PHYSIOLOGICAL SECRETION OF CHEMOKINES IN HUMAN BREAST-MILK

Human breast milk has been observed to contain high concentrations of the chemotactic cytokines (chemokines) interleukin-8 (IL-8) and RANTES . Concentrations are greatest in colostrum, but are measurable in milk after several months of lactation. These chemokines are also found in the secretions of patients with galactorrhoea and in the ''witch's mi lk'' of the newborn, Chemokine levels show good correlation with the s odium levels but not with cell counts or the creamatocrit of the secre ted milk. Mothers with pre-term deliveries show no statistical differe nce in chemokine secretion in comparison with those with term deliveri es. Immunohistochemisty demonstrates IL-8 and RANTES immunoreactivity in the acinary epithelial cells of normal mammary tissue and IL-8 and RANTES were shown to be produced by cultured, human mammary epithelial cells (HMEC) after stimulation with different cytokines. These result s suggest that mammary epithelial cells are the source of chemokines i n human milk and that the recruitment of leukocytes in human milk is l ikely to be chemokine-driven.