Acquired Circulating Anticoagulants Other than Lupus Anticoagulants
E. Nigel Harris, Thomas Exner, Graham R. V. Hughes, Ronald A. Asherson in Phospholipid-Binding Antibodies, 2020
Several attempts have been made to standardize the titer of factor VIII inhibitors. The Oxford and New Oxford units are based on diluting test plasmas in lu/ml factor VIII for 4 h at 37°C.43 More recently a standard method based on pooled normal plasma as a source of factor VIII was agreed on by a number of laboratories in the U.S. and is called the Bethesda unit.44 Such quantitation is useful for the measurement of inhibitors arising in hemophiliacs, but the complexity of reaction kinetics and variations in antibody affinities for factor VIII, particularly in nonhemophilic inhibitors with high residual factor VIII, limits its usefulness to judging individual patient’s responses to treatment.2,14 In principal the test plasma is diluted in saline and the dilutions are mixed with pooled normal plasma for a period of 2 h at 37°C. Then a factor VIII assay is performed on each of these mixtures and the dilution of test plasma which inhibits 50% of the factor VIII level is assigned one Bethesda unit. From this dilution the inverse is calculated to yield the concentration of the original sample in Bethesda units/ml. The two methods are not exactly comparable.45
Venous anatomy and pathophysiology
Helane S Fronek in The Fundamentals of Phlebology: Venous Disease for Clinicians, 2007
Laboratory evaluation of a patient presenting with VTE begins with baseline hematologic and coagulation studies. A complete blood count may detect a myeloproliferative disorder, while a prolonged aPTT may indicate a lupus anticoagulant. A detailed patient and family history of thrombosis and a discussion of the clinical circumstances related to the venous thromboembolism will help to uncover a precipitating cause of thrombosis or genetic factor. If all of these are unrevealing, the following thrombophilic screening tests should be done prior to anticoagulation: activated protein C (APC) resistance (clotting-based assay or molecular-based assay for factor V Leiden), antiphospholipid antibodies (lupus anticoagulant assay, ELISA for anticardiolipin antibody), prothrombin 20210 mutation, fasting homocysteine level, and a factor VIII level. It is important to note that heparin interferes with clotting-based assays for APC resistance, lupus anticoagulant, and factor VIII levels. Other tests, such as protein C, protein S, and antithrombin levels, should be reserved for patients with VTE prior to age 50, recurrent VTE, or an extensive family history of VTE ,and should be performed at least 3 weeks after anticoagulant therapy has been discontinued. The prevalence
Consequences of an incomplete differential diagnosis
James W. Albers, Stanley Berent in Neurobehavioral Toxicology: Neurological and Neuropsychological Perspectives, 2005
Conventional laboratory studies of blood and urine were normal. Pertinent negative studies identified in the evaluation included a normal or negative test of: complete blood count; vitamin B12; syphilis (venereal disease research laboratory (VDRL) and fluorescent Treponema antibody absorption (FTA-ABS)); WESR; liver function; thyroid function; serum protein electrophoresis (SPEP); mononucleosis screen; antineutrophil cytoplasmic antibodies (C-ANCA and P-ANCA); paraneoplastic conditions (anti-Hu, Purkinje cell (anti-YO)); Lyme disease; GMI ganglioside; cryoglobulins; anti-double-stranded DNA; rheumatoid factor; Sjogren’s disease (SSA (RO) and SSB (LA) autoantibodies); parietal cell antibodies; complement (C3 and C4); lupus anticoagulant; and urine heavy metals (including arsenic, mercury, thallium, and lead). Lumbar puncture showed normal cerebrospinal fluid with normal cell count, total protein, and glucose. Nerve conduction studies showed absent sensory responses but normal motor studies.
The association between prolactin concentration and aggression in female patients with schizophrenia
Published in The World Journal of Biological Psychiatry, 2021
Kresimir Puljic, Miroslav Herceg, Lucija Tudor, Nela Pivac
Within 48 h of arriving at the hospital, 5 ml of blood was extracted in tubes without anticoagulant from Becton, Dickinson and Company (BD Vacutainer®, Franklin Lakes, NJ, USA), from the cubital vein after overnight fasting to determine PRL concentration in serum. PRL concentration was determined by electro-chemiluminescence (ECLIA) method using a Cobas e411 Analyser (Roche Diagnostics, Mannheim, Germany), with the original Roche Diagnostics reagent. Blood was allowed to coagulate for 30 min and then centrifuged for 10 min at 3500 g/min. Serum samples for the determination of PRL concentration were aliquoted and stored at −20 °C. In the first incubation, the prolactin-specific monoclonal antibody to which the biotin is bound and the test antigen from the sample react to form the first complex. In the second incubation, a ruthenium-specific monoclonal antibody was added with ruthenium and streptavidin-coated micro-particles yielding a sandwich immune-complex. The following is the coupling of the previously formed complex to the solid support by the interaction of streptavidin and biotin. In this reaction mixture, application of a voltage to the electrode then induces chemiluminescent emission measured via photomultiplier. All assays were performed within a 6-month period. PRL concentration was measured in monograms per millilitre (ng/ml). The lower limit of detection was 0.047 ng/mL, laboratory reference ranges were 0.0470–470 ng/mL, the intra-assay and inter-assay coefficients of variation were 2.65% and 3.78%, respectively.
Prevalence and identification of arthropod-transmitted viruses in Kassala state, Eastern Sudan
Published in Libyan Journal of Medicine, 2019
Nahla Mohamed, Mamoun Magzoub, Rania El Hadi Mohamed, Fadilah Sfouq Aleanizy, Fulwah Y. Alqahtani, Bakri Y. M. Nour, Mubark M.S. Alkarsany
Five millilitres blood samples were collected using sterile syringes from all the admitted patients (119) who exhibited suspected signs and symptoms of vector-borne viral diseases. The blood samples divided in two blood containers: 2.5 mL blood was collected into anticoagulants free containers to obtain serum used for enzyme-linked immunosorbent assay (ELISA); where the remaining 2 mL blood was divided into: 1.5 mL anticoagulant EDTA containers for performing malaria rapid diagnostic test and the rest whole blood sample (0.5 mL) spotted on filter papers (Whatman FTA classic card (GE Healthcare, Little Chalfont, UK)); dried overnight at room temperature before being processed for PCR (polymerase chain reaction) to assess the stability of viral RNA; cDNA was reverse transcribed from RNA and used for quantitative polymerase chain reaction (qPCR).
Pediatric immune thrombocytopenia: a focus on eltrombopag as second-line therapy
Published in Hematology, 2023
Giuseppe Palumbo, Piero Farruggia, Ugo Ramenghi, Giovanna Russo, Alessandra Borchiellini, Marco Spinelli, Carlo Dufour, Fiorina Giona, Saverio Ladogana, Marco Zecca, Silverio Perrotta, Andrea Pession, Paola Giordano
A recent expert consensus from the US considered TPO-RA tapering inappropriate in the following conditions in both adult and pediatric patients [25]: low platelet count (30–50 × 109/L)lower than normal platelet count (50–150 × 109/L) with a history of significant bleedingplatelet count below normal (50–150 × 109/L) with the need of intensification of treatment in the previous three to six months and on anticoagulants or antiplatelet drugshigh risk of trauma on anticoagulant or anti-platelet therapy, regardless of platelet count
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