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Harraka P, Wightman T, Akom S, Sandhu K, Colville D, Catran A, Langsford D, Pianta T, Barit D, Ierino F, Skene A, Mack H, Savige J. Increased retinal drusen in IgA glomerulonephritis are further evidence for complement activation in disease pathogenesis. Sci Rep 2022; 12:18301. [PMID: 36316518 PMCID: PMC9622730 DOI: 10.1038/s41598-022-21386-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 09/27/2022] [Indexed: 12/31/2022] Open
Abstract
Drusen are retinal deposits comprising cell debris, immune material and complement that are characteristic of macular degeneration but also found in glomerulonephritis. This was a pilot cross-sectional study to determine how often drusen occurred in IgA glomerulonephritis and their clinical significance. Study participants underwent non-mydriatic retinal photography, and their deidentified retinal images were examined for drusen by two trained graders, who compared central drusen counts, counts ≥ 10 and drusen size with those of matched controls. The cohort comprised 122 individuals with IgA glomerulonephritis including 89 males (73%), 49 individuals (40%) of East Asian or Southern European ancestry, with an overall median age of 54 years (34-64), and median disease duration of 9 years (4-17). Thirty-nine (33%) had an eGFR < 60 ml/min/1.73 m2 and 72 had previously reached kidney failure (61%). Overall mean drusen counts were higher in IgA glomerulonephritis (9 ± 27) than controls (2 ± 7, p < 0.001). Central counts ≥ 10 were also more common (OR = 3.31 (1.42-7.73, p = 0.006), and were associated with longer disease duration (p = 0.03) but not kidney failure (p = 0.31). Larger drusen were associated with more mesangial IgA staining (p = 0.004). Increased drusen counts were also present in IgA glomerulonephritis secondary to Crohn's disease but not with Henoch-Schonlein purpura. The finding of retinal drusen in IgA glomerulonephritis is consistent with complement activation and represents a model for better understanding glomerular immune deposition and a supporting argument for treatment with anti-complement therapies.
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Affiliation(s)
- P. Harraka
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, Melbourne Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Tony Wightman
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, Melbourne Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Sarah Akom
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, Melbourne Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Kieran Sandhu
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, Melbourne Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Deb Colville
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, Melbourne Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Andrew Catran
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, Melbourne Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - David Langsford
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Timothy Pianta
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - David Barit
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Frank Ierino
- grid.1008.90000 0001 2179 088XDepartment of Nephrology, Austin Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Alison Skene
- grid.1008.90000 0001 2179 088XDepartment of Pathology, Austin Health, The University of Melbourne, Parkville, VIC 3050 Australia
| | - Heather Mack
- grid.410670.40000 0004 0625 8539The University of Melbourne Department of Ophthalmology, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC 3002 Australia
| | - Judy Savige
- grid.1008.90000 0001 2179 088XDepartment of Medicine, Northern Health, The University of Melbourne, Parkville, VIC 3050 Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, Melbourne Health, The University of Melbourne, Parkville, VIC 3050 Australia
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Dasdemir S, Yildiz M, Celebi D, Sahin S, Aliyeva N, Haslak F, Gunalp A, Adrovic A, Barut K, Artim Esen B, Kasapcopur O. Genetic screening of early-onset patients with systemic lupus erythematosus by a targeted next-generation sequencing gene panel. Lupus 2022; 31:330-337. [PMID: 35086391 DOI: 10.1177/09612033221076733] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE In this study, we aimed to screen 31 genes (C1QA, C1QB, C1QC, C1R, C1S, C2, C3, TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR, DNASE1, DNASE1L3, PRKCD, ACP5, SLC7A7, IFIH1, TMEM173, ISG15, CYBB, FAS, FASLG, KRAS, NRAS, MAN2B1, PEPD, PTPN11, RAG2, and SHOC2), that we have categorized under the umbrella term "monogenic lupus" using a targeted next-generation sequencing (NGS) panel in 24 individuals with early-onset (≤10 years of age) systemic lupus erythematosus (SLE) and in 24 patients with late-onset (>10 years of age) disease. METHODS A total of 48 SLE patients (24 with disease onset ≤10 years of age and 24 with disease onset >10 years of age) were included. Patients with late-onset disease have been used as patient controls. Sequencing was carried out using 400 bp kit on the Ion S5 system. RESULTS Among the 48 patients, three had one pathogenic variant and 45 patients had at least one rare variant classified as benign, likely benign or variant of unknown significance (VUS). In all three patients with a pathogenic variant, the onset of disease was before 10 years of age. Two patients (they were siblings) carried C1QA homozygote pathogenic allele (p.Gln208Ter, rs121909581), and one patient carried PEPD heterozygote pathogenic allele (p.Arg184Gln, rs121917722). CONCLUSION We demonstrated a pathogenic variant in our target gene panel with a frequency of 9.52% in patients with a disease onset ≤10 years of age. All patients with early-onset SLE phenotype, irrespective of a positive family history for SLE or parental consanguinity, should be scanned for a single-gene defect by a targeted gene panel sequencing. With the discovery of many single-gene defects and ongoing efforts to identify novel genes in SLE, similar gene panels including even more genes will possibly become more necessary and practical in the future.
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Affiliation(s)
- Selcuk Dasdemir
- Department of Medical Biology, Istanbul Faculty of Medicine, 64041Istanbul University, Istanbul, Turkey
| | - Mehmet Yildiz
- Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, 532719Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Damla Celebi
- Department of Medical Biology, Istanbul Faculty of Medicine, 64041Istanbul University, Istanbul, Turkey
| | - Sezgin Sahin
- Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, 532719Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Numune Aliyeva
- Department of Internal Medicine, Istanbul Faculty of Medicine, Division of Rheumatology, 64041Istanbul University, Istanbul, Turkey
| | - Fatih Haslak
- Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, 532719Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Aybuke Gunalp
- Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, 532719Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Amra Adrovic
- Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, 532719Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Kenan Barut
- Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, 532719Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Bahar Artim Esen
- Department of Internal Medicine, Istanbul Faculty of Medicine, Division of Rheumatology, 64041Istanbul University, Istanbul, Turkey
| | - Ozgur Kasapcopur
- Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, 532719Istanbul University-Cerrahpasa, Istanbul, Turkey
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Freiwald T, Afzali B. Renal diseases and the role of complement: Linking complement to immune effector pathways and therapeutics. Adv Immunol 2021; 152:1-81. [PMID: 34844708 PMCID: PMC8905641 DOI: 10.1016/bs.ai.2021.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The complement system is an ancient and phylogenetically conserved key danger sensing system that is critical for host defense against pathogens. Activation of the complement system is a vital component of innate immunity required for the detection and removal of pathogens. It is also a central orchestrator of adaptive immune responses and a constituent of normal tissue homeostasis. Once complement activation occurs, this system deposits indiscriminately on any cell surface in the vicinity and has the potential to cause unwanted and excessive tissue injury. Deposition of complement components is recognized as a hallmark of a variety of kidney diseases, where it is indeed associated with damage to the self. The provenance and the pathophysiological role(s) played by complement in each kidney disease is not fully understood. However, in recent years there has been a renaissance in the study of complement, with greater appreciation of its intracellular roles as a cell-intrinsic system and its interplay with immune effector pathways. This has been paired with a profusion of novel therapeutic agents antagonizing complement components, including approved inhibitors against complement components (C)1, C3, C5 and C5aR1. A number of clinical trials have investigated the use of these more targeted approaches for the management of kidney diseases. In this review we present and summarize the evidence for the roles of complement in kidney diseases and discuss the available clinical evidence for complement inhibition.
