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Vera IM, Kessler A, Harawa V, Ahmadu A, Keller TE, Ray ST, Taylor TE, Rogerson SJ, Mandala WL, Reyes Gil M, Seydel KB, Kim K. Prothrombotic autoantibodies targeting platelet factor 4/polyanion are associated with pediatric cerebral malaria. J Clin Invest 2024; 134:e176466. [PMID: 38652559 PMCID: PMC11142751 DOI: 10.1172/jci176466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 04/09/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUNDFeatures of consumptive coagulopathy and thromboinflammation are prominent in cerebral malaria (CM). We hypothesized that thrombogenic autoantibodies contribute to a procoagulant state in CM.METHODSPlasma from children with uncomplicated malaria (UM) (n = 124) and CM (n = 136) was analyzed by ELISA for a panel of 8 autoantibodies including anti-platelet factor 4/polyanion (anti-PF4/P), anti-phospholipid, anti-phosphatidylserine, anti-myeloperoxidase, anti-proteinase 3, anti-dsDNA, anti-β-2-glycoprotein I, and anti-cardiolipin. Plasma samples from individuals with nonmalarial coma (NMC) (n = 49) and healthy controls (HCs) (n = 56) were assayed for comparison. Associations with clinical and immune biomarkers were determined using univariate and logistic regression analyses.RESULTSMedian anti-PF4/P and anti-PS IgG levels were elevated in individuals with malaria infection relative to levels in HCs (P < 0.001) and patients with NMC (PF4/P: P < 0.001). Anti-PF4/P IgG levels were elevated in children with CM (median = 0.27, IQR: 0.19-0.41) compared with those with UM (median = 0.19, IQR: 0.14-0.22, P < 0.0001). Anti-PS IgG levels did not differ between patients with UM and those with CM (P = 0.39). When patients with CM were stratified by malaria retinopathy (Ret) status, the levels of anti-PF4/P IgG correlated negatively with the peripheral platelet count in patients with Ret+ CM (Spearman's rho [Rs] = 0.201, P = 0.04) and associated positively with mortality (OR = 15.2, 95% CI: 1.02-275, P = 0.048). Plasma from patients with CM induced greater platelet activation in an ex vivo assay relative to plasma from patients with UM (P = 0.02), and the observed platelet activation was associated with anti-PF4/P IgG levels (Rs= 0.293, P = 0.035).CONCLUSIONSThrombosis mediated by elevated anti-PF4/P autoantibodies may be one mechanism contributing to the clinical complications of CM.
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Affiliation(s)
- Iset M. Vera
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, University of South Florida, Tampa, Florida, USA
| | - Anne Kessler
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York, USA
| | - Visopo Harawa
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Biomedical Department, University of Malawi College of Medicine, Blantyre, Malawi
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Ajisa Ahmadu
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Thomas E. Keller
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, University of South Florida, Tampa, Florida, USA
| | - Stephen T.J. Ray
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Terrie E. Taylor
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, Michigan State University, East Lansing, Michigan, USA
| | - Stephen J. Rogerson
- Department of Medicine (RMH), and
- Department of Infectious Diseases, Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Wilson L. Mandala
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Biomedical Department, University of Malawi College of Medicine, Blantyre, Malawi
- Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo, Malawi
| | - Morayma Reyes Gil
- Department of Pathology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, USA
| | - Karl B. Seydel
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- Department of Osteopathic Medical Specialties, Michigan State University, East Lansing, Michigan, USA
| | - Kami Kim
- Division of Infectious Disease and International Medicine, Department of Internal Medicine, University of South Florida, Tampa, Florida, USA
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Liu Z, Li L, Zhang H, Pang X, Qiu Z, Xiang Q, Cui Y. Platelet factor 4(PF4) and its multiple roles in diseases. Blood Rev 2024; 64:101155. [PMID: 38008700 DOI: 10.1016/j.blre.2023.101155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 10/24/2023] [Accepted: 11/19/2023] [Indexed: 11/28/2023]
Abstract
Platelet factor 4 (PF4) combines with heparin to form an antigen that could produce IgG antibodies and participate in heparin-induced thrombocytopenia (HIT). PF4 has attracted wide attention due to its role in novel coronavirus vaccine-19 (COVID-9)-induced immune thrombotic thrombocytopenia (VITT) and cognitive impairments. The electrostatic interaction between PF4 and negatively charged molecules is vital in the progression of VITT, which is similar to HIT. Emerging evidence suggests its multiple roles in hematopoietic and angiogenic inhibition, platelet coagulation interference, host inflammatory response promotion, vascular inhibition, and antitumor properties. The emerging pharmacological effects of PF4 may help deepen the exploration of its mechanism, thus accelerating the development of targeted therapies. However, due to its pleiotropic properties, the development of drugs targeting PF4 is at an early stage and faces many challenges. Herein, we discussed the characteristics and biological functions of PF4, summarized PF4-mediated signaling pathways, and discussed its multiple roles in diseases to inform novel approaches for successful clinical translational research.
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Affiliation(s)
- Zhiyan Liu
- Department of Pharmacy, Peking University First Hospital, China; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China; Institute of Clinical Pharmacology, Peking University First Hospital, China.
| | - Longtu Li
- Department of Pharmacy, Peking University First Hospital, China; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China.
| | - Hanxu Zhang
- Department of Pharmacy, Peking University First Hospital, China; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Xiaocong Pang
- Department of Pharmacy, Peking University First Hospital, China; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China; Institute of Clinical Pharmacology, Peking University First Hospital, China
| | - Zhiwei Qiu
- Department of Pharmacy, Peking University First Hospital, China; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China; Institute of Clinical Pharmacology, Peking University First Hospital, China
| | - Qian Xiang
- Department of Pharmacy, Peking University First Hospital, China; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China; Institute of Clinical Pharmacology, Peking University First Hospital, China.
| | - Yimin Cui
- Department of Pharmacy, Peking University First Hospital, China; Department of Pharmacy Administration and Clinical Pharmacy, School of Pharmaceutical Sciences, Peking University, Beijing, China; Institute of Clinical Pharmacology, Peking University First Hospital, China.
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Yang C, Wang I, Chitkara A, Swankutty J, Patel R, Kubba SV. Anti-PF4 antibodies and their relationship with COVID infection. Hematol Transfus Cell Ther 2024:S2531-1379(24)00005-1. [PMID: 38388299 DOI: 10.1016/j.htct.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 02/24/2024] Open
Abstract
Detecting anti-PF4 antibodies remains the golden diagnostic method for heparin-induced thrombocytopenia (HIT) diagnosis with high sensitivity and specificity. Various lab tests detect anti-PF4 antibodies, including immunoassays and functional assays. Even with positive detection of the anti-PF4 antibody, several factors are involved in the result. The concept of anti-PF4 disorders was recently brought to light during the COVID pandemic since the development of vaccine-induced thrombotic thrombocytopenia (VITT) with the adenovirus-vectored-DNA vaccine during the pandemic. Circumstances that detect anti-PF4 antibodies are classified as anti-PF4 disorders, including VITT, autoimmune HIT and spontaneous HIT. Some studies showed a higher percentage of anti-PF4 antibody detection among the population infected by COVID-19 without heparin exposure and some supported the theory that the anti-PF4 antibodies were related to the disease severity. In this review article, we provide a brief review of anti-PF4 disorders and summarize the current studies of anti-PF4 antibodies and COVID-19 infection.
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Affiliation(s)
- Chieh Yang
- School of Medicine, University of California Riverside, USA
| | - Irene Wang
- School of Medicine, University of California Riverside, USA
| | | | | | | | - Samir V Kubba
- School of Medicine, University of California Riverside, USA.
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4
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Warkentin TE. Autoimmune Heparin-Induced Thrombocytopenia. J Clin Med 2023; 12:6921. [PMID: 37959386 PMCID: PMC10649402 DOI: 10.3390/jcm12216921] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/27/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
Autoimmune thrombocytopenia (aHIT) is a severe subtype of heparin-induced thrombocytopenia (HIT) with atypical clinical features caused by highly pathological IgG antibodies ("aHIT antibodies") that activate platelets even in the absence of heparin. The clinical features of aHIT include: the onset or worsening of thrombocytopenia despite stopping heparin ("delayed-onset HIT"), thrombocytopenia persistence despite stopping heparin ("persisting" or "refractory HIT"), or triggered by small amounts of heparin (heparin "flush" HIT), most cases of fondaparinux-induced HIT, and patients with unusually severe HIT (e.g., multi-site or microvascular thrombosis, overt disseminated intravascular coagulation [DIC]). Special treatment approaches are required. For example, unlike classic HIT, heparin cessation does not result in de-escalation of antibody-induced hemostasis activation, and thus high-dose intravenous immunoglobulin (IVIG) may be indicated to interrupt aHIT-induced platelet activation; therapeutic plasma exchange may be required if high-dose IVIG is ineffective. Also, aHIT patients are at risk for treatment failure with (activated partial thromboplastin time [APTT]-adjusted) direct thrombin inhibitor (DTI) therapy (argatroban, bivalirudin), either because of APTT confounding (where aHIT-associated DIC and resulting APTT prolongation lead to systematic underdosing/interruption of DTI therapy) or because DTI inhibits thrombin-induced protein C activation. Most HIT laboratories do not test for aHIT antibodies, contributing to aHIT under-recognition.
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Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular Medicine and Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada; ; Tel.: +1-(905)-527-0271 (ext. 46139)
- Service of Benign Hematology, Hamilton Health Sciences (General Site), Hamilton, ON L8L 2X2, Canada
- Transfusion Medicine, Hamilton Regional Laboratory Medicine Program, Hamilton, ON L8L 2X2, Canada
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Dabbiru VAS, Müller L, Schönborn L, Greinacher A. Vaccine-Induced Immune Thrombocytopenia and Thrombosis (VITT)-Insights from Clinical Cases, In Vitro Studies and Murine Models. J Clin Med 2023; 12:6126. [PMID: 37834770 PMCID: PMC10573542 DOI: 10.3390/jcm12196126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/15/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
An effective worldwide vaccination campaign started and is still being carried out in the face of the coronavirus disease 2019 (COVID-19) pandemic. While vaccines are great tools to confront the pandemic, predominantly adenoviral vector-based vaccines can cause a rare severe adverse effect, termed vaccine-induced immune thrombocytopenia and thrombosis (VITT), in about 1 in 100,000 vaccinated individuals. VITT is diagnosed 5-30 days post-vaccination and clinically characterized by thrombocytopenia, strongly elevated D-dimer levels, platelet-activating anti-platelet factor 4 (PF4) antibodies and thrombosis, especially at atypical sites such as the cerebral venous sinus and/or splanchnic veins. There are striking similarities between heparin-induced thrombocytopenia (HIT) and VITT. Both are caused by anti-PF4 antibodies, causing platelet and leukocyte activation which results in massive thrombo-inflammation. However, it is still to be determined why PF4 becomes immunogenic in VITT and which constituent of the vaccine triggers the immune response. As VITT-like syndromes are increasingly reported in patients shortly after viral infections, direct virus-PF4 interactions might be most relevant. Here we summarize the current information and hypotheses on the pathogenesis of VITT and address in vivo models, especially murine models for further studies on VITT.
