Human Milk Anti-inflammatory Component Contents during Acute Mastitis

Mastitis is a common complication of human lactation. We examined milk specimens from eight women with clinical mastitis to determine their content of anti-inflammatory components. Antioxidant activity (spontaneous cytochrome c reducing activity), selected pro-inflammatory cytokines (IL-6, IL-1β), selected endogenous cytokine control molecules (sIL-6R, sIL-1RII, and sTNFRI), lactoferrin, Na+:K+ ratios, and milk bioactivities that cause shedding of sIL-1RII from human polymorphonuclear leukocytes (PMN), suppress PMN aggregation, and suppress PMN adherence responses were not increased compared to normal milks. Neither the bioactivities that deplete PMN intracellular Ca2+ stores nor those that block Ca2+ influx into fMLP-stimulated PMN were significantly increased in mastitis milks. In contrast, levels of TNFα, sTNFRII, and IL-1RA and bioactivities that cause shedding of sTNFRI from human PMN were significantly increased compared to normal milks. Mastitis milk has the same anti-inflammatory components and characteristics of normal milk, with elevations in selected components/activities that may help protect the nursing infant from developing clinical illness due to feeding on mastitis milk.