Azd-1222

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An event is serious (based on the ICH definition) when the patient outcome is:

• * death

• * life-threatening

• * hospitalisation

• * disability

• * congenital anomaly

• * other medically important event

In a study, seven patients (3 men and 4 women) aged 21−48 years were described, who developed immune thrombocytopenia and thrombosis (ITT) following immunisation with AZD-1222[route, dosage and duration of treatment to reaction onset not stated].

Patient 1: A 48-year-old man received first dose of AZD-1222 vaccine as a part of COVID-19 immunisation and 14 days after the vaccination, he presented to the hospital with cerebral venous sinus thrombosis. He underwent laboratory testing that showed decreased platelet count, elevated D-dimer, high anti-PF4 IgG antibody level and fibrinogen 1.2 g/L. Thus, he was treated with corticosteroid therapy and dabigatran that led to improvement. Subsequently, he was discharged on dabigatran. At that time, he had a mild headache and persistent pyramidal weakness that gradually resolved. However, he had persistent thrombocytopenia and increased headaches requiring retreatment with immune-globulin [IVIG] that led to normalization of platelet count and resolution of the symptoms. During follow-up, his PF4 antibody level remained high. It was concluded that the ITT was secondary to AZD-1222.

Patient 2: A 21-year-old man received the first dose of AZD-1222 vaccine as a part of COVID-19 immunisation and 10 days after the vaccination, he presented to the hospital with a right middle cerebral artery infarct. He underwent laboratory testing that showed decreased platelet count, elevated D-dimer, high anti-PF4 IgG antibody level and fibrinogen 0.98 g/L. Thus, he was treated with corticosteroid therapy and apixaban that led to improvement and he was discharged. But, he had mild left sided weakness that resolved eventually. During follow-up, his PF4 antibody level remained high. It was concluded that the ITT was secondary to AZD-1222.

Patient 3: A 46-year-old woman received the first dose of AZD-1222 vaccine as a part of COVID-19 immunisation and 14 days after the vaccination, she presented to the hospital with cerebral venous sinus thrombosis. She underwent laboratory testing that showed decreased platelet count, elevated D-dimer, high anti-PF4 IgG antibody level and fibrinogen 1.1 g/L. Thus, she was treated with corticosteroid therapy and dabigatran that led to improvement. Subsequently, she was discharged on dabigatran. At that time, she had a mild headaches requiring two readmissions. She had recurrence of mild thrombocytopenia that treated with prednisolone and then immune-globulin plus rituximab. Eventually, her platelet count became normal and headache resolved. During follow-up, her PF4 antibody level remained high. It was concluded that the ITT was secondary to AZD-1222.

Patient 4: A 43-year-old woman received the first dose of AZD-1222 vaccine as a part of COVID-19 immunisation and 11 days after the vaccination, she presented to the hospital with cerebral venous sinus thrombosis. She underwent laboratory testing that showed decreased platelet count, elevated D-dimer, high anti-PF4 IgG antibody level and fibrinogen 1.07 g/L. Thus, she was treated with corticosteroid therapy, immune-globulin, plasma exchange and dabigatran that led to improvement. Subsequently, she was discharged on dabigatran. Eventually, her platelet count became normal and she became completely symptom free. During follow-up, her PF4 antibody level remained high. It was concluded that the ITT was secondary to AZD-1222.

Patient 5: A 44-year-old man received the first dose of AZD-1222 vaccine as a part of COVID-19 immunisation and nine days after the vaccination, he presented to the hospital with a cerebral venous sinus thrombosis. He underwent laboratory testing that showed decreased platelet count, elevated D-dimer, high anti-PF4 IgG antibody level and fibrinogen less than 0.35 g/L. Thus, he was treated with corticosteroid therapy. However, he had progressive thrombosis, recurrent thrombocytopenia and persistent hypofibrinogenaemia requiring re-treatment. Thereafter, he developed ventilator-associated pneumonia with thrombocytosis. Thus, he was shifted to the rehabilitation center with right sided weakness 73 days after the initial presentation. Subsequently, he was successfully treated and platelet count, D-dimer and fibrinogen became normal. During follow-up, his PF4 antibody level remained high. It was concluded that the ITT was secondary to AZD-1222.

Patient 6: A 47-year-old woman received the first dose of AZD-1222 vaccine as a part of COVID-19 immunisation and 20 days after the vaccination, she presented to the hospital with cerebral venous sinus thrombosis. She underwent laboratory testing that showed decreased platelet count, elevated D-dimer, high anti-PF4 IgG antibody level and fibrinogen 1.54 g/L. Thus, she was treated with dexamethasone, immune-globulin and fondaparinux-sodium [fondaparinux]. She also required plasma exchange and thrombectomy that led to improvement. Subsequently, she was discharged on dabigatran. Eventually, her platelet count, fibrinogen and D-dimer became normal. During follow-up, her PF4 antibody level remained high. It was concluded that the ITT was secondary to AZD-1222. She had mild headache since discharge.

Patient 7: A 48-year-old woman received the first dose of AZD-1222 vaccine as a part of COVID-19 immunisation and 20 days after the vaccination, she presented to the hospital with cerebral venous sinus thrombosis. She underwent laboratory testing that showed decreased platelet count, elevated D-dimer, high anti-PF4 IgG antibody level and fibrinogen 4.09 g/L. Thus, she was treated with dexamethasone, immune-globulin and fondaparinux-sodium [fondaparinux]. She also required plasma exchange and thrombectomy that led to improvement. Subsequently, she was discharged on dabigatran. Eventually, her platelet count, fibrinogen and D-dimer became normal. During follow-up, her PF4 antibody level remained high. It was concluded that the ITT was secondary to AZD-1222.