Challenges in Treating Extensive Deep Vein Thrombosis with Severe Thrombocytopenia in Patients with Antiphospholipid Syndrome—A Follow-up of 2 Years

Thrombocytopenia is one of the most common manifestations of antiphospholipid syndrome (APS). There is little evidence or definitive guidelines regarding the treatment of APS with thrombocytopenia. We describe a patient with APS and moderate-to-severe thrombocytopenia and the challenges of balancing anticoagulation with thrombocytopenia. A 19-year-old male patient presented with right lower limb swelling to the emergency department with a history of gradually worsening right leg swelling for 1 week and was diagnosed with right leg proximal deep vein thrombosis. Ultrasound Doppler of the right lower limb revealed complete venous thrombosis from the level of the popliteal vein to the distal superficial femoral vein. Subsequently, he was found to have triple-positive APS and moderate-to-severe immune thrombocytopenia, with a platelet count nadir of 31 × 10 to the ninth power/L. He was started on anticoagulation with warfarin. The severe thrombocytopenia was not treated with immunosuppressants and the platelets fluctuated in the range of moderate-to-severe thrombocytopenia but did not develop any rethrombotic or bleeding events. His platelets varied from 31 × 10 to the ninth power/L to 106 × 10 to the ninth power/L. This case report demonstrates that it may be safe to hold off treatment for thrombocytopenia in APS, even in cases of severe thrombocytopenia. Treatment with immunosuppressants may be instituted only when platelet levels fall below 20 × 10 to the ninth power/L or when there is clinically significant bleeding, as in primary immune thrombocytopenia.