is acquired at birth by vertical transmission from mother to baby. HBV vertical transmission has been hypothesized to cause immune tolerance to HBV and thus promoting the subsequent HBV chronicity. Such hypothesis has never been tested and nothing is known about HBV-specific adaptive immune response occurring before birth in baby born form HBV chronically infected mothers. This study aims to gain an understanding of the key components of the immune response to hepatitis B present in cord blood of HBV infected mothers. The characterization of the HBV immune response in utero will provide informations about the cause of HBV chronicity in Asian patients in the management of baby born from HBsAg+ mothers.
Anti - viral immune response in cord blood of newborn infants born to HBV+ mothers [ Time Frame: At birth (baseline) ]
Immune response was defined as activation of innate immune effectors (NK cells, monocytes) and production of TH1 cytokines IL - 2, TNF - a and IFN - g from T cells.
Secondary Outcome Measures :
Expression of immune genes from immune cells [ Time Frame: At birth (baseline) ]
Expression of immune gene cells was measured using Nanostring technology and epigenetic analysis.
Biospecimen Retention: Samples Without DNA
Cord Blood of HBsAg+ mothers will be collected at delivery after seeking informed consent. Mononuclear cells (T cells and monocytes) will be isolated.Purified populations of T cells will be stimulated with different mixtures of HBV peptides covering HBV proteins and experiments of ELISPOT or intracellular cytokine staining will be carried out to detect the specificty of the responsive T cell population. In addition, T cells willbe stained with HLA-tetramers specific for different HBV epitopes to directly analyze the frequency and phenotype of HBV-specific CD8+Tcells present in cord blood.
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Ages Eligible for Study:
21 Years to 45 Years (Adult)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
HBsAg+ mothers are the source of possible in utero infection.Thus, the cord blood collected from these mothers after delivery would provide information about the cause of HBV chronicity in Asian patients and about the management of baby born from HBsAg+ mothers.