Bilirubin binding and neonatal acidosis

Plasma of neonates with severe metabolic acidosis secondary to fetal hypoxia bound less bilirubin than that of neonates without acidosis, as determined by Sephadex gel filtration. There was a significant correlation between the amount of bilirubin adsorbed by Sephadex and the base deficit. The method used ruled out any influence of plasma pH per se on binding. Our results suggest that organic anions that accumulate in the plasma of asphyxiated acidotic neonates may compete with bilirubin for binding sites on albumin.