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Affiliation(s)
- Tilo Freiwald
- Immunoregulation Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, MD, United States; Department of Nephrology, University Hospital Frankfurt, Goethe-University, Frankfurt am Main, Germany
| | - Behdad Afzali
- Department of Nephrology, University Hospital Frankfurt, Goethe-University, Frankfurt am Main, Germany.
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Weisenburger T, von Neubeck B, Schneider A, Ebert N, Schreyer D, Acs A, Winkler TH. Epistatic Interactions Between Mutations of Deoxyribonuclease 1-Like 3 and the Inhibitory Fc Gamma Receptor IIB Result in Very Early and Massive Autoantibodies Against Double-Stranded DNA. Front Immunol 2018; 9:1551. [PMID: 30026744 PMCID: PMC6041390 DOI: 10.3389/fimmu.2018.01551] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 06/22/2018] [Indexed: 01/02/2023] Open
Abstract
Autoantibodies against double-stranded DNA (anti-dsDNA) are a hallmark of systemic lupus erythematosus (SLE). It is well documented that anti-dsDNA reactive B lymphocytes are normally controlled by immune self-tolerance mechanisms operating at several levels. The evolution of high levels of IgG anti-dsDNA in SLE is dependent on somatic hypermutation and clonal selection, presumably in germinal centers from non-autoreactive B cells. Twin studies as well as genetic studies in mice indicate a very strong genetic contribution for the development of anti-dsDNA as well as SLE. Only few single gene defects with a monogenic Mendelian inheritance have been described so far that are directly responsible for the development of anti-dsDNA and SLE. Recently, among other mutations, rare null-alleles for the deoxyribonuclease 1 like 3 (DNASE1L3) and the Fc gamma receptor IIB (FCGR2B) have been described in SLE patients and genetic mouse models. Here, we demonstrate that double Dnase1l3- and FcgR2b-deficient mice in the C57BL/6 background exhibit a very early and massive IgG anti-dsDNA production. Already at 10 weeks of age, autoantibody production in double-deficient mice exceeds autoantibody levels of diseased 9-month-old NZB/W mice, a long established multigenic SLE mouse model. In single gene-deficient mice, autoantibody levels were moderately elevated at early age of the mice. Premature autoantibody production was accompanied by a spontaneous hyperactivation of germinal centers, early expansions of T follicular helper cells, and elevated plasmablasts in the spleen. Anti-dsDNA hybridomas generated from double-deficient mice show significantly elevated numbers of arginines in the CDR3 regions of the heavy-chain as well as clonal expansions and diversification of B cell clones with moderate numbers of somatic mutations. Our findings show a strong epistatic interaction of two SLE-alleles which prevent early and high-level anti-dsDNA autoantibody production. Both genes apparently synergize to keep in check excessive germinal center reactions evolving into IgG anti-dsDNA antibody producing B cells.
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Affiliation(s)
- Thomas Weisenburger
- Department of Biology, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Bettina von Neubeck
- Department of Biology, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Andrea Schneider
- Department of Biology, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Nadja Ebert
- Department of Biology, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Daniel Schreyer
- Department of Biology, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Andreas Acs
- Department of Biology, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Thomas H Winkler
- Department of Biology, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.,Medical Immunology Campus Erlangen, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
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5
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Hiraki LT, Silverman ED. Genomics of Systemic Lupus Erythematosus: Insights Gained by Studying Monogenic Young-Onset Systemic Lupus Erythematosus. Rheum Dis Clin North Am 2018; 43:415-434. [PMID: 28711143 DOI: 10.1016/j.rdc.2017.04.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Systemic lupus erythematosus (SLE) is a systemic, autoimmune, multisystem disease with a heterogeneous clinical phenotype. Genome-wide association studies have identified multiple susceptibility loci, but these explain a fraction of the estimated heritability. This is partly because within the broad spectrum of SLE are monogenic diseases that tend to cluster in patients with young age of onset, and in families. This article highlights insights into the pathogenesis of SLE provided by these monogenic diseases. It examines genetic causes of complement deficiency, abnormal interferon production, and abnormalities of tolerance, resulting in monogenic SLE with overlapping clinical features, autoantibodies, and shared inflammatory pathways.
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Affiliation(s)
- Linda T Hiraki
- Division of Rheumatology, SickKids Hospital, SickKids Research Institute, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada; Department of Paediatrics, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada; Epidemiology, Dalla Lana School of Public Health, 155 College Street, Toronto, Ontario M5T 3M7, Canada
| | - Earl D Silverman
- Division of Rheumatology, SickKids Hospital, SickKids Research Institute, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada; Department of Paediatrics, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
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6
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Ghebrehiwet B, Kandov E, Kishore U, Peerschke EIB. Is the A-Chain the Engine That Drives the Diversity of C1q Functions? Revisiting Its Unique Structure. Front Immunol 2018; 9:162. [PMID: 29459870 PMCID: PMC5807628 DOI: 10.3389/fimmu.2018.00162] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 01/18/2018] [Indexed: 12/27/2022] Open
Abstract
The immunopathological functions associated with human C1q are still growing in terms of novelty, diversity, and pathologic relevance. It is, therefore, not surprising that C1q is being recognized as an important molecular bridge between innate and adaptive immunity. The secret of this functional diversity, in turn, resides in the elegant but complex structure of the C1q molecule, which is assembled from three distinct gene products: A, B, and C, each of which has evolved from a separate and unique ancestral gene template. The C1q molecule is made up of 6A, 6B, and 6C polypeptide chains, which are held together through strong covalent and non-covalent bonds to form the 18-chain, bouquet-of-flower-like protein that we know today. The assembled C1q protein displays at least two distinct structural and functional regions: the collagen-like region (cC1q) and the globular head region (gC1q), each being capable of driving a diverse range of ligand- or receptor-mediated biological functions. What is most intriguing, however, is the observation that most of the functions appear to be predominantly driven by the A-chain of the molecule, which begs the question: what are the evolutionary modifications or rearrangements that singularly shaped the primordial A-chain gene to become a pluripotent and versatile component of the intact C1q molecule? Here, we revisit and discuss some of the known unique structural and functional features of the A-chain, which may have contributed to its versatility.
