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Brandwijk RJMGE, Michels MAHM, van Rossum M, de Nooijer AH, Nilsson PH, de Bruin WCC, Toonen EJM. Pitfalls in complement analysis: A systematic literature review of assessing complement activation. Front Immunol 2022; 13:1007102. [PMID: 36330514 PMCID: PMC9623276 DOI: 10.3389/fimmu.2022.1007102] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/13/2022] [Indexed: 11/13/2022] Open
Abstract
Background The complement system is an essential component of our innate defense and plays a vital role in the pathogenesis of many diseases. Assessment of complement activation is critical in monitoring both disease progression and response to therapy. Complement analysis requires accurate and standardized sampling and assay procedures, which has proven to be challenging. Objective We performed a systematic analysis of the current methods used to assess complement components and reviewed whether the identified studies performed their complement measurements according to the recommended practice regarding pre-analytical sample handling and assay technique. Results are supplemented with own data regarding the assessment of key complement biomarkers to illustrate the importance of accurate sampling and measuring of complement components. Methods A literature search using the Pubmed/MEDLINE database was performed focusing on studies measuring the key complement components C3, C5 and/or their split products and/or the soluble variant of the terminal C5b-9 complement complex (sTCC) in human blood samples that were published between February 2017 and February 2022. The identified studies were reviewed whether they had used the correct sample type and techniques for their analyses. Results A total of 92 out of 376 studies were selected for full-text analysis. Forty-five studies (49%) were identified as using the correct sample type and techniques for their complement analyses, while 25 studies (27%) did not use the correct sample type or technique. For 22 studies (24%), it was not specified which sample type was used. Conclusion A substantial part of the reviewed studies did not use the appropriate sample type for assessing complement activation or did not mention which sample type was used. This deviation from the standardized procedure can lead to misinterpretation of complement biomarker levels and hampers proper comparison of complement measurements between studies. Therefore, this study underlines the necessity of general guidelines for accurate and standardized complement analysis
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Affiliation(s)
| | - Marloes A. H. M. Michels
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, Netherlands
| | - Mara van Rossum
- R&D Department, Hycult Biotechnology b.v., Uden, Netherlands
| | - Aline H. de Nooijer
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Per H. Nilsson
- Department of Immunology, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway
- Linnaeus Centre for Biomaterials Chemistry, Linnaeus University, Kalmar, Sweden
- Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden
| | | | - Erik J. M. Toonen
- R&D Department, Hycult Biotechnology b.v., Uden, Netherlands
- *Correspondence: Erik J. M. Toonen,
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2
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Variation of Complement Protein Levels in Maternal Plasma and Umbilical Cord Blood during Normal Pregnancy: An Observational Study. J Clin Med 2022; 11:jcm11133611. [PMID: 35806894 PMCID: PMC9267899 DOI: 10.3390/jcm11133611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/19/2022] [Accepted: 06/20/2022] [Indexed: 11/17/2022] Open
Abstract
The complement system constitutes a crucial part of the innate immunity, mediating opsonization, lysis, inflammation, and elimination of potential pathogens. In general, there is an increased activity of the complement system during pregnancy, which is essential for maintaining the host’s defense and fetal survival. Unbalanced or excessive activation of the complement system in the placenta is associated with pregnancy complications, such as miscarriage, preeclampsia, and premature birth. Nonetheless, the actual clinical value of monitoring the activation of the complement system during pregnancy remains to be investigated. Unfortunately, normal reference values specifically for pregnant women are missing, and for umbilical cord blood (UCB), data on complement protein levels are scarce. Herein, complement protein analyses (C1q, C3, C4, C3d levels, and C3d/C3 ratio) were performed in plasma samples from 100 healthy, non-medicated and non-smoking pregnant women, collected during different trimesters and at the time of delivery. In addition, UCB was collected at all deliveries. Maternal plasma C1q and C3d/C3 ratio showed the highest mean values during the first trimester, whereas C3, C4, and C3d had rising values until delivery. We observed low levels of C1q and C4 as well as increased C3d and C3d/C3 ratio, particularly during the first trimester, as a sign of complement activation in some women. However, the reference limits of complement analyses applied for the general population appeared appropriate for the majority of the samples. As expected, the mean complement concentrations in UCB were much lower than in maternal plasma, due to the immature complement system in neonates.
