APAS Flashcards
A 30-year-old woman presents with recurrent deep vein thrombosis (DVT) and has had two miscarriages at 8 weeks of gestation. The patient also has livedo reticularis. Which of the following is the most likely diagnosis?
A) Systemic lupus erythematosus
B) Antiphospholipid syndrome (APS)
C) Behçet’s disease
D) Hyperthyroidism
B) Antiphospholipid syndrome (APS)
The patient’s presentation with recurrent thrombosis, pregnancy morbidity (miscarriages), and livedo reticularis is highly suggestive of antiphospholipid syndrome (APS). APS is characterized by both clinical criteria (vascular thrombosis or pregnancy morbidity) and laboratory criteria (positive antiphospholipid antibodies, such as anti-cardiolipin, anti-β2GPI, or lupus anticoagulant). Systemic lupus erythematosus (A) can be associated with APS but is not the primary diagnosis here. Behçet’s disease (C) involves mucocutaneous lesions and systemic vasculitis, and hyperthyroidism (D) would not explain the patient’s thrombosis or miscarriages.
Which of the following is the primary cause of antiphospholipid syndrome (APS)?
A) Genetic mutation leading to clotting factor abnormalities
B) Autoimmune production of antibodies targeting phospholipids and phospholipid-binding proteins
C) Increased platelet production
D) Vitamin K deficiency
B) Autoimmune production of antibodies
Rationale: APS is an autoimmune disorder in which the body produces antibodies against negatively charged phospholipids and phospholipid-binding proteins (such as β2-glycoprotein I and prothrombin). These antibodies promote clot formation and are associated with both thrombosis and pregnancy complications. Genetic mutations (A) and increased platelet production (C) do not directly cause APS, and vitamin K deficiency (D) is not related to APS.
A patient with antiphospholipid syndrome (APS) has experienced a deep vein thrombosis and is started on warfarin. What is the target international normalized ratio (INR) for this patient?
A) 1.0-2.0
B) 2.0-3.0
C) 3.0-4.0
D) 5.0-6.0
B) 2.0-3.0
Rationale: In patients with APS who have experienced an unprovoked venous thrombosis, the recommended target INR is 2.0–3.0. For arterial thrombosis, a higher INR of 3.0-4.0 may be targeted depending on the individual’s risk profile. A target INR of 1.0-2.0 (A) would be insufficient for preventing recurrent thrombotic events, and an INR of 5.0-6.0 (D) would increase the risk of bleeding.
In the context of antiphospholipid syndrome (APS), which of the following conditions is most likely to trigger catastrophic APS (CAPS)?
A) Routine exercise
B) Recent surgical trauma or infection
C) Prolonged use of aspirin
D) Long-term corticosteroid use
B) Recent surgical trauma or infection
Rationale: Catastrophic APS (CAPS) is a life-threatening form of APS involving rapid and widespread thrombosis in multiple organs, and it is often triggered by events such as infection, oxidative stress, or major physical stressors like surgery or trauma.
A 28-year-old woman with a history of recurrent miscarriages and unexplained fetal deaths beyond 10 weeks of gestation is diagnosed with antiphospholipid syndrome (APS). What is the recommended treatment during pregnancy?
A) High-dose corticosteroids alone
B) Low-dose aspirin and prophylactic low molecular-weight heparin (LMWH)
C) Only oral anticoagulation with warfarin
D) Intravenous immunoglobulin (IVIG) alone
B) Low-dose aspirin and prophylactic low
Rationale: In pregnant women with APS and a history of obstetric complications, the recommended treatment includes low-dose aspirin and prophylactic low molecular-weight heparin (LMWH). This combination helps reduce the risk of recurrent pregnancy morbidity.
Which of the following laboratory criteria is used in the diagnosis of antiphospholipid syndrome (APS)?
A) Presence of anticentromere antibodies
B) Positive lupus anticoagulant (LA) test
C) High levels of serum complement
D) Presence of rheumatoid factor
B) Positive lupus anticoagulant (LA) test
Rationale: One of the laboratory criteria for APS includes the presence of lupus anticoagulant (LA), along with positive tests for anti-cardiolipin (aCL) and/or anti-β2GPI antibodies, measured at high titers on two separate occasions 12 weeks apart.
A patient with catastrophic antiphospholipid syndrome (CAPS) presents with multi-organ failure. Which of the following treatments is most appropriate?
A) Combination therapy with glucocorticoids, heparin, and plasma exchange or intravenous immunoglobulin (IVIG)
B) Monotherapy with hydroxychloroquine
C) Routine anticoagulation with warfarin
D) Plasmapheresis alone
A) Combination therapy with glucocorticoids, heparin, and plasma exchange or intravenous immunoglobulin (IVIG)
Rationale: CAPS is a severe, rapidly progressive form of APS requiring combination therapy with glucocorticoids, heparin, and either plasma exchange or intravenous immunoglobulin (IVIG). These treatments aim to stabilize the patient and prevent further thrombotic events.
A 45-year-old woman presents with a history of recurrent miscarriages and a cerebral vascular accident (CVA) at the age of 42. She also has livedo reticularis and thrombocytopenia. What is the next step in the diagnosis of antiphospholipid syndrome (APS)?