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Affiliation(s)
| | | | | | - Andreas Greinacher
- Institut für Transfusionsmedizin, Universitätsmedizin Greifswald, 17489 Greifswald, Germany; (V.A.S.D.); (L.M.); (L.S.)
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Warkentin TE, Greinacher A. Laboratory Testing for Heparin-Induced Thrombocytopenia and Vaccine-Induced Immune Thrombotic Thrombocytopenia Antibodies: A Narrative Review. Semin Thromb Hemost 2023; 49:621-633. [PMID: 36455619 PMCID: PMC10421650 DOI: 10.1055/s-0042-1758818] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Heparin-induced thrombocytopenia (HIT) and vaccine-induced immune thrombotic thrombocytopenia (VITT) are highly prothrombotic (thrombosis frequency ≥50%). Both are caused by platelet-activating anti-platelet factor 4 (PF4) antibodies, forming PF4/IgG-containing immune complexes that engage platelet FcγIIa receptors, producing strong platelet activation. In HIT, heparin crosslinks several PF4 molecules, whereas in VITT, anti-PF4 antibodies alone crosslink PF4. Sufficient levels of circulating anti-PF4 antibodies are needed to create the pathogenic immune complexes on platelet surfaces; this explains why certain serum (plasma)-based assays are highly sensitive for detecting HIT/VITT antibodies. Accordingly, HIT and VITT are "clinical-pathological" disorders, that is, positive testing for such antibodies-together with a compatible clinical picture-is integral for diagnosis. Heparin (low concentrations) enhances HIT antibody-induced platelet activation, but platelet activation by VITT sera is usually inhibited by heparin. For both HIT and VITT, high sensitivity (>99% and >95%, respectively) characterizes PF4-dependent enzyme immunoassays (EIAs) and PF4-enhanced platelet activation assays; in contrast, certain rapid immunoassays have high sensitivity for HIT (>90-97%) but poor sensitivity (<25%) for VITT. HIT and VITT antibodies are directed at distinct sites on PF4: solid-phase EIAs and platelet activation assays are indifferent to these distinct antigen targets, but rapid immunoassays are not. We discuss a conceptual model where PF4 is viewed as a "globe," with the heparin-binding site the "equator"; in this model, HIT antibodies are primarily directed at antigen site(s) at the north and south "poles" of PF4 (formed when PF4 binds to heparin), whereas VITT antibodies recognize sites on the equator.
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Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Transfusion Medicine, Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada
- Service of Benign Hematology, Hamilton Health Sciences, Hamilton General Hospital, Hamilton, Ontario, Canada
| | - Andreas Greinacher
- Institute for Transfusion Medicine, University Medicine Greifswald, Greifswald, Germany
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7
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Batool A, Chaudhry S, Javaid A, Kenney A. Autoimmune Heparin-Induced Thrombocytopenia: A Diagnostic and Management Challenge After Transcatheter Aortic Valve Replacement. Cureus 2023; 15:e45453. [PMID: 37859883 PMCID: PMC10583616 DOI: 10.7759/cureus.45453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2023] [Indexed: 10/21/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a commonly encountered condition, especially in inpatient settings, and is often attributed to high mortality and prolonged hospital stays. A rare entity, autoimmune heparin-induced thrombocytopenia (aHIT) refers to a condition in which antiplatelet factor-4 (PF4) antibodies activate platelets even in the absence of heparin. Our patient presented 12 days after transcatheter aortic valve replacement (TAVR) with altered mental status and severe thrombocytopenia. Further work-up revealed acute thromboembolic cerebrovascular accident (CVA), and the HIT antibody was positive. He was started on intravenous argatroban infusion with poor response. Platelet factor-4 antibodies were positive as well, and he was started on intravenous immunoglobulins (IVIG) therapy resulting in platelet recovery. This case is a reminder to consider autoimmune HIT, especially when platelet count fails to improve with conventional therapy.
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Affiliation(s)
- Aisha Batool
- Internal Medicine, Columbia St. Mary Hospital, Milwaukee, USA
| | | | | | - Ashley Kenney
- Hospital Medicine, Health Partners, Minneapolis, USA
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8
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Cai Z, Bdeir K, Yarovoi SV, Rauova L, Arepally GM, Khandelwal S, Rollin J, Gruel Y, Zaitsev S, Poncz M, Greene MI, Cines DB. Modulation of ultralarge immune complexes in heparin-induced thrombocytopenia. J Thromb Haemost 2023; 21:652-666. [PMID: 36696211 DOI: 10.1016/j.jtha.2022.11.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 09/21/2022] [Accepted: 11/04/2022] [Indexed: 01/26/2023]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is a serious thrombotic disorder caused by ultralarge immune complexes (ULICs) containing platelet factor 4 (PF4) and heparin that form the HIT antigen, together with a subset of anti-PF4 antibodies. ULICs initiate prothrombotic responses by engaging Fcγ receptors on platelets, neutrophils, and monocytes. Contemporary anti-thrombotic therapy for HIT is neither entirely safe nor entirely successful and acts downstream of ULIC formation and Fcγ receptor-initiated generation of thrombin. OBJECTIVES To determine whether HIT antigen and ULIC formation and stability could be modified favorably by inhibiting PF4-heparin interactions with fondaparinux, together with blocking formation of PF4 tetramers using a humanized monoclonal anti-PF4 antibody (hRTO). METHODS Results: The combination of fondaparinux and hRTO inhibited HIT antigen formation, promoted antigen dissociation, inhibited ULIC formation, and promoted ULIC disassembly at concentrations below the effective concentration of either alone and blocked Fcγ receptor-dependent induction of factor Xa activity by monocytic THP1 cells and activation of human platelets in whole blood. Combined with hRTO, fondaparinux inhibited HIT antigen and immune complex formation and activation through Fcγ receptors at concentrations at or below those used clinically to inhibit FXa coagulant activity. CONCLUSIONS HIT antigen and immune complexes are dynamic and amenable to modulation. Fondaparinux can be converted from an anticoagulant that acts at a downstream amplification step into a rationale, disease-specific intervention that blocks ULIC formation. Interventions that prevent ULIC formation and stability might increase the efficacy, permit use of lower doses, shorten the duration of antithrombotic therapy, and help prevent this serious thrombotic disorder.
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Affiliation(s)
- Zheng Cai
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Khalil Bdeir
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Serge V Yarovoi
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lubica Rauova
- Children's Hospital of Philadelphia, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Gowthami M Arepally
- Division of Hematology, Duke University Medical Center, Durham, North Carolina, USA
| | - Sanjay Khandelwal
- Division of Hematology, Duke University Medical Center, Durham, North Carolina, USA
| | - Jerome Rollin
- Department of Hemostasis, University of Tours, Tours, France; Centre Hospitalier Régional Universitaire de Tours, Service d'Hémostase, Tours, France
| | - Yves Gruel
- Department of Hemostasis, University of Tours, Tours, France; Centre Hospitalier Régional Universitaire de Tours, Service d'Hémostase, Tours, France
| | - Sergei Zaitsev
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Mortimer Poncz
- Children's Hospital of Philadelphia, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Mark I Greene
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Douglas B Cines
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA; Department of Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
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Mochizuki T, Ushiki T, Watanabe S, Omori G, Kawase T. The levels of TGFβ1, VEGF, PDGF-BB, and PF4 in platelet-rich plasma of professional soccer players: a cross-sectional pilot study. J Orthop Surg Res 2022; 17:465. [PMID: 36303196 PMCID: PMC9615199 DOI: 10.1186/s13018-022-03362-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 10/20/2022] [Indexed: 11/10/2022] Open
Abstract
Background Regenerative therapy using platelet-rich plasma (PRP), a rich source of growth factors, has become popular in orthopedic sports medicine. Elite athletes prefer PRP therapy for their injured muscles and tendons primarily to avoid the possible risks of surgical treatment. However, the clinical effectiveness of PRP therapy in elite athletes compared to that in non-athletes remains unknown. Therefore, to investigate the effectiveness of PRP therapy in professional athletes (pro-athletes), we focused on the quality of PRP preparations and compared the levels of bioactive molecules between pro-athletes and non-athletes.
Methods PRP was prepared from healthy, non-smoking male professional soccer players (pro-athletes) (n = 22) and non-athletes (VEGF: n = 34, others: n = 38). The levels of TGFβ1, PDGF-BB, VEGF, and PF4 were determined using ELISA kits. Polyphosphate was probed with 4’,6-diamidino-2-phenylindole and monitored using a fluorometer. The body composition of the donors was determined using a bathroom weighing scale. Results The levels of TGFβ1 and VEGF were significantly lower in pro-athletes than in non-athletes, whereas PF4 levels were significantly higher in pro-athletes. No significant difference was found in PDGF-BB levels between these groups. Biomolecule levels were not correlated with polyphosphate levels. Conclusion TGFβ1, VEGF, and PDGF-BB levels in pro-athletes were not higher than those in non-athletes. These findings suggest that growth factor levels in PRP may not be a predominant determinant of the clinical effectiveness of PRP therapy in pro-athletes. Increased PF4 levels in pro-athletes suggest an immunological function of PRP that may positively influence tissue regeneration.
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Affiliation(s)
- Tomoharu Mochizuki
- Department of Orthopaedic Surgery, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Takashi Ushiki
- Division of Hematology and Oncology, Graduate School of Health Sciences, Niigata University, Niigata, Japan.,Department of Transfusion Medicine, Cell Therapy and Regenerative Medicine, Niigata University Medical and Dental Hospital, Niigata, Japan.,Department of Hematology, Endocrinology and Metabolism, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Satoshi Watanabe
- Department of Orthopaedic Surgery, Niigata Medical Center, Niigata, Japan
| | - Go Omori
- Department of Health and Sports, Faculty of Health Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Tomoyuki Kawase
- Division of Oral Bioengineering, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
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The interaction between anti-PF4 antibodies and anticoagulants in vaccine-induced thrombotic thrombocytopenia. Blood 2022; 139:3430-3438. [PMID: 35679071 PMCID: PMC8949646 DOI: 10.1182/blood.2021013839] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 03/18/2022] [Indexed: 02/08/2023] Open
Abstract
Life-threatening thrombotic events at unusual sites have been reported after vector-based vaccinations against severe acute respiratory syndrome coronavirus 2. This phenomenon is now termed vaccine-induced immune thrombotic thrombocytopenia (VITT). The pathophysiology of VITT is similar to that of heparin-induced thrombocytopenia (HIT) and is associated with platelet-activating antibodies (Abs) against platelet factor 4 (PF4). Therefore, current guidelines suggest nonheparin anticoagulants to treat VITT patients. In this study, we investigated the interactions of heparin, danaparoid, fondaparinux, and argatroban with VITT-Ab/PF4 complexes using an ex vivo model for thrombus formation as well as in vitro assays to analyze Ab binding and platelet activation. We found that immunoglobulin Gs (IgGs) from VITT patients induce increased adherent platelets/thrombus formation in comparison with IgGs from healthy controls. In this ex vivo flow-based model, the procoagulant activity of VITT IgGs was effectively inhibited with danaparoid and argatroban but also by heparin. Interestingly, heparin and danaparoid not only inhibited IgG binding to PF4 but were also able to effectively dissociate the preformed PF4/IgG complexes. Fondaparinux reduced the in vitro generation of procoagulant platelets and thrombus formation; however, it did not affect platelet aggregation. In contrast, argatroban showed no effect on procoagulant platelets and aggregation but significantly inhibited VITT-mediated thrombus formation. Taken together, our data indicate that negatively charged anticoagulants can disrupt VITT-Ab/PF4 interactions, which might serve as an approach to reduce Ab-mediated complications in VITT. Our results should be confirmed, however, in a clinical setting before a recommendation regarding the selection of anticoagulants in VITT patients could be made.