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Dunphy K, O’Mahoney K, Dowling P, O’Gorman P, Bazou D. Clinical Proteomics of Biofluids in Haematological Malignancies. Int J Mol Sci 2021; 22:ijms22158021. [PMID: 34360786 PMCID: PMC8348619 DOI: 10.3390/ijms22158021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/25/2022] Open
Abstract
Since the emergence of high-throughput proteomic techniques and advances in clinical technologies, there has been a steady rise in the number of cancer-associated diagnostic, prognostic, and predictive biomarkers being identified and translated into clinical use. The characterisation of biofluids has become a core objective for many proteomic researchers in order to detect disease-associated protein biomarkers in a minimally invasive manner. The proteomes of biofluids, including serum, saliva, cerebrospinal fluid, and urine, are highly dynamic with protein abundance fluctuating depending on the physiological and/or pathophysiological context. Improvements in mass-spectrometric technologies have facilitated the in-depth characterisation of biofluid proteomes which are now considered hosts of a wide array of clinically relevant biomarkers. Promising efforts are being made in the field of biomarker diagnostics for haematologic malignancies. Several serum and urine-based biomarkers such as free light chains, β-microglobulin, and lactate dehydrogenase are quantified as part of the clinical assessment of haematological malignancies. However, novel, minimally invasive proteomic markers are required to aid diagnosis and prognosis and to monitor therapeutic response and minimal residual disease. This review focuses on biofluids as a promising source of proteomic biomarkers in haematologic malignancies and a key component of future diagnostic, prognostic, and disease-monitoring applications.
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Affiliation(s)
- Katie Dunphy
- Department of Biology, National University of Ireland, W23 F2K8 Maynooth, Ireland; (K.D.); (P.D.)
| | - Kelly O’Mahoney
- Department of Haematology, Mater Misericordiae University Hospital, D07 WKW8 Dublin, Ireland; (K.O.); (P.O.)
| | - Paul Dowling
- Department of Biology, National University of Ireland, W23 F2K8 Maynooth, Ireland; (K.D.); (P.D.)
| | - Peter O’Gorman
- Department of Haematology, Mater Misericordiae University Hospital, D07 WKW8 Dublin, Ireland; (K.O.); (P.O.)
| | - Despina Bazou
- Department of Haematology, Mater Misericordiae University Hospital, D07 WKW8 Dublin, Ireland; (K.O.); (P.O.)
- Correspondence:
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Lipcsey M, Persson B, Eriksson O, Blom AM, Fromell K, Hultström M, Huber-Lang M, Ekdahl KN, Frithiof R, Nilsson B. The Outcome of Critically Ill COVID-19 Patients Is Linked to Thromboinflammation Dominated by the Kallikrein/Kinin System. Front Immunol 2021; 12:627579. [PMID: 33692801 PMCID: PMC7937878 DOI: 10.3389/fimmu.2021.627579] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/18/2021] [Indexed: 01/08/2023] Open
Abstract
An important manifestation of severe COVID-19 is the ARDS-like lung injury that is associated with vascular endothelialitis, thrombosis, and angiogenesis. The intravascular innate immune system (IIIS), including the complement, contact, coagulation, and fibrinolysis systems, which is crucial for recognizing and eliminating microorganisms and debris in the body, is likely to be involved in the pathogenesis of COVID-19 ARDS. Biomarkers for IIIS activation were studied in the first 66 patients with COVID-19 admitted to the ICU in Uppsala University Hospital, both cross-sectionally on day 1 and in 19 patients longitudinally for up to a month, in a prospective study. IIIS analyses were compared with biochemical parameters and clinical outcome and survival. Blood cascade systems activation leading to an overreactive conjunct thromboinflammation was demonstrated, reflected in consumption of individual cascade system components, e.g., FXII, prekallikrein, and high molecular weight kininogen and in increased levels of activation products, e.g., C4d, C3a, C3d,g, sC5b-9, TAT, and D-dimer. Strong associations were found between the blood cascade systems and organ damage, illness severity scores, and survival. We show that critically ill COVID-19 patients display a conjunct activation of the IIIS that is linked to organ damage of the lung, heart, kidneys, and death. We present evidence that the complement and in particular the kallikrein/kinin system is strongly activated and that both systems are prognostic markers of the outcome of the patients suggesting their role in driving the inflammation. Already licensed kallikrein/kinin inhibitors are potential drugs for treatment of critically ill patients with COVID-19.