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Affiliation(s)
- Berhane Ghebrehiwet
- Departments of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Evelyn Kandov
- Departments of Medicine, Stony Brook University, Stony Brook, NY, United States
| | - Uday Kishore
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Ellinor I B Peerschke
- Department of Laboratory Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, United States
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Ekinci Z, Ozturk K. Systemic lupus erythematosus with C1q deficiency: treatment with fresh frozen plasma. Lupus 2017; 27:134-138. [PMID: 29113537 DOI: 10.1177/0961203317741565] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Treatment and outcome of systemic lupus erythematosus (SLE) in C1q deficient patients are rarely reported. The aim of this report is to share our experience about the course of management of three cases diagnosed as SLE with C1q deficiency, in light of present literature. Initial and dominant complaints of three cases from two different families were cutaneous manifestations. One patient was also diagnosed with arthritis and thrombocytopenia. Antinuclear antibody was positive in all cases, whereas anti-dsDNA was negative with normal levels of complement C3, C4 and decreased CH50 activity. C1QA gene of two patients had homozygous nonsense mutation (c.622 > T/p.Gln208Ter). Previously, all of them had been treated with steroids, hydroxychloroquine and methotrexate or azathioprine. It was learned that they had responded only to high dosage prednisolone and their symptoms flared up during dosage reduction even under methotrexate or azathioprine. All symptoms of all three cases improved by daily fresh frozen plasma (FFP) infusions, and once cutaneous lesions subsided, the infusions were reduced to a frequency that would prevent the flare up of the symptoms. Literature search revealed seven reports on fresh frozen plasma treatment in SLE with C1q deficient patients. In this report, it is concluded that severe cutaneous lesions, as seen in these C1q deficient SLE patients, cannot be controlled with conventional immunosuppressive treatment. Instead, regular fresh frozen plasma infusions are proposed as a more reasonable method of treatment.
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Affiliation(s)
- Z Ekinci
- 1 Kadıköy Florence Nightingale Medical Center, Istanbul, Turkey
| | - K Ozturk
- 2 Cengiz Gökçek Kadın Doğum ve Çocuk Hastalıkları Hastanesi, Gaziantep, Turkey
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Vignesh P, Rawat A, Sharma M, Singh S. Complement in autoimmune diseases. Clin Chim Acta 2017; 465:123-130. [PMID: 28040558 DOI: 10.1016/j.cca.2016.12.017] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/15/2016] [Accepted: 12/17/2016] [Indexed: 12/18/2022]
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Insights from Mendelian Interferonopathies: Comparison of CANDLE, SAVI with AGS, Monogenic Lupus. J Mol Med (Berl) 2016; 94:1111-1127. [PMID: 27678529 DOI: 10.1007/s00109-016-1465-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/16/2016] [Accepted: 08/18/2016] [Indexed: 01/13/2023]
Abstract
Autoinflammatory disorders are sterile inflammatory conditions characterized by episodes of early-onset fever and disease-specific patterns of organ inflammation. Recently, the discoveries of monogenic disorders with strong type I interferon (IFN) signatures caused by mutations in proteasome degradation and cytoplasmic RNA and DNA sensing pathways suggest a pathogenic role of IFNs in causing autoinflammatory phenotypes. The IFN response gene signature (IGS) has been associated with systemic lupus erythematosus (SLE) and other autoimmune diseases. In this review, we compare the clinical presentations and pathogenesis of two IFN-mediated autoinflammatory diseases, CANDLE and SAVI, with Aicardi Goutières syndrome (AGS) and monogenic forms of SLE (monoSLE) caused by loss-of-function mutations in complement 1 (C1q) or the DNA nucleases, DNASE1 and DNASE1L3. We outline differences in intracellular signaling pathways that fuel a pathologic type I IFN amplification cycle. While IFN amplification is caused by predominantly innate immune cell dysfunction in SAVI, CANDLE, and AGS, autoantibodies to modified RNA and DNA antigens interact with tissues and immune cells including neutrophils and contribute to IFN upregulation in some SLE patients including monoSLE, thus justifying a grouping of "autoinflammatory" and "autoimmune" interferonopathies. Understanding of the differences in the cellular sources and signaling pathways will guide new drug development and the use of emerging targeted therapies.
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Kim H, Hwang D, Han J, Lee HK, Yang WJ, Jin J, Kim KH, Kim SI, Yoo DK, Kim S, Chung J. Genetic Polymorphism in Proteins of the Complement System. KOREAN JOURNAL OF TRANSPLANTATION 2016. [DOI: 10.4285/jkstn.2016.30.2.59] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Hyori Kim
- Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Dobeen Hwang
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Jungwon Han
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
- Biomedical Science, Seoul National University College of Medicine, Seoul, Korea
| | - Hwa Kyoung Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
- Biomedical Science, Seoul National University College of Medicine, Seoul, Korea
| | - Won Jun Yang
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
| | - Junyeong Jin
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
- Biomedical Science, Seoul National University College of Medicine, Seoul, Korea
| | - Ki-hyun Kim
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
| | - Sang Il Kim
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
| | - Duck-Kyun Yoo
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
- Biomedical Science, Seoul National University College of Medicine, Seoul, Korea
| | - Soohyun Kim
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
| | - Junho Chung
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul, Korea
- Biomedical Science, Seoul National University College of Medicine, Seoul, Korea
- Transplantation Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea
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Lintner KE, Wu YL, Yang Y, Spencer CH, Hauptmann G, Hebert LA, Atkinson JP, Yu CY. Early Components of the Complement Classical Activation Pathway in Human Systemic Autoimmune Diseases. Front Immunol 2016; 7:36. [PMID: 26913032 PMCID: PMC4753731 DOI: 10.3389/fimmu.2016.00036] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/24/2016] [Indexed: 01/06/2023] Open
Abstract
The complement system consists of effector proteins, regulators, and receptors that participate in host defense against pathogens. Activation of the complement system, via the classical pathway (CP), has long been recognized in immune complex-mediated tissue injury, most notably systemic lupus erythematosus (SLE). Paradoxically, a complete deficiency of an early component of the CP, as evidenced by homozygous genetic deficiencies reported in human, are strongly associated with the risk of developing SLE or a lupus-like disease. Similarly, isotype deficiency attributable to a gene copy-number (GCN) variation and/or the presence of autoantibodies directed against a CP component or a regulatory protein that result in an acquired deficiency are relatively common in SLE patients. Applying accurate assay methodologies with rigorous data validations, low GCNs of total C4, and heterozygous and homozygous deficiencies of C4A have been shown as medium to large effect size risk factors, while high copy numbers of total C4 or C4A as prevalent protective factors, of European and East-Asian SLE. Here, we summarize the current knowledge related to genetic deficiency and insufficiency, and acquired protein deficiencies for C1q, C1r, C1s, C4A/C4B, and C2 in disease pathogenesis and prognosis of SLE, and, briefly, for other systemic autoimmune diseases. As the complement system is increasingly found to be associated with autoimmune diseases and immune-mediated diseases, it has become an attractive therapeutic target. We highlight the recent developments and offer a balanced perspective concerning future investigations and therapeutic applications with a focus on early components of the CP in human systemic autoimmune diseases.