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Lee CSM, Selvadurai MV, Pasalic L, Yeung J, Konda M, Kershaw GW, Favaloro EJ, Chen V. Measurement of procoagulant platelets provides mechanistic insight and diagnostic potential in heparin-induced thrombocytopenia. J Thromb Haemost 2022; 20:975-988. [PMID: 35038779 PMCID: PMC9303365 DOI: 10.1111/jth.15650] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 12/03/2022]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is a prothrombotic, immune-mediated adverse drug reaction associated with high rates of thrombosis-related morbidity and mortality caused by FcγRIIa-activating pathogenic antibodies to PF4-heparin. Procoagulant platelets are a platelet subset that promote thrombin generation, are clinically relevant in prothrombotic diseases, and are formed when platelet G-protein-coupled receptor (GPCR) and ITAM-linked receptors are co-stimulated. OBJECTIVES We examined the procoagulant platelet response of healthy donors to platelet agonists in the presence of HIT plasma and determined the contribution of FcγRIIa. PATIENTS/METHODS Our previously established flow cytometry-based procoagulant platelet assay was modified to incorporate plasma samples, performed using FcγRIIa-responsive donor platelets. Plasma samples were serotonin-release assay-confirmed HIT (HIT+), or negative on HIT screening. RESULTS In response to GPCR stimulation, only HIT+ plasma produced a heparin-dependent sensitization that required active FcγRIIa. As a potential diagnostic tool, the procoagulant platelet assay achieved 98% accuracy in identifying clinically verified HIT when performed blinded to the diagnoses of a validation cohort. Samples inducing a higher procoagulant platelet response were more likely from patients with thrombotic complications. Thrombin stimulation markedly increased the procoagulant platelet response with HIT+ plasma that was heparin independent and only partially reversed by FcγRIIa blockade, possibly reflecting ongoing thrombotic risk after heparin cessation. CONCLUSIONS We demonstrate that HIT plasma together with platelet agonists increased the procoagulant platelet proportions, which may contribute to thrombotic risk in HIT. Targeting procoagulant platelet activation may represent a novel treatment strategy. This assay may be a rapid, clinically relevant functional assay for accurately detecting pathological HIT antibodies.
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Affiliation(s)
| | - Maria V. Selvadurai
- ANZAC Research InstituteUniversity of SydneySydneyNew South WalesAustralia
- Faculty of Medicine, Nursing and Health SciencesMonash UniversityMelbourneVicAustralia
| | - Leonardo Pasalic
- Department of HaematologyInstitute of Clinical Pathology and Medical Research (ICPMR)NSW Health PathologyWestmead HospitalWestmeadNew South WalesAustralia
- Sydney Centres for Thrombosis and HaemostasisWestmead HospitalWestmeadNew South WalesAustralia
- Sydney Medical SchoolUniversity of SydneySydneyNew South WalesAustralia
| | - James Yeung
- ANZAC Research InstituteUniversity of SydneySydneyNew South WalesAustralia
- Department of HaematologyConcord Repatriation General Hospital and NSW Health PathologySydneyNew South WalesAustralia
| | - Maria Konda
- Diagnostic Pathology UnitConcord Repatriation General HospitalSydneyNew South WalesAustralia
| | - Geoffrey W. Kershaw
- ANZAC Research InstituteUniversity of SydneySydneyNew South WalesAustralia
- Institute of HaematologyRoyal Prince Alfred HospitalSydneyNew South WalesAustralia
| | - Emmanuel J. Favaloro
- Department of HaematologyInstitute of Clinical Pathology and Medical Research (ICPMR)NSW Health PathologyWestmead HospitalWestmeadNew South WalesAustralia
- Sydney Centres for Thrombosis and HaemostasisWestmead HospitalWestmeadNew South WalesAustralia
- Faculty of Science and HealthCharles Sturt UniversityWagga WaggaNew South WalesAustralia
| | - Vivien M. Chen
- ANZAC Research InstituteUniversity of SydneySydneyNew South WalesAustralia
- Sydney Medical SchoolUniversity of SydneySydneyNew South WalesAustralia
- Department of HaematologyConcord Repatriation General Hospital and NSW Health PathologySydneyNew South WalesAustralia
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12
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Warkentin TE, Greinacher A. Seminars in Hematology Laboratory testing for VITT antibodies. Semin Hematol 2022; 59:80-88. [DOI: 10.1053/j.seminhematol.2022.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 01/07/2023]
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13
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Toh CH, Wang G, Parker AL. The aetiopathogenesis of vaccine-induced immune thrombotic thrombocytopenia. Clin Med (Lond) 2022; 22:140-144. [PMID: 38589175 PMCID: PMC8966812 DOI: 10.7861/clinmed.2022-0006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In the new science emanating from the COVID-19 pandemic, effective vaccine development has made a huge difference and saved countless lives. Vaccine roll-out led to the identification of rare cases of severe thrombotic and thrombocytopenic problems in some recipients. This apparent coupling of thrombosis with haemorrhagic potentiation might seem baffling but the ensuing clinical investigation rapidly shed important light on its molecular mechanism. This review outlines the current understanding on the role of adenovirus-based platforms, the immunogenic triggers and the immunothrombotic response underlying vaccine-induced immune thrombotic thrombocytopenia.
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14
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Alban S, Neupane S, Girreser U, Sönnichsen FD, Greinacher A. The COVID-19 vaccine ChAdOx1-S is not contaminated with sulfated glycosaminoglycans. J Thromb Haemost 2022; 20:777-780. [PMID: 34971474 PMCID: PMC9906281 DOI: 10.1111/jth.15633] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 12/30/2021] [Accepted: 12/30/2021] [Indexed: 12/01/2022]
Affiliation(s)
- Susanne Alban
- Pharmazeutisches Institut, Abteilung Pharmazeutische Biologie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Sandesh Neupane
- Pharmazeutisches Institut, Abteilung Pharmazeutische Biologie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Ulrich Girreser
- Pharmazeutisches Institut, Abteilung Pharmazeutische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Frank D Sönnichsen
- Otto Diels Institut für Organische Chemie, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Andreas Greinacher
- Institut für Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
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15
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Uematsu T, Sato A, Aizawa H, Tsujino T, Watanabe T, Isobe K, Kawabata H, Kitamura Y, Tanaka T, Kawase T. Effects of SARS‑CoV‑2 mRNA vaccines on platelet polyphosphate levels and inflammation: A pilot study. Biomed Rep 2022; 16:21. [PMID: 35251608 PMCID: PMC8850965 DOI: 10.3892/br.2022.1504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/10/2022] [Indexed: 11/25/2022] Open
Abstract
Platelets function as immune cells in conjunction with white blood cells, targeting invading pathogens and inducing immune reactions. Intercellular communications among these immune cells are partly mediated by platelet polyphosphate (polyP), which was originally recognized as a thrombotic and hemostatic biomolecule. To determine the involvement of polyP in SARS-CoV-2-mRNA vaccine-induced immune responses, specifically in inflammatory responses, the effects of mRNA vaccines on platelet polyP levels were examined. Before and after vaccination with the COVID-19 vaccine (BNT162b2), blood samples were obtained from healthy, non-smoking individuals who did not have any systemic diseases. Test group demographics skewed somewhat towards either older males (first vaccination, n=6; second vaccination, n=8) or younger females (first vaccination, n=14; second vaccination, n=23). polyP levels in washed platelets from the blood samples were determined using the fluorometric method with DAPI. The side-effects of vaccination were recorded as scores. In the female group, platelet polyP levels decreased after the first vaccination, and the side-effect score increased after the second vaccination. Moderate correlation coefficients were observed between the reduction in polyP levels and the side-effect scores and pre-vaccination polyP levels. Despite the small sample size, this pilot study suggests that platelet polyP may suppress the side effects induced by the mRNA vaccines after the first vaccination, but not the second vaccination in younger female subjects, who generally have higher immune responsiveness than their male counterparts.
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Affiliation(s)
| | - Atsushi Sato
- Tokyo Plastic Dental Society, Tokyo 114‑0002, Japan
| | | | | | | | | | | | | | - Takaaki Tanaka
- Department of Materials, Science and Technology, Niigata University, Niigata 950‑2181, Japan
| | - Tomoyuki Kawase
- Division of Oral Bioengineering, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951‑8514, Japan
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16
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Warkentin TE. Platelet-activating anti-PF4 disorders: an overview. Semin Hematol 2022; 59:59-71. [DOI: 10.1053/j.seminhematol.2022.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 11/11/2022]
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17
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Proposed mechanism for rare thrombotic events after use of some Covid-19 vaccines. Med Hypotheses 2022; 159:110756. [PMID: 35002021 PMCID: PMC8722443 DOI: 10.1016/j.mehy.2021.110756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/09/2021] [Accepted: 11/19/2021] [Indexed: 11/20/2022]
Abstract
Administration of AstraZeneca/Oxford and Johnson & Johnson/Janssen Covid-19 vaccines which use an adenovirus vector for DNA delivery has been associated with very rare thromboembolic complications coupled with an immune response to platelet factor 4 protein. The cause of this has not yet been identified. It is known that binding of coagulation factor proteins to the surface of some adenoviruses can protect their function. Here I propose that the thromboembolic events are caused by impairment of coagulation factor X binding to the virus capsid. The unprotected capsid then stimulates an immune response leading to platelet activation, increased thrombogenicity and formation of an antibody complex with platelet factor 4. Impaired binding of factor X may be due to an undiagnosed mutation in affected individuals. Options to test this mechanism experimentally and potential remedial actions to resolve the hazard are described. This mechanism offers a remedial route to address concerns about the safety of these vaccines, which are otherwise well-positioned to deliver global Covid-19 immunity across diverse healthcare economies.