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Affiliation(s)
- Miklós Lipcsey
- Department of Surgical Sciences, Anesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
- Hedenstierna Laboratory, Anesthesiology and Intensive Care, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Barbro Persson
- Department of Immunology Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Oskar Eriksson
- Department of Immunology Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Anna M. Blom
- Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Karin Fromell
- Department of Immunology Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Michael Hultström
- Department of Surgical Sciences, Anesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
- Unit for Integrative Physiology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Markus Huber-Lang
- Institute for Clinical and Experimental Trauma-Immunology, University Hospital of Ulm, Ulm, Germany
| | - Kristina N. Ekdahl
- Department of Immunology Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Linnaeus Centre for Biomaterials Chemistry, Linnaeus University, Kalmar, Sweden
| | - Robert Frithiof
- Department of Surgical Sciences, Anesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden
| | - Bo Nilsson
- Department of Immunology Genetics and Pathology, Uppsala University, Uppsala, Sweden
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5
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Mastellos DC, Pires da Silva BGP, Fonseca BAL, Fonseca NP, Auxiliadora-Martins M, Mastaglio S, Ruggeri A, Sironi M, Radermacher P, Chrysanthopoulou A, Skendros P, Ritis K, Manfra I, Iacobelli S, Huber-Lang M, Nilsson B, Yancopoulou D, Connolly ES, Garlanda C, Ciceri F, Risitano AM, Calado RT, Lambris JD. Complement C3 vs C5 inhibition in severe COVID-19: Early clinical findings reveal differential biological efficacy. Clin Immunol 2020; 220:108598. [PMID: 32961333 PMCID: PMC7501834 DOI: 10.1016/j.clim.2020.108598] [Citation(s) in RCA: 167] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/16/2020] [Accepted: 09/16/2020] [Indexed: 12/15/2022]
Abstract
Growing clinical evidence has implicated complement as a pivotal driver of COVID-19 immunopathology. Deregulated complement activation may fuel cytokine-driven hyper-inflammation, thrombotic microangiopathy and NET-driven immunothrombosis, thereby leading to multi-organ failure. Complement therapeutics have gained traction as candidate drugs for countering the detrimental consequences of SARS-CoV-2 infection. Whether blockade of terminal complement effectors (C5, C5a, or C5aR1) may elicit similar outcomes to upstream intervention at the level of C3 remains debated. Here we compare the efficacy of the C5-targeting monoclonal antibody eculizumab with that of the compstatin-based C3-targeted drug candidate AMY-101 in small independent cohorts of severe COVID-19 patients. Our exploratory study indicates that therapeutic complement inhibition abrogates COVID-19 hyper-inflammation. Both C3 and C5 inhibitors elicit a robust anti-inflammatory response, reflected by a steep decline in C-reactive protein and IL-6 levels, marked lung function improvement, and resolution of SARS-CoV-2-associated acute respiratory distress syndrome (ARDS). C3 inhibition afforded broader therapeutic control in COVID-19 patients by attenuating both C3a and sC5b-9 generation and preventing FB consumption. This broader inhibitory profile was associated with a more robust decline of neutrophil counts, attenuated neutrophil extracellular trap (NET) release, faster serum LDH decline, and more prominent lymphocyte recovery. These early clinical results offer important insights into the differential mechanistic basis and underlying biology of C3 and C5 inhibition in COVID-19 and point to a broader pathogenic involvement of C3-mediated pathways in thromboinflammation. They also support the evaluation of these complement-targeting agents as COVID-19 therapeutics in large prospective trials.
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Affiliation(s)
- Dimitrios C Mastellos
- National Center for Scientific Research 'Demokritos', Aghia Paraskevi, Athens, Greece
| | - Bruno G P Pires da Silva
- Department of Medical Imaging, Hematology and Clinical Oncology, University of São Paulo, Ribeirão Preto, School of Medicine, Brazil
| | - Benedito A L Fonseca
- Department of Internal Medicine, University of São Paulo, Ribeirão Preto School of Medicine, Brazil
| | - Natasha P Fonseca
- Department of Medical Imaging, Hematology and Clinical Oncology, University of São Paulo, Ribeirão Preto, School of Medicine, Brazil
| | - Maria Auxiliadora-Martins
- Intensive Care Unit, University Hospital, University of São Paulo, Ribeirão Preto School of Medicine, Brazil
| | - Sara Mastaglio
- Hematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Annalisa Ruggeri
- Hematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marina Sironi
- Humanitas Clinical and Research Center, IRCCS, Rozzano, Milan, Italy
| | - Peter Radermacher
- Sektion Anästhesiologische Pathophysiologie und Verfahrensentwicklung, University Hospital of Ulm, Ulm, Germany
| | - Akrivi Chrysanthopoulou
- First Department of Internal Medicine and Laboratory of Molecular Hematology, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece
| | - Panagiotis Skendros
