Italy, 11 May 2021, European Journal of Haematology
To date, 40 cases of VITT have been published. Sixty-seven percent (27/40) of patients were females with a female/male ratio of 2.1. The median age was 40.5 years, ranging between 21 and 77 years. According to these literature data, the thrombotic complications occurred after a median of 10 days (range 5-24 days) from the first dose of AstraZeneca COVID-19 vaccine. In the majority of the cases (27/39, 69.2%), the site of thrombosis was the cerebral veins, while splanchnic vein thrombosis and pulmonary embolism were present in 17.9% (7/39) and 23.1% (9/39) of cases, respectively.
The median platelet count was 23,000/mm3 ranging from 7000 to 113 000 mm3. A severe thrombocytopenia, defined as a platelet count below 25 000/mm3, was present in 52.6% (20/38) of the evaluable cases.38 Notably, a hormonal contraception or treatment was present in 25.9% (7/27) of women, while a congenital or thrombophilic status was detected in 7 (17.9%) cases.