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18
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Müller WEG, Wang X, Neufurth M, Schröder HC. Polyphosphate in Antiviral Protection: A Polyanionic Inorganic Polymer in the Fight Against Coronavirus SARS-CoV-2 Infection. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2022; 61:145-189. [PMID: 35697940 DOI: 10.1007/978-3-031-01237-2_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Polyanions as polymers carrying multiple negative charges have been extensively studied with regard to their potential antiviral activity. Most studies to date focused on organic polyanionic polymers, both natural and synthetic. The inorganic polymer, polyphosphate (polyP), despite the ubiquitous presence of this molecule from bacteria to man, has attracted much less attention. More recently, and accelerated by the search for potential antiviral agents in the fight against the pandemic caused by the coronavirus SARS-CoV-2, it turned out that polyP disrupts the first step of the viral replication cycle, the interaction of the proteins in the virus envelope and in the cell membrane that are involved in the docking process of the virus with the target host cell. Experiments on a molecular level using the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein and the cellular angiotensin converting enzyme 2 (ACE2) receptor revealed that polyP strongly inhibits the binding reaction through an electrostatic interaction between the negatively charged centers of the polyP molecule and a cationic groove, which is formed by positively charged amino acids on the RBD surface. In addition, it was found that polyP, due to its morphogenetic and energy delivering activities, enhances the antiviral host innate immunity defense of the respiratory epithelium. The underlying mechanisms and envisaged application of polyP in the therapy and prevention of COVID-19 are discussed.
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Affiliation(s)
- Werner E G Müller
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
| | - Xiaohong Wang
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Meik Neufurth
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Heinz C Schröder
- ERC Advanced Investigator Group, Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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19
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Ahmed SH, Shaikh TG, Waseem S, Qadir NA, Yousaf Z, Ullah I. Vaccine-induced thrombotic thrombocytopenia following coronavirus vaccine: A narrative review. Ann Med Surg (Lond) 2022; 73:102988. [PMID: 34745596 PMCID: PMC8556865 DOI: 10.1016/j.amsu.2021.102988] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 12/26/2022] Open
Abstract
The novel coronavirus pandemic has taken a toll on the global healthcare systems and economy. Safety precautions, along with vaccination, are the most effective preventive measures. The global vaccination program against COVID-19 has dramatically reduced the number of deaths and cases. However, the incidence of thrombotic events and thrombocytopenia post-COVID-19 vaccination known as vaccine-induced thrombotic thrombocytopenia has raised safety concerns. This has led to an element of vaccine hesitancy. The exact mechanism for vaccine-induced thrombotic thrombocytopenia is unknown. Although the incidence of thrombosis associated with COVID-19 vaccination is low, it still requires attention, especially in older people, smokers, and people with preexisting comorbidities. This study aims to review the pathophysiology, diagnosis, and management of vaccine-induced thrombotic thrombocytopenia, to provide a concise and comprehensive update.
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Affiliation(s)
| | | | | | | | - Zohaib Yousaf
- Department of Internal Medicine, Hamad Medical Corporation, Doha, Qatar
| | - Irfan Ullah
- Kabir Medical College, Gandhara University, Peshawar, Pakistan
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20
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SARS-CoV-2 vaccine-induced immune thrombotic thrombocytopenia. Thromb Res 2021; 209:75-79. [PMID: 34894531 PMCID: PMC8647389 DOI: 10.1016/j.thromres.2021.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 12/11/2022]
Abstract
SARS-CoV-2 vaccines have been carefully developed and significantly alleviate the global pandemic. However, a rare but severe complication after vaccination of adenoviral vector vaccines has attracted worldwide attention. It is characterized by thrombosis at unusual sites (often cerebral or abdominal), thrombocytopenia, and the presence of antibodies against platelet factor 4 (PF4), termed vaccine-induced immune thrombotic thrombocytopenia (VITT). Its pathogenesis is similar to that of heparin-induced thrombocytopenia (HIT). VITT progresses rapidly and has a high mortality rate. Clinicians and the public should raise their vigilance to this disease so that accurate and timely treatment is provided.
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21
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Camoin-Jau L, Mariotti A, Suchon P, Morange PE. [Heparin-induced thrombocytopenia: Update]. Rev Med Interne 2021; 43:18-25. [PMID: 34535328 DOI: 10.1016/j.revmed.2021.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/27/2021] [Accepted: 08/29/2021] [Indexed: 11/26/2022]
Abstract
Heparin-induced thrombocytopenia (HIT) is a serious complication of heparin therapy. It is due to the synthesis of antibodies most often directed against platelet factor 4 (FP4) modified by heparin (H). HIT is manifested by a platelet count fall, associated with a high risk of venous or arterial thrombosis. The diagnosis of HIT is based on the assessment of clinical probability (4Ts score or change in platelet count after cardiac surgery) and the demonstration of heparin-modified anti-FP4 antibodies (FP4/H). If the immunological tests are positive, functional tests should be performed. In case of suspicion of HIT, it is necessary to urgently stop heparin therapy, to perform a doppler ultrasound of the lower limbs, and to prescribe an alternative anticoagulation agent at a curative dose. Currently, danaparoid sodium and argatroban are authorized. The diagnosis and management of HIT remain complex and requires multidisciplinary collaboration.
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Affiliation(s)
- L Camoin-Jau
- Laboratoire d'hématologie, hôpital de la Timone, AP-HM, boulevard Jean-Moulin, 13005 Marseille, France; Aix-Marseille univsersité, IRD, AP-HM, MEPHI, IHU Méditerranée infection, Marseille, France.
| | - A Mariotti
- Laboratoire d'hématologie, hôpital de la Timone, AP-HM, boulevard Jean-Moulin, 13005 Marseille, France
| | - P Suchon
- Laboratoire d'hématologie, hôpital de la Timone, AP-HM, boulevard Jean-Moulin, 13005 Marseille, France; C2VN, Aix-Marseille université, Inserm, INRAE, Marseille, France
| | - P-E Morange
- Laboratoire d'hématologie, hôpital de la Timone, AP-HM, boulevard Jean-Moulin, 13005 Marseille, France; C2VN, Aix-Marseille université, Inserm, INRAE, Marseille, France
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22
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De Cristofaro R, Sanguinetti M. Vaccine-induced thrombotic thrombocytopenia, a rare but severe case of friendly fire in the battle against COVID-19 pandemic: What pathogenesis? Eur J Intern Med 2021; 91:88-89. [PMID: 34244023 PMCID: PMC8238658 DOI: 10.1016/j.ejim.2021.06.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/08/2021] [Accepted: 06/17/2021] [Indexed: 02/05/2023]
Affiliation(s)
- Raimondo De Cristofaro
- Dipartimento di Diagnostica per immagini, Radioterapia oncologica ed Ematologia, Fondazione Policlinico Universitario "Gemelli" IRCCS,and Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica S. Cuore, Facoltà di Medicina e Chirurgia "Agostino Gemelli", Rome, Italy.
| | - Maurizio Sanguinetti
- Dipartimento di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS and Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Rome, Italy
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23
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Tiede A, Sachs UJ, Czwalinna A, Werwitzke S, Bikker R, Krauss JK, Donnerstag F, Weißenborn K, Höglinger G, Maasoumy B, Wedemeyer H, Ganser A. Prothrombotic immune thrombocytopenia after COVID-19 vaccination. Blood 2021; 138:350-353. [PMID: 34323939 PMCID: PMC8084604 DOI: 10.1182/blood.2021011958] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/22/2021] [Accepted: 04/26/2021] [Indexed: 12/15/2022] Open
Abstract
We report 5 cases of prothrombotic immune thrombocytopenia after exposure to the ChAdOx1 vaccine (AZD1222, Vaxzevria) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Patients presented 5 to 11 days after first vaccination. The spectrum of clinical manifestations included cerebral venous sinus thrombosis, splanchnic vein thrombosis, arterial cerebral thromboembolism, and thrombotic microangiopathy. All patients had thrombocytopenia and markedly elevated D-dimer. Autoantibodies against platelet factor 4 (PF4) were detected in all patients, although they had never been exposed to heparin. Immunoglobulin from patient sera bound to healthy donor platelets in an AZD1222-dependent manner, suppressed by heparin. Aggregation of healthy donor platelets by patient sera was demonstrated in the presence of buffer or AZD1222 and was also suppressed by heparin. Anticoagulation alone or in combination with eculizumab or intravenous immunoglobulin (IVIG) resolved the pathology in 3 patients. Two patients had thromboembolic events despite anticoagulation at a time when platelets were increasing after IVIG. In summary, an unexpected autoimmune prothrombotic disorder is described after vaccination with AZD1222. It is characterized by thrombocytopenia and anti-PF4 antibodies binding to platelets in AZD1222-dependent manner. Initial clinical experience suggests a risk of unusual and severe thromboembolic events.
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Affiliation(s)
- Andreas Tiede
- Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Ulrich J Sachs
- Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
- Department of Thrombosis and Hemostasis, Giessen University Hospital, Giessen, Germany
| | - Andreas Czwalinna
- Amedes MVZ WagnerStibbe Center for Laboratory Medicine, Hannover, Germany; and
| | - Sonja Werwitzke
- Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | | | | | | | | | | | - Benjamin Maasoumy
- Department of Gastroenterology, Hepatology, and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology, and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Arnold Ganser
- Department of Hematology, Hemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
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24
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Arepally GM, Ortel TL. Vaccine-induced immune thrombotic thrombocytopenia: what we know and do not know. Blood 2021; 138:293-298. [PMID: 34323940 PMCID: PMC8172307 DOI: 10.1182/blood.2021012152] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 05/27/2021] [Indexed: 02/08/2023] Open
Abstract
The development of vaccines to fight COVID-19 has been a remarkable medical achievement. However, this global immunization effort has been complicated by a rare vaccine-related outcome characterized by thrombocytopenia and thrombosis in association with platelet-activating anti-platelet factor 4 antibodies. In this Spotlight, we will discuss the recently described complication of vaccine-induced immune thrombotic thrombocytopenia (VITT) occurring in response to certain COVID-19 vaccines. Although information about this clinical condition is rapidly evolving, we will summarize our current understanding of VITT.
