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Xourgia E, Tektonidou MG. Antiphospholipid syndrome nephropathy: Current knowledge and unanswered questions. Clin Immunol 2023; 255:109735. [PMID: 37572950 DOI: 10.1016/j.clim.2023.109735] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 08/09/2023] [Indexed: 08/14/2023]
Abstract
The definition of acute and chronic antiphospholipid syndrome (APS) nephropathy was recently updated using a multiphase methodology in the context of the development of the new APS classification criteria. Currently, there is no consensus for the treatment of APS nephropathy, which mainly relies on the general recommendations for the management of APS. Based on evidence from experimental studies and a few clinical studies and case series, targeted treatments such as B-cell depletion, anti-B-cell activating factor antibody, complement inhibition, mammalian target of rapamycin inhibition, and neutrophil extracellular traps or interferon targeting may show promise for the treatment of microvascular manifestations in APS, including APS nephropathy. Validation of the new APS nephropathy definition and/or efforts for improvement in proposed terminology, along with the assessment of the safety and efficacy of potential targeted treatments in randomized controlled trials, are major future research directions. In this review, we summarize the current knowledge of APS nephropathy and discuss unanswered questions.
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Affiliation(s)
- Eleni Xourgia
- First Department of Propaedeutic Internal Medicine, Joint Academic Rheumatology Program, School of Medicine, National and Kapodistrian University of Athens, Laiko General Hospital, Athens, Greece
| | - Maria G Tektonidou
- First Department of Propaedeutic Internal Medicine, Joint Academic Rheumatology Program, School of Medicine, National and Kapodistrian University of Athens, Laiko General Hospital, Athens, Greece.
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2
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Abstract
Antiphospholipid syndrome (APS) is a thrombo-inflammatory disease propelled by circulating autoantibodies that recognize cell surface phospholipids and phospholipid binding proteins. The result is an increased risk of thrombotic events, pregnancy morbidity, and various other autoimmune and inflammatory complications. Although antiphospholipid syndrome was first recognized in patients with lupus, the stand alone presentation of antiphospholipid syndrome is at least equally common. Overall, the diagnosis appears to affect at least one in 2000 people. Studies of antiphospholipid syndrome pathogenesis have long focused on logical candidates such as coagulation factors, endothelial cells, and platelets. Recent work has shed light on additional potential therapeutic targets within the innate immune system, including the complement system and neutrophil extracellular traps. Vitamin K antagonists remain the mainstay of treatment for most patients with thrombotic antiphospholipid syndrome and, based on current data, appear superior to the more targeted direct oral anticoagulants. The potential role of immunomodulatory treatments in antiphospholipid syndrome management is receiving increased attention. As for many systemic autoimmune diseases, the most important future direction is to more precisely identify mechanistic drivers of disease heterogeneity in pursuit of unlocking personalized and proactive treatments for patients.
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Affiliation(s)
- Jason S Knight
- Division of Rheumatology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - D Ware Branch
- James R. and Jo Scott Research Chair, Department of Obstetrics and Gynecology, University of Utah Health and Intermountain Healthcare, Salt Lake City, Utah, USA
| | - Thomas L Ortel
- Division of Hematology, Departments of Medicine and Pathology, Duke University, Durham, North Carolina, USA
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3
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Hubben A, McCrae KR. Emerging Therapies in Antiphospholipid Syndrome. Transfus Med Rev 2022; 36:195-203. [PMID: 36272841 PMCID: PMC10162403 DOI: 10.1016/j.tmrv.2022.09.002] [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: 06/21/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/15/2022]
Abstract
The antiphospholipid syndrome (APS) is the most common cause of acquired immune-mediated thrombophilia. This syndrome is broadly defined by the presence of arterial or venous thrombosis, or pregnancy morbidity, in the presence of high levels of antiphospholipid antibodies. Despite recognition of this disorder more than 50 years ago, a fundamental unifying pathogenesis has not been determined. Due to this, mechanism-based therapies for APS are not available, and current management following thrombotic events suggests anticoagulation of indeterminate duration, or for obstetric complications, heparin/low molecular weight heparin and aspirin. However, APS is an autoimmune disorder, and several approaches focused on modulating the immune response or its effectors have been employed. Those which have been most extensively studied include hydroxychloroquine, rituximab and eculizumab, an inhibitor of complement C5. In this report, we review in depth, and critique, key clinical studies of these agents. Since all of these studies are small, our conclusions are qualified. However, it appears that hydroxychloroquine may enhance the anticoagulant efficacy of vitamin K antagonists in APS patients, and that rituximab may ameliorate some of the "non-criteria" manifestations of APS. The catastrophic antiphospholipid syndrome (CAPS) is associated with diffuse thrombosis, multi-organ dysfunction, and ∼30% mortality. A high incidence of complement regulatory gene mutations, and compelling data concerning the efficacy of eculizumab in CAPS, suggests an important role for complement in this disorder. However, additional work is needed to clarify the role of complement in non-catastrophic APS, though emerging data suggests that complement inhibition may be effective in preventing thrombosis in these patients as well.
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Affiliation(s)
- Anne Hubben
- Department of Cardiovascular and Metabolic Sciences, Taussig Cancer Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Keith R McCrae
- Department of Cardiovascular and Metabolic Sciences, Taussig Cancer Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
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4
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Fernandez-Ruiz R, Belmont HM. The role of anticomplement therapy in lupus nephritis. Transl Res 2022; 245:1-17. [PMID: 35158097 DOI: 10.1016/j.trsl.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 10/19/2022]
Abstract
The complement system plays crucial roles in homeostasis and host defense against microbes. Deficiency of early complement cascade components has been associated with increased susceptibility to systemic lupus erythematosus (SLE), whereas excessive complement consumption is a hallmark of this disease. Although enhanced classical pathway activation by immune complexes was initially thought to be the main contributor to lupus nephritis (LN) pathogenesis, an increasing body of evidence has suggested the alternative and the lectin pathways are also involved. Therapeutic agents targeting complement activation have been used in LN patients and clinical trials are ongoing. We review the mechanisms by which complement system dysregulation contributes to renal injury in SLE and summarize the latest evidence on the use of anticomplement agents to manage this condition.