- First Department of Internal Medicine and Laboratory of Molecular Hematology, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece
| | - Konstantinos Ritis
- First Department of Internal Medicine and Laboratory of Molecular Hematology, University Hospital of Alexandroupolis, Democritus University of Thrace, Alexandroupolis, Greece
| | - Ilenia Manfra
- AORN San Giuseppe Moscati, Hematology and Hematopoietic Stem Cell Transplantation Unit, Avellino, Italy
| | - Simona Iacobelli
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Markus Huber-Lang
- Institute for Clinical and Experimental Trauma-Immunology, University Hospital of Ulm, Ulm, Germany
| | - Bo Nilsson
- Division of Clinical Immunology, Uppsala University Hospital, Uppsala, Sweden
| | | | - E Sander Connolly
- Department of Neurological Surgery, Columbia University, New York, NY, USA
| | - Cecilia Garlanda
- Humanitas Clinical and Research Center, IRCCS, Rozzano, Milan, Italy; Humanitas University, Pieve Emanuele, Milan, Italy
| | - Fabio Ciceri
- Hematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy; University Vita Salute San Raffaele, Milan, Italy
| | - Antonio M Risitano
- AORN San Giuseppe Moscati, Hematology and Hematopoietic Stem Cell Transplantation Unit, Avellino, Italy; Federico II University of Naples, Naples, Italy
| | - Rodrigo T Calado
- Department of Medical Imaging, Hematology and Clinical Oncology, University of São Paulo, Ribeirão Preto, School of Medicine, Brazil
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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6
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Tjernberg AR, Woksepp H, Sandholm K, Johansson M, Dahle C, Ludvigsson JF, Bonnedahl J, Nilsson P, Ekdahl KN. Celiac disease and complement activation in response to Streptococcus pneumoniae. Eur J Pediatr 2020; 179:133-140. [PMID: 31691001 PMCID: PMC6942560 DOI: 10.1007/s00431-019-03490-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/16/2019] [Accepted: 09/26/2019] [Indexed: 11/29/2022]
Abstract
Individuals with celiac disease (CD) are at increased risk of invasive pneumococcal disease (IPD). The aim of this study was to explore whether the complement response to Streptococcus pneumoniae differed according to CD status, and could serve as an explanation for the excess risk of IPD in CD. Twenty-two children with CD and 18 controls, born 1999-2008, were included at Kalmar County Hospital, Sweden. The degree of complement activation was evaluated by comparing levels of activation products C3a and sC5b-9 in plasma incubated for 30 min with Streptococcus pneumoniae and in non-incubated plasma. Complement analyses were performed with enzyme-linked immunosorbent assay (ELISA). Pneumococcal stimulation caused a statistically significant increase in C3a as well as sC5b-9 in both children with CD and controls but there was no difference in response between the groups. After incubation, C3a increased on average 4.6 times and sC5b-9 22 times in both the CD and the control group (p = 0.497 and p = 0.724 respectively).Conclusion: Complement response to Streptococcus pneumoniae seems to be similar in children with and without CD and is thus unlikely to contribute to the increased susceptibility to invasive pneumococcal disease in CD.What is Known:• An excess risk of pneumococcal infections has been demonstrated in individuals with celiac disease.• Infectious complications can depend on hyposplenism but alternative mechanisms are sparsely examined.What is New:• Complement activation in response to Streptococcus pneumoniae was examined in children with and without celiac disease but no differences could be demonstrated.
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Affiliation(s)
- Anna Röckert Tjernberg
- Department of Pediatrics, Kalmar County Hospital, SE-391 85, Kalmar, Sweden. .,School of Medical Sciences, Örebro University, SE-701 82, Örebro, Sweden.
| | - Hanna Woksepp
- Research section, Department of Development and Public Health, Kalmar County Hospital, SE-391 85 Kalmar, Sweden
| | - Kerstin Sandholm
- Linnaeus Center for Biomaterials Chemistry, Linnaeus University, SE-391 82 Kalmar, Sweden
| | - Marcus Johansson
- Department of Clinical Microbiology, Kalmar County Hospital, SE-391 85 Kalmar, Sweden ,Department of Clinical and Experimental Medicine, Linköping University, SE-581 85 Linköping, Sweden
| | - Charlotte Dahle
- Department of Clinical and Experimental Medicine, Linköping University, SE-581 85 Linköping, Sweden ,Department of Clinical Immunology and Transfusion Medicine, Linköping University Hospital, SE-581 85 Linköping, Sweden
| | - Jonas F Ludvigsson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, SE-171 77 Stockholm, Sweden ,Department of Pediatrics, Örebro University Hospital, SE-701 85 Örebro, Sweden
| | - Jonas Bonnedahl
- Department of Clinical and Experimental Medicine, Linköping University, SE-581 85 Linköping, Sweden
| | - Per Nilsson
- Linnaeus Center for Biomaterials Chemistry, Linnaeus University, SE-391 82 Kalmar, Sweden ,Department of Immunology, Oslo University Hospital, University of Oslo, 0424 Oslo, Norway
| | - Kristina Nilsson Ekdahl
- Linnaeus Center for Biomaterials Chemistry, Linnaeus University, SE-391 82 Kalmar, Sweden ,Department of Immunology, Genetics and Pathology, Uppsala University, SE-751 85 Uppsala, Sweden
