lactoferrin and Anemia--Neonatal

The regulation of the availability of micronutrients is particularly critical during periods of rapid growth and differentiation such as the fetal and neonatal stages. Both iron deficiency and excess during the early weeks of life can have severe effects on neurodevelopment that may persist into adulthood and may not be corrected by restoration of normal iron levels. This article provides a succinct overview of our current understanding of the extent to which newborns, particularly premature newborns, are able (or not able) to regulate their iron status according to physiologic need. Postnatal development of factors important to iron homeostasis such as intestinal transport, extracellular transport, cellular uptake and storage, intracellular regulation, and systemic control are examined. Also reviewed are how factors peculiar to the sick and premature neonate can further adversely influence iron homeostasis and exacerbate iron-induced oxidative stress, predispose the infant to bacterial infections, and, thus, compromise his or her clinical situation further. The article concludes with a discussion of the areas of relative ignorance that require urgent investigation to rectify our lack of understanding of iron homeostasis in what is a critical stage of development.

Topics: Anemia, Neonatal; Animals; Antimicrobial Cationic Peptides; Blood-Brain Barrier; Brain; Breast Feeding; Cation Transport Proteins; Child Development; Hepcidins; Homeostasis; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Intestinal Absorption; Iron; Lactoferrin; Oxidative Stress; Serum Albumin

The amount of iron in a 1.0 kg preterm infant at birth is sufficient to synthesise only about 18.0 grams of haemoglobin. Since breast milk contains only 40 microgramsFe/100 ml, anaemia will develop in a premature baby fed breast milk unless supplementary iron is given. Preterm infants fed on breast milk are in negative iron balance averaging -0.24 mg/kg X day for at least thirty days after birth, and it can be estimated that they require an intake of about 0.6 mg/kg X day to compensate for obligatory intestinal iron losses. Insensible skin losses, estimated from measurements in adults, are small--of the order of 0.02 micrograms/kg X day, but losses due to venesection may be considerable since each gram of haemoglobin contains 3.4 mg of iron. Absorption of supplementary iron by preterm infants is a linear function of intake, which suggests immature control of iron absorption. Giving blood transfusions seem to diminish iron absorption but may not prevent it altogether. Giving repeated blood transfusions results in high serum ferritin levels similar to those seen in iron overload--however these levels decline spontaneously with age. Preterm infants who are given repeated transfusions do not require iron supplements until the transfusions cease.

Topics: Absorption; Anemia, Neonatal; Blood Transfusion; Ferritins; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Iron; Lactoferrin; Milk, Human