α2-MACROGLOBULIN AND ANTITHROMBIN III ARE EQUALLY IMPORTANT INHIBITORS OF THROMBIN IN NEONATAL PLASMA

Healthy newborn infants rarely Buffer from thrombosis, despite their low plasma antithrombin III (ATIII) levels. In adults, ATIII is the main inhibitor of thrombin; α2-macroglobulin (α2M) and heparin-cofactor (HCII) are of lesser importance. In infants and children, plasma α2M concentrations are higher than in adults and exceed ATIII activities by about 2-fold. Therefore we determined the contribution of all 3 antiproteases to the inhibition of …