Clinical significance of amphiregulin and epidermal growth factor in colostrum

Colostrum contains a wide variety of crucial nutritional elements including growth factors for newborn infants to adapt to the extrauterine environment. To investigate the clinical significance of epidermal growth factor receptor ligands in milk during the first month of lactation. The concentrations of epidermal growth factor (EGF), amphiregulin (AR) and transforming growth factor-alpha (TGF-alpha) in milk sampled from a total of 31 normal mothers at days 1-3, 5, and 30 postpartum were examined using ELISA. At days 1-3, the concentration of EGF was extremely high [131.6 +/- A 20.4 (mean +/- A SEM) ng/ml] compared to that of AR (4,197.2 +/- A 1,055.2 pg/ml) or TGF-alpha (261.7 +/- A 33.6 pg/ml), while the concentration of AR was significantly elevated compared to that of TGF-alpha. At days 5 and 30, the concentration of EGF was significantly elevated compared to that of AR or TGF-alpha. In 16 mothers among the same 31 subjects, samples were longitudinally obtained on days 1, 2, 5, and 30 postpartum. Concentrations of AR were higher on days 1 and 2 and rapidly declined to below 1 ng/ml on day 5, and were maintained at lower levels on day 30. Concentrations of EGF were high on day 1 (greater than 10 ng/ml) but gradually declined by days 2, 5, and 30. Concentrations of TGF-alpha remained at lower levels of below 1 ng/ml throughout the lactation period from days 1 to 30. These results suggested that EGF and amphiregulin in colostrum might contribute to the early stage of development of neonatal gastrointestinal function.