Presence of IL-9 in paired samples of human colostrum and transitional milk.

BACKGROUND: Human colostrum and breast milk are known to contain high levels of cytokines, cytokine receptors, and chemokines. OBJECTIVE: To investigate the presence and compare levels of soluble cytokines in paired samples of human colostrum and milk. METHODS: Levels of 27 cytokines were measured in 9 paired samples of human colostrum (day 2 after delivery) and breast milk (day 4 or 5 after delivery) by using multiplex technology. RESULTS: The majority of cytokines and chemokines investigated have been previously described in colostrum and/or breast milk. For the first time, we describe the presence of IL-9 in both human colostrum and milk. Of the 27 cytokines investigated, only IL-5 was absent in both colostrum and milk, whereas IL-1ß, IL-2, IL-4, IL-15, IL-17, and MIP-1α were present in colostrum, but not in breast milk. In general, colostrum contained higher concentrations of cytokines with respect to human milk. CONCLUSION: Our data confirm and expand previous studies showing that human colostrum and breast milk are rich in cytokines and chemokines, including IL-9, which might contribute to the development of the immune system of the newborn.

Presence of CTAK/CCL27, MCP-3/CCL7 and LIF in human colostrum and breast milk.

Human colostrum and breast milk are known to contain high levels of cytokines and chemokines, which are thought to contribute to the development of the newborn. The aim of this study was to investigate the difference in the presence and levels of 21 soluble cytokines and chemokines in paired samples of human colostrum (day 2 after delivery) and breast milk (day 4-5 after delivery) by using the multiplex technology. Of the 21 cytokine investigated in 10 pairs of samples, only ß-NGF was absent in both colostrum and milk, while INF-α2, SCF and TNF-ß were present in colostrum but not in human milk. As a general rule, colostrum contained higher concentrations of cytokines and chemokines with respect to breast milk. The majority of cytokines, detected in colostrum alone or in colostrum and human milk (IL-1α, IL-2Rα, IL-3, IL-16, IL-18, GRO-α, HGF, IFN-α2, M-CSF, MIF, MIG, TNF-ß, SDF-1α, TRAIL) have been described in previous studies, while for the first time we describe the presence of additional cytokines either in colostrum alone (SCF) or in both colostrum and breast milk (CTAK/CCL27, MCP-3/CCL7, LIF). Our data confirm and expand previous studies showing that some cytokines/chemokines, which might contribute to the development of the gastro-intestinal and nervous systems, are overexpressed in human colostrum and breast milk, and might contribute to the development of these systems.