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7
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Kim AHJ, Strand V, Sen DP, Fu Q, Mathis NL, Schmidt MJ, Bruchas RR, Staten NR, Olson PK, Stiening CM, Atkinson JP. Association of Blood Concentrations of Complement Split Product iC3b and Serum C3 With Systemic Lupus Erythematosus Disease Activity. Arthritis Rheumatol 2019; 71:420-430. [PMID: 30294950 PMCID: PMC6393208 DOI: 10.1002/art.40747] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 09/27/2018] [Indexed: 12/15/2022]
Abstract
Objective To examine correlations between blood levels of complement split product iC3b and serum component C3 with clinically meaningful changes in disease activity in patients with systemic lupus erythematosus (SLE). Methods A total of 159 consecutive patients with SLE, diagnosed according to the American College of Rheumatology or Systemic Lupus International Collaborating Clinics classification criteria, were enrolled in CASTLE (Complement Activation Signatures in Systemic Lupus Erythematosus), a prospective observational study. Patients with 1–7 study visits were included in this longitudinal analysis. In addition, 48 healthy volunteers were enrolled to establish a normal reference value for the ratio of blood iC3b to serum C3 concentrations. Serum C3 and C4 levels were measured by nephelometry, and blood iC3b levels were measured by a lateral flow assay. SLE disease activity was monitored with the Responder Index 50 instrument of the SLE Disease Activity Index 2000. Results Relative changes in the iC3b:C3 ratio, levels of anti–double‐stranded DNA (anti‐dsDNA) antibodies, and use of a supraphysiologic dose of prednisone (>7.5 mg/day) each independently correlated with SLE disease activity, as determined in multilevel multiple logistic regression analyses. Only the iC3b:C3 ratio was significantly associated with clinically meaningful improvements in disease activity among patients with SLE who were receiving a supraphysiologic dose of prednisone. The iC3b:C3 ratio outperformed C3 and C4 levels with regard to discriminating active SLE from inactive SLE, and major flares from no disease activity. The iC3:C3 ratio, anti‐dsDNA antibody levels, erythrocyte sedimentation rate, and use of a supraphysiologic prednisone dose were each independently associated with the presence of lupus nephritis, whereas none of these measures was associated with SLE rash. The association of the iC3b:C3 ratio with lupus nephritis was independent of other observed clinical manifestations. Conclusion The ratio of blood iC3b to serum C3 concentrations correlates with the extent of SLE disease activity and with clinically meaningful changes in disease activity in patients with SLE. Furthermore, the iC3b:C3 ratio may discriminate between active and inactive SLE, and between major flares and no active disease.
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Affiliation(s)
- Alfred H J Kim
- Washington University School of Medicine, Saint Louis, Missouri
| | - Vibeke Strand
- Stanford University School of Medicine, Palo Alto, California
| | - Deepali P Sen
- Washington University School of Medicine, Saint Louis, Missouri
| | - Qiang Fu
- Saint Louis University, Saint Louis, Missouri
| | - Nancy L Mathis
- Washington University School of Medicine, Saint Louis, Missouri
| | | | | | | | | | | | - John P Atkinson
- Washington University School of Medicine, Saint Louis, Missouri
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8
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Ekdahl KN, Persson B, Mohlin C, Sandholm K, Skattum L, Nilsson B. Interpretation of Serological Complement Biomarkers in Disease. Front Immunol 2018; 9:2237. [PMID: 30405598 PMCID: PMC6207586 DOI: 10.3389/fimmu.2018.02237] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/10/2018] [Indexed: 01/07/2023] Open
Abstract
Complement system aberrations have been identified as pathophysiological mechanisms in a number of diseases and pathological conditions either directly or indirectly. Examples of such conditions include infections, inflammation, autoimmune disease, as well as allogeneic and xenogenic transplantation. Both prospective and retrospective studies have demonstrated significant complement-related differences between patient groups and controls. However, due to the low degree of specificity and sensitivity of some of the assays used, it is not always possible to make predictions regarding the complement status of individual patients. Today, there are three main indications for determination of a patient's complement status: (1) complement deficiencies (acquired or inherited); (2) disorders with aberrant complement activation; and (3) C1 inhibitor deficiencies (acquired or inherited). An additional indication is to monitor patients on complement-regulating drugs, an indication which may be expected to increase in the near future since there is now a number of such drugs either under development, already in clinical trials or in clinical use. Available techniques to study complement include quantification of: (1) individual components; (2) activation products, (3) function, and (4) autoantibodies to complement proteins. In this review, we summarize the appropriate indications, techniques, and interpretations of basic serological complement analyses, exemplified by a number of clinical disorders.