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Affiliation(s)
| | - Thomas L Ortel
- Division of Hematology, Duke University Medical Center, Durham, NC
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25
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Thaler J, Ay C, Gleixner KV, Hauswirth AW, Cacioppo F, Grafeneder J, Quehenberger P, Pabinger I, Knöbl P. Successful treatment of vaccine-induced prothrombotic immune thrombocytopenia (VIPIT). J Thromb Haemost 2021; 19:1819-1822. [PMID: 33877735 PMCID: PMC8362082 DOI: 10.1111/jth.15346] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 04/18/2021] [Indexed: 01/10/2023]
Abstract
Cases of unusual thrombosis and thrombocytopenia after administration of the ChAdOx1 nCoV-19 vaccine (AstraZeneca) have been reported. The term vaccine-induced prothrombotic immune thrombocytopenia (VIPIT) was coined to reflect this new phenomenon. In vitro experiments with VIPIT patient sera indicated that high-dose intravenous immunoglobulins (IVIG) competitively inhibit the platelet-activating properties of ChAdOx1 nCoV-19 vaccine induced antibodies. Here, we report a case of a 62-year-old woman who had received this vaccine and developed VIPIT. She visited the emergency ward because of petechiae and hematomas. In the laboratory work-up, thrombocytopenia, low fibrinogen, elevated D-dimer, and positivity in the platelet factor 4/heparin-enzyme-immunoassay were present. Signs and symptoms of thrombosis were absent. Upon immediate therapy with non-heparin anticoagulation, high-dose IVIG, and prednisolone, laboratory parameters steadily improved and the patient was discharged from hospital without thrombotic complications. We conclude that early initiation of VIPIT treatment results in a swift response without thrombotic complications.
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Affiliation(s)
- Johannes Thaler
- Department of Medicine I, Division of Hematology and HemostaseologyMedical University of ViennaViennaAustria
| | - Cihan Ay
- Department of Medicine I, Division of Hematology and HemostaseologyMedical University of ViennaViennaAustria
| | - Karoline V. Gleixner
- Department of Medicine I, Division of Hematology and HemostaseologyMedical University of ViennaViennaAustria
| | - Alexander W. Hauswirth
- Department of Medicine I, Division of Hematology and HemostaseologyMedical University of ViennaViennaAustria
| | - Filippo Cacioppo
- Department of Emergency MedicineMedical University of ViennaViennaAustria
| | - Jürgen Grafeneder
- Department of Emergency MedicineMedical University of ViennaViennaAustria
| | - Peter Quehenberger
- Department of Laboratory MedicineMedical University of ViennaViennaAustria
| | - Ingrid Pabinger
- Department of Medicine I, Division of Hematology and HemostaseologyMedical University of ViennaViennaAustria
| | - Paul Knöbl
- Department of Medicine I, Division of Hematology and HemostaseologyMedical University of ViennaViennaAustria
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26
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Douxfils J, Favresse J, Dogné JM, Lecompte T, Susen S, Cordonnier C, Lebreton A, Gosselin R, Sié P, Pernod G, Gruel Y, Nguyen P, Vayne C, Mullier F. Hypotheses behind the very rare cases of thrombosis with thrombocytopenia syndrome after SARS-CoV-2 vaccination. Thromb Res 2021; 203:163-171. [PMID: 34029848 PMCID: PMC8123522 DOI: 10.1016/j.thromres.2021.05.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 01/17/2023]
Abstract
As of 4 April 2021, a total of 169 cases of cerebral venous sinus thrombosis (CVST) and 53 cases of splanchnic vein thrombosis were reported to EudraVigilance among around 34 million people vaccinated in the European Economic Area and United Kingdom with COVID-19 Vaccine AstraZeneca, a chimpanzee adenoviral vector (ChAdOx1) encoding the spike protein antigen of the SARS-CoV-2 virus. The first report of the European Medicines Agency gathering data on 20 million people vaccinated with Vaxzevria® in the UK and the EEA concluded that the number of post-vaccination cases with thromboembolic events as a whole reported to EudraVigilance in relation to the number of people vaccinated was lower than the estimated rate of such events in the general population. However, the EMA's Pharmacovigilance Risk Assessment Committee concluded that unusual thromboses with low blood platelets should be listed as very rare side effects of Vaxzevria®, pointing to a possible link. The same issue was identified with the COVID-19 Vaccine Janssen (Ad26.COV2.S). Currently, there is still a sharp contrast between the clinical or experimental data reported in the literature on COVID-19 and the scarcity of data on the unusual thrombotic events observed after the vaccination with these vaccines. Different hypotheses might support these observations and should trigger further in vitro and ex vivo investigations. Specialized studies were needed to fully understand the potential relationship between vaccination and possible risk factors in order to implement risk minimization strategies.
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Affiliation(s)
- Jonathan Douxfils
- University of Namur, Department of Pharmacy, Namur Research for Life Sciences, Namur Thrombosis and Hemostasis Center, Namur, Belgium; QUALIblood s.a., Namur, Belgium.
| | - Julien Favresse
- University of Namur, Department of Pharmacy, Namur Research for Life Sciences, Namur Thrombosis and Hemostasis Center, Namur, Belgium; Clinique Saint-Luc Bouge, Department of Laboratory Medicine, Bouge, Belgium
| | - Jean-Michel Dogné
- University of Namur, Department of Pharmacy, Namur Research for Life Sciences, Namur Thrombosis and Hemostasis Center, Namur, Belgium
| | - Thomas Lecompte
- Départements de Médecine, Hôpitaux Universitaires de Genève, service d'angiologie et d'hémostase et Faculté de Médecine, Geneva Platelet Group (GpG), Université de Genève, Geneva, Switzerland
| | - Sophie Susen
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011- EGID, F-59000 Lille, France
| | - Charlotte Cordonnier
- Univ Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, F-59000 Lille, France
| | - Aurélien Lebreton
- Service d'hématologie biologique, CHU Clermont-Ferrand, Clermont-Ferrand, France
| | - Robert Gosselin
- University of California, Davis Health System, Thrombosis and Hemostasis Center, Sacramento, United States
| | - Pierre Sié
- University Paul Sabatier, CHU of Toulouse, Laboratory of Hematology, F-31069 Toulouse, France
| | - Gilles Pernod
- CHU Grenoble Alpes, Department of Vascular Medicine, CNRS/TIMC-IMAG UMR 5525/Themas, Grenoble, France
| | - Yves Gruel
- University of Tours, EA7501 GICC, CHRU de Tours, Department of Haemostasis, Tours, France
| | | | - Caroline Vayne
- University of Tours, EA7501 GICC, CHRU de Tours, Department of Haemostasis, Tours, France
| | - François Mullier
- CHU UCL Namur, Université catholique de Louvain, Hematology Laboratory, Namur Research for Life Sciences, Namur Thrombosis and Hemostasis Center, Yvoir, Belgium
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Complement mediates binding and procoagulant effects of ultra-large HIT immune complexes. Blood 2021; 138:2106-2116. [PMID: 34189574 DOI: 10.1182/blood.2020009487] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 06/02/2021] [Indexed: 01/19/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder mediated by ultra-large immune complexes (ULICs) containing IgG antibodies to a multivalent antigen composed of platelet factor 4 (PF4) and heparin. The limitations of current anti-thrombotic therapy in HIT supports the need to identify additional pathways that may be targets for therapy. Activation of FcgRIIA by HIT ULICs initiates diverse procoagulant cellular effector functions. HIT ULICs are also known to activate complement, but the contribution of this pathway to the pathogenesis of HIT has not been studied in detail. We observed that HIT ULICs physically interact with C1q in buffer and plasma, activate complement via the classical pathway, promote co-deposition of IgG and activated C3 complement fragments (C3c) on neutrophil and monocyte cell surfaces. Complement activation by ULICs, in turn, facilitates Fcg receptor(R)-independent monocyte tissue factor expression, enhances IgG binding to the cell surface FcgRs and promotes platelet adhesion to injured endothelium. Inhibition of the proximal, but not terminal, steps in the complement pathway, abrogates monocyte tissue factor expression by HIT ULICs. Together, these studies suggest a major role for complement activation in regulating Fc-dependent effector functions of HIT ULICs, identify potential non-anticoagulant targets for therapy, and provide insights into the broader roles of complement in immune complex-mediated thrombotic disorders.
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Sachs UJ, Cooper N, Czwalinna A, Müller J, Pötzsch B, Tiede A, Althaus K. PF4-Dependent Immunoassays in Patients with Vaccine-Induced Immune Thrombotic Thrombocytopenia: Results of an Interlaboratory Comparison. Thromb Haemost 2021; 121:1622-1627. [PMID: 34169493 DOI: 10.1055/a-1535-9002] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Coronavirus disease 2019 vaccine ChAdOx1 nCov-19 may rarely lead to vaccine-induced thrombotic thrombocytopenia (VITT). Antibody-mediated, platelet factor 4 (PF4)-dependent platelet activation appears to resemble a key mechanism in VITT, partially comparable to heparin-induced thrombocytopenia. The use of PF4/heparin immunoassays has been proposed as part of a diagnostic approach, but their sensitivity has not been established. METHODS Sera from 12 well-defined VITT patients were first studied by two different laboratories in functional assays. Sera where then used for an interlaboratory comparison, in which five different PF4/heparin immunoassays were used by four laboratories. RESULTS Results for functional testing were highly concordant. VITT antibodies were also reliably detected by PF4/heparin enzyme-linked immunosorbent assays (ELISAs) (92-100%). In contrast, only 25% of VITT antibodies were reactive in a particle gel immunoassay (PaGIA), and 8% in a lateral flow assay (LFA). An automated chemiluminescence immunoassay (CLIA) was negative for all sera tested (0%). CONCLUSION It seems feasible to establish functional antibody testing for the confirmation of VITT. For the initial screening of suspected VITT cases, PaGIA, LFA, and CLIA are useless when applied as single tests. Only ELISA-based PF4/heparin immunoassays are sensitive enough to be incorporated in the diagnostic workup. However, a combination of a positive ELISA and a negative CLIA may be useful to identify VITT antibodies in the absence of confirmatory functional assays.
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Affiliation(s)
- Ulrich J Sachs
- Department of Thrombosis and Haemostasis, Giessen University Hospital, Giessen, Germany.,Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
| | - Nina Cooper
- Department of Thrombosis and Haemostasis, Giessen University Hospital, Giessen, Germany.,Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany
| | | | - Jens Müller
- Institute for Experimental Haematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Bernd Pötzsch
- Institute for Experimental Haematology and Transfusion Medicine, University of Bonn, Bonn, Germany
| | - Andreas Tiede
- Department of Haematology, Haemostasis, Oncology, and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Karina Althaus
- Institute for Clinical and Experimental Transfusion Medicine, Medical Faculty of Tuebingen, University Hospital of Tuebingen, Tuebingen, Germany
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Warkentin TE, Greinacher A. Spontaneous HIT syndrome: Knee replacement, infection, and parallels with vaccine-induced immune thrombotic thrombocytopenia. Thromb Res 2021; 204:40-51. [PMID: 34144250 DOI: 10.1016/j.thromres.2021.05.018] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/26/2021] [Accepted: 05/28/2021] [Indexed: 12/21/2022]
Abstract
Heparin-induced thrombocytopenia (HIT) is characterized clinically by thrombocytopenia, hypercoagulability, and increased thrombosis risk, and serologically by platelet-activating anti-platelet factor 4 (PF4)/heparin antibodies. Heparin-"induced" acknowledges that HIT is usually triggered by a proximate immunizing exposure to heparin. However, certain non-heparin medications (pentosan polysulfate, hypersulfated chondroitin sulfate, fondaparinux) can trigger "HIT". Further, naturally-occurring polyanions (bacterial lipopolysaccharide, DNA/RNA) can interact with PF4 to recapitulate HIT antigens. Indeed, immunologic presensitization to naturally-occurring polyanions could explain why HIT more closely resembles a secondary, rather than a primary, immune response. In 2008 it was first reported that a HIT-mimicking disorder can occur without any preceding exposure to heparin or polyanionic medications. Termed "spontaneous HIT syndrome", two subtypes are recognized: (a) surgical (post-orthopedic, especially post-total knee arthroplasty, and (b) medical (usually post-infectious). Recently, COVID-19 adenoviral vector vaccination has been associated with a thrombotic thrombocytopenic disorder associated with positive PF4-dependent enzyme-immunoassays and serum-induced platelet activation that is maximal when PF4 is added. Vaccine-induced immune thrombotic thrombocytopenia (VITT) features unusual thromboses (cerebral venous thrombosis, splanchnic vein thrombosis) similar to those seen in spontaneous HIT syndrome. The emerging concept is that classic HIT reflects platelet-activating anti-PF4/heparin antibodies whereas spontaneous HIT syndrome and other atypical "autoimmune HIT" presentations (delayed-onset HIT, persisting HIT, heparin "flush" HIT) reflect heparin-independent platelet-activating anti-PF4 antibodies-although the precise relationships between PF4 epitope targets and the clinical syndromes remain to be determined. Treatment of spontaneous HIT syndrome includes non-heparin anticoagulation (direct oral Xa inhibitors favored over direct thrombin inhibitors) and high-dose immunoglobulin.
