Cytokines in human colostrum and neonatal jaundice.

Breast-fed infants have higher bilirubin levels than formula-fed infants, possibly because of variations in the composition of the breast milk. The aim of this study was to investigate whether there is a relationship between cytokine levels in the colostrum of nursing mothers and neonatal jaundice (NJ). Breast milk samples were collected from breast-feeding mothers of healthy full-term neonates, 32 with NJ and 29 without jaundice. The concentrations of IL-1beta, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-alpha were measured by chemiluminescence enzyme immunometric assays. Mothers of infants with NJ had a higher concentration of IL-1beta in colostrum, compared with those feeding neonates without NJ, and similar trends were seen for IL-6, IL-8, IL-10, and for TNF-alpha. The concentrations of IL-1beta significantly correlated with IL-6, IL-8, IL-10, and TNF-alpha concentrations, but not with serum bilirubin levels of infants with NJ. In conclusion, the concentrations of IL-1beta were increased in colostrum from breast-feeding mothers whose infants had NJ. The correlation between the concentrations of cytokines involved in the function of hepatic uptake and excretory systems and in the enterohepatic circulation of bilirubin provides additional data to the delineation of the cascade of pathophysiological events that can lead to NJ.