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Affiliation(s)
- Katherine E Lintner
- Center for Molecular and Human Genetics, Division of Pediatric Rheumatology, Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University , Columbus, OH , USA
| | - Yee Ling Wu
- Center for Molecular and Human Genetics, Division of Pediatric Rheumatology, Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University , Columbus, OH , USA
| | - Yan Yang
- Center for Molecular and Human Genetics, Division of Pediatric Rheumatology, Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University , Columbus, OH , USA
| | - Charles H Spencer
- Center for Molecular and Human Genetics, Division of Pediatric Rheumatology, Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University , Columbus, OH , USA
| | - Georges Hauptmann
- Laboratoire d'Immuno-Rhumatologie Moleculaire, INSERM UMR_S 1109, LabEx Transplantex, Faculté de Médecine, Université de Strasbourg , Strasbourg , France
| | - Lee A Hebert
- Division of Nephrology, College of Medicine, The Ohio State University , Columbus, OH , USA
| | - John P Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine , St. Louis, MO , USA
| | - C Yung Yu
- Center for Molecular and Human Genetics, Division of Pediatric Rheumatology, Department of Pediatrics, Nationwide Children's Hospital, The Ohio State University , Columbus, OH , USA
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Early Complement Component Deficiency in a Single-Centre Cohort of Pediatric Onset Lupus. J Clin Immunol 2015; 35:777-85. [PMID: 26563161 DOI: 10.1007/s10875-015-0212-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/05/2015] [Indexed: 11/26/2022]
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13
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Clinical presentation of human C1q deficiency: How much of a lupus? Mol Immunol 2015; 67:3-11. [DOI: 10.1016/j.molimm.2015.03.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/05/2015] [Accepted: 03/05/2015] [Indexed: 11/20/2022]
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14
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van Schaarenburg RA, Schejbel L, Truedsson L, Topaloglu R, Al-Mayouf SM, Riordan A, Simon A, Kallel-Sellami M, Arkwright PD, Åhlin A, Hagelberg S, Nielsen S, Shayesteh A, Morales A, Tam S, Genel F, Berg S, Ketel AG, Merlijn van den Berg J, Kuijpers TW, Olsson RF, Huizinga TWJ, Lankester AC, Trouw LA. Marked variability in clinical presentation and outcome of patients with C1q immunodeficiency. J Autoimmun 2015; 62:39-44. [PMID: 26119135 DOI: 10.1016/j.jaut.2015.06.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/22/2015] [Accepted: 06/01/2015] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Globally approximately 60 cases of C1q deficiency have been described with a high prevalence of Systemic Lupus Erythematosus (SLE). So far treatment has been guided by the clinical presentation rather than the underlying C1q deficiency. Recently, it was shown that C1q production can be restored by allogeneic hematopoietic stem cell transplantation. Current literature lacks information on disease progression and quality of life of C1q deficient persons which is of major importance to guide clinicians taking care of patients with this rare disease. METHODS We performed an international survey, of clinicians treating C1q deficient patients. A high response rate of >70% of the contacted clinicians yielded information on 45 patients with C1q deficiency of which 25 are published. RESULTS Follow-up data of 45 patients from 31 families was obtained for a median of 11 years after diagnosis. Of these patients 36 (80%) suffer from SLE, of which 16 suffer from SLE and infections, 5 (11%) suffer from infections only and 4 (9%) have no symptoms. In total 9 (20%) of the C1q deficient individuals had died. All except for one died before the age of 20 years. Estimated survival times suggest 20% case-fatality before the age of 20, and at least 50% of patients are expected to reach their middle ages. CONCLUSION Here we report the largest phenotypic data set on C1q deficiency to date, revealing high variance; with high mortality but also a subset of patients with an excellent prognosis. Management of C1q deficiency requires a personalized approach.
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Affiliation(s)
| | - Lone Schejbel
- Department of Clinical Immunology, Laboratory of Molecular Medicine, Rigshospitalet, Copenhagen, Denmark
| | - Lennart Truedsson
- Department of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology, Lund University, Lund, Sweden
| | - Rezan Topaloglu
- Dept of Pediatric Nephrology and Rheumatology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Sulaiman M Al-Mayouf
- Pediatric Rheumatology Department, King Faisal Specialist Hospital & Research Center, Alfaisal University, Riyadh, Kingdom of Saudi Arabia
| | - Andrew Riordan
- Alder Hey Children's NHS Foundation Trust, Liverpool, United Kingdom
| | - Anna Simon
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Anders Åhlin
- Department of Clinical Science and Education, Sachs' Children's Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Stefan Hagelberg
- Department of Clinical Science and Education, Sachs' Children's Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Susan Nielsen
- Pediatric Rheumatology Rigshospitalet, Copenhagen, Denmark
| | | | - Adelaida Morales
- Nephrology Unit from Hospital Dr Molina Orosa. Ctra. Arrecife-Tinajo, Lanzarote, Spain
| | - Schuman Tam
- Asthma & Allergy Clinic of Marin & San Francisco Inc, San Francisco, USA
| | - Ferah Genel
- Dr Behcet Uz Children's Hospital, Izmir/Konak, Turkey
| | - Stefan Berg
- Pediatric Immunology, The Queen Silvia Children's Hospital, Goteborg, Sweden
| | - Arnoldus G Ketel
- Department of Pediatrics, Spaarne Hospital, Hoofddorp, The Netherlands
| | - J Merlijn van den Berg
- Emma Children's Hospital, Academic Amsterdam Medical Center (AMC), Dept of Pediatric Hematology, Immunology and Infectious Disease, University of Amsterdam (UvA), Amsterdam, The Netherlands
| | - Taco W Kuijpers
- Emma Children's Hospital, Academic Amsterdam Medical Center (AMC), Dept of Pediatric Hematology, Immunology and Infectious Disease, University of Amsterdam (UvA), Amsterdam, The Netherlands
| | - Richard F Olsson
- Centre for Allogeneic Stem Cell Transplantation, Karolinska University Hospital, Sweden; Division of Therapeutic Immunology, Department of Laboratory Medicine, Karolinska Institutet, Sweden; Centre for Clinical Research Sörmland, Uppsala University, Sweden
| | - Tom W J Huizinga
- Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Arjan C Lankester
- Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Leendert A Trouw
- Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
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15
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Jlajla H, Sellami MK, Sfar I, Laadhar L, Zerzeri Y, Abdelmoula MS, Gorgi Y, Dridi MF, Makni S. New C1q mutation in a Tunisian family. Immunobiology 2014; 219:241-6. [DOI: 10.1016/j.imbio.2013.10.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 10/22/2013] [Accepted: 10/28/2013] [Indexed: 10/26/2022]
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16
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Genetics of SLE: functional relevance for monocytes/macrophages in disease. Clin Dev Immunol 2012; 2012:582352. [PMID: 23227085 PMCID: PMC3511832 DOI: 10.1155/2012/582352] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 08/24/2012] [Accepted: 09/25/2012] [Indexed: 01/13/2023]
Abstract
Genetic studies in the last 5 years have greatly facilitated our understanding of how the dysregulation of diverse components of the innate immune system contributes to pathophysiology of SLE. A role for macrophages in the pathogenesis of SLE was first proposed as early as the 1980s following the discovery that SLE macrophages were defective in their ability to clear apoptotic cell debris, thus prolonging exposure of potential autoantigens to the adaptive immune response. More recently, there is an emerging appreciation of the contribution both monocytes and macrophages play in orchestrating immune responses with perturbations in their activation or regulation leading to immune dysregulation. This paper will focus on understanding the relevance of genes identified as being associated with innate immune function of monocytes and macrophages and development of SLE, particularly with respect to their role in (1) immune complex (IC) recognition and clearance, (2) nucleic acid recognition via toll-like receptors (TLRs) and downstream signalling, and (3) interferon signalling. Particular attention will be paid to the functional consequences these genetic associations have for disease susceptibility or pathogenesis.
