Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019087 (hemorrhagic diathesis)
 678 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The PFA-100 instrument (Platelet Function Analyzer, Dade Behring) has been reported to be superior to the bleeding time (BT) as a screening test of primary hemostasis. However evaluation of this device has been principally limited to selected populations. The study's aim was to determine testing performance in clinical practice, by comparing the PFA-100 to the BT for the identification of von Willebrand disease (VWD) and intrinsic platelet hypofunction. From 1998-2000, PFA-100 closure time (CT) for epinephrinecollagen (EPI) and ADP-collagen (ADP) cartridges and modified Ivy BTs were performed on outpatients referred for testing for suspected or known hemorrhagic diathesis (n = 346). Evaluation included assays of von Willebrand factor and platelet aggregometry in addition to platelet flow cytometry and electron microscopy when indicated. The normal distribution of PFA-100 CTs was determined using blood samples from 61 normal donors studied on 155 occasions. Results show that thirty-four patients met the diagnostic criteria for VWD and 31 patients were diagnosed with congenital or acquired intrinsic platelet hypofunction. The sensitivity of the PFA-100 for identification of VWD was significantly better (p < 0.01) than the BT with similar specificity. In contrast, the PFA-100 was comparable, but not superior to the BT for detecting platelet hypofunction. We conclude that the PFA-100 performance compares favorably to the BT for the identification of intrinsic platelet hypofunction in clinical practice with superior sensitivity for detecting VWD. Therefore, the PFA-100 could replace the BT for purposes of screening for VWD and intrinsic platelet hypofunction. When clinical suspicion is strong, testing should be supplemented with assays of von Willebrand factor and platelet aggregometry.
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PMID:Comparison of PFA-100 testing and bleeding time for detecting platelet hypofunction and von Willebrand disease in clinical practice. 1295 18

Hemorrhagic diseases are common in dogs. Current coagulation assays do not model all aspects of in vivo hemostasis and may not predict bleeding risk. The Total-Thrombus Analysis System (T-TAS) is a novel hemostasis assay system in which whole blood flows through microfluidic channels at defined shear rates to provide qualitative and quantitative evaluation of platelet function (PL-chip) and coagulation function (AR-chip). The present study evaluated the T-TAS in dogs with hereditary bleeding disorders and with acquired hemorrhagic syndromes (Group 1), and healthy controls (Group 2). Hereditary defects included von Willebrand's disease (VWD; n = 4), hemophilia A (n = 2), and canine Scott syndrome (n = 2). Acquired hemorrhagic disorders included neoplastic hemoperitoneum (n = 2) and acute hemorrhagic diarrhea syndrome (n = 1). Citrate anticoagulated samples were collected from diseased dogs (Group 1, n = 11) and controls (Group 2, n = 11) for coagulation screening tests, fibrinogen analyses, D-dimer concentration, antithrombin activity, von Willebrand Factor antigen, PFA-100 closure time (PFA-CT), and thromboelastography (TEG). Citrate and hirudin anticoagulated samples were used for T-TAS analyses at two shear rates. Qualitative thrombus formation in each chip was recorded using the T-TAS video camera. Numeric parameters, derived from the instrument software, included occlusion start time (OST; time to 10 kPa), occlusion time (OT; time to 60 kPa (PL-chip) or 80 kPa (AR-chip)), and area under the pressure curve (AUC). Correlations between continuous variables were evaluated by Spearman's rank. Continuous variables were compared between groups by Student's t-test or the Mann-Whitney U-test. Alpha was set at 0.05. In combined analyses of all dogs, significant correlations were identified between T-TAS variables, between the PFA-CT and PL-chip parameters and between TEG variables and AR-chip parameters. The prothrombin time correlated with the AR-chip AUC at both shear rates. In Group 1 dogs, the AR-chip AUC at low shear was significantly reduced compared with Group 2 dogs. Aberrant thrombus formation was seen in video images recorded from dogs with VWD and hemophilia A. The T-TAS AR-chip analysis distinguished dogs with bleeding risk compared to healthy controls. Initial evaluations of the T-TAS suggest it may aid characterization of hemostasis in patients at-risk of bleeding and assist with delineating bleeding phenotypes.
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PMID:A Novel Microchip Flow Chamber (Total Thrombus Analysis System) to Assess Canine Hemostasis. 3258 82