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Efficacy of Newborn Vitamin A Supplementation in Improving Immune Function

Information source: USDA, Western Human Nutrition Research Center
ClinicalTrials.gov processed this data on August 23, 2015
Link to the current ClinicalTrials.gov record.

Condition(s) targeted: Vitamin A Deficiency

Intervention: retinyl palmitate (Dietary Supplement); Placebo (Dietary Supplement)

Phase: N/A

Status: Completed

Sponsored by: USDA, Western Human Nutrition Research Center

Official(s) and/or principal investigator(s):
Charles B. Stephensen, Ph.D., Principal Investigator, Affiliation: USDA, Western Human Nutrition Research Center

Summary

Vitamin A supplementation at birth may increase survival of infants through one year of age by reducing mortality from infectious diseases, though current studies are not conclusive on this point. The goal of our study is to determine if supplementation of newborn infants with 50,000 IU of vitamin A improves aspects of immune function that may be impaired by vitamin A deficiency. Our underlying assumption is that supplementation may thus decrease risk of death by improving immune function and the ability to survive infections. This project will be limited to the examination of the impact of vitamin A on immune function and will not aim to determine the impact on morbidity or mortality, which would require larger sample sizes. The hypotheses addressed by this study are as follows: Provision of vitamin A supplements to newborns at risk of vitamin A deficiency will (1) improve functioning of the thymus (the source of T lymphocytes, cells of the immune system that are important in response to infection and immunization); (2) enhance T lymphocyte-mediated responses to standard vaccines given at birth and early in infancy; and (3) improve gut barrier function (i. e., ability to prevent bacterial infection across the epithelial barrier), relative to provision of a placebo.

Clinical Details

Official title: Efficacy of Newborn Vitamin A Supplementation in Improving Immune Function

Study design: Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Primary outcome:

Thymus size measured by ultrasound

peripheral blood naive T-helper lymphocyte concentration

T-cell receptor excision circle (TREC) level in peripheral blood mononuclear cells (PBMC)

T-cell response to BCG (Bacillus Calmette-Guérin; to protect against tuberculosis) and oral polio virus (OPV) immunization

Antibody response to oral polio virus (OPV) immunization

T-cell and antibody response to tetanus toxoid (TT) and hepatitis B virus (HBV) vaccinations given at 6, 10 and 14 wk of age

bacterial translocation to blood

Secondary outcome:

vitamin A status by modified, relative dose-response (MRDR) test

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Detailed description: This project will examine the effect of vitamin A supplementation (50,000 IU) or placebo given with BCG and oral polio virus (OPV) immunization within 48 h of birth on immune function in 300 Bangladeshi infants (150 in each group) at risk of vitamin A deficiency recruited in a poor community of Dhaka, Bangladesh. Infants will be followed from birth through 15 wk of age. Current evidence from community-based mortality trials is not conclusive but suggests that such supplementation will decrease infant mortality from infectious disease through 6 m of age. The biological mechanism underlying this potential benefit is unclear but is presumed to include improving immune function. The investigators hypothesize that vitamin A supplementation at birth prevents vitamin A deficiency during a critical window of a few days to weeks when the immune system is first exposed to both normal, non-pathogenic organisms (e. g., commensal gut flora) and to potential pathogens. During this period the investigators propose that vitamin A supplementation will improve three aspects of immune function that will have sustained benefits throughout infancy: (1) normal thymus maturation and function; (2) development and mucosal targeting of adaptive immune responses, including regulatory T-cells (Treg), T-helper type 2 (Th2) cells, and IgA-secreting plasma cells and memory B-cells; and (3) mucosal barrier function. The three specific objectives of our project are: (1) Determine if vitamin A supplementation improves thymus maturation and function as indicated by ultrasonic analysis of thymus size and by analysis of thymic output of naïve T-cells using flow cytometric analysis of peripheral blood T-cells and by quantification of T-cell-receptor excision circles (TRECs) in peripheral blood. (2) Determine if vitamin A supplementation at birth alters (2. 1) the T-cell response to BCG and OPV immunization assessed at 6 and 15 wk of age; (2. 2) the T- and B-cell response to OPV immunization, assessed at 15 wk of age, and the secretory IgA response to OPV assessed at 6, 11 and 15 wk of age; and (2. 3) the B-cell response to tetanus toxoid (TT) immunization, assessed at 15 wk of age. (3) Determine if vitamin A supplementation at birth will decrease bacterial lipopolysaccharide (LPS) concentrations in capillary blood, a marker of bacterial translocation.

Eligibility

Minimum age: N/A. Maximum age: 48 Hours. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Infant receiving OPV and BCG within 48 hr of birth

Exclusion Criteria:

- Mother is less than 18 years of age

- Infant is part of a multiple birth

- Infant will likely not remain in the study area for the next 4 months

- Infant has a condition precluding vaccination

- Infant is unable to breastfeed or drink other fluids

- Birth weight is less than 1. 5 kg

Locations and Contacts

International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
Additional Information

Starting date: January 2012
Last updated: August 22, 2014

Page last updated: August 23, 2015

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