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17
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Microglia, Alzheimer's disease, and complement. Int J Alzheimers Dis 2012; 2012:983640. [PMID: 22957298 PMCID: PMC3432348 DOI: 10.1155/2012/983640] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 05/01/2012] [Accepted: 05/07/2012] [Indexed: 02/02/2023] Open
Abstract
Microglia, the immune cell of the brain, are implicated in cascades leading to neuronal loss and cognitive decline in Alzheimer's disease (AD). Recent genome-wide association studies have indicated a number of risk factors for the development of late-onset AD. Two of these risk factors are an altered immune response and polymorphisms in complement receptor 1. In view of these findings, we discuss how complement signalling in the AD brain and microglial responses in AD intersect. Dysregulation of the complement cascade, either by changes in receptor expression, enhanced activation of different complement pathways or imbalances between complement factor production and complement cascade inhibitors may all contribute to the involvement of complement in AD. Altered complement signalling may reduce the ability of microglia to phagocytose apoptotic cells and clear amyloid beta peptides, modulate the expression by microglia of complement components and receptors, promote complement factor production by plaque-associated cytokines derived from activated microglia and astrocytes, and disrupt complement inhibitor production. The evidence presented here indicates that microglia in AD are influenced by complement factors to adopt protective or harmful phenotypes and the challenge ahead lies in understanding how this can be manipulated to therapeutic advantage to treat late onset AD.
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18
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C1q deficiency: identification of a novel missense mutation and treatment with fresh frozen plasma. Clin Rheumatol 2012; 31:1123-6. [DOI: 10.1007/s10067-012-1978-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 02/07/2012] [Accepted: 03/17/2012] [Indexed: 10/28/2022]
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19
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Namjou B, Keddache M, Fletcher D, Dillon S, Kottyan L, Wiley G, Gaffney PM, Wakeland BE, Liang C, Wakeland EK, Scofield RH, Kaufman K, Harley JB. Identification of novel coding mutation in C1qA gene in an African-American pedigree with lupus and C1q deficiency. Lupus 2012; 21:1113-8. [PMID: 22472776 DOI: 10.1177/0961203312443993] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Homozygous C1q deficiency is an extremely rare condition and strongly associated with systemic lupus erythematosus. To assess and characterize C1q deficiency in an African-American lupus pedigree, C1q genomic region was evaluated in the lupus cases and family members. METHODS Genomic DNA from patient was obtained and C1q A, B and C gene cluster was sequenced using next generation sequencing method. The identified mutation was further confirmed by direct Sanger sequencing method in the patient and all blood relatives. C1q levels in serum were measured using sandwich ELISA method. RESULTS In an African-American patient with lupus and C1q deficiency, we identified and confirmed a novel homozygote start codon mutation in C1qA gene that changes amino acid methionine to arginine at position 1. The Met1Arg mutation prevents protein translation (Met1Arg). Mutation analyses of the patient's family members also revealed the Met1Arg homozygote mutation in her deceased brother who also had lupus with absence of total complement activity consistent with a recessive pattern of inheritance. CONCLUSION The identification of new mutation in C1qA gene that disrupts the start codon (ATG to AGG (Met1Arg)) has not been reported previously and it expands the knowledge and importance of the C1q gene in the pathogenesis of lupus especially in the high-risk African-American population.
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Affiliation(s)
- B Namjou
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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20
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Genetic risk factors of systemic lupus erythematosus in the Malaysian population: a minireview. Clin Dev Immunol 2011; 2012:963730. [PMID: 21941582 PMCID: PMC3176625 DOI: 10.1155/2012/963730] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 07/20/2011] [Indexed: 12/27/2022]
Abstract
SLE is an autoimmune disease that is not uncommon in Malaysia. In contrast to Malays and Indians, the Chinese seem to be most affected. SLE is characterized by deficiency of body's immune response that leads to production of autoantibodies and failure of immune complex clearance. This minireview attempts to summarize the association of several candidate genes with risk for SLE in the Malaysian population and discuss the genetic heterogeneity that exists locally in Asians and in comparison with SLE in Caucasians. Several groups of researchers have been actively investigating genes that are associated with SLE susceptibility in the Malaysian population by screening possible reported candidate genes across the SLE patients and healthy controls. These candidate genes include MHC genes and genes encoding complement components, TNF, FcγR, T-cell receptors, and interleukins. However, most of the polymorphisms investigated in these genes did not show significant associations with susceptibility to SLE in the Malaysian scenario, except for those occurring in MHC genes and genes coding for TNF-α, IL-1β, IL-1RN, and IL-6.
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21
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Molecular basis of hereditary C1q deficiency--revisited: identification of several novel disease-causing mutations. Genes Immun 2011; 12:626-34. [PMID: 21654842 DOI: 10.1038/gene.2011.39] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
C1q is the central pattern-recognition molecule in the classical pathway of the complement system and is known to have a key role in the crossroads between adaptive and innate immunity. Hereditary C1q deficiency is a rare genetic condition strongly associated with systemic lupus erythematosus and increased susceptibility to bacterial infections. However, the clinical symptoms may vary. For long, the molecular basis of C1q deficiency was ascribed to only six different mutations. In the present report, we describe five new patients with C1q deficiency, present the 12 causative mutations described till now and review the clinical spectrum of symptoms found in patients with C1q deficiency. With the results presented here, confirmed C1q deficiency is reported in 64 patients from at least 38 families.
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22
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Welch TR, Blystone LW. Renal disease associated with inherited disorders of the complement system. Pediatr Nephrol 2009; 24:1439-44. [PMID: 18958500 DOI: 10.1007/s00467-008-1027-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 09/23/2008] [Accepted: 09/24/2008] [Indexed: 12/25/2022]
Abstract
The human complement system is vital for host defense and plays a role in a number of inflammatory disorders. Inherited deficiency or dysfunction of most of the individual complement components occurs uncommonly. The phenotype displayed by such patients varies with the specific component deficiency and ranges from recurrent infections to autoimmune diseases. Most of the latter are associated with glomerulonephritis. The onset of severe lupus erythematosus in a young child, with prominent cutaneous and renal manifestations, especially if a similar disorder is present in another family member, is a clue to the presence of a complement component deficiency. The distinguishing of acquired deficiencies from inherited deficiencies in complement components is sometimes difficult and may require sophisticated laboratory testing.
