Normal Thymic Size and Low Rate of Infections in Human Donor Milk Fed HIV-Exposed Uninfected Infants from Birth to 18 Months of Age

Dorthe Lisbeth Jeppesen,Annette Kjær Ersbøll,Susanne Dam Nielsen,Niels Henrik Valerius,Tine Ursula Hoppe

doi:10.1155/2013/373790

Abstract

Objective. To evaluate the immune function in HIV-exposed uninfected (HIV-EU) infants fed human donor milk. Methods. Ultrasound-obtained thymic index (Ti), T-lymphocyte subsets, and the number of infections were examined from birth to 18 months of age in 18 HIV-EU infants. The infants were compared to a cohort of 47 term, HIV-unexposed breastfed or formula-fed infants. Results. The thymic size at 12 months of age was not significantly different between the HIV-EU group and the control infants (P = 0.56). At 4 months of age, the HIV-EU infants had significantly fewer infections than the control infants (P < 0.001). Furthermore, in the control group, the infants exclusively breastfed at 4 months of age had significantly fewer infections at 8 months when compared to age-matched formula-fed infants (P = 0.001). Conclusion. HIV-EU infants fed human donor milk have normal growth of thymus and contract fewer infections than other healthy infants. This finding along with fewer infections in exclusively breastfed infants compared to formula-fed infants supports the beneficial effect of human milk on the immune system. We suggest, when breastfeeding is not possible, that providing human donor milk to vulnerable groups of infants will be beneficial for their maturing immune system.

Highlights

Vertical transmission of HIV from HIV-positive mothers to their infants is, in industrialised countries, reduced to less than 1-2% [1,2,3]
One infant born to an HIV-positive mother was born preterm at a gestational age (GA) of 31 weeks (GA being the age of the infant determined as the number of weeks after the first day of the last menstrual period)
thymic index (Ti) in HIV-exposed uninfected (HIV-EU) infants and in the cohort of term HIV-unexposed infants is shown in Tables 1 and 2, respectively

Summary

Introduction

Vertical transmission of HIV from HIV-positive mothers to their infants is, in industrialised countries, reduced to less than 1-2% [1,2,3]. The number of HIV-exposed uninfected (HIV-EU) infants in the world is growing. Despite HIV-EU infants remaining uninfected, there have been reports of impaired immune function and reduced CD4 counts in HIV-EU newborns [4,5,6,7,8]. The thymus plays a key role in the development of a functional immune system, providing the environment for T-lymphocyte maturation and being a central organ for the development and maintenance of cell-mediated immunity. The thymus is known to be a target organ in HIVinfection [11]. The transition of T-cell progenitors in the thymus has been extensively evaluated, but the significance of the size or alterations in the size of the thymus in infancy is still unclear [12,13,14,15]

Methods

Results

Discussion

Conclusion