A NEW ONE STAGE CLOTTING ASSAY FOR HEPARIN AND LOW MOLECULAR WEIGHT HEPARINS
Heparin and its low molecular weight (LMW) derivatives are usually measured by chromogenic or fluorogenic synthetic substrate assays and by coagulation tests. Since the activated partial thromboplastin time (aPTT) and thrombin clotting time (TCT) are insensitive to LMW heparins, we report here of data obtained with heptest, a new one stage modification of the original heparin in plasma assay of Yin. The assay was compared with the antifactor Xa chromogenic substrate S2222 method, the TCT and aPTT tests in 100 patients receiving unfractionated pig intestinal mucosa heparin and 100 patients treated with low molecular weight heparin Kabi 2165. The results indicate a high correlation between the heptest and the anti Xa chromogenic substrate method, whereas the correlations were lower for the aPTT and TCT. correlations with LMW heparinThe lowest detection limit of the heptest is 0,005 heparin units per ml plasma. The test is very sensitive, simple, highly reproducable and reliable clotting assay for unfractionated and low molecular weight heparins in human plasma. The test detects with high preference the inhibition on factor Xa but also the other anticoagulant effects on die coagulation tractors.