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Affiliation(s)
- Theodore E Warkentin
- Department of Pathology and Molecular Medicine, and Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Hamilton Regional Laboratory Medicine Program (Transfusion Medicine), Hamilton, Ontario, Canada; Service of Benign Hematology, Hamilton Health Sciences (Hamilton General Hospital), Canada.
| | - Andreas Greinacher
- From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
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30
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Chong BH. Evolving concepts of pathogenesis of heparin-induced thrombocytopenia: Diagnostic and therapeutic implications. Int J Lab Hematol 2021; 42 Suppl 1:25-32. [PMID: 32543064 DOI: 10.1111/ijlh.13223] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/08/2020] [Accepted: 04/10/2020] [Indexed: 01/09/2023]
Abstract
Heparin-induced thrombocytopenia (HIT) is an immune reaction to heparin. It often causes severe thrombosis which may lead to limb gangrene and thrombosis-associated death. The concept of its pathogenesis has been evolving during the past five decades. Initially, HIT was thought to be caused by disseminated intravascular coagulation. Later it became clear that HIT was mediated by an immune mechanism whereby an IgG antibody induced platelet aggregation, release of procoagulant materials and consequently thrombus formation. The antigen comprises Platelet Factor 4 (PF4) and heparin which have a tendency to form ultralarge complexes. The HIT immune response has atypical features. IgG antibody appears early without IgM precedence and lasts transiently. One explanation is that there is prior priming by bacterial infection. Another unique characteristic is that it is processed as if it is a particulate antigen involving complement activation and B cells. Antigen-presenting cells/monocytes are also involved but the role of T cells is controversial. Recent advances have provided new insights into the underlying mechanisms of HIT-related thrombosis. Previously, platelets were believed to play a central role; their activation and consequently the induction of blood coagulation was the basis of the hypercoagulability in HIT. More recently, several studies have provided clear evidence that neutrophil and NETosis, monocytes and endothelial cells contribute significantly to the thrombosis in HIT. These new insights may result in development of better diagnostic laboratory assays and more effective treatments for HIT.
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Affiliation(s)
- Beng H Chong
- Heamatology Department, New South Wales Health Pathology, Kogarah and Sutherland Campuses, Sydney, NSW, Australia.,Heamatolgy Department, St George and Sutherland Hospitals, Sydney, NSW, Australia.,St George Clinical School, University of New South Wales, Sydney, NSW, Australia
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31
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Abstract
Heparin-induced thrombocytopenia is an immune-mediated disorder caused by antibodies that recognize complexes of platelet factor 4 and heparin. Thrombosis is a central and unpredictable feature of this syndrome. Despite optimal management, disease morbidity and mortality from thrombosis remain high. The hypercoagulable state in heparin-induced thrombocytopenia is biologically distinct from other thrombophilic disorders in that clinical complications are directly attributable to circulating ultra-large immune complexes. In some individuals, ultra-large immune complexes elicit unchecked cellular procoagulant responses that culminate in thrombosis. To date, the clinical and biologic risk factors associated with thrombotic risk in heparin-induced thrombocytopenia remain elusive. This review will summarize our current understanding of thrombosis in heparin-induced thrombocytopenia with attention to its clinical features, cellular mechanisms, and its management.
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Affiliation(s)
| | - Anand Padmanabhan
- Divisions of Hematopathology, Transfusion Medicine, and Experimental Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN (A.P.)
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32
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Arepally GM, Cines DB. Pathogenesis of heparin-induced thrombocytopenia. Transl Res 2020; 225:131-140. [PMID: 32417430 PMCID: PMC7487042 DOI: 10.1016/j.trsl.2020.04.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 01/19/2023]
Abstract
There are currently no effective substitutes for high intensity therapy with unfractionated heparin (UFH) for cardiovascular procedures based on its rapid onset of action, ease of monitoring and reversibility. The continued use of UFH in these and other settings requires vigilance for its most serious nonhemorrhagic complication, heparin induced thrombocytopenia (HIT). HIT is an immune prothrombotic disorder caused by antibodies that recognize complexes between platelet factor 4 (PF4) and polyanions such as heparin (H).The pathogenicity of anti-PF4/H antibodies is likely due to the formation of immune complexes that initiate intense procoagulant responses by vascular and hematopoietic cells that lead to the generation of platelet microparticles, monocyte and endothelial cell procoagulant activity, and neutrophil extracellular traps, among other outcomes. The development of anti-PF4/H antibodies after exposure to UFH greatly exceeds the incidence of clinical disease, but the biochemical features that distinguish pathogenic from nonpathogenic antibodies have not been identified. Diagnosis relies on pretest clinical probability, screening for anti-PF4/H antibodies and documentation of their platelet activating capacity. However, both clinical algorithms and test modalities have limited predictive values making diagnosis and management challenging. Given the unacceptable rates of recurrent thromboembolism and bleeding associated with current therapies, there is an unmet need for novel rational nonanticoagulant therapeutics based on the pathogenesis of HIT. We will review recent developments in our understanding of the pathogenesis of HIT and its implications for future approaches to diagnosis and management.
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Affiliation(s)
- Gowthami M Arepally
- Division of Hematology, Duke University Medical Center, Durham, North Carolina.
| | - Douglas B Cines
- Department of Pathology and Laboratory Medicine, Perelman-University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
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33
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Vayne C, Nguyen TH, Rollin J, Charuel N, Poupon A, Pouplard C, Normann N, Gruel Y, Greinacher A. Characterization of New Monoclonal PF4-Specific Antibodies as Useful Tools for Studies on Typical and Autoimmune Heparin-Induced Thrombocytopenia. Thromb Haemost 2020; 121:322-331. [PMID: 33086397 DOI: 10.1055/s-0040-1717078] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Heparin-induced thrombocytopenia (HIT) is typically caused by platelet-activating immunoglobulin G (IgG) antibodies (Abs) against platelet factor 4 (PF4) complexed with heparin (H). Much less frequent "autoimmune" HIT is distinguished from typical HIT by platelet activation without heparin and the presence of both anti-PF4/H and anti-PF4 IgG. We developed three murine monoclonal anti-PF4 Abs with a human Fc-part, 1E12, 1C12, and 2E1, resembling autoimmune HIT Abs. OBJECTIVES To characterize 1E12, 1C12, and 2E1 in comparison to the heparin-dependent monoclonal anti-PF4/H Abs 5B9 and KKO, and polyclonal Abs from patients with typical HIT (group-2) and autoimmune HIT (group-3). METHODS Interactions of Abs with PF4 and PF4/H were studied by enzyme-linked-immunosorbent assay, single-molecule force spectroscopy, isothermal titration calorimetry, and dynamic light scattering. Serotonin release assay and heparin-induced platelet activation assay were used to assess platelet activation. The binding sites of monoclonal Abs on PF4 were predicted in silico (MAbTope method). RESULTS 1C12, 1E12, and 2E1 displayed higher affinity for PF4/H complexes than 5B9 and KKO, comparable to human group-3 Abs. Only 1C12, 1E12, 2E1, and group-3 Abs formed large complexes with native PF4, and activated platelets without heparin. The predicted binding sites of 1C12, 1E12, and 2E1 on PF4 differed from those of KKO and 5B9, but were close to each other. 2E1 exhibited unique bivalent binding, involving its antigen recognition site to PF4 and charge-dependent interactions with heparin. CONCLUSION 1C12, 1E12, and 2E1 are tools for studying the pathophysiology of autoimmune HIT. 2E1 provides evidence for a new binding mechanism of HIT Abs.
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Affiliation(s)
- Caroline Vayne
- EA7501 GICC, University of Tours, Tours, France.,Department of Haemostasis, Regional University Hospital Centre Tours, Tours, France
| | - Thi-Huong Nguyen
- Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, Greifswald, Germany.,Institute for Bioprocessing and Analytical Measurement Techniques, Heilbad Heiligenstadt, Germany
| | - Jérôme Rollin
- EA7501 GICC, University of Tours, Tours, France.,Department of Haemostasis, Regional University Hospital Centre Tours, Tours, France
| | | | - Anne Poupon
- PRC, INRA, CNRS, University of Tours, Nouzilly, France.,MAbSilico SAS, Nouzilly, France
| | - Claire Pouplard
- EA7501 GICC, University of Tours, Tours, France.,Department of Haemostasis, Regional University Hospital Centre Tours, Tours, France
| | - Nicole Normann
- Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Yves Gruel
- EA7501 GICC, University of Tours, Tours, France.,Department of Haemostasis, Regional University Hospital Centre Tours, Tours, France
| | - Andreas Greinacher
- Institute for Immunology and Transfusion Medicine, University Medicine Greifswald, Greifswald, Germany
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Anti-CXCL4 Antibody Reactivity Is Present in Systemic Sclerosis (SSc) and Correlates with the SSc Type I Interferon Signature. Int J Mol Sci 2020; 21:ijms21145102. [PMID: 32707718 PMCID: PMC7404208 DOI: 10.3390/ijms21145102] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/07/2020] [Accepted: 07/14/2020] [Indexed: 12/26/2022] Open
Abstract
Systemic sclerosis (SSc) is characterized by skin/internal organ fibrosis, vasculopathy and autoimmunity. Chemokine (C-X-C motif) ligand 4 (CXCL4) is an SSc biomarker, predicting unfavorable prognosis and lung fibrosis. CXCL4 binds DNA/RNA and favors interferon (IFN)-α production by plasmacytoid dendritic cells (pDCs), contributing to the type I IFN (IFN-I) signature in SSc patients. However, whether CXCL4 is an autoantigen in SSc is unknown. Here, we show that at least half of SSc patients show consistent antibody reactivity to CXCL4. T-cell proliferation to CXCL4, tested in a limited number of patients, correlates with anti-CXCL4 antibody reactivity. Antibodies to CXCL4 mostly correlate with circulating IFN-α levels and are significantly higher in patients with lung fibrosis in two independent SSc cohorts. Antibodies to CXCL4 implement the CXCL4-DNA complex's effect on IFN-α production by pDCs; CXCL4-DNA/RNA complexes stimulate purified human B-cells to become antibody-secreting plasma cells in vitro. These data indicate that CXCL4 is indeed an autoantigen in SSc and suggest that CXCL4, and CXCL4-specific autoantibodies, can fuel a harmful loop: CXCL4-DNA/RNA complexes induce IFN-α in pDCs and direct B-cell stimulation, including the secretion of anti-CXCL4 antibodies. Anti-CXCL4 antibodies may further increase pDC stimulation and IFN-α release in vivo, creating a vicious cycle which sustains the SSc IFN-I signature and general inflammation.
