High DMBT1 concentrations in breast milk correlate with increased risk of infection in preterm and term neonates

DMBT1 was detected in breast milk by Western blotting and its concentration was quantified by ELISA in 95 breast milk samples collected from mothers of preterm and term neonates during the first four weeks after delivery. Possible effects of maternal or neonatal parameters were analyzed by different statistical tests.The mean DMBT1 concentration (± standard error of the mean) in the tested milk samples was 2.48？±？0.26？μg/mL (range: 0.112？μg/mL to 17.984？μg/mL) and represented 0.0087% of the total protein content. The comparison between the newborns with infection and the newborns without infection revealed significantly higher DMBT1 concentrations in breast milk in the group with infection (6.72？±？2.53？μg/mL versus 2.20？±？0.35？μg/mL (P？=？0.031)). Neither maternal nor neonatal parameters showed a correlation with the milk DMBT1 levels.DMBT1 is a component of breast milk after birth and is up-regulated in the breast milk from mothers with newborns suffering from neonatal infection. Thus, breast milk DMBT1 may be part of the innate immunity similar to secretory IgA.The glycoprotein Deleted in Malignant Brain Tumors 1 (DMBT1), also known as glycoprotein 340 (gp-340) or as salivary agglutinin, is a member of the scavenger receptor cysteine-rich (SRCR) proteins with functions in innate immunity and epithelial differentiation [1,2]. Up-regulation of DMBT1 was observed in different tissues with inflammation [3-5]. The protein DMBT1 interacts with various defense factors such as, e.g., surfactant protein A and D and secretory IgA [1]. DMBT1 is able to directly bind to and aggregate various bacteria, which is sufficient to substantially suppress bacterial infection in vitro[6]. The broad bacterial-binding specificity is at least in part based on DMBT1 functioning as a pattern recognition molecule for poly-sulfated and poly-phosphorylated ligands [7].In newborns, innate immunity is of particular importance, because the function of the adaptive immune system is not yet well est