Serum copper concentrations in hospitalized newborns.

Background: Low serum Cu and ceruloplasmin (Cp) concentrations in newborns can be the first indication of a severe Cu deficient intake or, alternatively, of genetic diseases affecting Cu metabolism. However, Cu and Cp concentrations can also be influenced by other variables that render their quantitative results difficult to interpret. Therefore, it is necessary to identify these variables and stratify Cu and Cp concentrations according to these altering factors.

Methods: Serum Cu and Cp concentrations for 564 hospitalized newborns (0-12days of life) are stratified according to their age, prematurity (birth weight or gestational age), type of feeding and inflammatory state (assessed by the serum high sensitivity C-reactive protein (hs-CRP) level) to identify potential correlations.

Results: Serum Cu and Cp concentrations are influenced by all four variables analyzed, although inflammation is the most significant: the greater the hs-CRP concentration, the greater the serum Cu and Cp concentrations. Prematurity is also an important factor and preterm infants often show very low Cu and Cp concentrations. Age of life and type of feeding have in turn a more modest effect on these magnitudes, being slightly greater at 3-5days of age in breastfed newborns.

Conclusions: Inflammation and prematurity are the main variables affecting serum Cu and Cp concentrations in newborns. Therefore, hs-CRP should always be assayed in parallel to Cu status. When there is an inflammatory state proper interpretation of these concentrations can be challenging.