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Affiliation(s)
- Kristina N Ekdahl
- Rudbeck Laboratory C5:3, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Centre of Biomaterials Chemistry, Linnaeus University, Kalmar, Sweden
| | - Barbro Persson
- Rudbeck Laboratory C5:3, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Camilla Mohlin
- Centre of Biomaterials Chemistry, Linnaeus University, Kalmar, Sweden
| | - Kerstin Sandholm
- Centre of Biomaterials Chemistry, Linnaeus University, Kalmar, Sweden
| | - Lillemor Skattum
- Section of Microbiology, Immunology and Glycobiology, Department of Laboratory Medicine, Clinical Immunology and Transfusion Medicine, Lund University, Lund, Sweden
| | - Bo Nilsson
- Rudbeck Laboratory C5:3, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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9
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Vlietstra WJ, Vos R, Sijbers AM, van Mulligen EM, Kors JA. Using predicate and provenance information from a knowledge graph for drug efficacy screening. J Biomed Semantics 2018; 9:23. [PMID: 30189889 PMCID: PMC6127943 DOI: 10.1186/s13326-018-0189-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/01/2018] [Indexed: 12/11/2022] Open
Abstract
Background Biomedical knowledge graphs have become important tools to computationally analyse the comprehensive body of biomedical knowledge. They represent knowledge as subject-predicate-object triples, in which the predicate indicates the relationship between subject and object. A triple can also contain provenance information, which consists of references to the sources of the triple (e.g. scientific publications or database entries). Knowledge graphs have been used to classify drug-disease pairs for drug efficacy screening, but existing computational methods have often ignored predicate and provenance information. Using this information, we aimed to develop a supervised machine learning classifier and determine the added value of predicate and provenance information for drug efficacy screening. To ensure the biological plausibility of our method we performed our research on the protein level, where drugs are represented by their drug target proteins, and diseases by their disease proteins. Results Using random forests with repeated 10-fold cross-validation, our method achieved an area under the ROC curve (AUC) of 78.1% and 74.3% for two reference sets. We benchmarked against a state-of-the-art knowledge-graph technique that does not use predicate and provenance information, obtaining AUCs of 65.6% and 64.6%, respectively. Classifiers that only used predicate information performed superior to classifiers that only used provenance information, but using both performed best. Conclusion We conclude that both predicate and provenance information provide added value for drug efficacy screening. Electronic supplementary material The online version of this article (10.1186/s13326-018-0189-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wytze J Vlietstra
- Department of Medical Informatics, Erasmus University Medical Centre, Rotterdam, 3015, GE, the Netherlands.
| | - Rein Vos
- Department of Medical Informatics, Erasmus University Medical Centre, Rotterdam, 3015, GE, the Netherlands.,Department of Methodology and Statistics, Maastricht University, Maastricht, 6200, MD, the Netherlands
| | - Anneke M Sijbers
- Centre for Molecular and Biomolecular Informatics, Radboudumc, Nijmegen, 6525, GA, the Netherlands
| | - Erik M van Mulligen
- Department of Medical Informatics, Erasmus University Medical Centre, Rotterdam, 3015, GE, the Netherlands
| | - Jan A Kors
- Department of Medical Informatics, Erasmus University Medical Centre, Rotterdam, 3015, GE, the Netherlands
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Troldborg A, Jensen L, Deleuran B, Stengaard-Pedersen K, Thiel S, Jensenius JC. The C3dg Fragment of Complement Is Superior to Conventional C3 as a Diagnostic Biomarker in Systemic Lupus Erythematosus. Front Immunol 2018; 9:581. [PMID: 29632534 PMCID: PMC5879092 DOI: 10.3389/fimmu.2018.00581] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/07/2018] [Indexed: 12/14/2022] Open
Abstract
Introduction/objectives In 2012, hypocomplementemia was included in the classification criteria of systemic lupus erythematosus (SLE). The suggested measurement of C3 or C4 often reflect disease activity poorly. Our objective was to establish an assay measuring C3dg, which is generated following complement activation, and to evaluate the assay in a cross-sectional SLE cohort. Method We included SLE patients (n = 169) and controls (n = 170) and developed a modified C3dg assay where C3dg fragments were separated from the large plasma proteins by polyethylene glycol (PEG), and the supernatant containing the C3dg fragment was used for analysis in an antibody-based sandwich-type assay. Gel permeation chromatography and western blotting were used to establish the optimal conditions for PEG precipitation. Results 16% PEG was optimal for separating C3dg from C3 and the larger protein fragments. The assay showed a high degree of stability when using EDTA plasma, and measurements correlated well with commercially available complement activation assays. SLE patients had higher concentrations in plasma of C3dg than controls (p < 0.05). ROC analysis showed that the C3dg activation fragment of C3 with an AUC of 0.96 (CI 0.94–0.98) was superior to C3 (AUC 0.52) in differentiating between patients and controls. Conclusion Our results present a modified assay for the measurement of C3dg. We demonstrate that C3dg was superior to conventional C3 measurements in discriminating SLE patients from controls. We suggest that C3dg should be considered as a complement activation measurement in the SLE classification criteria.