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Affiliation(s)
- Ruth Fernandez-Ruiz
- Division of Rheumatology, NYU Grossman School of Medicine, New York, New York
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5
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Knight JS, Kanthi Y. Mechanisms of immunothrombosis and vasculopathy in antiphospholipid syndrome. Semin Immunopathol 2022; 44:347-362. [PMID: 35122116 PMCID: PMC8816310 DOI: 10.1007/s00281-022-00916-w] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/19/2022] [Indexed: 12/14/2022]
Abstract
Antiphospholipid syndrome (APS) is an autoimmune thrombophilia propelled by circulating antiphospholipid antibodies that herald vascular thrombosis and obstetrical complications. Antiphospholipid antibodies recognize phospholipids and phospholipid-binding proteins and are not only markers of disease but also key drivers of APS pathophysiology. Thrombotic events in APS can be attributed to various conspirators including activated endothelial cells, platelets, and myeloid-lineage cells, as well as derangements in coagulation and fibrinolytic systems. Furthermore, recent work has especially highlighted the role of neutrophil extracellular traps (NETs) and the complement system in APS thrombosis. Beyond acute thrombosis, patients with APS can also develop an occlusive vasculopathy, a long-term consequence of APS characterized by cell proliferation and infiltration that progressively expands the intima and leads to organ damage. This review will highlight known pathogenic factors in APS and will also briefly discuss similarities between APS and the thrombophilic coagulopathy of COVID-19.
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Affiliation(s)
- Jason S Knight
- Division of Rheumatology, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI, 48109, USA.
| | - Yogendra Kanthi
- Division of Intramural Research National Heart, Lung, and Blood Institute, Bethesda, MD, USA
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6
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Macpherson A, Laabei M, Ahdash Z, Graewert MA, Birtley JR, Schulze MSE, Crennell S, Robinson SA, Holmes B, Oleinikovas V, Nilsson PH, Snowden J, Ellis V, Mollnes TE, Deane CM, Svergun D, Lawson AD, van den Elsen JM. The allosteric modulation of complement C5 by knob domain peptides. eLife 2021; 10:63586. [PMID: 33570492 PMCID: PMC7972453 DOI: 10.7554/elife.63586] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/11/2021] [Indexed: 12/22/2022] Open
Abstract
Bovines have evolved a subset of antibodies with ultra-long heavy chain complementarity determining regions that harbour cysteine-rich knob domains. To produce high-affinity peptides, we previously isolated autonomous 3–6 kDa knob domains from bovine antibodies. Here, we show that binding of four knob domain peptides elicits a range of effects on the clinically validated drug target complement C5. Allosteric mechanisms predominated, with one peptide selectively inhibiting C5 cleavage by the alternative pathway C5 convertase, revealing a targetable mechanistic difference between the classical and alternative pathway C5 convertases. Taking a hybrid biophysical approach, we present C5-knob domain co-crystal structures and, by solution methods, observed allosteric effects propagating >50 Å from the binding sites. This study expands the therapeutic scope of C5, presents new inhibitors, and introduces knob domains as new, low molecular weight antibody fragments, with therapeutic potential. Antibodies are proteins produced by the immune system that can selectively bind to other molecules and modify their behaviour. Cows are highly equipped at fighting-off disease-causing microbes due to the unique shape of some of their antibodies. Unlike other jawed vertebrates, cows’ antibodies contain an ultra-long loop region that contains a ‘knob domain’ which sticks out from the rest of the antibody. Recent research has shown that when detached, the knob domain behaves like an antibody fragment, and can independently bind to a range of different proteins. Antibody fragments are commonly developed in the laboratory to target proteins associated with certain diseases, such as arthritis and cancer. But it was unclear whether the knob domains from cows’ antibodies could also have therapeutic potential. To investigate this, Macpherson et al. studied how knob domains attach to complement C5, a protein in the inflammatory pathway which is a drug target for various diseases, including severe COVID-19. The experiments identified various knob domains that bind to complement C5 and inhibits its activity by altering its structure or movement. Further tests studying the structure of these interactions, led to the discovery of a common mechanism by which inhibitors can modify the behaviour of this inflammatory protein. Complement C5 is involved in numerous molecular pathways in the immune system, which means many of the drugs developed to inhibit its activity can also leave patients vulnerable to infection. However, one of the knob domains identified by Macpherson et al. was found to reduce the activity of complement C5 in some pathways, whilst leaving other pathways intact. This could potentially reduce the risk of bacterial infections which sometimes arise following treatment with these types of inhibitors. These findings highlight a new approach for developing drug inhibitors for complement C5. Furthermore, the ability of knob domains to bind to multiple sites of complement C5 suggests that this fragment could be used to target proteins associated with other diseases.
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Affiliation(s)
- Alex Macpherson
- UCB, Slough, United Kingdom.,Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Maisem Laabei
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | | | | | | | | | - Susan Crennell
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Sarah A Robinson
- Department of Statistics, University of Oxford, Oxford, United Kingdom
| | | | | | - Per H Nilsson
- UCB, Slough, United Kingdom.,Department of Chemistry and Biomedicine, Linnaeus University, Kalmar, Sweden.,Department of Immunology, Oslo University Hospital, University of Oslo, Oslo, Norway
| | | | | | - Tom Eirik Mollnes
- Department of Immunology, Oslo University Hospital, University of Oslo, Oslo, Norway.,Research Laboratory, Bodø Hospital, K.G. Jebsen TREC, University of Tromsø, Tromsø, Norway.,Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Charlotte M Deane
- Department of Statistics, University of Oxford, Oxford, United Kingdom
| | - Dmitri Svergun
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | | | - Jean Mh van den Elsen
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom.,Centre for Therapeutic Innovation, University of Bath, Bath, United Kingdom
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7
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Van Avondt K, Nur E, Zeerleder S. Mechanisms of haemolysis-induced kidney injury. Nat Rev Nephrol 2019; 15:671-692. [PMID: 31455889 DOI: 10.1038/s41581-019-0181-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2019] [Indexed: 12/16/2022]
Abstract
Intravascular haemolysis is a fundamental feature of chronic hereditary and acquired haemolytic anaemias, including those associated with haemoglobinopathies, complement disorders and infectious diseases such as malaria. Destabilization of red blood cells (RBCs) within the vasculature results in systemic inflammation, vasomotor dysfunction, thrombophilia and proliferative vasculopathy. The haemoprotein scavengers haptoglobin and haemopexin act to limit circulating levels of free haemoglobin, haem and iron - potentially toxic species that are released from injured RBCs. However, these adaptive defence systems can fail owing to ongoing intravascular disintegration of RBCs. Induction of the haem-degrading enzyme haem oxygenase 1 (HO1) - and potentially HO2 - represents a response to, and endogenous defence against, large amounts of cellular haem; however, this system can also become saturated. A frequent adverse consequence of massive and/or chronic haemolysis is kidney injury, which contributes to the morbidity and mortality of chronic haemolytic diseases. Intravascular destruction of RBCs and the resulting accumulation of haemoproteins can induce kidney injury via a number of mechanisms, including oxidative stress and cytotoxicity pathways, through the formation of intratubular casts and through direct as well as indirect proinflammatory effects, the latter via the activation of neutrophils and monocytes. Understanding of the detailed pathophysiology of haemolysis-induced kidney injury offers opportunities for the design and implementation of new therapeutic strategies to counteract the unfavourable and potentially fatal effects of haemolysis on the kidney.
