INTRODUCTION Lupus anticoagulant (LAC) testing is challenging. Most data are derived from a well-controlled study environment with potential alterations to daily routines. The aim of this retrospective cohort study was to assess the capacity of various LAC screening tests and derived mixing tests to predict a positive result in subsequent confirmation tests in a large cohort of patients. MATE...

AIMS To examine the sensitivity and specificity to past thrombotic events of four different coagulation tests, which screen for lupus anticoagulant (LA), and of anticardiolipin antibodies in patients with systemic lupus erythematosus. METHODS Fifty three consecutive patients with systemic lupus erythematosus were studied of whom three males and 21 females, aged 21-60 years, had a history of v...

The activated partial thromboplastin time (aPTT) is widely used as a screening coagulation test and for monitoring unfractionated heparin therapy. Various commercial reagents are available, with different performance characteristics, particularly responsiveness to the lupus anticoagulant (LA). Because aPTT reagent selection significantly affects the interpretation of results, we reviewed Colleg...

heparin is frequently used in different clinical settings to reduce the coagulating ability of the blood. because of probable adverse effects owing to heparin therapy and regarding variability of patients’ responses to heparin, which make it very unreliable, it seems prudent to monitor meticulously its effects on the human body. there are a lot of laboratory tests to watch its effects on the bo...

Laboratory monitoring is widely recommended to measure the anticoagulant effect of unfractionated heparin and to adjust the dose to maintain levels in the target therapeutic range. The most widely used laboratory assay for monitoring unfractionated heparin therapy is the activated partial thromboplastin time (aPTT). A fixed therapeutic range for the aPTT of 1.5 to 2.5 times the control value ha...

An 80-year-old man was admitted for acute subdural hematoma caused by a mild brain injury. His coagulation test showed an isolated prolongation of activated partial thromboplastin time (aPTT). Though the subdural hematoma did not progress, oozing bleed from the wound of tracheostomy continued. Failure of correction on aPTT mixing test supported the presence of an inhibitor to a coagulation fact...

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 In critically ill patients, dosing of unfractionated heparin (UFH) is difficult due to unpredictable pharmacokinetics, which has an impact on the time to reach therapeutic anticoagulation. We evaluated the quality of UFH therapy in critically ill patients in terms of activated partial thromboplastin time (APTT) test values and time to therapeutic range. METHODS Patients admitted to...

We utilized a kaolin-activated partial thromboplastin time (APTT) using rabbit brain phospholipid, in which the capacity of a fourfold increased "high" phospholipid concentration (PC) to normalize the abnormal "standard" PC-APTT in patients with lupus anticoagulants is assessed. This system was also used to measure factors VIIIC, IX, and XI. The tissue thromboplastin inhibition test (TTI), a pr...

Delays in processing statium (STAT) blood samples have led to the production of an increasing number of point-of-care tests. Product inserts recommend measuring blood samples immediately after procurement, suggesting that delays may invalidate the test results. We studied the effect of the age of blood samples on point-of-care (POC) prothrombin time (PT) and an activated partial thromboplastin ...