Clot Waveform Analysis Demonstrates Low Blood Coagulation Ability in Patients with Idiopathic Thrombocytopenic Purpura.

Background: Although platelets, which contain large amounts of phospholipids, play an important role in blood coagulation, there is still no routine assay to examine the effects of platelets in blood coagulation.
Methods: Hemostatic abnormalities in patients with thrombocytopenia, including those with idiopathic thrombocytopenic purpura (ITP), were examined using clot wave analysis (CWA)-small-amount tissue-factor-induced FIX activation (sTF/FIXa) and thrombin time (TT).
Results: Although there were no marked differences in the three parameters of activated partial thromboplastin time (APTT) between normal healthy volunteers and typical patients with ITP, the peak heights of the CWA-sTF/FIXa were markedly low in patients with ITP. The three peak times of the CWA-sTF/FIXa in patients with a platelet count of ≤8.0 × 10 ¹⁰ /L were significantly longer than those in patients with a platelet count > 8.0 × 10 ¹⁰ /L and the peak heights of the CWA-sTF/FIXa in patients with a platelet count of ≤8.0 × 10 ¹⁰ /L were significantly lower than those in patients with >8.0 × 10 ¹⁰ /L. The peak heights of the CWA-APTT in patients with ITP were significantly lower than in patients with other types of thrombocytopenia. The three peak heights of the CWA-sTF/FIXa in ITP patients were significantly lower than those in patients with other types of thrombocytopenia. The CWA-TT showed lower peak heights and longer peak times in patients with ITP in comparison to patients with other types of thrombocytopenia.
Conclusions: The CWA-sTF/FIXa and CWA-TT results showed that blood coagulation is enhanced by platelets and that the blood coagulation ability in ITP patients was low in comparison to healthy volunteers and patients with other types of thrombocytopenia.