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Affiliation(s)
- Kristof Van Avondt
- Department of Immunopathology, Sanquin Research, and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. .,Institute for Cardiovascular Prevention (IPEK), Ludwig Maximilian University of Munich, Munich, Germany.
| | - Erfan Nur
- Department of Haematology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Sacha Zeerleder
- Department of Immunopathology, Sanquin Research, and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. .,Department of Haematology and Central Haematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland. .,Department for BioMedical Research, University of Bern, Bern, Switzerland.
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8
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Sezin T, Murthy S, Attah C, Seutter M, Holtsche MM, Hammers CM, Schmidt E, Meshrkey F, Mousavi S, Zillikens D, Nunn MA, Sadik CD. Dual inhibition of complement factor 5 and leukotriene B4 synergistically suppresses murine pemphigoid disease. JCI Insight 2019; 4:128239. [PMID: 31391346 DOI: 10.1172/jci.insight.128239] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/09/2019] [Indexed: 11/17/2022] Open
Abstract
The treatment of most autoimmune diseases still relies on systemic immunosuppression and is associated with severe side effects. The development of drugs that more specifically abrogate pathogenic pathways is therefore most desirable. In nature, such specificity is exemplified, e.g., by the soft tick-derived biotherapeutic Coversin, which locally suppresses immune responses by inhibiting complement factor 5 (C5) and leukotriene B4 (LTB4). C5a, a proteolytic fragment of C5, and LTB4 are critical drivers of skin inflammation in pemphigoid diseases (PDs), a group of autoimmune blistering skin diseases. Here, we demonstrate that both Coversin and its mutated form L-Coversin, which inhibits LTB4 only, dose dependently attenuate disease in a model of bullous pemphigoid-like epidermolysis bullosa acquisita (BP-like EBA). Coversin, however, reduces disease more effectively than L-Coversin, indicating that inhibition of C5 and LTB4 synergize in their suppressing effects in this model. Further supporting the therapeutic potential of Coversin in humans, we found that C5a and LTB4 are both present in the blister fluid of patients with BP in quantities inducing the recruitment of granulocytes and that the number of cells expressing their receptors, C5aR1 and BLT1, respectively, is increased in perilesional skin. Collectively, our results highlight Coversin and possibly L-Coversin as potential therapeutics for PDs.
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Affiliation(s)
- Tanya Sezin
- Department of Dermatology, Allergy, and Venereology
| | | | | | | | | | | | - Enno Schmidt
- Lübeck Institute for Experimental Dermatology, and.,Center for Research on Inflammation of the Skin, University of Lübeck, Lübeck, Germany
| | | | | | - Detlef Zillikens
- Department of Dermatology, Allergy, and Venereology.,Center for Research on Inflammation of the Skin, University of Lübeck, Lübeck, Germany
| | | | - Christian D Sadik
- Department of Dermatology, Allergy, and Venereology.,Center for Research on Inflammation of the Skin, University of Lübeck, Lübeck, Germany
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9
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Chmelař J, Kotál J, Kovaříková A, Kotsyfakis M. The Use of Tick Salivary Proteins as Novel Therapeutics. Front Physiol 2019; 10:812. [PMID: 31297067 PMCID: PMC6607933 DOI: 10.3389/fphys.2019.00812] [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: 04/25/2019] [Accepted: 06/11/2019] [Indexed: 12/12/2022] Open
Abstract
The last three decades of research into tick salivary components have revealed several proteins with important pharmacological and immunological activities. Two primary interests have driven research into tick salivary secretions: the search for suitable pathogen transmission blocking or “anti-tick” vaccine candidates and the search for novel therapeutics derived from tick salivary components. Intensive basic research in the field of tick salivary gland transcriptomics and proteomics has identified several major protein families that play important roles in tick feeding and overcoming vertebrate anti-tick responses. Moreover, these families contain members with unrealized therapeutic potential. Here we review the major tick salivary protein families exploitable in medical applications such as immunomodulation, inhibition of hemostasis and inflammation. Moreover, we discuss the potential, opportunities, and challenges in searching for novel tick-derived drugs.
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Affiliation(s)
- Jindřich Chmelař
- Department of Medical Biology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czechia
| | - Jan Kotál
- Department of Medical Biology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czechia.,Laboratory of Genomics and Proteomics of Disease Vectors, Biology Centre CAS, Institute of Parasitology, České Budějovice, Czechia
| | - Anna Kovaříková
- Department of Medical Biology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czechia
| | - Michail Kotsyfakis
- Department of Medical Biology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czechia.,Laboratory of Genomics and Proteomics of Disease Vectors, Biology Centre CAS, Institute of Parasitology, České Budějovice, Czechia
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10
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The Extended Use of Eculizumab in Pregnancy and Complement Activation⁻Associated Diseases Affecting Maternal, Fetal and Neonatal Kidneys-The Future Is Now? J Clin Med 2019; 8:jcm8030407. [PMID: 30909646 PMCID: PMC6463259 DOI: 10.3390/jcm8030407] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 12/18/2022] Open
Abstract
Excessive complement activation is involved in the pathogenesis of many diseases and the kidney is an organ with particular susceptibility to complement-mediated injury. Apart from paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS), there are several other diseases with clear evidence of complement activation affecting both maternal and fetal kidneys during pregnancy and causing long-term adverse outcomes. Several novel drugs have been recently developed for blocking the complement cascade, including purified plasma proteins, new monoclonal antibodies, recombinant proteins, small molecules, and small interfering RNA agents. Eculizumab, the humanized monoclonal IgG2/4-antibody targeting C5 was approved by the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for treatment of two rare diseases: PNH in 2007 and aHUS in 2011. There is an increasing number of publications of successful use of eculizumab for off-label indications, e.g., in pregnant women with antiphospholipid syndrome, sickle-cell anemia, and HELLP syndrome. These severe diseases are associated with both high maternal and fetal morbidity and mortality rate and substantial prematurity. Eculizumab has considerably improved overall outcome of patients with PNH and aHUS, enabling safe pregnancy for many women. Prolongation of pregnancy and the use of eculizumab, even for only a few weeks, may protect not only maternal renal function, but also alleviate acute and long-term renal consequences of prematurity in offspring.
