LBP and LPS priming of PMN. The relation of LBP to priming activity of plasma obtained from newborn infants (•) and from adults (○) is illustrated. As shown here the range of concentrations of LBP for neonatal and adult plasma were similar, 50 to 200 U. Relationship of LBP to priming activity for newborn plasma is shown by the solid line (r = .40, slope1.4). The relationship of LPS priming activity using adult plasma to LBP is shown with the dotted line (r = .02, slope = 17.9).