Case 1
A 38-year-old Tunisian woman with no medical history presenting with dizziness and ecchymosis in her upper limbs was referred to the hematology department. The patient reported that she had received a first dose of an inactivated virus COVID-19 vaccine Sinopharm (BBIBP-CorV) twenty days before symptom onset. Laboratory findings revealed hemoglobin 6 g/dl, platelet count 6×109/L, lactate dehydrogenase (LDH) 1074 UI/L, haptoglobin 0.54 g/l, creatinine 66 µmol/L, urea 20.7 mg/dl, total bilirubin 3.75 mg/dl and indirect bilirubin 2.88 mg/dl. Peripheral blood smear showed schistocytes (1 to 2%). During her hospital stay, the patient presented left hemi-body heaviness and dysarthria. A brain MRI revealed an ischemic stroke in the territory of the infero-posterior cerebellar artery. A curative anticoagulation was started. A few hours after ICU admission, the patient presented a sudden generalized tonico-clonic seizure with status epilepticus requiring her intubation. Glycemia and electrolytes were within the normal ranges. The patient was promptly given clonazepam and intravenous sodium valproate. Analgo-sedation was prolonged with remifentanyl and midazolam to achieve a Richmond Agitation Sedation Scale (RASS)17 at -5 to control the status epilepticus and obtain patient-ventilator synchronization. The presence of thrombocytopenia, hemolytic anemia and neurologic symptoms were indicative of a presumptive diagnosis of TTP. The PLASMIC score, used to identify patients with ADAMTS-13 deficiency in suspected TTP patients, was at 6 (range, 0-7) indicating a high risk of severe ADAMTS-13 deficiency ˂10%. The patient was promptly treated by methylprednisolone 1000 mg daily for three consecutive days, then 1 mg/kg/day in combination with daily plasma exchange therapy (PEX).
Infectious screening tests (e.g., Human immunodeficiency virus (HIV), hepatitis, SARS-CoV-2, Epstein-Barr Virus, and Cytomegalovirus) were negative. Autoimmunity investigations revealed severe ADAMTS-13 deficiency (6%) with positive anti ADAMTS-13 autoantibodies more than 15 U/ml (normal<12 U/ml) confirming the diagnosis of an acquired TTP.
The patient remained seizure free and was extubated on day 5 of ICU stay. She had a fully recovery after a 17-day course of glucocorticoids, 12 sessions of PEX and Rituximab. Laboratory parameters improvement trends (platelet and hemoglobin level) are displayed in figure 1 . The patient was discharged with hemoglobin at 10 g/dl and platelet count at 370 ×109/L with a follow up at the hematology department. Prednisone was tapered off over 5 weeks. The patient made a complete recovery and is currently living a normal life. The latest ADAMTS-13 activity at the 6-month follow up visit showed 94%.