摘要
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.
基金
National Institutes of Health(No.R01 HL128895).
