Case2. Vaccine induced thrombotic thrombocytopenia (VITT)
A 70-year-old female with a past medical history of diabetes mellitus type 2, hypertension, and coronary artery disease (had undergone percutaneous coronary intervention 10 years ago) received her first shot of COVID19 AstraZeneca vaccine in late May 2021(day 0). The following day she developed a generalized persistent headache that, despite consumption of acetaminophen, didn’t improve. The next day she experienced a single episode of generalized tonic-clonic seizure that led to refer to the local hospital. During the hospital stay, laboratory findings revealed a mild leukocytosis (WBC: 12000/μL), mildly elevated Aspartate aminotransferase test (AST: 60U/L), an increased Lactic Acid Dehydrogenase (LDH: 630U/L) and a high creatine phosphokinase level (CPK: 450mcg/L) however the rest (BUN, Creatinine, ESR, CRP and urine analysis) were normal. The neuroimaging findings including brain computed tomography (CT), magnetic resonance imaging (MRI) imaging, and magnetic resonance venography (MRV), were unremarkable. The patient was discharged five days later due to normal workups, no new seizure and amelioration of her headache.
After a few days, headache and convulsions commenced again, and their severity and frequency worsened gradually that finally led to hospitalization at our center after approximately two weeks (day 21). At the admission, the patient was lethargic and was experiencing seizure episodes 2-3 times per day, each one lasting 2-3 minutes. Clinical and neurologic examinations showed no remarkable findings, and all her vital signs were within a normal range (BP: 120/80, T: 36.8°C, HR: 75, RR: 14, O2sat:96%). The primary ECG showed no pathologic findings. At this time, moderate thrombocytopenia [78× 103 /ml; normal reference range (NRR) 150–450 × 103 /ml] with normal peripheral blood smear morphology, markedly elevated D-dimer (11 µg/ml (<0.5)), a fibrinogen level at the lower limit of the normal range, anemia (Hgb: 9.4g/dl) and elevated inflammatory markers (ESR: 45 mm/1hr, CRP: 25 mg/L) were detected. Other blood tests were normal. Thus, vaccine-induced thrombotic thrombocytopenia (VITT) was suggested(9) and, further investigations were requested.
The anti-PF4 IgG antibody ELISA tests was positive (380 ng/ml (42.1-313.40)). Brain CT venography findings were in favor of cerebral venous sinus (sagittal sinus) thrombosis (CVST), so the patient underwent brain MRI. In brain MRI, periventricular abnormal signals without diffusion restriction were seen in favor of small vessel, ischemic changes (FAZEKAS III) and T2 and diffusion-weighted signal changes representative of acute infarction was also visible in left occipital lobe. In brain MRV filling defect in favor of left transverse sinus thrombosis was seen (figure2). Finally, brain and cervical MRA were also unremarkable and no pathologic finding was observed.
During hospital stay, Intravenous immunoglobulin (IVIG) (1gr/kg/day for 2 days), corticosteroids (0.5 mg/kg prednisolone), rivaroxaban (15 mg/BID), sodium valproate and levetiracetam were started. Convulsions ceased within two days, and platelet began going up on the 3rd day. The patient’s general condition gradually improved, seizures were controlled, the patient’s D-dimer decreased, and platelets and hemoglobin returned to normal and after 10 days, the patient was discharged from the hospital with continued anticoagulants and anticonvulsants drugs.