THROMBOCYTOPENIA IN THE ANTIPHOSPHOLIPID SYNDROME
Cuadrado MJ, et al. Thrombocytopenia in the antiphospholipid syndrome.
Galindo M, et al. Splenectomy for refractory thrombocytopenia in the antiphospholipid syndrome.
Take home points:
1. Approximately 25% of patients with antiphospholipid antibody syndrome (APLAS) will have
2. There are no clinical or serologic features that distinguish APLAS patients with thrombocytopenia from
those without it.
3. For patients with APLAS and refractory thrombocytopenia, splenectomy is a viable treatment option and
is associated with a good long-term response.
Features of thrombocytopenia in APLAS:
• Thrombocytopenia can be the first (and only) manifestation of APLAS and can be misdiagnosed as
immune thrombocytopenic purpura (ITP).
• According to the largest study on this topic, approximately 25% of patients with APLAS will have
• Thrombocytopenia in APLAS is usually mild and benign (platelet count 70-120K) and is not associated
with bleeding; these patients do not require treatment.
• There are no clinical or serologic features that distinguish APLAS patients with thrombocytopenia from
those without it.
• The pathophysiology behind thrombocytopenia in APLAS is unknown. Most authors state that it is
likely immune-mediated, much like ITP and not due to a consumptive process (except, perhaps in
catastrophic APLAS which presents much like a thrombotic microangiopathy).
• Approximately 20% of patients with APLAS and thrombocytopenia will have very low platelet counts
that are refractory to medical and pheresis therapy. In these patients, splenectomy is a viable treatment
option and is associated with a good long-term response.
For review: Approach to the diagnosis of lupus anticoagulant
A lupus coagulant (LA) is diagnosed in the context of a prolonged phospholipid-dependent coagulation test, most often the activated partial thromboplastin time (aPTT; Test 1)