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11
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Ruffatti A, Tarzia V, Fedrigo M, Calligaro A, Favaro M, Macor P, Tison T, Cucchini U, Cosmi E, Tedesco F, Angelini A, Gerosa G. Evidence of complement activation in the thrombotic small vessels of a patient with catastrophic antiphospholipid syndrome treated with eculizumab. Autoimmun Rev 2019; 18:561-563. [PMID: 30844561 DOI: 10.1016/j.autrev.2019.03.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 01/16/2019] [Indexed: 11/25/2022]
Affiliation(s)
- Amelia Ruffatti
- Rheumatology Unit, Department of Medicine, University Hospital of Padua, Via Giustiniani, 2, 35128 Padua, Italy.
| | - Vincenzo Tarzia
- Cardiac Surgery Unit, Department of Cardiac, Thoracic and Vascular Sciences, University Hospital of Padua, Via Giustiniani, 2, 35, 128 Padua, Italy.
| | - Marny Fedrigo
- Cardiovascular Pathology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University Hospital of Padua, Via A. Gabelli, 61, 35121 Padua, Italy.
| | - Antonia Calligaro
- Rheumatology Unit, Department of Medicine, University Hospital of Padua, Via Giustiniani, 2, 35128 Padua, Italy
| | - Maria Favaro
- Rheumatology Unit, Department of Medicine, University Hospital of Padua, Via Giustiniani, 2, 35128 Padua, Italy
| | - Paolo Macor
- Department of Life Sciences, University of Trieste, Strada di Fiume, 447, 34149 Trieste, Italy.
| | - Tiziana Tison
- Immunohematology and Transfusion Medicine Unit, University Hospital of Padua, Via Giustiniani, 2, 35128 Padua, Italy.
| | - Umberto Cucchini
- Cardiology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University Hospital of Padua, Via Giustiniani, 2, 35128 Padua, Italy
| | - Erich Cosmi
- Obstetrics and Gynecology Unit, Department of Woman's and Child's Health, University Hospital of Padua, Via Giustiniani, 3, 35128 Padua, Italy
| | - Francesco Tedesco
- Clinical Immunology and Rheumatology Research Department Auxologico Institute Milan, IRCCS, Via G. Spagnoletto, 3, 20149 Milan, Italy.
| | - Annalisa Angelini
- Cardiovascular Pathology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University Hospital of Padua, Via A. Gabelli, 61, 35121 Padua, Italy.
| | - Gino Gerosa
- Cardiac Surgery Unit, Department of Cardiac, Thoracic and Vascular Sciences, University Hospital of Padua, Via Giustiniani, 2, 35, 128 Padua, Italy.
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12
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McDonnell T, Artim-Esen B, Wincup C, Ripoll VM, Isenberg D, Giles IP, Rahman A, Pericleous C. Antiphospholipid Antibodies to Domain I of Beta-2-Glycoprotein I Show Different Subclass Predominance in Comparison to Antibodies to Whole Beta-2-glycoprotein I. Front Immunol 2018; 9:2244. [PMID: 30323817 PMCID: PMC6173128 DOI: 10.3389/fimmu.2018.02244] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/10/2018] [Indexed: 11/19/2022] Open
Abstract
Antiphospholipid antibodies (aPL), the serological hallmark of antiphospholipid syndrome (APS), are a heterogeneous group of autoantibodies raised against circulating blood proteins. Of these proteins, the phospholipid-binding b2-glycoprotein I (β2GPI) is considered to be the main autoantigen in APS. Indeed, IgG antibodies targeting b2GPI (ab2GPI) directly cause both thrombosis and pregnancy morbidity in several mouse models. While antibodies raised against all five domains of b2GPI have been reported, a subgroup of IgG ab2GPI raised against the first domain (DI) of b2GPI (aDI), strongly correlate with thrombotic APS, and drive thrombosis and pregnancy loss in vivo. Few studies have focused on determining the type of IgG subclass(es) for aPL. The subclass of an antibody is important as this dictates the potential activity of an antibody; for example, IgG1 and IgG3 can fix complement better and are able to cross the placenta compared to IgG2 and IgG4. It is unknown what subclass IgG aDI are, and whether they are the same as ab2GPI. To determine IgG subclass distribution for ab2GPI and aDI, we purified total IgG from the serum of 19 APS patients with known ab2GPI and aDI activity. Using subclass-specific conjugated antibodies, we modified our established in-house ab2GPI and aDI ELISAs to individually measure IgG1, IgG2, IgG3, and IgG4. We found that while IgG1, IgG2, and IgG3 ab2GPI levels were similar, a marked difference was seen in IgG subclass aDI levels. Specifically, significantly higher levels of IgG3 aDI were detected compared to IgG1, IgG2, or IgG4 (p < 0.05 for all comparisons). Correlation analysis of subclass-specific ab2GPI vs. aDI demonstrated that IgG3 showed the weakest correlation (r = 0.45, p = 0.0023) compared to IgG1 (r = 0.61, p = 0.0001) and IgG2 (r = 0.81, p = 0.0001). Importantly, total subclass levels in IgG purified from APS and healthy serum (n = 10 HC n = 12 APS) did not differ, suggesting that the increased IgG3 aDI signal seen in APS-derived IgG is antigen-specific. To conclude, our data suggests that aDI show a different IgG subclass distribution to ab2GPI. Our results highlight the importance of aDI testing for patient stratification and may point toward differential underlying aPL-driven pathogenic processes that may be subclass restricted.
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Affiliation(s)
- Thomas McDonnell
- Division of Medicine, Rayne Institute, University College London, London, United Kingdom
| | - Bahar Artim-Esen
- Division of Rheumatology, Department of Internal Medicine, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Chris Wincup
- Division of Medicine, Rayne Institute, University College London, London, United Kingdom
| | - Vera M. Ripoll
- Division of Medicine, Rayne Institute, University College London, London, United Kingdom
| | - David Isenberg
- Division of Medicine, Rayne Institute, University College London, London, United Kingdom
| | - Ian P. Giles
- Division of Medicine, Rayne Institute, University College London, London, United Kingdom
| | - Anisur Rahman
- Division of Medicine, Rayne Institute, University College London, London, United Kingdom
| | - Charis Pericleous
- Imperial College Vascular Sciences National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine (ICTEM), London, United Kingdom
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13
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Tektonidou MG. Antiphospholipid Syndrome Nephropathy: From Pathogenesis to Treatment. Front Immunol 2018; 9:1181. [PMID: 29904380 PMCID: PMC5990608 DOI: 10.3389/fimmu.2018.01181] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/11/2018] [Indexed: 11/13/2022] Open
Abstract
Kidney damage is a well-recognized complication of the antiphospholipid syndrome (APS), either primary or systemic lupus erythematosus (SLE)-associated APS. Kidney involvement in APS involves a variety of manifestations, such as renal artery thrombosis or stenosis, renal vein thrombosis, allograft loss due to thrombosis after kidney transplantation, and injury to the renal microvasculature, also known as APS nephropathy. Biopsy in patients with APS nephropathy includes acute thrombotic microangiopathy lesions and chronic intrarenal vascular lesions such as interlobular fibrous intimal hyperplasia, arterial and arteriolar recanalizing thrombosis, fibrous arterial occlusion, and focal cortical atrophy. The most frequent clinical features are hypertension, microscopic hematuria, proteinuria (ranging from mild to nephritic levels), and renal insufficiency. It is uncertain whether antiphospholipid antibodies or other factors are implicated in the development of APS nephropathy, and whether it is driven mainly by thrombotic or by inflammatory processes. Experimental models and clinical studies of thrombotic microangiopathy lesions implicate activation of the complement cascade, tissue factor, and the mTORC pathway. Currently, the management of APS nephropathy relies on expert opinion, and consensus is lacking. There is limited evidence about the effect of anticoagulants, and their use remains controversial. Treatment approaches in patients with APS nephropathy lesions may include the use of heparin based on its role on complement activation pathway inhibition or the use of intravenous immunoglobulin and/or plasma exchange. Targeted therapies may also be considered based on potential APS nephropathy pathogenetic mechanisms such as B-cell directed therapies, complement inhibition, tissue factor inhibition, mTOR pathway inhibition, or anti-interferon antibodies, but prospective multicenter studies are needed to address their role.
