Introduction: Dilute Russell's viper venom time (dRVVT) and activated partial thromboplastin time (APTT) are the mainstay assays in lupus anticoagulant (LA) detection yet they have limitations, particularly in relation to interferences and specificity. The recently validated Taipan snake venom time (TSVT) screening with ecarin time (ET) confirmatory assays overcome many of those limitations due to the innate specificity engendered from direct prothrombin activation, and insensitivity to the effects of vitamin K antagonists (VKA). The present study aimed to further evidence diagnostic utility of TSVT/ET by performing them in samples from 116 nonanticoagulated patients with established triple-positive antiphospholipid syndrome (APS).
View Article and Find Full Text PDFHematology Am Soc Hematol Educ Program
December 2023
Acquired hemophilia A (AHA) is a rare disorder in which autoantibodies against factor VIII (FVIII) lead to a bleeding phenotype that varies from life-threatening to no bleeding at all. Prolonged activated partial thromboplastin times (APTT) in patients with a bleeding phenotype should be investigated to rule out AHA and should never be ignored in a preprocedure patient. Most inhibitors in AHA are heat and time dependent, so mixing studies performed only on an immediate mix are not useful: both lupus anticoagulants and treatment with direct oral anticoagulants can coexist with AHA and confound the diagnosis.
View Article and Find Full Text PDFBackground: Triple positivity for all 3 criteria antiphospholipid antibodies confers high risk of symptom development in carriers, and recurrence in antiphospholipid syndrome (APS). Most triple-positivity studies report lupus anticoagulant (LA) testing as positive without distinguishing between positivity with dilute Russell's viper venom time (dRVVT) and activated partial thromboplastin time (APTT) and single-assay positivity or only perform dRVVT. Single LA assay repertoires remain in use in some centers, which risks missing some triple positives.
View Article and Find Full Text PDFBackground: The benefit of administering pharmacologic thromboprophylaxis following renal transplantation remains uncertain.
Objectives: To compare hemostatic parameters before and after renal transplant surgery in both recipients and their donors at predetermined time points.
Methods: Blood samples were collected at baseline (T1), immediately after surgery (T2), and at 24 hours after surgery (T3) in both recipients and donors and at 72 (T4) and 120 hours (T5) from recipients only.
Background: Conventional clotting tests are not expeditious enough to allow timely targeted interventions in trauma, and current point-of-care analyzers, such as rotational thromboelastometry (ROTEM), have limited sensitivity for hyperfibrinolysis and hypofibrinogenemia.
Objectives: To evaluate the performance of a recently developed global fibrinolysis capacity (GFC) assay in identifying fibrinolysis and hypofibrinogenemia in trauma patients.
Methods: Exploratory analysis of a prospective cohort of adult trauma patients admitted to a single UK major trauma center and of commercially available healthy donor samples was performed.
Introduction: Therapeutic plasma exchange (TPE) is used for several chronic conditions with little evidence on the efficacy and safety of different choice of replacement fluid. Measurement of haemostasis, particularly in vitro thrombin generation, could play a role in determining the immediate efficacy of different fluid replacement.
Aim: To determine the impact of different TPE replacement fluid regimens on haemostatic assays.
Haemophilia B is a rare X-linked genetic deficiency of coagulation factor IX (FIX) that, if untreated, can cause recurrent and disabling bleeding, potentially leading to severe arthropathy and/or life-threatening haemorrhage. Recent decades have brought significant improvements in haemophilia B management, including the advent of recombinant FIX and extended half-life FIX. This therapeutic landscape continues to evolve with several non-factor replacement therapies and gene therapies under investigation.
View Article and Find Full Text PDFIntroduction: Acquired haemophilia A (AHA) is a rare bleeding disorder caused by development of auto-antibodies to endogenous coagulation factor VIII (FVIII). Recombinant porcine factor VIII (rpFVIII) is currently licensed only for the management of bleeding in patients with AHA. Regular monitoring of rpFVIII is recommended to assess treatment effectiveness.
View Article and Find Full Text PDFBackground: Lupus anticoagulant (LA) assays are compromised in anticoagulated patients, and existing strategies to overcome the interferences have limitations. The prothrombin-activating Taipan snake venom time (TSVT) screening test and ecarin time (ET) confirmatory test are innately insensitive to vitamin K antagonists (VKA) and direct factor Xa inhibitors (DFXaI).
Objectives: Validate standardized TSVT/ET reagents for LA detection, in a multicenter, multiplatform study.
Introduction: Vaccine-induced immune thrombocytopenia and thrombosis (VITT) following ChAdOx1 nCOV-19 vaccine has been described, associated with unusual site thrombosis, thrombocytopenia, raised D-dimer, and high-titer immunoglobulin-G (IgG) class anti-platelet factor 4 (PF4) antibodies. Enzyme-linked immunosorbent assays (ELISA) have been shown to detect anti-PF4 in patients with VITT, but chemiluminescence assays do not reliably detect them. ELISA assays are not widely available in diagnostic laboratories, and, globally, very few laboratories perform platelet activation assays.
View Article and Find Full Text PDFIntroduction: Acquired haemophilia A (AHA) is a rare bleeding disorder caused by the development of autoantibodies to endogenous human factor VIII (hFVIII). If treatment of bleeding is required, one option is recombinant porcine FVIII (rpFVIII). Cross-reactivity between factor VIII inhibitors and rpFVIII has previously been described.
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