Thrombotic Disorders Flashcards
Confer a risk of venous/arterial thrombosis (a condition called antiphospholipid syndrome or APS)
Chronic antiphospholipid antibodies (APLAs)
Often accompany autoimmune connective tissue disorder
Chronic antiphospholipid antibodies (APLAs)
Caused by stem cell mutation that modifies membrane-anchored platelet activation suppressors
PNH
most common inherited thrombosis risk factor
FVL gene mutation
second most common inherited thrombophilia in patients with a personal and family history of deep vein thrombosis
Prothrombin G20210A gene mutation
Thrombosis is often associated with a combination of genetic defect, disease, and lifestyle influences
Thrombosis Double Hit
Comprise a family of immunoglobulins that bind protein-phospholipid complexes
Antiphospholipid Antibodies
Are sometimes called nonspecific inhibitors
Antiphospholipid Antibodies
the plasma protein most often bound to APLAs
B2-GPI
Most APLAs arise in response to a bacterial, viral, fungal, or parasitic infection or to treatment with one of a variety of drugs
Transient alloimmune APLAs
Part of the autoantibodies that arise in collagen vascular diseases, SLE, RA, scleroderma, and Sjogren’s syndrome
Autoimmune APLAs
Detection and confirmation of antiphospholipid antibodies
- Mixing study
- Lupus anticoagulant Test profile
- Dilute thromboplastin time (dtt)
Detection and confirmation of antiphospholipid antibodies
Important first step
Mixing study
Detection and confirmation of antiphospholipid antibodies
Con differentiate Lac from a factor deficiency
Mixing study
Detection and confirmation of antiphospholipid antibodies
In Lupus Anticoagulant Test Profile, what are the two commonly used test and both are required
A. Dilute Russel Viper Venom Time (DRVVT)
B. Silica-based PTT or Silica clot time (SCT)
Detection and confirmation of antiphospholipid antibodies
A confirmed positive result in one system is conclusive despite a negative result from the other
Lupus Anticoagulant Test Profile
Detection and confirmation of antiphospholipid antibodies
Also named tissue thromboplastin inhibitor (TTI)
Dilute thromboplastin time (DTT)
Review the Detection and confirmation of antiphospholipid antibodies
PTT initiates coagulation at factor XII
DRVV at factor X
DTT at factor VII
considered the more specific of the LAC assay.
DRVVT
uses low-phospholipid reagent.
DRVVT Screening
uses high-phospholipid reagent
DRVVT Confirmatory
In Factor V Leiden Mutation, there is A mutation in the factor V gene
substitutes glutamine for arginine at position 506 of the factor V molecule (FV R506Q)
named for the city it, Leiden mutation (or APC resistance)
factor V R506Q mutation
A guanine-to-adenine mutation at base 20210 of the 3’ untranslated region of the prothrombin gene has been associated with mildly elevated plasma prothrombin levels
Prothrombin G20210A
Is a serine protease inhibitor (SERPIN) that neutralizes factors IIa, IXa, Xa, XIa, XIIa, all of the coagulation system serine proteases except factor VIIa.
Antithrombin
Arterial Thrombosis Predictors
Lipoprotein A
CRP
Fibrinogen
Plasma Homocysteine and Factor VIII
A low-density lipoprotein that may contribute to thrombosis by its antifibrinolytic property
Competes with plasminogen for binding sites
on newly formed fibrin polymer
Lipoprotein A
An acute phase reactant whose plasma concentration rises 1000-fold 6 to 8 hours after the onset of an inflammatory event
CRP
a naturally occurring sulfur-containing amino acid intermediate in the metabolism of dietary methionine
Homocysteine
Misidentified as muscle strain or a
“charley horse”
Deep vein thrombosis (DVT)
the most prevalent VTE; caused by clots that form in the iliac, popliteal, and femoral veins of the calves and upper legs
Deep vein thrombosis (DVT)
fragments of thrombi (called emboli) may separate from the proximal end of a venous thrombus, move swiftly through the right chambers of the heart, and lodge in the arterial pulmonary vasculature, causing ischemia and necrosis of lung tissue
Pulmonary embolism (PE)
Nicknamed “the great masquerader”
Pulmonary embolism (PE)
e ective for most DVT cases
Ultrasonography
reference method for PE
Multislice or spiral chest computed
tomography (CT) angiography
can not be employed to “rule in” DVT or PE but a normal result reliably rules out either condition without the need for imaging
D-dimer assay
A term for tumor-induced DIC that generates DVT and migrating sub-epithelial thromboses causing ecchymosis and purpura fulminans
Trousseau syndrome
Is the consequence of an immune response to UFH (standard IV heparin), and LMWH that is reflected in a reduced platelet count
Heparin-Induced Thrombocytopenia
HIT antibodies are specific for
platelet factor 4 (PF4) complexed with heparin
is a hapten that triggers immune production of IgG isotype anti-H:PF4 antibodies
H:PF4