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Zhou P, Yin JX, Tao HL, Zhang HW. Pathogenesis and management of heparin-induced thrombocytopenia and thrombosis. Clin Chim Acta 2020; 504:73-80. [DOI: 10.1016/j.cca.2020.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/30/2020] [Accepted: 02/03/2020] [Indexed: 01/19/2023]
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Johnston I, Sarkar A, Hayes V, Koma GT, Arepally GM, Chen J, Chung DW, López JA, Cines DB, Rauova L, Poncz M. Recognition of PF4-VWF complexes by heparin-induced thrombocytopenia antibodies contributes to thrombus propagation. Blood 2020; 135:1270-1280. [PMID: 32077913 PMCID: PMC7146020 DOI: 10.1182/blood.2018881607] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/23/2020] [Indexed: 01/19/2023] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder mediated by complexes between platelet factor 4 (PF4) and heparin or other polyanions, but the risk of thrombosis extends beyond exposure to heparin implicating other PF4 partners. We recently reported that peri-thrombus endothelium is targeted by HIT antibodies, but the binding site(s) has not been identified. We now show that PF4 binds at multiple discrete sites along the surface of extended strings of von Willebrand factor (VWF) released from the endothelium following photochemical injury in an endothelialized microfluidic system under flow. The HIT-like monoclonal antibody KKO and HIT patient antibodies recognize PF4-VWF complexes, promoting platelet adhesion and enlargement of thrombi within the microfluidic channels. Platelet adhesion to the PF4-VWF-HIT antibody complexes is inhibited by antibodies that block FcγRIIA or the glycoprotein Ib-IX complex on platelets. Disruption of PF4-VWF-HIT antibody complexes by drugs that prevent or block VWF oligomerization attenuate thrombus formation in a murine model of HIT. Together, these studies demonstrate assembly of HIT immune complexes along VWF strings released by injured endothelium that might propagate the risk of thrombosis in HIT. Disruption of PF4-VWF complex formation may provide a new therapeutic approach to HIT.
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Affiliation(s)
- Ian Johnston
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
- Department of Pharmacology and
| | - Amrita Sarkar
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Vincent Hayes
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
- Departments of Pathology and Laboratory Medicine and Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Gavin T Koma
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | | | | | - Dominic W Chung
- Bloodworks Northwest, Seattle, WA
- Departments of Medicine and Biochemistry, University of Washington, Seattle, WA; and
| | - José A López
- Bloodworks Northwest, Seattle, WA
- Departments of Medicine and Biochemistry, University of Washington, Seattle, WA; and
| | - Douglas B Cines
- Departments of Pathology and Laboratory Medicine and Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Lubica Rauova
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Mortimer Poncz
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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Wang L, Gong T, Brown Z, Randle C, Guan Y, Ye W, Ming W. Ascidian-Inspired Heparin-Mimetic Magnetic Nanoparticles with Potential for Application in Hemodialysis as Recycling Anticoagulants. ACS Biomater Sci Eng 2020; 6:1998-2006. [PMID: 33455351 DOI: 10.1021/acsbiomaterials.9b01865] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In the present study, heparin-mimetic magnetic nanoparticles (HMNPs), which might be used as recycling anticoagulants, were synthesized by coating heparin-mimetic sodium alginate (HLSA) on the surface of iron oxide magnetic nanoparticles (MNPs), using 3,4,5-trihydroxyphenylalanine (TOPA) as a biological adhesive. HLSA was successfully immobilized on the MNP surface, as revealed by Fourier transform infrared spectroscopy and thermal gravimetric analysis, and the core (MNP)-shell (TOPA, HLSA) structure was confirmed by transmission electron microscopy observations. In addition, in vitro studies of protein adsorption, blood clotting time, and contact activation confirmed that the blood compatibility of the HMNP was significantly enhanced compared with the bare MNP. The improved hemocompatibility was attributed to the introduction of the multiple heparin-mimetic groups (-SO3Na, -COONa, and -OH). In addition, the HMNP showed outstanding recycle stability and, thus, can be reused if needed. The synthesized HMNP appeared to be a suitable biomaterial to safely replace heparin as an anticoagulant in patients undergoing long-term hemodialysis.
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Affiliation(s)
- Lingren Wang
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China.,Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
| | - Tao Gong
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Zachary Brown
- Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
| | - Christopher Randle
- Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
| | - Yingying Guan
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Wei Ye
- Department of Mechanical and Materials Engineering, Huaiyin Institute of Technology, Huaian 223003, China
| | - Weihua Ming
- Department of Chemistry and Biochemistry, Georgia Southern University, P.O. Box 8064, Statesboro, Georgia 30460, United States
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Warkentin TE. High-dose intravenous immunoglobulin for the treatment and prevention of heparin-induced thrombocytopenia: a review. Expert Rev Hematol 2019; 12:685-698. [DOI: 10.1080/17474086.2019.1636645] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Theodore E. Warkentin
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
- McMaster Centre for Transfusion Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
- Hamilton Regional Laboratory Medicine Program, Hamilton General Hospital, Hamilton Health Sciences, Hamilton, Ontario, Canada
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Ning S, Warkentin TE. IV Immunoglobulin for Autoimmune Heparin-Induced Thrombocytopenia. Chest 2019; 152:453-455. [PMID: 28889872 DOI: 10.1016/j.chest.2017.05.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 05/26/2017] [Indexed: 01/23/2023] Open
Affiliation(s)
- Shuoyan Ning
- Department of Medicine (Division of Hematology and Thromboembolism), Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
| | - Theodore E Warkentin
- Department of Medicine (Division of Hematology and Thromboembolism), Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada; Department of Pathology and Molecular Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada; McMaster Centre for Transfusion Research, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada.
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40
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Mailer RKW, Hänel L, Allende M, Renné T. Polyphosphate as a Target for Interference With Inflammation and Thrombosis. Front Med (Lausanne) 2019; 6:76. [PMID: 31106204 PMCID: PMC6499166 DOI: 10.3389/fmed.2019.00076] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/28/2019] [Indexed: 12/19/2022] Open
Abstract
Activated platelets and mast cells expose the inorganic polymer, polyphosphate (polyP) on their surfaces. PolyP initiates procoagulant and proinflammatory reactions and the polymer has been recognized as a therapeutic target for interference with blood coagulation and vascular hyperpermeability. PolyP content and chain length depend on the specific cell type and energy status, which may affect cellular functions. PolyP metabolism has mainly been studied in bacteria and yeast, but its roles in eukaryotic cells and mammalian systems have remained enigmatic. In this review, we will present an overview of polyP functions, focusing on intra- and extracellular roles of the polymer and discuss open questions that emerge from the current knowledge on polyP regulation.
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Affiliation(s)
- Reiner K W Mailer
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lorena Hänel
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mikel Allende
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas Renné
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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41
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Heparin-Induced Thrombocytopenia. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00041-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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42
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Nguyen TH, Greinacher A. Distinct Binding Characteristics of Pathogenic Anti-Platelet Factor-4/Polyanion Antibodies to Antigens Coated on Different Substrates: A Perspective on Clinical Application. ACS NANO 2018; 12:12030-12041. [PMID: 30540167 DOI: 10.1021/acsnano.8b04487] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The polyanion heparin, which is frequently used in patients, complexes with the platelet-derived cationic chemokine platelet factor (PF4, CXCL4). This results in the formation of anti-PF4/heparin antibodies (anti-PF4/H Abs). Anti-PF4/H Abs are classified into three groups: (i) nonpathogenic Abs (group 1) with no clinical relevance; (ii) pathogenic heparin-dependent Abs (group 2), which activate platelets and can cause the severe adverse drug effect heparin-induced thrombocytopenia (HIT); and (iii) pathogenic autoimmune-HIT Abs (group 3), in which group 3 anti-PF4/H Abs causes a HIT-like autoimmune disease in the absence of heparin. Enzyme immunoassays using PF4/H complexes coated on the solid phase for detection of anti-PF4/H Abs cannot differentiate between pathogenic and nonpathogenic anti-PF4/H Abs. By single-molecule force spectroscopy, we identify a specific feature of pathogenic group 2 and group 3 Abs antibodies that (in contrast to nonpathogenic group 1 Abs) their binding forces to PF4/H complexes coated on platelets were significantly higher compared with those of PF4/H complexes immobilized on a solid phase. Only group 3 Abs showed high binding forces to platelets without the addition of PF4. In the presence of 50 μg/mL PF4, group 2 Abs also showed high binding forces to platelets. In contrast, binding forces of group 1 Abs always remained low (<100 pN). Our findings may have major relevance for the development of clinically applicable solid-phase assays, which allow differentiation of pathogenic platelet-activating from nonpathogenic anti-PF4/H Abs. Membrane-based expression of antigens might also increase the specificity of other assays for the detection of pathogenic (auto)-antibodies in clinical medicine.
