Effect of Breast Milk Interleukin-7 on Thymic Development in Young Infants

Abstract

This study is aimed to investigate the impact of human breast milk interleukin-7 concentration on thymic development as evaluated by thymic size and functions. It is a longitundal study conducted on a stratified non-random sample including 55 healthy infants and their mothers. The infants of each studied group were consecutively recruited at the age of two months, from the Out-patient Clinic of the Children's Hospital, Ain Shams University and were followed up and re-evaluated at the ages of 4 and 6 months in the period from February 2015 to April 2016. The study groups comprised 19 infants who were exclusively breast fed (Group I), 17 exclusively formula-fed infants (Group II) and 19 mixed breast and formula-fed infants (Group III). Radiological evaluation of thymus by ultrasound and estimation of thymic index was performed at 2, 4 and 6 months of age. Complete blood counting (CBC) and flow cytometric immunophenotyping for (CD3+, CD4+ and CD8+) T lymphocytes counts were performed in the studied infants' sample at time of enrollment and at the age of 6 months. Thymic indices were significantly higher among the exclusively breast fed and the mixed fed group in comparison to the formula fed group. The indices increased progressively with age from the 2nd month to the 6th month.