Successful venous thromboprophylaxis in a patient with vaccine-induced immune thrombotic thrombocytopenia (VITT): a case report of the first reported case in Thailand

Background: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare but fatal complication of the Coronavirus Disease 2019 vaccine. The many reports of VITT have mostly been in the Caucasian population. Here, we present the first reported case in an Asian population. Case presentation: A 26-year-old female had severe headache and severe thrombocytopenia 8 days after administration of the ChAdOx1 nCoV-19 vaccine developed by AstraZeneca. Although no thrombosis was demonstrated by imaging studies, she had very highly elevated d-dimer levels during hospitalization. Serology for antibodies against platelet factor 4 was positive on several days with very high optical density readings. We found that the antibody could induce spontaneous platelet aggregation without the presence of heparin. We decided to treat her with intravenous immunoglobulin, high-dose dexamethasone, and a prophylactic dose of apixaban. She improved rapidly and was discharged from the hospital 6 days after admission. Neither thrombocytopenia nor thrombosis was subsequently detected at the three-week follow-up. Conclusions: Despite the lower rate of thrombosis, VITT can occur in the Asian population. Early detection and prompt treatment of VITT can improve the patient’s clinical outcome. Thromboprophylaxis with nonheparin anticoagulants also prevents clot formation.