A rare case of vaccine-induced immune thrombosis and thrombocytopenia and approach to management

Background: The use of the COVID-19 vaccines Vaxzevria from AstraZeneca and Covishield from Janssen has been associated with sporadic reports of thrombosis with thrombocytopenia, a complication referred to as vaccine-induced immune thrombotic thrombocytopenia (VITT) or vaccine-induced prothrombotic immune thrombocytopenia. It presents commonly as cerebral sinus venous thrombosis (CSVT), within 4–30 days of vaccination. Females under 55 years of age are considered to be especially at high risk. Mortality up to 50% has been reported in some countries. Identification of early warning signs and symptoms with prompt medical intervention is crucial. Case Description: We report here a case of VITT in a young female who presented 11 days after receiving the first dose of the Covishield vaccine, with severe headache and hemiparesis. She was diagnosed with CSVT with a large intraparenchymal bleed, requiring decompressive craniectomy and extended period on mechanical ventilation. Conclusion: The patient was successfully treated with intravenous immunoglobulin and discharged after 19 days in ICU. Although she was left with long-term neurological deficits, an early presentation and a multidisciplinary approach to management contributed toward a relatively short stay in hospital and avoided mortality.

Vaccine-induced Immune Thrombotic Thrombocytopenia: Current Evidence, Potential Mechanisms, Clinical Implications, and Future Directions

Vaccine-induced Immune Thrombotic Thrombocytopenia (VITT) (also termed thrombosis with thrombocytopenia syndrome or vaccine-induced thrombotic thrombocytopenia or vaccine-induced immune thrombocytopenia) is characterized by (i) venous or arterial thrombosis; (ii) mild to severe thrombocytopenia; (iii) positive antiplatelet factor 4 (PF4)–polyanion antibodies or anti-PF4-heparin antibodies detected by the HIT (heparin-induced thrombocytopenia) ELISA assay (iv) occurring 5 to 30 days after ChAdOx1 nCoV-19 (AstraZeneca) or Ad26.COV2.S (Johnson & Johnson/Janssen) vaccination. VITT’s incidence is 1 per 100.000 vaccinated people irrespective of age and up to 1 in 50.000 for people < 50 years of age with the AstraZeneca COVID-19 vaccine. The exact mechanism by which adenovirus-vectored COVID-19 vaccines trigger this syndrome is still unclear, as for the increased risk for acute cerebral sinus venous thrombosis and splanchnic vein thrombosis as compared to other locations of venous thrombotic events. VITT is associated with the detection of anti-PF4 antibodies, unrelated to previous use of heparin therapy. PF4 antibodies are sought to activate platelets via the platelet FcγRIIA receptors leading to further platelet activation that causes thrombosis and thrombocytopenia.