Eltrombopag for refractory vaccine-induced immune thrombotic thrombocytopenia.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a life-threatening complication described after administration of recombinant adenoviral vector encoding the spike protein antigen of Severe Acute Respiratory Syndrome CoronaVirus-2. The syndrome is characterized by platelet consumption and thrombosis. High levels of antibodies to platelet factor 4 (PF4)-polyanion complexes were identified in many patients with VITT by enzyme-linked immunosorbent assay (ELISA). A 64-year-old woman presented with thrombocytopenia, right renal vein thrombosis with renal infarction, right intra-right atrium and intra-right ventricle thrombosis and pulmonary embolism after ChAdOx1-S vaccine administration. ELISA for antibodies to PF4-polyanion complexes tested positive, while functional tests were not. Thrombocytopenia was refractory to intravenous immunoglobulins and corticosteroids. Eltrombopag was introduced and platelet gradually rose to normal values. VITT is a novel complication yet to be understood. The clinical case we reported highlights the difficulties in the management of this disorder and discloses a new potential therapy in refractory conditions.