Clinical significance of antithrombin III concentration with immunological and biological methods

This study was carried out to know how to play Antithrombin III (AT III) had taken in thromboembolic disorders, and which of two methods that consisted of immunological method by single radial immunodiffusion and quantitative clotting assay for AT III, showed in more significant and useful for clinical survey to thromboembolic disorders.1) AT III normal healthy persons (n=300) were decreasing to low level according to age in both sex. In sex difference, AT III of male group was higher value than female until third decade. And female group showed in higher value of AT III than male after fourth decade. Thus, AT III in normal have been influenced significantly by the difference of sex and age.2) In thromboembolic disorders, it was presumed that increase and decrease of AT III would be evaluated in comparison with strict age and sex matched control. 24 cases to be chosen from within DIC group corresponded to the cases of same age and sex from other groups with liver cirrhosis, myocardial infarction and malignant tumor. The lowest mean value of 18.2±5.4mg/dl was found in DIC group (n=24) and second in low AT III was the death group with myocardial infarction of 20.7±2.9mg/dl (n=24). Third group was liver cirrhosis of 21.6±6.1mg/dl (n=24).3) In hereditary AT III deficiency, the propositus had both of low levels of AT III obtained from immunological concentration and doting assay. The discrepancy between two methods were found in her young brother, and child. Those two blood relatives were shown in normal clotting activity and in pathological low level of immunological concentration. The same discrepancy was found in the clinical condition of secondary decrease of AT III such as liver cirrhosis.It is suggested that clotting activity and immunological concentration in AT III were found to have good correlation in normal, and pathological conditions in low level of AT III would appeared to be the discrepancy between the results from two methods.