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Affiliation(s)
- Maria G Tektonidou
- Joint Rheumatology Academic Program, First Department of Propaedeutic Internal Medicine, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
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Radic M, Pattanaik D. Cellular and Molecular Mechanisms of Anti-Phospholipid Syndrome. Front Immunol 2018; 9:969. [PMID: 29867951 PMCID: PMC5949565 DOI: 10.3389/fimmu.2018.00969] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/18/2018] [Indexed: 01/10/2023] Open
Abstract
The primary anti-phospholipid syndrome (APS) is characterized by the production of antibodies that bind the phospholipid-binding protein β2 glycoprotein I (β2GPI) or that directly recognize negatively charged membrane phospholipids in a manner that may contribute to arterial or venous thrombosis. Clinically, the binding of antibodies to β2GPI could contribute to pathogenesis by formation of immune complexes or modification of coagulation steps that operate along cell surfaces. However, additional events are likely to play a role in pathogenesis, including platelet and endothelial cell activation. Recent studies focus on neutrophil release of chromatin in the form of neutrophil extracellular traps as an important disease contributor. Jointly, the participation of both the innate and adaptive arms of the immune system in aspects of the APS make the complete understanding of crucial steps in pathogenesis extremely difficult. Only coordinated and comprehensive analyses, carried out in different clinical and research settings, are likely to advance the understanding of this complex disease condition.
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Affiliation(s)
- Marko Radic
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Debendra Pattanaik
- Division of Rheumatology, Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
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Chighizola CB, Andreoli L, Gerosa M, Tincani A, Ruffatti A, Meroni PL. The treatment of anti-phospholipid syndrome: A comprehensive clinical approach. J Autoimmun 2018; 90:1-27. [PMID: 29449131 DOI: 10.1016/j.jaut.2018.02.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 02/06/2018] [Indexed: 01/02/2023]
Abstract
Anti-phospholipid syndrome (APS) is an acquired pro-thrombotic autoimmune disease that predisposes to thrombotic events and/or obstetric complications, in the persistent presence of anti-phospholipid antibodies (aPL). Life long moderate-intensity anticoagulation is the option of choice for aPL-positive patients with a previous thrombosis; critical issues concern the management of those with a history of arterial event due to the high rate of recurrence. Alternatives comprise anti-platelet agents and high-intensity anticoagulation. Low dose aspirin (LDASA) and low molecular weight heparin provide the mainstay of the treatment of obstetric APS, allowing a birth rate in 70% of cases. The management of refractory APS, thrombotic as well as obstetric, is highly debated, but an increasing burden of evidence points towards the beneficial effects of multiple treatments. Similarly, a management envisaging multiple drugs (anticoagulation, steroids, plasma exchange and/or intravenous immunoglobulins) is the most effective approach in catastrophic APS. Asymptomatic aPL carriers are at higher risk of thrombotic and obstetric complications compared to the general population, thus potentially benefitting of a pharmacological intervention. LDASA and hydroxychloroquine can be considered as options, in particular in case of high risk aPL profile, concomitant cardiovascular risk factors or associated autoimmune disease. APS is apparently a simple condition, but its multifaceted nature requires a complex and tailored treatment.
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Affiliation(s)
- Cecilia Beatrice Chighizola
- Department of Clinical Sciences and Community Health, University of Milan, Via Festa del Perdono 7, 20122, Milan, Italy; Experimental Laboratory of Immunological and Rheumatologic Researches, IRCCS Istituto Auxologico Italiano, Via Zucchi 18, 20095 Cusano Milanino, Milan, Italy; Allergology, Clinical Immunology and Rheumatology, Piazzale Brescia 20, 20149, Milan, Italy.
| | - Laura Andreoli
- Rheumatology and Clinical Immunology, Spedali Civili of Brescia, Department of Clinical and Experimental Sciences, University of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Maria Gerosa
- Department of Clinical Sciences and Community Health, University of Milan, Via Festa del Perdono 7, 20122, Milan, Italy; Experimental Laboratory of Immunological and Rheumatologic Researches, IRCCS Istituto Auxologico Italiano, Via Zucchi 18, 20095 Cusano Milanino, Milan, Italy; Department of Rheumatology, ASST Istituto Gaetano Pini & CTO, Piazza Cardinal Ferrari, 1 20122, Milan, Italy
| | - Angela Tincani
- Rheumatology and Clinical Immunology, Spedali Civili of Brescia, Department of Clinical and Experimental Sciences, University of Brescia, Piazzale Spedali Civili 1, 25123, Brescia, Italy
| | - Amelia Ruffatti
- Rheumatology Unit, Department of Medicine, University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Pier Luigi Meroni
- Experimental Laboratory of Immunological and Rheumatologic Researches, IRCCS Istituto Auxologico Italiano, Via Zucchi 18, 20095 Cusano Milanino, Milan, Italy
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Brocklebank V, Kavanagh D. Complement C5-inhibiting therapy for the thrombotic microangiopathies: accumulating evidence, but not a panacea. Clin Kidney J 2017; 10:600-624. [PMID: 28980670 PMCID: PMC5622895 DOI: 10.1093/ckj/sfx081] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/21/2017] [Indexed: 02/07/2023] Open
Abstract
Thrombotic microangiopathy (TMA), characterized by organ injury occurring consequent to severe endothelial damage, can manifest in a diverse range of diseases. In complement-mediated atypical haemolytic uraemic syndrome (aHUS) a primary defect in complement, such as a mutation or autoantibody leading to over activation of the alternative pathway, predisposes to the development of disease, usually following exposure to an environmental trigger. The elucidation of the pathogenesis of aHUS resulted in the successful introduction of the complement inhibitor eculizumab into clinical practice. In other TMAs, although complement activation may be seen, its role in the pathogenesis remains to be confirmed by an interventional trial. Although many case reports in TMAs other than complement-mediated aHUS hint at efficacy, publication bias, concurrent therapies and in some cases the self-limiting nature of disease make broader interpretation difficult. In this article, we will review the evidence for the role of complement inhibition in complement-mediated aHUS and other TMAs.
