BACKGROUND Vaccine-induced immune thrombotic thrombocytopenia(VITT)is a rare and potentially life-threatening condition after receiving coronavirus disease vaccines.It is characterized by symptom onset at 5 to 30 d po...BACKGROUND Vaccine-induced immune thrombotic thrombocytopenia(VITT)is a rare and potentially life-threatening condition after receiving coronavirus disease vaccines.It is characterized by symptom onset at 5 to 30 d postvaccination,thrombocytopenia,thrombosis,high D-dimer level,and antiplatelet factor 4(anti-PF4)antibody positivity.VITT can progress very fast,requiring urgent management.Only few studies have described its detailed clinical course and imaging changes.We report a typical VITT case in a patient who underwent regular repeated brain imaging examinations.CASE SUMMARY A young woman presented with headaches at 7 d after the ChAdOx1 nCoV-19vaccine(AZD1222)injection.She then showed progressive symptoms of left upper limb clumsiness.Brain computed tomography revealed venous infarction at the right parietal lobe with a hyperacute thrombus in the cortical vein.Two hours later,brain magnetic resonance imaging revealed hemorrhage at the same area.Magnetic resonance venography showed an irregular contour of the right transverse sinus.Laboratory examination revealed a high D-dimer level,thrombocytopenia,and a high titer for anti-PF4 antibodies.She was treated with anticoagulants,intravenous immunoglobulin,and steroids and analgesic agents were administered for pain control.She had a marked improvement on headaches and clumsiness after treatment along with radiological thrombus resolution.During follow-up at the outpatient department,her modified Rankin scale at 90 d was 1.CONCLUSION Clinicians should be alerted whenever patients present with persistent and progressive headaches or focal motor/sensory deficits postvaccination.展开更多
The coronavirus disease 2019(COVID-19)pandemic was triggered by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a previously unknown strain of coronavirus.To fully understand the consequences and complicat...The coronavirus disease 2019(COVID-19)pandemic was triggered by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a previously unknown strain of coronavirus.To fully understand the consequences and complications of SARS-CoV-2 infections,we have reviewed current literature on coagulation dysfunctions that are related to the disease and vaccination.While COVID-19 is more commonly considered as a respiratory illness,studies indicate that,in addition to respiratory illness,a coagulation dysfunction may develop in individuals after the initial infection,placing them at the risk of developing thrombotic events.Patients who died of COVID-19 had higher levels of D-dimer,a biomarker for blood clot formation and breakdown.Effective treatments for coagulation dysfunctions are critically needed to improve patient survival.On the other hand,antibodies against platelet factor 4(PF4)/heparin may be found in patients with rare instances of vaccine-induced immunological thrombotic thrombocytopenia(VITT)following vaccination with adenovirus-based vaccines.VITT is characterized by atypical thrombosis and thrombocytopenia,similar to immune-mediated heparin-induced thrombocytopenia(HIT),but with no need for heparin to trigger the immune response.Although both adenovirus-based and mRNA-based vaccines express the Spike protein of SARS-CoV-2,VITT is exclusively related to adenovirus-based vaccines.Due to the resemblance with HIT,the use of heparin is highly discouraged against treating patients with thrombotic thrombocytopenia after SARS-CoV-2 infection or with VITT after vaccination.Intravenous immunoglobulin therapy coupled with anticoagulation is recommended instead.The well-studied anti-PF4 monoclonal antibody RTO,which does not induce pathologic immune complexes in the presence of heparin and has been humanized for a potential treatment modality for HIT,may provide a nonanticoagulant HIT-specific solution to the problem of increased blood coagulation after SARS-CoV-2 infection or the VITT after immunization.展开更多
文摘BACKGROUND Vaccine-induced immune thrombotic thrombocytopenia(VITT)is a rare and potentially life-threatening condition after receiving coronavirus disease vaccines.It is characterized by symptom onset at 5 to 30 d postvaccination,thrombocytopenia,thrombosis,high D-dimer level,and antiplatelet factor 4(anti-PF4)antibody positivity.VITT can progress very fast,requiring urgent management.Only few studies have described its detailed clinical course and imaging changes.We report a typical VITT case in a patient who underwent regular repeated brain imaging examinations.CASE SUMMARY A young woman presented with headaches at 7 d after the ChAdOx1 nCoV-19vaccine(AZD1222)injection.She then showed progressive symptoms of left upper limb clumsiness.Brain computed tomography revealed venous infarction at the right parietal lobe with a hyperacute thrombus in the cortical vein.Two hours later,brain magnetic resonance imaging revealed hemorrhage at the same area.Magnetic resonance venography showed an irregular contour of the right transverse sinus.Laboratory examination revealed a high D-dimer level,thrombocytopenia,and a high titer for anti-PF4 antibodies.She was treated with anticoagulants,intravenous immunoglobulin,and steroids and analgesic agents were administered for pain control.She had a marked improvement on headaches and clumsiness after treatment along with radiological thrombus resolution.During follow-up at the outpatient department,her modified Rankin scale at 90 d was 1.CONCLUSION Clinicians should be alerted whenever patients present with persistent and progressive headaches or focal motor/sensory deficits postvaccination.
文摘The coronavirus disease 2019(COVID-19)pandemic was triggered by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a previously unknown strain of coronavirus.To fully understand the consequences and complications of SARS-CoV-2 infections,we have reviewed current literature on coagulation dysfunctions that are related to the disease and vaccination.While COVID-19 is more commonly considered as a respiratory illness,studies indicate that,in addition to respiratory illness,a coagulation dysfunction may develop in individuals after the initial infection,placing them at the risk of developing thrombotic events.Patients who died of COVID-19 had higher levels of D-dimer,a biomarker for blood clot formation and breakdown.Effective treatments for coagulation dysfunctions are critically needed to improve patient survival.On the other hand,antibodies against platelet factor 4(PF4)/heparin may be found in patients with rare instances of vaccine-induced immunological thrombotic thrombocytopenia(VITT)following vaccination with adenovirus-based vaccines.VITT is characterized by atypical thrombosis and thrombocytopenia,similar to immune-mediated heparin-induced thrombocytopenia(HIT),but with no need for heparin to trigger the immune response.Although both adenovirus-based and mRNA-based vaccines express the Spike protein of SARS-CoV-2,VITT is exclusively related to adenovirus-based vaccines.Due to the resemblance with HIT,the use of heparin is highly discouraged against treating patients with thrombotic thrombocytopenia after SARS-CoV-2 infection or with VITT after vaccination.Intravenous immunoglobulin therapy coupled with anticoagulation is recommended instead.The well-studied anti-PF4 monoclonal antibody RTO,which does not induce pathologic immune complexes in the presence of heparin and has been humanized for a potential treatment modality for HIT,may provide a nonanticoagulant HIT-specific solution to the problem of increased blood coagulation after SARS-CoV-2 infection or the VITT after immunization.
