Critical Care Medicine-Hematologic and Oncologic Disorders>>>>>Hypercoagulable States
Question 5#

Which of the following laboratory findings is MOST likely to be found in a patient diagnosed with antiphospholipid syndrome?

A. Platelets 65 × 109/L
B. Hgb 15 g/dL
C. Leukocytes 23 × 109 /L
D. aPTT 35 seconds

Correct Answer is A


Correct Answer: A

Antiphospholipid syndrome is a systemic autoimmune disorder leading to a hypercoagulable state characterized by venous or arterial thrombosis in the presence of evidence of persistent antiphospholipid antibodies (anticardiolipin, anti-beta-2-glycoprotein, lupus anticoagulant). Antiphospholipid syndrome can occur as a primary condition or in the presence of another systemic autoimmune disease.

Diagnosis is made by a combination of clinical factors and laboratory tests:

  1. The occurrence of one or more otherwise unexplained arterial or venous thrombotic events, especially in young patients.
  2. Adverse pregnancy outcomes including fetal death after 10 weeks gestation, premature birth due to severe preeclampsia or placental insufficiency, or multiple embryonic losses (<10 weeks gestation).
  3. Persistent detection of one or more of the antiphospholipid antibodies on two occasions at least 12 weeks apart. 

Other laboratory findings include thrombocytopenia, prolonged aPTT in patients not receiving anticoagulation, and a history of false-positive serologic test for syphilis (antigen used in venereal disease research laboratory [VDRL] and rapid plasma reagin [RPR] tests contains cardiolipin). Leukocyte count and hemoglobin are not specifically associated with antiphospholipid syndrome.


  1. Ruiz-Irastorza G, Crowther M, Branch W, Khamashta MA. Antiphospholipid syndrome. Lancet. 2010;376:1498.
  2. Giannakopoulos B, Passam F, Ioannou Y, Krilis SA. How we diagnose the antiphospholipid syndrome. Blood. 2009;113:985.