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Affiliation(s)
- Thomas R Welch
- Department of Pediatrics, State University of New York, Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA.
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23
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Abe K, Endo Y, Nakazawa N, Kanno K, Okubo M, Hoshino T, Fujita T. Unique Phenotypes of C1s Deficiency and Abnormality Caused by Two Compound Heterozygosities in a Japanese Family. THE JOURNAL OF IMMUNOLOGY 2009; 182:1681-8. [DOI: 10.4049/jimmunol.182.3.1681] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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24
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Chew CH, Chua KH, Lian LH, Puah SM, Tan SY. PCR-RFLP genotyping of C1q mutations and single nucleotide polymorphisms in Malaysian patients with systemic lupus erythematosus. Hum Biol 2008; 80:83-93. [PMID: 18505047 DOI: 10.3378/1534-6617(2008)80[83:pgocma]2.0.co;2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Five types of known mutations within the C1q gene [located at C1qA-Gln186 (C >T), C1qB-Gly15 (G >A), C1qB-Arg150 (C >T), C1qC-Gly6 (G >A), and C1qC-Arg41 (C >T)] and two SNPs located at C1qA-Gly70 (G/A) and C1qC-Pro14 (T/C) were screened in a multiracial Malaysian population. One hundred thirty patients with systemic lupus erythematosus (SLE) and 130 matched healthy control subjects were genotyped using PCR-RFLP methods. We found no occurrence of the five types of mutations in either the homozygous or heterozygous form among the 260 samples studied. Statistical analysis also revealed that there were no significant associations observed in the genotype distributions and allele frequencies among the patients with SLE and healthy control subjects with both C1qA-Gly70 (G/A) and C1qC-Pro14 (T/C) SNPs. Overall, C1q deficiency was not proven as a primary causative genetic predisposition factor for SLE in the Malaysian population.
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Affiliation(s)
- C H Chew
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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25
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C1q deficiency in an Inuit family: Identification of a new class of C1q disease-causing mutations. Clin Immunol 2007; 124:33-40. [DOI: 10.1016/j.clim.2007.03.547] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 03/26/2007] [Accepted: 03/28/2007] [Indexed: 11/22/2022]
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26
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Petry F, Loos M. Common silent mutations in all types of hereditary complement C1q deficiencies. Immunogenetics 2005; 57:566-71. [PMID: 16086173 DOI: 10.1007/s00251-005-0023-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 07/08/2005] [Indexed: 10/25/2022]
Abstract
Hereditary complete deficiency of complement component C1q is a rare genetic disorder that is associated with severe recurrent infections and a high prevalence of lupus-erythematosus-like symptoms. In the past, several single nucleotide polymorphisms have been identified in all three genes coding for the C1q A, B, and C chains. These point mutations which either lead to termination codons, frameshift, or amino acid exchanges were thought to be responsible for these defects as no other nonsense or missense mutations were found. As a result of the aberrations, either a nonfunctional C1q antigen is present or no C1q protein is detectable in the patients' sera. Screening 46 individuals from seven families with different forms of C1q deficiencies identified a homologous silent mutation at position Gly70 (GGG > GGA) of the C1q A gene of all 11 C1q-deficient patients. A high number of family members that were heterozygous for the coding mutations carried the silent mutation in the homozygous (18%) or heterozygous (36%) state. In addition to the Gly70 mutation in the A gene, another homozygous silent mutation (C gene at position Pro14, CCT >CCC) was detected in all C1q-deficient patients.
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Affiliation(s)
- Franz Petry
- Institute of Medical Microbiology and Hygiene, Johannes Gutenberg-University Mainz, Germany.
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27
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Racila DM, Sontheimer CJ, Sheffield A, Wisnieski JJ, Racila E, Sontheimer RD. Homozygous single nucleotide polymorphism of the complement C1QA gene is associated with decreased levels of C1q in patients with subacute cutaneous lupus erythematosus. Lupus 2003; 12:124-32. [PMID: 12630757 DOI: 10.1191/0961203303lu329oa] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We report an association between a non-familial form of photosensitive Lupus-specific skin disease, subacute cutaneous lupus erythematosus (SCLE), and a new single nucleotide polymorphism (SNP) in the C1QA gene. We also describe an association between this SNP and lower levels of serum C1q. This SNP consists of adenine replacing the third guanine in the codon for aminoacid residue Gly70 (position excludes the 22 amino acid leading peptide) that is located in the second exon of the C1QA gene. We have designated this SNP C1qA-Gly70GGA (the GenBank sequence at this location is C1qA-Gly70GGG). A survey of 19 SCLE patients showed that 11 (58%) were homozygous for C1qA-Gly70GGA SNP, seven (37%) were heterozygous, and only one patient (5%) was homozygous for the GenBank sequence. In contrast, only 13 of 62 (21%) normal controls were homozygous for the C1qA-Gly70GGA SNP, 41 (66%) controls were heterozygous and eight (13%) controls were homozygous for the GenBank sequence. Thus, the C1qA-Gly70GGA SNP is strongly associated with SCLE (P-value = 0.005 by chi-square analysis with Yates correction). This SNP would traditionally be classified as clinically silent as it does not encode a different amino acid. However, our studies have suggested that this SNP appears to be associated with a functional abnormality of C1q expression since its presence correlates inversely with serum levels of C1q antigenic protein in both SCLE patients and normal controls. The mechanism by which this phenotypic change is associated with the translationally silent (synonymous) ClqA-Gly70GGA genetic variation is currently unknown.
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Affiliation(s)
- D M Racila
- Department of Dermatology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA
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28
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Miura-Shimura Y, Nakamura K, Ohtsuji M, Tomita H, Jiang Y, Abe M, Zhang D, Hamano Y, Tsuda H, Hashimoto H, Nishimura H, Taki S, Shirai T, Hirose S. C1q regulatory region polymorphism down-regulating murine c1q protein levels with linkage to lupus nephritis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:1334-9. [PMID: 12133956 DOI: 10.4049/jimmunol.169.3.1334] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Much of the pathology of systemic lupus erythematosus (SLE) is caused by deposition of immune complexes (ICs) into various tissues, including renal glomeruli. Because clearance of ICs depends largely on early complement component C1q, homozygous C1q deficiency is a strong genetic risk factor in SLE, although it is rare in SLE patients overall. In this work we addressed the issue of whether genetic polymorphisms affecting C1q levels may predispose to SLE, using the (NZB x NZW)F(1) model. C1q genes are composed of three genes, C1qa, C1qc, and C1qb, arranged in this order, and each gene consists of two exons separated by one intron. Sequence analysis of the C1q gene in New Zealand Black (NZB), New Zealand White (NZW), and BALB/c mice showed no polymorphisms in exons and introns of three genes. However, Southern blot analysis revealed unique insertion polymorphism of a total of approximately 3.5 kb in the C1qa upstream region of NZB mice. C1q levels in sera and culture supernatants of LPS-stimulated peritoneal macrophages and C1q messages in spleen cells were all lower in disease-free young NZB and (NZB x NZW)F(1) mice than in age-matched non-autoimmune NZW and BALB/c mice. Quantitative trait loci analysis using (NZB x NZW)F(1) x NZW backcrosses showed that NZB microsatellites in the vicinity of the C1q allele on chromosome 4 were significantly linked to low serum C1q levels and the development of nephritis. These data imply that not only C1q deficiency but also regulatory region polymorphisms down-regulating C1q levels may confer the risk for lupus nephritis by reducing IC clearance and thus promoting IC deposition in glomeruli.