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Affiliation(s)
- Anne Troldborg
- Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Lisbeth Jensen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Bent Deleuran
- Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.,Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Kristian Stengaard-Pedersen
- Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Angioi A, Fervenza FC, Sethi S, Zhang Y, Smith RJ, Murray D, Van Praet J, Pani A, De Vriese AS. Diagnosis of complement alternative pathway disorders. Kidney Int 2016; 89:278-88. [DOI: 10.1016/j.kint.2015.12.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 08/13/2015] [Accepted: 08/19/2015] [Indexed: 02/06/2023]
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12
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Frazer-Abel A, Sepiashvili L, Mbughuni MM, Willrich MAV. Overview of Laboratory Testing and Clinical Presentations of Complement Deficiencies and Dysregulation. Adv Clin Chem 2016; 77:1-75. [PMID: 27717414 DOI: 10.1016/bs.acc.2016.06.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Historically, complement disorders have been attributed to immunodeficiency associated with severe or frequent infection. More recently, however, complement has been recognized for its role in inflammation, autoimmune disorders, and vision loss. This paradigm shift requires a fundamental change in how complement testing is performed and interpreted. Here, we provide an overview of the complement pathways and summarize recent literature related to hereditary and acquired angioedema, infectious diseases, autoimmunity, and age-related macular degeneration. The impact of complement dysregulation in atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria, and C3 glomerulopathies is also described. The advent of therapeutics such as eculizumab and other complement inhibitors has driven the need to more fully understand complement to facilitate diagnosis and monitoring. In this report, we review analytical methods and discuss challenges for the clinical laboratory in measuring this complex biochemical system.
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13
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Complement diagnostics: concepts, indications, and practical guidelines. Clin Dev Immunol 2012; 2012:962702. [PMID: 23227092 PMCID: PMC3511841 DOI: 10.1155/2012/962702] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 10/17/2012] [Indexed: 12/11/2022]
Abstract
Aberrations in the complement system have been shown to be direct or indirect pathophysiological mechanisms in a number of diseases and pathological conditions such as autoimmune disease, infections, cancer, allogeneic and xenogeneic transplantation, and inflammation. Complement analyses have been performed on these conditions in both prospective and retrospective studies and significant differences have been found between groups of patients, but in many diseases, it has not been possible to make predictions for individual patients because of the lack of sensitivity and specificity of many of the assays used. The basic indications for serological diagnostic complement analysis today may be divided into three major categories: (a) acquired and inherited complement deficiencies; (b) disorders with complement activation; (c) inherited and acquired C1INH deficiencies. Here, we summarize indications, techniques, and interpretations for basic complement analyses and present an algorithm, which we follow in our routine laboratory.
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14
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Åhlin E, Mathsson L, Eloranta ML, Jonsdottir T, Gunnarsson I, Rönnblom L, Rönnelid J. Autoantibodies associated with RNA are more enriched than anti-dsDNA antibodies in circulating immune complexes in SLE. Lupus 2012; 21:586-95. [DOI: 10.1177/0961203311434938] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To what extent different autoantibodies accumulate in systemic lupus erythematosus (SLE) immune complexes (ICs), and whether such accumulation is associated with disease activity has been investigated. ICs were isolated from SLE sera by both polyethylene glycol (PEG) precipitation and C1q-binding. Autoantibody specificities were determined using a lineblot assay quantified by densitometry. To compare the relative levels of autoantibodies, levels were normalized to the total levels of IgG measured by ELISA in sera and parallel ICs. Samples were investigated both in a cross-sectional design as well as in a paired design with samples obtained during both active and inactive SLE. All investigated autoantibody specificities except anti-dsDNA were enriched in circulating ICs as compared with parallel sera. The group of antibodies against RNA-associated antigens (anti-RNP/Sm, anti-Sm, anti-SSA/Ro60, anti-SSA/Ro52, anti-SSB/La) all exhibited higher median enrichment than the DNA-associated (anti-dsDNA, anti-histones, anti-nucleosomes) or cytoplasmic (anti-ribosomal P) antigens. In particular autoantibodies against RNP/Sm and SSA/Ro52 had the highest degree of enrichment in SLE PEG precipitates. These findings were corroborated by analysis of autoantibody content in C1q-bound ICs. There was no difference in degree of IC accumulation of the investigated autoantibodies during active and inactive SLE. Our findings demonstrate a difference in enrichment between autoantibodies against RNA- and DNA-associated autoantigens in isolated SLE IC, suggesting that the RNA-associated autoantibodies are more prone to form circulating ICs in SLE, in contrast to antibodies against DNA-associated autoantigens such as dsDNA. These finding have implications in understanding mechanisms of differential autoantibody accumulation in target organs in SLE.
