[At II in liver diseases. Comparison between immunological determination and that with chromogenic substrate]

Plasma antithrombin III activity determined as a heparinic cofactor, by means of chromogenic substrate (Cromozym TH) has been compared with protein concentration of AT III (radial immunodiffusion) in patients with a variety of liver conditions. Reference values for AT III were obtained from the plasma of 50 donors whose state of health was confirmed by simultaneous determination of 20 haematochemical parameters (SMAC-Technicon). The patients were classified according to clinical, laparobioptic and laboratory data and put through a series of clotting tests including PT, fibrinogen, FDP, Hepatoquick, Platelet count. In healthy donors, the activity and protein concentration of antithrombin III were interrelated, as they were even in cirrhotic patients (r = 0.77) both being markedly reduced; in chronic hepatitis, diminution with both methods was modest and correlation less apparent (r = 0.48).