Inhibitory effects of bilirubin and photobilirubin on neonatal and adult T lymphocytes and granulocytes.

The lymphoproliferative response to phytohemagglutinin of lymphocytes and spontaneous motility, chemotaxis and phagocytic activity of granulocytes were studied in the newborn and adult blood in the presence of bilirubin and photobilirubin. All of these activities were inhibited to the same extent by these substances. In addition, a significant difference between newborn and adult values was found. In conclusion, the authors suggest that phototherapy does not decrease bilirubin cellular toxicity.