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Affiliation(s)
- E Åhlin
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - L Mathsson
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - M-L Eloranta
- Department of Medical Sciences, Section of Rheumatology, Uppsala University, Sweden
| | - T Jonsdottir
- Department of Medicine, Unit of Rheumatology, Karolinska Institutet, Stockholm, Sweden
| | - I Gunnarsson
- Department of Medicine, Unit of Rheumatology, Karolinska Institutet, Stockholm, Sweden
| | - L Rönnblom
- Department of Medical Sciences, Section of Rheumatology, Uppsala University, Sweden
| | - J Rönnelid
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
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15
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Biglarnia AR, Nilsson B, Nilsson T, von Zur-Mühlen B, Wagner M, Berne C, Wanders A, Magnusson A, Tufveson G. Prompt reversal of a severe complement activation by eculizumab in a patient undergoing intentional ABO-incompatible pancreas and kidney transplantation. Transpl Int 2011; 24:e61-6. [PMID: 21696455 DOI: 10.1111/j.1432-2277.2011.01290.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We describe the presumably first intentional ABO-incompatible deceased-donor kidney and pancreas transplantation with a severe antibody-mediated rejection during a rebound of isoagglutinins. Rejection was successfully treated with eculizumab, which inhibits the terminal pathway of complement. Complement analysis (C3, C3d,g, and a modified assay of classical complement-related hemolytic function) documented complement activation and confirmed that eculizumab completely blocked complement function. At 6 months, the patient had normal kidney and pancreas function, and histological evaluations revealed no evidence of sustained graft damage. This successful transplantation suggests that ABO barriers can safely be overcome without extensive preconditioning, when the complement inhibitor eculizumab is included.
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Affiliation(s)
- Ali-Reza Biglarnia
- Section of Transplantation Surgery, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
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16
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Wang Z, Zhang S, Tong Z, Li L, Wang G. Maternal transfer and protective role of the alternative complement components in zebrafish Danio rerio. PLoS One 2009; 4:e4498. [PMID: 19223977 PMCID: PMC2637980 DOI: 10.1371/journal.pone.0004498] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Accepted: 01/08/2009] [Indexed: 11/20/2022] Open
Abstract
Embryos of most fish develop externally and are exposed to an aquatic environment full of potential pathogens, whereas they have little or only limited ability to mount an efficient and protective response. How fish embryos survive pathogenic attacks remains poorly defined. Here we demonstrate that the maternal immunization of female zebrafish with formalin-killed Aeromonas hydrophila causes a significant increase in C3 and Bf contents in the mother, a corresponding rise in the offspring, and induces a remarkable increase in the hemolytic activities in both the mother and offspring. In addition, the embryos derived from the immunized mother are significantly more tolerant to A. hydrophila challenge than those from the unimmunized fish, and blocking C3 and Bf activities by injection of the antibodies against C3 and Bf into the embryos render them more susceptible to A. hydrophila. These results clearly show that the protection of zebrafish embryos against A. hydrophila can be achieved by the maternally-transferred immunity of the complement system operating via the alternative pathway. This appears to be the first report providing in vivo evidences for the protective role of the alternative complement components in the early embryos of zebrafish, paving the way for insights into the in vivo function of other maternally-transferred factors in fish.
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Affiliation(s)
- Zhiping Wang
- Department of Marine Biology, Ocean University of China, Qingdao, People's Republic of China
| | - Shicui Zhang
- Department of Marine Biology, Ocean University of China, Qingdao, People's Republic of China
- * E-mail:
| | - Zhou Tong
- Department of Marine Biology, Ocean University of China, Qingdao, People's Republic of China
| | - Lei Li
- Department of Marine Biology, Ocean University of China, Qingdao, People's Republic of China
| | - Guangfeng Wang
- Department of Marine Biology, Ocean University of China, Qingdao, People's Republic of China
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Mollnes TE, Jokiranta TS, Truedsson L, Nilsson B, Rodriguez de Cordoba S, Kirschfink M. Complement analysis in the 21st century. Mol Immunol 2007; 44:3838-49. [PMID: 17768101 DOI: 10.1016/j.molimm.2007.06.150] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Indexed: 11/17/2022]
Abstract
Complement analysis in the clinic is usually associated with the quantification of C3 and C4, measurement of C1-inhibitor and screening for complement activity. These analyses have been available in routine diagnostic laboratories for decades. In recent years, however, the field of complement analysis has expanded considerably, with the introduction of novel assays to detect complement activation products, and spreading still further towards genetic analysis to reveal the basis of complement deficiencies and identify mutations and polymorphisms associated with defined diseases such as atypical haemolytic uraemic syndrome and age related macular degeneration. Here we review the current status of complement analysis, including assays for the quantification of complement activity and complement activation products, together with genetic methods for the detection of deficiencies, mutations and polymorphisms. This is an area where significant developments have been made recently, paralleling the research advances into the role of complement in human disease. It is clear, however, that there is a need for consensus and standardisation of analytical methods. This will be a major challenge for the complement society in the future.
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Affiliation(s)
- Tom Eirik Mollnes
- Institute of Immunology, University of Oslo, and Rikshospitalet, N-0027 Oslo, Norway.
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