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Affiliation(s)
- Yuko Miura-Shimura
- Department of Pathology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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29
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Pickering MC, Botto M, Taylor PR, Lachmann PJ, Walport MJ. Systemic lupus erythematosus, complement deficiency, and apoptosis. Adv Immunol 2001; 76:227-324. [PMID: 11079100 DOI: 10.1016/s0065-2776(01)76021-x] [Citation(s) in RCA: 405] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
MESH Headings
- Adolescent
- Adult
- Alleles
- Animals
- Antibody Formation
- Antigen-Antibody Complex/immunology
- Antigen-Antibody Complex/metabolism
- Apoptosis/immunology
- Autoantibodies/immunology
- Autoantigens/immunology
- Autoimmune Diseases/epidemiology
- Autoimmune Diseases/etiology
- Autoimmune Diseases/genetics
- Autoimmune Diseases/immunology
- Bias
- Carrier Proteins/genetics
- Child
- Child, Preschool
- Collectins
- Complement Activation
- Complement C1 Inactivator Proteins/deficiency
- Complement C1 Inactivator Proteins/genetics
- Complement C1q/deficiency
- Complement C1q/genetics
- Complement C1q/immunology
- Complement System Proteins/deficiency
- Complement System Proteins/genetics
- Complement System Proteins/physiology
- Disease Models, Animal
- Female
- Genetic Predisposition to Disease
- Genotype
- Guinea Pigs
- Humans
- Infant
- Lupus Erythematosus, Systemic/epidemiology
- Lupus Erythematosus, Systemic/etiology
- Lupus Erythematosus, Systemic/genetics
- Lupus Erythematosus, Systemic/immunology
- Male
- Mice
- Mice, Inbred MRL lpr
- Mice, Knockout
- Mice, Mutant Strains
- Middle Aged
- Models, Immunological
- Polymorphism, Genetic
- Receptors, Complement/chemistry
- Receptors, Complement/genetics
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Affiliation(s)
- M C Pickering
- Rheumatology Section, Imperial College School of Medicine, London, England
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30
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Abstract
Although in the past protein stability commonly has been considered an inherent property of a given protein, the truth is far more complex. Elaborate enzymatic systems exist in multiple intracellular compartments to hydrolyze proteins. These systems are capable of providing a sensitive mechanism to regulate protein expression, a mechanism that is complementary to the transcriptional and translational control mechanisms that influence protein synthesis. The power of regulated proteolysis has been well-demonstrated in the abrupt degradation of cyclins that underlies eukaryotic cell cycle progression. Coincidental with the recent rapid gains in understanding proteolysis at a biochemical level, several human diseases have been found to result from disordered proteolysis. This article reviews several examples of human disease resulting from mutations of genes encoding serine proteases, cysteine proteases, and their inhibitors. Examples are also presented of human diseases resulting from disorders in the highly intricate ubiquitin-proteasome pathway of protein degradation. It is certain that many more human diseases will be associated in the future with disorders of proteolysis.
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Affiliation(s)
- G J Kato
- Division of Pediatric Hematology, Johns Hopkins University School of Medicine, and the Johns Hopkins Oncology Center, Baltimore, Maryland, USA.
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31
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Berkel AI, Birben E, Oner C, Oner R, Loos M, Petry F. Molecular, genetic and epidemiologic studies on selective complete C1q deficiency in Turkey. Immunobiology 2000; 201:347-55. [PMID: 10776791 DOI: 10.1016/s0171-2985(00)80089-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Selective complete C1q deficiencies (SCDC1q) of the complement component C1q are rare genetic disorders with high prevalence of lupus-erythematosus-like symptoms and recurrent infections. Among the 41 published cases from 23 families, 10 derive from 6 Turkish families. One particular mutation leading to a stop codon in the C1q A gene was first identified in members of a Gypsy family from the Slovac Republic. Later the same mutation has been found in all cases in four SCDC1q families from Turkey suggesting that one particular defective allele may be present in the populations of Southeastern Europe and Turkey. This study was undertaken to investigate the frequency of C-->T mutation in exon II of C1qA gene in Turkish population by using allele-specific polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). Among the 1544 patients from 15 pediatric departments and an additional 89 SLE patients of various ages no C1qA gene mutation was found. There were 43 heterozygous and 4 homozygous mutations in 161 family members or relatives investigated from the 4 families known with SCDC1q. Among the 223 inhabitants who were nonrelative to the 3 SCDC1q families living in the same village were screened for mutation and one heterozygous individual was observed. Although this mutant allele appears to be at a low prevalence in the population tested, individuals with recurrent infections or symptoms of lupus erythematosus-like syndrome should be tested for this mutation to rule out this type of C1q deficiency.
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Affiliation(s)
- A I Berkel
- Dept. of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
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Endo Y, Kanno K, Takahashi M, Yamaguchi KI, Kohno Y, Fujita T. Molecular Basis of Human Complement C1s Deficiency. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.4.2180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
This is the first report on the molecular basis of human complement C1s deficiency. Two abnormalities in the C1s gene were identified in a Japanese family, including one patient, by using exon-specific PCR, single-strand conformation polymorphism analysis, and nucleotide sequencing. A deletion of 4 bp, TTTG, was identified in exon X when using genomic DNA from the patient, his father, and his paternal grandmother. They were all heterozygous for the mutation. The mutant gene encodes a truncated C1s from the N terminus to the short consensus repeat domain. By further sequencing the PCR products, a nonsense mutation from G to T was identified at codon 608 in exon XII in the patient, his mother, and his sister. They were all heterozygous for the nonsense mutation. The mutant gene encodes a truncated form of C1s that lacks the C-terminal 80 amino acids. These results indicate that the patient was a compound heterozygote with the 4-bp deletion on the paternal allele and the nonsense mutation on the maternal allele. The levels of serum C1s seem to be correlated to the genotypes of the C1s gene in which no C1s was detected in the patient, and one-half of the normal level in the family members who are heterozygous for either mutation. The present study demonstrates that the disease is inherited in an autosomal recessive mode.