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Affiliation(s)
- Vicky Brocklebank
- The National Renal Complement Therapeutics Centre (NRCTC), Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - David Kavanagh
- The National Renal Complement Therapeutics Centre (NRCTC), Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
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Rand JH, Wu XX, Wolgast LR, Lei V, Conway EM. A novel 2-stage approach that detects complement activation in patients with antiphospholipid antibody syndrome. Thromb Res 2017. [PMID: 28628799 DOI: 10.1016/j.thromres.2017.06.014] [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] [Indexed: 12/16/2022]
Abstract
INTRODUCTION The antiphospholipid syndrome (APS) is marked by autoantibodies that recognize anionic phospholipids in a cofactor-dependent manner. A role for complement has been implicated in the pathophysiology, however, elevations of complement activation markers have not been consistently demonstrated in clinical studies. We therefore designed a proof-of-principle study to determine whether complement activation might be detectable in APS by first exposing plasmas to phospholipid vesicles. METHODS We examined complement activation markers in patients with APS, non-APS thrombosis, systemic lupus erythematosus, cancer, patients with antiphospholipid antibodies without thrombosis (APL) and healthy controls. Direct measurements of plasma C5a and sC5b-9 levels were compared to levels that were generated in normal serum by phospholipid vesicles that had been pre-incubated with the same plasmas. We then determined the effects of the C5 inhibitor, eculizumab, examined the complement pathways involved, and determined whether the effects could be reproduced with purified IgGs and β2-glycoprotein I (β2GPI). RESULTS Plasma levels of C5a and sC5b-9 were higher, but not significantly increased in APS patients compared to healthy controls. In contrast, phospholipid vesicles pre-incubated with APS plasmas generated significantly higher levels than healthy controls and the other groups, except for APL patients. Complement activation was abrogated by addition of eculizumab. The results with substrate sera indicated that the alternative and classical/lectin pathways were involved. The results were reproducible with purified IgGs and β2GPI. CONCLUSION This proof-of-principle study confirms a role for complement in APS and opens the possibility of monitoring complement activation by including phospholipid vesicles in assay systems.
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Affiliation(s)
- Jacob H Rand
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, United States
| | - Xiao-Xuan Wu
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, United States
| | - Lucia R Wolgast
- Department of Pathology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Victor Lei
- Centre for Blood Research, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Edward M Conway
- Centre for Blood Research, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Arachchillage DRJ, Laffan M. Pathogenesis and management of antiphospholipid syndrome. Br J Haematol 2017; 178:181-195. [PMID: 28339096 DOI: 10.1111/bjh.14632] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Antiphospholipid antibodies are a heterogeneous group of autoantibodies that have clear associations with thrombosis and pregnancy morbidity, and which together constitute the 'antiphospholipid syndrome' (APS). However, the pathophysiology of these complications is not well understood and their heterogeneity suggests that more than one pathogenic process may be involved. Diagnosis remains a combination of laboratory analysis and clinical observation but there have been significant advances in identifying specific pathogenic features, such as domain I-specific anti-β2-glycoprotein-I antibodies. This in turn has pointed to endothelial and complement activation as important factors in the pathogenesis of APS. Consequently, although anticoagulation remains the standard treatment for thrombotic APS and during pregnancy, the realisation that these additional pathways are involved in the pathogenesis of APS has significant implications for treatment: agents acting outside the coagulation system, such as hydroxychloroquine for pregnancy complications and sirolimus as an inhibitor of the mammalian target of rapamycin (mTOR) pathway, are now under evaluation and represent a radical change in thinking for haematologists. Conventional anticoagulation is also under challenge from new, direct acting anticoagulants. This review will provide a comprehensive overview of the evolving understanding of APS pathogenesis and how this and novel therapeutics will alter diagnosis and management.
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Affiliation(s)
- Deepa R J Arachchillage
- Department of Haematology, Imperial College Healthcare NHS Trust and Imperial College London, Hammersmith Hospital, London, UK
| | - Mike Laffan
- Department of Haematology, Imperial College Healthcare NHS Trust and Imperial College London, Hammersmith Hospital, London, UK
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Gustavsen A, Skattum L, Bergseth G, Lorentzen B, Floisand Y, Bosnes V, Mollnes TE, Barratt-Due A. Effect on mother and child of eculizumab given before caesarean section in a patient with severe antiphospholipid syndrome: A case report. Medicine (Baltimore) 2017; 96:e6338. [PMID: 28296762 PMCID: PMC5369917 DOI: 10.1097/md.0000000000006338] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
RATIONALE Antiphospholipid syndrome (APS) in pregnancy may trigger the life-threatening catastrophic antiphospholipid syndrome (CAPS). Complement activation is implicated in the pathogenesis, and inhibition of complement factor C5 is suggested as an additional treatment option. PATIENT CONCERNS, DIAGNOSIS AND INTERVENTIONS We present a pregnant patient treated with the C5-inhibitor eculizumab due to high risk of developing devastating APS-related complications. The complement inhibitory effects of the treatment were examined both in the patient and the premature infant. OUTCOMES Complement activity in the mother recovered considerably faster than anticipated; however, no new thrombosis or CAPS developed during the last week of pregnancy or postpartum. Blood sampling from the umbilical vein and artery, and from the infant after delivery showed low complement activity; however, only 0.3% of the eculizumab concentration detected in the mother, consistent with low placental passage of eculizumab. LESSONS The data underscore the importance of close monitoring of complement inhibition and individualizing dosage regimens in pregnant patients receiving eculizumab. We document how traditional functional complement activity tests cannot assess the effect of eculizumab in premature infants due to the very low levels of complement factors detected in this infant born in gestational week 33. Only trace amounts of eculizumab passed the placenta. In conclusion, complement C5 inhibition might be a safe candidate treatment option for APS during pregnancy and delivery, and additionally, enables prolongation of pregnancy with important weeks.
