Clinical studies on plasma antithrombin III using an antiserum prepared in our laboratories.

Using an antiserum obtained in rabbits injected with antithrombin III purified in our laboratories, the plasma level of this inhibitor of coagulation was found to be significantly (p less than 0.001) decreased in 8 patients with decompensated cirrhosis of the liver (15.66 mg/dl +/- 2.22) and in 18 nephrotic patients (21.74 mg/dl +/- 1.75). When compared to values noted in 22 normal-weight normolipidemic control subjects (31.54 mg/dl +/- 0.81), the plasma level of antithrombin III was slightly (p less than 0.05) higher in the 18 hyperlipidemic subjects (36.11 mg/dl +/- 1.9). Owing to an extremely wide dispersion of individual values, the mean level of antithrombin III noted in 16 critically ill postoperative patients (28.16 mg/dl +/- 2.98) did not significantly differ from control values, although this protease inhibitor was obviously decreased in those postoperative patients who developed multiple organ failure or disseminated intravascular-coagulation. Among the 11 patients with recurrent venous thrombosis, two subjects with familial deficiency in antithrombin III were detected. The results provide evidence that the antiserum prepared in our laboratories is a useful tool for detecting acquired and inherited antithrombin III deficiencies.