[Anti-heparin activity of plasma with various low density lipoprotein content]

Anti-heparin activity correlated with LDL concentration in the plasma. Blood plasma of women in labour is characterized by the high antiheparin activity and low LDL levels. Anti-heparin activity is low and LDL levels are low in blood plasma in childhood. An effect of other factors neutralizing heparin (e.g. fibrinogen, platelet factor 4, acid alpha 1-glycoprotein, globulins, basic proteins) and differences of anti-thrombin III on plasma anti-heparin activity has been excluded. Neutralization of heparin anticoagulation activity by LDL is of clinical value. Blood LDL level should be considered, while heparin therapeutical doses are under scrutiny.