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Affiliation(s)
- Alice Gustavsen
- Department of Immunology, Oslo University Hospital, and K.G. Jebsen IRC, University of Oslo, Oslo, Norway
| | - Lillemor Skattum
- Department of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology, Lund University and Clinical Immunology and Transfusion Medicine, Region Skane, Lund, Sweden
| | - Grethe Bergseth
- Research Laboratory, Nordland Hospital Bodø, and K.G. Jebsen TREC, University of Tromsø
| | | | | | - Vidar Bosnes
- Department of Immunology, Section of Medical Immunology, Oslo University Hospital, Oslo
| | - Tom Eirik Mollnes
- Department of Immunology, Oslo University Hospital, and K.G. Jebsen IRC, University of Oslo, Oslo, Norway
- Research Laboratory, Nordland Hospital Bodø, and K.G. Jebsen TREC, University of Tromsø
- Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim
| | - Andreas Barratt-Due
- Department of Immunology, Oslo University Hospital, and K.G. Jebsen IRC, University of Oslo, Oslo, Norway
- Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway
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Arachchillage DRJ, Mackie IJ, Efthymiou M, Chitolie A, Hunt BJ, Isenberg DA, Khamashta M, Machin SJ, Cohen H. Rivaroxaban limits complement activation compared with warfarin in antiphospholipid syndrome patients with venous thromboembolism. J Thromb Haemost 2016; 14:2177-2186. [PMID: 27541499 DOI: 10.1111/jth.13475] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Indexed: 12/19/2022]
Abstract
Essentials Complement activation has a pathogenic role in thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Complement activation markers were elevated in anticoagulated thrombotic APS patients. Complement activation decreased in APS patients switching from warfarin to rivaroxaban. SUMMARY Background Complement activation may play a major role in the pathogenesis of thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Aims To establish whether rivaroxaban, a direct factor Xa inhibitor, limits complement activation compared with warfarin in APS patients with previous venous thromboembolism (VTE). Methods A total of 111 APS patients with previous VTE, on warfarin target INR 2.5, had blood samples taken at baseline and at day 42 after randomization in the RAPS (Rivaroxaban in Antiphospholipid Syndrome) trial. Fifty-six patients remained on warfarin and 55 switched to rivaroxaban. Fifty-five normal controls (NC) were also studied. Markers of complement activation (C3a, C5a, terminal complement complex [SC5b-9] and Bb fragment) were assessed. Results APS patients had significantly higher complement activation markers compared with NC at both time-points irrespective of the anticoagulant. There were no differences between the two patient groups at baseline, or patients remaining on warfarin at day 42. In 55 patients randomized to rivaroxaban, C3a, C5a and SC5b-9 were lower at day 42 (median (ng mL-1 ) [confidence interval] 64 [29-125] vs. 83 [35-147], 9 [2-15] vs. 12 [4-18] and 171 [56-245] vs. 201 [66-350], respectively) but levels of Bb fragment were unchanged. There were no correlations between rivaroxaban levels and complement activation markers. Conclusions APS patients with previous VTE on warfarin exhibit increased complement activation, which is likely to occur via the classical pathway and is decreased by rivaroxaban administration. Rivaroxaban may therefore potentially provide an additional benefit to its anticoagulant effect in this patient group by limiting complement activation.
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Affiliation(s)
- D R J Arachchillage
- Department of Haematology, Haemostasis Research Unit, University College London, London, UK
| | - I J Mackie
- Department of Haematology, Haemostasis Research Unit, University College London, London, UK
| | - M Efthymiou
- Department of Haematology, Haemostasis Research Unit, University College London, London, UK
| | - A Chitolie
- Department of Haematology, Haemostasis Research Unit, University College London, London, UK
| | - B J Hunt
- Thrombosis and Haemophilia, Guy's and St Thomas' NHS Foundation Trust, London, UK
- Department of Haematology, Kings College London, London, UK
| | - D A Isenberg
- Centre for Rheumatology, Division of Medicine, University College London, London, UK
| | - M Khamashta
- Lupus Research Unit, Guy's and St Thomas' NHS Foundation Trust, London, UK
- Department of Rheumatology, Kings College London, London, UK
| | - S J Machin
- Department of Haematology, Haemostasis Research Unit, University College London, London, UK
| | - H Cohen
- Department of Haematology, Haemostasis Research Unit, University College London, London, UK
- Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
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Kuhn N, Schmidt CQ, Schlapschy M, Skerra A. PASylated Coversin, a C5-Specific Complement Inhibitor with Extended Pharmacokinetics, Shows Enhanced Anti-Hemolytic Activity in Vitro. Bioconjug Chem 2016; 27:2359-2371. [PMID: 27598771 DOI: 10.1021/acs.bioconjchem.6b00369] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The Ornithodoros moubata Complement Inhibitor (OmCI) binds complement component 5 (C5) with high affinity and, thus, selectively prevents proteolytic activation of the terminal lytic complement pathway. A recombinant version of OmCI (also known as Coversin and rEV576) has proven efficacious in several animal models of complement-mediated diseases and successfully completed a phase Ia clinical trial. Coversin is a small 17 kDa lipocalin protein which has a very short plasma half-life if not bound to C5; therefore, the drug requires frequent dosing. We have improved the pharmacokinetics of Coversin by N-terminal translational conjugation with a 600 residue polypeptide composed of Pro, Ala, and Ser (PAS) residues. To this end, PAS-Coversin as well as the unmodified Coversin were functionally expressed in the cytoplasm of E. coli and purified to homogeneity. Both versions showed identical affinity to human C5, as determined by surface plasmon resonance measurements, and revealed similar complement inhibitory activity, as measured in ELISAs with human serum. In line with the PEG-like biophysical properties, PASylation dramatically prolonged the plasma half-life of uncomplexed Coversin by a factor ≥50 in mice. In a clinically relevant in vitro model of the complement-mediated disease paroxysmal nocturnal hemoglobinuria (PNH) both versions of Coversin effectively reduced erythrocyte lysis. Unexpectedly, while the IC50 values were comparable, PAS-Coversin reached a substantially lower plateau of residual lysis at saturating inhibitor concentrations. Taken together, our data demonstrate two clinically relevant improvements of PASylated Coversin: markedly increased plasma half-life and considerably reduced background hemolysis of erythrocytes with PNH-induced phenotype.
