Quantitative and functional assay of AT III in neoplastic pathology

: Our study compares the results obtained through the assay of AT III following two methods, the functional and the immunological one, carried out on plasma of 222 patients affected with solid malignant neoplasia. The purpose of our research was to examine the behaviour of AT III, a protein having a peculiar function in the complex coagulation mechanism. At least among healthy people, this function was and is correlated to its blood concentration. All examined subjects suffered from solid malignant neoplasia either of the respiratory tract or gastro-intestinal tract or sexual organs or urinary tract. From our research patients with liver neoplasia diagnosis have been excluded since the cancer seat might have significant implications on the genesis of coagulation factors and therefore on AT III itself. The age of patients as well as controls - formed by 100 clinically healthy donors-ranged between 30 and 70. At the very beginning patients were divided into groups according to the basic pathology (cancer seat) but then, since no great differences were noted between the groups, all patients were examined irrespective of the type and seat of neoplasia. The followed methods are: a functional method which tends to measure the total AT III capacity assay acting in enzyme excess. S 2238 (Kabi) being the chromogene substratum used; an immunological method which tends to measure the molecule blood concentration taking advantage of its antigenic properties. While on one hand the obtained results have shown a good correlation between the two methods in controls i.c. healthy subjects, on the other hand a significant difference has been noted between the AT III activity and its blood concentration in non healthy subjects as if to prove the interference of neoplasia in the blood coagulation process. In the patients affected with neoplasia the functional as well as the quantitative aspect - which can be considered synonyms in healthy subjects being the one indicative of the other - show that the delicate balance on which the coagulation mechanism is based has been upset.