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Affiliation(s)
- Yuichi Endo
- *Department of Biochemistry, Fukushima Medical University School of Medicine, 1-Hikarigaoka, Fukushima, Japan; and
| | - Kazuko Kanno
- *Department of Biochemistry, Fukushima Medical University School of Medicine, 1-Hikarigaoka, Fukushima, Japan; and
| | - Minoru Takahashi
- *Department of Biochemistry, Fukushima Medical University School of Medicine, 1-Hikarigaoka, Fukushima, Japan; and
| | - Ken-ichi Yamaguchi
- †Department of Pediatrics, Chiba University School of Medicine, Inohana, Chyuo-ku, Chiba, Japan
| | - Yoichi Kohno
- †Department of Pediatrics, Chiba University School of Medicine, Inohana, Chyuo-ku, Chiba, Japan
| | - Teizo Fujita
- *Department of Biochemistry, Fukushima Medical University School of Medicine, 1-Hikarigaoka, Fukushima, Japan; and
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Abstract
Complete selective deficiencies of the complement component C1q are rare genetic disorders which are associated with recurrent infections and a high prevalence of lupus erythematosus-like symptoms. The improvements in molecular biology techniques have facilitated the analysis of such genetic defects to a great extend. To date the basis of C1q deficiencies from 13 families have been studied at the genetic level. In each case single base mutations leading to either termination codons, frame shift or amino acid exchanges were thought to be responsible for these defects as no other aberrations were found. In addition to DNA analysis, conventional immunochemical and biochemical methods have contributed substantially to the elucidation of the structural and functional requirements of this complex macromolecule. The present article reviews the different types of C1q defects in regard to structure and function whereas a detailed presentation on the clinical aspects of C1q deficiencies will be given in this issue of the Journal (by WALPORT, DAVIES and BOTTO).
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Affiliation(s)
- F Petry
- Institute of Medical Microbiology and Hygiene, Johannes Gutenberg University, Mainz, Germany
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Abstract
In this chapter we review the association between SLE and C1q. In the first part of the chapter we discuss the clinical associations of C1q deficiency, and tabulate the available information in the literature relating to C1q deficiency and autoimmune disease. Other clinical associations of C1q deficiency are then considered, and we mention briefly the association between other genetically determined complement deficiencies and lupus. In the review we explore the relationship between C1q consumption and lupus and we discuss the occurrence of low molecular weight (7S) C1q in lupus, which raises the possibility that increased C1q turnover in the disease may result in unbalanced chain synthesis of the molecule. Anti-C1q antibodies are also strongly associated with severe SLE affecting the kidney, and with hypocomplementaemic urticarial vasculitis, and these associations are also examined. We address the question of how C1q deficiency may cause SLE, discussing the possibility that this may be due to abnormalities of immune complex processing, which have been well characterised in a umber of different human models. There is clear evidence that immune complex processing is abnormal in patients with hypocomplementaemia, and this is compatible with the hypothesis that ineffective immune complex clearance could cause tissue injury, and this may in turn stimulate an autoantibody response. We have also considered the possibility that C1q-C1q receptor interactions are critical in the regulation of apoptosis, and we explore the hypothesis that dysregulation of apoptosis could explain important features in the development of autoimmune disease associated with C1q deficiency. An abnormally high rate of apoptosis, or defective clearance of apoptotic cells, could promote the accumulation of abnormal cellular products that might drive an autoimmune response. Anti-C1q antibodies have been described in a number of murine models of lupus, and these are also briefly discussed. We focus on the recently developed C1q "knockout" mice, which have been developed in our laboratory. Amongst the C1q deficient mice of a mixed genetic background high titres of antinuclear antibodies were detected in approximately half the animals, and around 25% of the mice, aged eight months had evidence of a glomerulonephritis with immune deposits. Large numbers of apoptotic bodies were also present in diseased glomeruli, and this supports the hypothesis that C1q may have a critical role to play in the physiological clearance of apoptotic cells.
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Affiliation(s)
- M J Walport
- Department of Medicine, Imperial College School of Medicine, London, U.K
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Botto M, Dell'Agnola C, Bygrave AE, Thompson EM, Cook HT, Petry F, Loos M, Pandolfi PP, Walport MJ. Homozygous C1q deficiency causes glomerulonephritis associated with multiple apoptotic bodies. Nat Genet 1998; 19:56-9. [PMID: 9590289 DOI: 10.1038/ng0598-56] [Citation(s) in RCA: 1053] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The complement system plays a paradoxical role in the development and expression of autoimmunity in humans. The activation of complement in systemic lupus erythematosus (SLE) contributes to tissue injury. In contrast, inherited deficiency of classical pathway components, particularly C1q (ref. 1), is powerfully associated with the development of SLE. This leads to the hypothesis that a physiological action of the early part of the classical pathway protects against the development of SLE (ref. 2) and implies that C1q may play a key role in this respect. C1q-deficient (C1qa-/-) mice were generated by gene targeting and monitored for eight months. C1qa-/- mice had increased mortality and higher titres of autoantibodies, compared with strain-matched controls. Of the C1qa-/- mice, 25% had glomerulonephritis with immune deposits and multiple apoptotic cell bodies. Among mice without glomerulonephritis, there were significantly greater numbers of glomerular apoptotic bodies in C1q-deficient mice compared with controls. The phenotype associated with C1q deficiency was modified by background genes. These findings are compatible with the hypothesis that C1q deficiency causes autoimmunity by impairment of the clearance of apoptotic cells.
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Affiliation(s)
- M Botto
- Rheumatology Section, Hammersmith Campus, Imperial College School of Medicine, London, UK
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Petry F, Hauptmann G, Goetz J, Grosshans E, Loos M. Molecular basis of a new type of C1q-deficiency associated with a non-functional low molecular weight (LMW) C1q: parallels and differences to other known genetic C1q-defects. IMMUNOPHARMACOLOGY 1997; 38:189-201. [PMID: 9476130 DOI: 10.1016/s0162-3109(97)00065-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Analysis of an abnormal C1q molecule of individuals of a Moroccan family by ultracentrifugation in sucrose gradients revealed a low molecular weight C1q (LMW-C1q). We investigated the molecular basis of this defect by sequencing all six exons of the three C1q genes. One point mutation in the codon for Gly at position 15 (GGT) of the B chain was found resulting in an amino acid substitution to Asp (GAT). The exchange not only leads to an interruption of the collagen-like motif Gly-X-Y, but also introduces one negatively charged residue per B chain which results in two additional charges per structural subunit (A-B, C-C, A-B). The mutation which has been identified by DNA-sequencing in the C1q-deficient younger brother of the propositus was confirmed by PCR-EcoRV-RFLP in the sister and the propositus himself. This mutation is very similar to a mutation previously described in another case of functional C1q deficiency where Gly at position 6 of the C chain was substituted by a large positively charged residue (Arg). Again, a LMW-C1q was demonstrated. These point mutations that lead to amino acid substitutions result in the production of a LMW-C1q where the formation of functionally active 11S C1q consisting of three structural subunits appears to be inhibited by the introduction of six additional charges, one per B or C chain, respectively, in the collagenous region of the molecule.
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Affiliation(s)
- F Petry
- Institut für Medizinische Mikrobiologie und Hygiene, Johannes Gutenberg Universität, Mainz, Germany.
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Affiliation(s)
- M J Walport
- Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom
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