Over the last year, reports of adverse events from SARS-CoV2 vaccines are proliferated, so we want to help improve knowledge on this subject by describing a case of de novo immune Thrombotic Thrombocytopenic Purpura (TTP) after Pfizer anti-SARS-CoV2 vaccination in a patient who achieved a long full remission of gray zon allogeneic hematopoietic stem cell transplantation.Our case describes a 33-yr-old white female who was admitted to Emergency Room of our hospital for marked asthenia, drowsiness, headache, nausea with abdominal pain, and lower extremity purpura, 9 days after I dose of Pfizer-BioNTech COVID19 vaccine. Phys. examination revealed a Glasgow Coma Scale (GCS) score 4. Laboratory tests.Revealed severe anemia (Hb 68 g/L) with reticulocytosis and critical thrombocytopenia (platelets 12109/L), elevated lactate dehydrogenase (1.280 U/L) and total bilirubin (2.3 mg/dL), and decreased haptoglobin level (<0.06 g/L), suggesting a hemolysis.Direct and indirect Coombs test was neg., standard coagulation tests were normal, creatinine was slightly altered (1.38 mg/dL), and neg. was the search for antiphospholipid antibodies. Peripheral blood smear (PBS) test showed the presence of 3% schistocytes, which indicated iTTP diagnosis.Baseline anal. of enzymic activity of ADAMTS13 with rapid test HemosIL AcuStar was performed, revealing reduced activity (8%), but the detection of antibodies against the metalloprotease was not valuable, due to defects in the sample.Brain Computed Tomog. scan documented the presence of hyper-attenuating micro-lesions, while microbiol. tests on blood and urine showed neg. results.The patient's basal laboratory results are shown in Table 1.The immunocompromised status of our patient, due to previous chemotherapy and autologous and allogeneic stem cell transplantations, could be assumed to be a contributing factor in triggering immune TTP.However, she has not shown more susceptibility to infections over the years, following allogeneic transplantation, and we have not sufficient data to claim that the dysregulation of her immune system may have encouraged the development of TTP.With increasing anti Covid-19 vaccine distribution, it is essential for emergency clinicians to be aware of the evaluation and management of some life-threatening autoimmune condition, such as immune TTP or VITT, similar clin. conditions but with different pathogenesis, thatdeserve different ready-to-use therapeutic approaches.
