Differential effects of heparins on tissue thromboplastin inhibition test
Fibrinolysis and Proteolysis, cilt.14, sa.SUPPL. 1, ss.49, 2000 (Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 14 Sayı: SUPPL. 1
- Basım Tarihi: 2000
- Dergi Adı: Fibrinolysis and Proteolysis
- Derginin Tarandığı İndeksler: Scopus
- Sayfa Sayıları: ss.49
- Trakya Üniversitesi Adresli: Evet
Özet
To evaluate the differential effects of low molecular weight heparins (LMWHs) on tissue thromboplastin inhibition test (TOT) and their comparison with unfractionated heparin (UFH). The UFH and LMWHs such as Enoxaparin, Ardeparin, Tinzaparin and Dalteparin were reconstituted in saline to obtain stock concentration of 100U/ml. They were further diluted in saline to obtain working concentrations of 10 U/ml. The drugs were supplemented individually in blood bank plasma (BBP) and serial dilutions were made to obtain final concentrations of 1, 0.5, 0.25, 0.125 and 0.062 U/ml. BBP was used as a control. The samples were kept on ice for further analysis. The steps to perform TTIT were: take 0.1 ml plasma supplemented with UFH or each of the LMWH; add 0.1 ml of the diluted simplastin reagent 1:50; incubate for 5 min; add 0.1 ml 0.025 M CaCl2 and start the fibrometer; record clotting time in seconds; repeat first four steps using 1:250 and 1:500 dilutions of simplastin; using BBP perform the test to obtain control values; the tests are performed in duplicate. UFH and all LMWHs tested showed concentration-dependent prolongation of TTIT clotting times. The most pronounced prolongation is seen with UFH>Ardeparin>Tinzaparin>Dalteparin>Enoxaparin. Patients with lupus anticoagulants who are given LMWHs may have false positive results of TTIT as a result of influence of LMWHs on this test and should be kept in mind when ordering TTTT assays.