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Affiliation(s)
- Thi-Huong Nguyen
- Institute for Immunology and Transfusion Medicine , University Medicine Greifswald , 17475 Greifswald , Germany
- ZIK HIKE - Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases , University of Greifswald , 17489 Greifswald , Germany
| | - Andreas Greinacher
- Institute for Immunology and Transfusion Medicine , University Medicine Greifswald , 17475 Greifswald , Germany
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43
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Warkentin TE. Heparin-induced thrombocytopenia-associated thrombosis: from arterial to venous to venous limb gangrene. J Thromb Haemost 2018; 16:2128-2132. [PMID: 30099843 DOI: 10.1111/jth.14264] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Indexed: 12/17/2022]
Abstract
Heparin-induced thrombocytopenia (HIT) is an acquired immune-mediated hypercoagulability state that is strongly associated with thrombosis. During the 1970s and 1980s, the prevailing concept was that HIT was associated only with arterial thrombosis, through its unique pathogenesis via heparin-dependent, platelet-activating IgG antibodies. However, in 1990, when I began to encounter HIT in my clinical practice, I found that most such patients developed symptomatic venous thrombosis. This historical sketch summarizes some of the research that challenged the dogma of HIT being a mainly arterial prothrombotic disorder. Two studies - one a substudy of a randomized trial of post-orthopedic surgery thromboprophylaxis, and the second a retrospective five-hospital analysis of consecutive patients with positive test results for HIT antibodies - showed a marked predominance of venous over arterial thrombosis complicating HIT (~ 4 : 1). By the end of the 1990s, an even more dramatic manifestation of HIT-associated venous thrombosis was recognized: venous limb gangrene. Here, ischemic limb necrosis occurs despite palpable arterial pulses, as a result of both macrovascular and microvascular venous thrombosis. The surprising explanation was natural anticoagulant impairment (severe depletion of protein C, a vitamin K-dependent anticoagulant) resulting from treatment of HIT-associated deep vein thrombosis with warfarin (vitamin K antagonist). These insights from HIT research helped to elucidate the pathogenesis of ischemic limb losses in other intense non-HIT hypercoagulability states, including warfarin-associated venous limb gangrene complicating cancer-associated hypercoagulability, and symmetrical peripheral gangrene complicating disseminated intravascular coagulation of critical illness, in which proximate 'shock liver' helps to explain the profound failure of natural anticoagulant systems (protein C; antithrombin) in predisposing to peripheral limb microthrombosis in circulatory shock.
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Affiliation(s)
- T E Warkentin
- Department of Pathology and Molecular Medicine, and Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
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44
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Rauova L, Arepally G, Poncz M, Cines DB. Molecular and cellular pathogenesis of heparin-induced thrombocytopenia (HIT). Autoimmun Rev 2018; 17:1046-1052. [PMID: 30103043 DOI: 10.1016/j.autrev.2018.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 05/09/2018] [Indexed: 01/19/2023]
Affiliation(s)
- Lubica Rauova
- Division of Hematology, Department of Pediatrics, Childrens Hospital of Philadelphia, USA; Department of Pediatrics, University of Pennsylvania, Perelman School of Medicine, USA
| | - Gowthami Arepally
- Division of Hematology, Department of Medicine, Duke University School of Medicine, USA
| | - Mortimer Poncz
- Division of Hematology, Department of Pediatrics, Childrens Hospital of Philadelphia, USA; Department of Pediatrics, University of Pennsylvania, Perelman School of Medicine, USA
| | - Douglas B Cines
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Perelman School of Medicine, USA; Department of Medicine, University of Pennsylvania, Perelman School of Medicine, USA.
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Platelet-Activating Antibodies Are Detectable at the Earliest Onset of Heparin-Induced Thrombocytopenia, With Implications for the Operating Characteristics of the Serotonin-Release Assay. Chest 2018; 153:1396-1404. [DOI: 10.1016/j.chest.2018.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/01/2017] [Accepted: 01/02/2018] [Indexed: 11/21/2022] Open
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Greinacher A, Selleng K, Warkentin TE. Autoimmune heparin-induced thrombocytopenia. J Thromb Haemost 2017; 15:2099-2114. [PMID: 28846826 DOI: 10.1111/jth.13813] [Citation(s) in RCA: 272] [Impact Index Per Article: 38.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Indexed: 01/18/2023]
Abstract
Autoimmune heparin-induced thrombocytopenia (aHIT) indicates the presence in patients of anti-platelet factor 4 (PF4)-polyanion antibodies that are able to activate platelets strongly even in the absence of heparin (heparin-independent platelet activation). Nevertheless, as seen with serum obtained from patients with otherwise typical heparin-induced thrombocytopenia (HIT), serum-induced platelet activation is inhibited at high heparin concentrations (10-100 IU mL-1 heparin). Furthermore, upon serial dilution, aHIT serum will usually show heparin-dependent platelet activation. Clinical syndromes associated with aHIT include: delayed-onset HIT, persisting HIT, spontaneous HIT syndrome, fondaparinux-associated HIT, heparin 'flush'-induced HIT, and severe HIT (platelet count of < 20 × 109 L-1 ) with associated disseminated intravascular coagulation (DIC). Recent studies have implicated anti-PF4 antibodies that are able to bridge two PF4 tetramers even in the absence of heparin, probably facilitated by non-heparin platelet-associated polyanions (chondroitin sulfate and polyphosphates); nascent PF4-aHIT-IgG complexes recruit additional heparin-dependent HIT antibodies, leading to the formation of large multimolecular immune complexes and marked platelet activation. aHIT can persist for several weeks, and serial fibrin, D-dimer, and fibrinogen levels, rather than the platelet count, may be helpful for monitoring treatment response. Although standard anticoagulant therapy for HIT ought to be effective, published experience indicates frequent failure of activated partial thromboplastin time (APTT)-adjusted anticoagulants (argatroban, bivalirudin), probably because of underdosing in the setting of HIT-associated DIC, known as 'APTT confounding'. Thus, non-APTT-adjusted therapies with drugs such as danaparoid and fondaparinux, or even direct oral anticoagulants, such as rivaroxaban or apixaban, are suggested therapies, especially for long-term management of persisting HIT. In addition, emerging data indicate that high-dose intravenous immunoglobulin can interrupt HIT antibody-induced platelet activation, leading to rapid platelet count recovery.
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MESH Headings
- Administration, Oral
- Animals
- Anticoagulants/administration & dosage
- Anticoagulants/adverse effects
- Anticoagulants/immunology
- Autoantibodies/blood
- Autoimmunity/drug effects
- Blood Coagulation/drug effects
- Blood Platelets/drug effects
- Blood Platelets/immunology
- Blood Platelets/metabolism
- Heparin/adverse effects
- Heparin/immunology
- Humans
- Immunoglobulins, Intravenous/administration & dosage
- Immunologic Factors/administration & dosage
- Partial Thromboplastin Time
- Platelet Activation/drug effects
- Platelet Factor 4/immunology
- Purpura, Thrombocytopenic, Idiopathic/blood
- Purpura, Thrombocytopenic, Idiopathic/chemically induced
- Purpura, Thrombocytopenic, Idiopathic/drug therapy
- Purpura, Thrombocytopenic, Idiopathic/immunology
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Affiliation(s)
- A Greinacher
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - K Selleng
- Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald, Germany
| | - T E Warkentin
- Department of Pathology and Molecular Medicine, Department of Medicine, and McMaster Centre for Transfusion Research, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
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Jones CG, Pechauer SM, Curtis BR, Bougie DW, Irani MS, Dhakal B, Pierce B, Aster RH, Padmanabhan A. A Platelet Factor 4-Dependent Platelet Activation Assay Facilitates Early Detection of Pathogenic Heparin-Induced Thrombocytopenia Antibodies. Chest 2017; 152:e77-e80. [PMID: 28991552 DOI: 10.1016/j.chest.2017.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/18/2017] [Accepted: 06/01/2017] [Indexed: 11/15/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a dangerous complication of heparin therapy. HIT diagnosis is established by recognizing thrombocytopenia and/or thrombosis in an affected patient and from the results of serological tests such as the platelet factor 4 (PF4)/heparin immunoassay (PF4 ELISA) and serotonin release assay (SRA). Recent studies suggest that HIT antibodies activate platelets by recognizing PF4 in a complex with platelet glycosaminoglycans (and/or polyphosphates) and that an assay based on this principle, the PF4-dependent P-selectin expression assay (PEA), may be even more accurate than the SRA for HIT diagnosis. Here, we demonstrate that the PEA detected pathogenic antibodies before the SRA became positive in two patients with HIT studied serially, in one case even before seropositivity in the PF4 ELISA. In one of the patients treated with plasma exchange, persistent dissociation between the PEA and SRA test results was observed. These results support a role for the PEA in early HIT diagnosis.
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Affiliation(s)
- Curtis G Jones
- Medical Sciences Institute, BloodCenter of Wisconsin, Milwaukee, WI
| | | | - Brian R Curtis
- Platelet and Neutrophil Immunology Laboratory, BloodCenter of Wisconsin, Milwaukee, WI
| | - Daniel W Bougie
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI
| | - Mehraboon S Irani
- Medical Sciences Institute, BloodCenter of Wisconsin, Milwaukee, WI; Department of Pathology, Medical College of Wisconsin, Milwaukee, WI
| | - Binod Dhakal
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI
| | - Brenda Pierce
- Division of Medical Oncology, Aurora Advanced Healthcare, Milwaukee, WI
| | - Richard H Aster
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI; Department of Medicine, Medical College of Wisconsin, Milwaukee, WI
| | - Anand Padmanabhan
- Medical Sciences Institute, BloodCenter of Wisconsin, Milwaukee, WI; Department of Pathology, Medical College of Wisconsin, Milwaukee, WI.
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Autoimmune HIT due to apheresis catheter heparin flushes for stem cell harvesting before autotransplantation for myeloma. Blood 2017; 130:1679-1682. [DOI: 10.1182/blood-2017-06-788679] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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49
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Platelet factor 4/heparin complexes present epitopes differently on solid-phase vs platelet surfaces. Blood 2017; 129:3498-3501. [DOI: 10.1182/blood-2017-02-769786] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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50
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Anti-platelet factor 4/polyanion antibodies mediate a new mechanism of autoimmunity. Nat Commun 2017; 8:14945. [PMID: 28530237 PMCID: PMC5458132 DOI: 10.1038/ncomms14945] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 02/15/2017] [Indexed: 01/07/2023] Open
Abstract
Antibodies recognizing complexes of the chemokine platelet factor 4 (PF4/CXCL4) and polyanions (P) opsonize PF4-coated bacteria hereby mediating bacterial host defense. A subset of these antibodies may activate platelets after binding to PF4/heparin complexes, causing the prothrombotic adverse drug reaction heparin-induced thrombocytopenia (HIT). In autoimmune-HIT, anti-PF4/P-antibodies activate platelets in the absence of heparin. Here we show that antibodies with binding forces of approximately 60–100 pN activate platelets in the presence of polyanions, while a subset of antibodies from autoimmune-HIT patients with binding forces ≥100 pN binds to PF4 alone in the absence of polyanions. These antibodies with high binding forces cluster PF4-molecules forming antigenic complexes which allow binding of polyanion-dependent anti-PF4/P-antibodies. The resulting immunocomplexes induce massive platelet activation in the absence of heparin. Antibody-mediated changes in endogenous proteins that trigger binding of otherwise non-pathogenic (or cofactor-dependent) antibodies may also be relevant in other antibody-mediated autoimmune disorders. Antibodies against the platelet factor 4 (PF4) support bacterial host defence but in some cases may lead to heparin-induced thrombocytopenia (HIT). Nguyen et al. show that in autoimmune HIT a subset of antibodies binds strongly to PF4 causing its conformational change that leads to association of non-pathogenic PF4 antibodies and thrombotic platelet activation.
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