A) Measure anti-cardiolipin antibodies and lupus anticoagulant
B) Start anticoagulation therapy immediately
C) Perform a genetic test for thrombophilia
D) Obtain a CT scan to assess for ischemic changes in the brain
A) Measure anti-cardiolipin antibodies and lupus anticoagulant
Rationale: In a patient with a history of recurrent miscarriages, thrombosis, and signs of APS (livedo reticularis and thrombocytopenia), anti-phospholipid antibodies (including anti-cardiolipin antibodies and lupus anticoagulant) should be measured. The diagnosis of APS requires the presence of at least one clinical and one laboratory criterion, which would be assessed after these tests.
Which of the following is a clinical criterion for the diagnosis of antiphospholipid syndrome (APS)?
A) One or more unexplained deaths of a morphologically normal fetus at or beyond the 10th week of gestation
B) A positive lupus anticoagulant (LA) test
C) A history of deep vein thrombosis (DVT) in a patient with a positive family history of thrombophilia
D) High titers of anti-β2-glycoprotein I antibodies
A) One or more unexplained deaths of a morphologically normal fetus at or beyond the 10th week of gestation
Rationale: One or more unexplained deaths of a morphologically normal fetus at or beyond the 10th week of gestation is one of the clinical criteria for APS under the category of pregnancy morbidity.
For a diagnosis of antiphospholipid syndrome (APS), how many clinical and laboratory criteria must be met?
A) At least two clinical criteria and one laboratory criterion
B) At least one clinical criterion and one laboratory criterion
C) Two laboratory criteria
D) One clinical criterion only
B) At least one clinical criterion and one laboratory criterion
Rationale: The diagnosis of APS requires at least one clinical criterion (vascular thrombosis or pregnancy morbidity) and one laboratory criterion (lupus anticoagulant, anti-cardiolipin antibodies, or anti-β2GPI antibodies) in the absence of other causes of thrombophilia.
A patient with antiphospholipid syndrome (APS) presents with an unprovoked venous thromboembolism (VTE). What is the most appropriate long-term management for this patient?
A) Aspirin alone
B) Vitamin K antagonists (VKAs) with an INR target of 2.0-3.0
C) Direct oral anticoagulants (DOACs)
D) Low-dose aspirin with prophylactic low molecular-weight heparin (LMWH)
B) Vitamin K antagonists (VKAs) with an INR target of 2.0-3.0
Rationale: For patients with APS who have had an unprovoked venous thromboembolism (VTE), the long-term management involves vitamin K antagonists (VKAs) with a target international normalized ratio (INR) of 2.0-3.0. This is the standard treatment for venous thrombosis in APS patients. Aspirin alone (A) is not sufficient for treating venous thromboembolism, and direct oral anticoagulants (C) have been shown to increase the risk of arterial events and are not recommended for patients with APS unless there are contraindications to VKAs. Low-dose aspirin with LMWH (D) is used in specific cases like pregnancy or thrombotic APS.
A 35-year-old woman with APS and a history of arterial thrombosis is being managed with anticoagulation. What is the appropriate INR target for her treatment?
A) 1.5-2.0
B) 2.0-3.0
C) 3.0-4.0
D) 4.0-5.0
Rationale: For patients with arterial thrombosis in APS, the appropriate INR target is typically 3.0-4.0. This is higher than the target for venous thrombosis (2.0-3.0) due to the increased risk of arterial events.
C) 3.0-4.0
Rationale: For patients with arterial thrombosis in APS, the appropriate INR target is typically 3.0-4.0. This is higher than the target for venous thrombosis (2.0-3.0) due to the increased risk of arterial events.
A pregnant woman with APS and a history of recurrent pregnancy loss is being treated for obstetric APS. What is the recommended treatment for her?
A) High-dose corticosteroids and aspirin
B) Low-dose aspirin (LDA) and prophylactic low molecular-weight heparin (LMWH)
C) Vitamin K antagonists (VKAs) and low-dose aspirin
D) Direct oral anticoagulants (DOACs) and low-dose aspirin
B) Low-dose aspirin (LDA) and prophylactic low molecular-weight heparin (LMWH)
Rationale: For pregnant women with a history of obstetric APS, the recommended treatment is a combination of low-dose aspirin (LDA) and prophylactic low molecular-weight heparin (LMWH). This combination helps reduce the risk of recurrent pregnancy complications.
In the management of catastrophic antiphospholipid syndrome (CAPS), when is B-cell depletion therapy with rituximab considered?
A) In cases of resistant infection
B) After failure of initial combination therapy
C) As the first-line treatment
D) Only in cases of recurrent thrombosis
B) After failure of initial combination therapy
Rationale: B-cell depletion therapy with rituximab is used in cases of refractory CAPS, where initial combination therapy with glucocorticoids, heparin, and plasma exchange or IVIG has not been effective.
A patient with CAPS is receiving glucocorticoids, heparin, and plasma exchange but remains refractory to treatment. Which of the following therapies could be considered next?
A) Start low-dose aspirin
B) Increase the dose of glucocorticoids
C) Begin B-cell depletion therapy with rituximab
D) Switch to high-dose corticosteroids and oral anticoagulants
C) Begin B-cell depletion therapy with rituximab
Rationale: For patients with refractory CAPS, B-cell depletion therapy with rituximab or complement inhibition with eculizumab are considered alternative options.
