Chromogenic substrate (S-2222) factor X assays in the follow-up of coumarin treated patients. No advantage over prothrombin time and/or thrombotest.
Factor X was assayed in 30 patients on long-term anticoagulation by means of a chromogenic substrate (S-2222) for a total of 120 determinations. The average level found was 25.38 +/- 9.38% of normal. A satisfactory correlation was found between the factor X chromogenic level and the prothrombin time or Thrombotest percental values. However, factor X levels as determined by the chromogenic assay were usually higher than the global tests percental figures. The factor X chromogenic level was also slightly higher than the RVV-cephalin factor X assay. Since the chromogenic assay does not allow any new information to be made on the coumarin induced defect and since the costs of the assay are about 20-30 times higher than those of a simple prothrombin time, the test seems to play no part in the follow-up of coumarin therapy.
D001780:Blood Coagulation Tests; D003374:Coumarins / Q000627:therapeutic use; D005170:Factor X / Q000032:analysis*; D006801:Humans; D009842:Oligopeptides; D010314:Partial Thromboplastin Time; D011517:Prothrombin Time; D013997:Time Factors
D003374:Coumarins; D009842:Oligopeptides; C015608:benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide; D005170:Factor X