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Affiliation(s)
- Nadine Kuhn
- Munich Center for Integrated Protein Science (CIPS-M) and Lehrstuhl für Biologische Chemie, Technische Universität München , Emil-Erlenmeyer-Forum 5, 85354 Freising (Weihenstephan), Germany
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm University , Helmholtzstrasse 20, 89081 Ulm, Germany
| | - Martin Schlapschy
- Munich Center for Integrated Protein Science (CIPS-M) and Lehrstuhl für Biologische Chemie, Technische Universität München , Emil-Erlenmeyer-Forum 5, 85354 Freising (Weihenstephan), Germany.,XL-protein GmbH , Lise-Meitner-Strasse 30, 85354 Freising, Germany
| | - Arne Skerra
- Munich Center for Integrated Protein Science (CIPS-M) and Lehrstuhl für Biologische Chemie, Technische Universität München , Emil-Erlenmeyer-Forum 5, 85354 Freising (Weihenstephan), Germany.,XL-protein GmbH , Lise-Meitner-Strasse 30, 85354 Freising, Germany
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Complement activation in antiphospholipid syndrome and its inhibition to prevent rethrombosis after arterial surgery. Blood 2016; 127:365-7. [DOI: 10.1182/blood-2015-09-672139] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Picceli VF, Skare TL, Nisihara RM, Nass FR, Messias-Reason IT, Utiyama SRR. BF*F allotype of the alternative pathway of complement: A marker of protection against the development of antiphospholipid antibodies in patients with systemic lupus erythematosus. Lupus 2015; 25:412-7. [DOI: 10.1177/0961203315615222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/02/2015] [Indexed: 12/18/2022]
Abstract
Background B factor (BF) from the alternative complement pathway seems to participate in the pathophysiology of systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). Objective To study the allotypic variability of BF in SLE and their associations with clinical and autoantibodies profile. Methods BF allotypes were determined by high-voltage agarose gel electrophoresis, under constant cooling, followed by immunofixation with anti-human BF antibody, in 188 SLE patients and 103 controls. Clinical and serological data were obtained from medical examination and records. Results No significant differences of BF variants between patients and controls were found, neither in relation to epidemiologic or clinical manifestations. Associations of phenotype BF SS07 and allotype BF*S07 were found with anticardiolipin IgM (aCl-IgM) antibodies ( p = 0.014 and p = 0.009 respectively), but not with aCl-IgG, lupus anticoagulant (LA), anti β2GPI or clinical APS. A significant decrease in BF*F allotype ( p = 0.043) and BF SF phenotype ( p = 0.018) was detected in patients with anti-phospholipid antibodies as a whole (aCl-IgG, aCl-IgM, LA and anti β2GPI). Conclusions There is a link between phenotype BF SS07 and allotype BF*S07 with aCl-IgM in SLE patients; BF*F allotype could be considered a marker of protection against the development of antiphospholipid antibodies in these patients.
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Affiliation(s)
- V F Picceli
- Laboratory of Immunopathology, Federal University of Paraná, Brazil
| | - T L Skare
- Rheumatology Unit, Evangelic University Hospital of Curitiba, Curitiba, Brazil
| | - R M Nisihara
- Department of Medicine, Positivo University Curitiba, Curitiba, Brazil
| | - F R Nass
- Laboratory of Immunopathology, Federal University of Paraná, Brazil
| | | | - S R R Utiyama
- Laboratory of Immunopathology, Federal University of Paraná, Brazil
- Department of Clinical Analysis, Federal University of Paraná, Curitiba, Brazil
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Merashli M, Noureldine MHA, Uthman I, Khamashta M. Antiphospholipid syndrome: an update. Eur J Clin Invest 2015; 45:653-62. [PMID: 25851448 DOI: 10.1111/eci.12449] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 04/04/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND Antiphospholipid syndrome (APS) or 'Hughes syndrome' is a prothrombotic disease characterized by thrombosis and pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). More than three decades have passed, and experts are still uncovering new pieces of this disease complex pathogenesis and management. MATERIALS AND METHODS We searched in literature using MEDLINE and PubMed databases focusing on the latest development on disease pathogenesis, risk assessment of thrombosis and treatment of APS. RESULTS The phosphatidylinositol 3-kinase (PI3K)-AKT-mTORC pathway was most recently identified to have a crucial role in activating inflammation among endothelial vessel wall causing vascular lesions in APS. Additionally, new variables are being implemented to assess the risk of thrombosis in patients with APS. Global APS Score (GAPSS) utilizes cardiovascular risk factors and new autoimmune antibodies as part of the score assessment and is the most valid so far. It can be a promising tool in the future for prediction of thrombosis. Anticoagulation remains the cornerstone in APS; however, many new potential therapeutic agents are developing and are currently under investigation. CONCLUSIONS The most recent advances in pathogenesis, risk stratification and treatment provide a platform for high yield studies with the ultimate goal of providing the optimal management to patients with APS.
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Affiliation(s)
- Mira Merashli
- Division of Rheumatology, Faculty of Medicine, The Royal London Hospital, London, UK
| | | | - Imad Uthman
- Division of Rheumatology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Munther Khamashta
- Graham Hughes Lupus Research Laboratory, Division of Women's Health King's College London, The Rayne Institute, St Thomas' Hospital, London, UK
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Regal JF, Gilbert JS, Burwick RM. The complement system and adverse pregnancy outcomes. Mol Immunol 2015; 67:56-70. [PMID: 25802092 DOI: 10.1016/j.molimm.2015.02.030] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 02/20/2015] [Accepted: 02/24/2015] [Indexed: 02/08/2023]
Abstract
Adverse pregnancy outcomes significantly contribute to morbidity and mortality for mother and child, with lifelong health consequences for both. The innate and adaptive immune system must be regulated to insure survival of the fetal allograft, and the complement system is no exception. An intact complement system optimizes placental development and function and is essential to maintain host defense and fetal survival. Complement regulation is apparent at the placental interface from early pregnancy with some degree of complement activation occurring normally throughout gestation. However, a number of pregnancy complications including early pregnancy loss, fetal growth restriction, hypertensive disorders of pregnancy and preterm birth are associated with excessive or misdirected complement activation, and are more frequent in women with inherited or acquired complement system disorders or complement gene mutations. Clinical studies employing complement biomarkers in plasma and urine implicate dysregulated complement activation in components of each of the adverse pregnancy outcomes. In addition, mechanistic studies in rat and mouse models of adverse pregnancy outcomes address the complement pathways or activation products of importance and allow critical analysis of the pathophysiology. Targeted complement therapeutics are already in use to control adverse pregnancy outcomes in select situations. A clearer understanding of the role of the complement system in both normal pregnancy and complicated or failed pregnancy will allow a rational approach to future therapeutic strategies for manipulating complement with the goal of mitigating adverse pregnancy outcomes, preserving host defense, and improving long term outcomes for both mother and child.
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Affiliation(s)
- Jean F Regal
- Department of Biomedical Sciences, University of Minnesota Medical School, 1035 University Drive, Duluth, MN 55812, USA.
| | - Jeffrey S Gilbert
- Department of Biomedical Sciences, University of Minnesota Medical School, 1035 University Drive, Duluth, MN 55812, USA.
| | - Richard M Burwick
- Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Oregon Health & Science University, Mail Code: L-458, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
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Complement-Targeted Therapies in Lupus. CURRENT TREATMENT OPTIONS IN RHEUMATOLOGY 2015. [DOI: 10.1007/s40674-014-0009-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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