OBJECTIVE To evaluate whether activated partial thromboplastin time (APTT) could be used in the laboratory diagnosis of hereditary or acquired angioedema (HAE or AAE) with and without C1 inhibitor (C1-INH) deficiency. METHODS In a prospective investigation, APTT and other coagulation parameters were determined in 149 adult patients with various types of angioedema and in 26 healthy participan...

The prothrombin time (PT) and activated partial thromboplastin time (APTT) are among the most commonly ordered coagulation tests. In 2005, more than 140,000 PT and more than 95,000 APTT tests were performed at Mayo Clinic. The most common indications for ordering these tests include anticoagulant monitoring, initial evaluation of hemorrhage, and, although not generally indicated, routine preope...

Background Clot waveform analysis (CWA) based on activated partial thromboplastin time (APTT) is a useful assay for hemostasis. However, the effects of activators and phospholipid conditions CWA have not been adequately investigated. Therefore, we characterized using four different APTT reagents.

Hemolysis is the most common reason why coagulation test samples are rejected. However, the effects of hemolysis on plasma prothrombin time (PPT) and activated partial thromboplastin time (APTT) are rarely investigated and the results are controversial. This research aims to analyze the effects of hemolysis on PPT and APPT using the photo-optical method.Nonhemolyzed citrate blood samples (n = 3...

A 67-year-old patient was admitted to the hospital to perform an esophagogastrectomy because a lesion at the lower esophagus was strongly suspicious for cancer. Her medical history and her family history were negative for bleeding tendency or thrombosis. Her activated partial thromboplastin time (aPTT) was prolonged (44 s) whereas her prothrombin time (PT) was normal (11 s) presurgery. Mixing o...

Activated partial thromboplastin times (APTT) for monitoring heparin therapy for venous thromboembolism tended to be inappropriately short if blood was collected in commercially available evacuated glass tubes. Five types of evacuated tubes marketed under the trade names Vacutainer and Venoject were examined. The APTT of heparinized blood collected in these tubes correlated poorly (r = 0.04 to ...

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies against factor VIII (FVIII). Treatment with clopidogrel is a cause of AHA, but its clinical course is unknown. Recently, we treated a 65-year-old man who was hospitalized for cerebellar infarction and had a prolonged activated partial thromboplastin time (aPTT) with soft tissue oozing after 3 weeks of clopidogrel u...

We herein present a case of acquired hemophilia A with a normal activated partial thromboplastin (aPTT), intramuscular hematoma and cerebral hemorrhage occurring in a 73-year-old man. The patient visited our emergency department with gait disturbance, pain and swelling in his right leg. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed intramuscular hematoma and intracrania...

BACKGROUND Ca(2+) activity close to the physiological concentration of 1.3 mmol/L is essential in blood coagulation. Is this also true for the performance of global diagnostic coagulation assays? We searched for compounds that would buffer Ca(2+) activity at approximately 1.3 mmol/L without disturbing coagulation reactions and investigated whether such Ca(2+) buffering improves diagnostic effic...