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Kandari S, Chakurkar V, Gaikwad S, Agarwal M, Phadke N, Lobo V. High prevalence of CFHR deletions in Indian women with pregnancy-associated hemolytic uremic syndrome. Nephrology (Carlton) 2021; 27:231-237. [PMID: 34796567 DOI: 10.1111/nep.14004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/13/2021] [Accepted: 11/11/2021] [Indexed: 11/28/2022]
Abstract
AIM Pregnancy-associated hemolytic uremic syndrome (P-aHUS) is an important cause of peripartum acute kidney injury. Studies from Europe have described mutations in complement regulator genes, and data in Indian patients is scarce. Hence this study used multiplex ligation-dependent probe amplification (MLPA) to identify variants in complement genes in P-aHUS patients. METHODS We present 17 patients of P-aHUS who were investigated for complement protein levels and genetic analysis with MLPA for complement genes. Plasma exchange therapy was offered to all patients presenting in acute phase. RESULTS Mean age 26.74 (3.36) years with 15/17 delivered by caesarean section. Eleven patients received early (within 7 days) plasma exchange, three were dialysis-dependent at 3 months and seven were dialysis-free. Only one of the three patients receiving late (after 7 days) plasma exchange was dialysis-free. MLPA showed that 11 patients had heterozygous deletions of exons 3, 5, 6 of CFHR1 and upstream region of exons 1, 2, 3, 6 and intron 4 of CFHR3 gene while four patients had homozygous deletions at the same loci. Two patients had no MLPA-detectable variations. CONCLUSION This study reports a high proportion of deletions of exons of CFHR1 & CFHR3 genes in Indian P-aHUS patients detectable by MLPA by copy number variations. This needs confirmation in large multicentre studies. Plasma exchange can be an effective therapy in the non-availability of Eculizumab.
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Zhang Y, Ghiringhelli Borsa N, Shao D, Dopler A, Jones MB, Meyer NC, Pitcher GR, Taylor AO, Nester CM, Schmidt CQ, Smith RJH. Factor H Autoantibodies and Complement-Mediated Diseases. Front Immunol 2020; 11:607211. [PMID: 33384694 PMCID: PMC7770156 DOI: 10.3389/fimmu.2020.607211] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/05/2020] [Indexed: 12/25/2022] Open
Abstract
Factor H (FH), a member of the regulators-of-complement-activation (RCA) family of proteins, circulates in human plasma at concentrations of 180–420 mg/L where it controls the alternative pathway (AP) of complement in the fluid phase and on cell surfaces. When the regulatory function of FH is impaired, complement-mediated tissue injury and inflammation occur, leading to diseases such as atypical hemolytic uremic syndrome (a thrombotic microangiopathy or TMA), C3 glomerulopathy (C3G) and monoclonal gammopathy of renal significance (MGRS). A pathophysiological cause of compromised FH function is the development of autoantibodies to various domains of the FH protein. FH autoantibodies (FHAAs) are identified in 10.9% of patients with aHUS, 3.2% of patients with C3G, and rarely in patients with MGRS. The phenotypic variability of FHAA-mediated disease reflects both the complexity of FH and the epitope specificity of FHAA for select regions of the native protein. In this paper, we have characterized FHAA epitopes in a large cohort of patients diagnosed with TMA, C3G or MGRS. We explore the epitopes recognized by FHAAs in these diseases and the association of FHAAs with the genetic deletion of both copies of the CFHR1 gene to show how these disease phenotypes are associated with this diverse spectrum of autoantibodies.
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Affiliation(s)
- Yuzhou Zhang
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Nicolo Ghiringhelli Borsa
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Dingwu Shao
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Arthur Dopler
- Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Michael B Jones
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Nicole C Meyer
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Gabriella R Pitcher
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Amanda O Taylor
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Carla M Nester
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products & Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States
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Yoshida Y, Kato H, Ikeda Y, Nangaku M. Pathogenesis of Atypical Hemolytic Uremic Syndrome. J Atheroscler Thromb 2018; 26:99-110. [PMID: 30393246 PMCID: PMC6365154 DOI: 10.5551/jat.rv17026] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a type of thrombotic microangiopathy (TMA) defined by thrombocytopenia, microangiopathic hemolytic anemia, and renal failure. aHUS is caused by uncontrolled complement activation in the alternative pathway (AP). A variety of genetic defects in complement-related factors or acquired autoantibodies to the complement regulators have been found in 50 to 60% of all cases. Recently, however, the classification and diagnosis of aHUS are becoming more complicated. One reason for this is that some factors, which have not been regarded as complement-related factors, have been reported as predisposing factors for phenotypic aHUS. Given that genotype is highly correlated with the phenotype of aHUS, careful analysis of underlying genetic abnormalities or acquired factors is needed to predict the prognosis or to decide an optimal treatment for the disease. Another reason is that complement dysregulation in the AP have also been found in a part of other types of TMA such as transplantation-related TMA and pregnancy-related complication. Based on these findings, it is now time to redefine aHUS according to the genetic or acquired background of abnormalities.Here, we review the pathogeneses and the corresponding phenotypes of aHUS and complement-related TMAs.
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Affiliation(s)
- Yoko Yoshida
- Division of Nephrology and Endocrinology, the University of Tokyo Hospital
| | - Hideki Kato
- Department of Prevention of Diabetes and Lifestyle-Related Diseases Graduate School of Medicine, the University of Tokyo
| | - Yoichiro Ikeda
- Division of Nephrology and Endocrinology, the University of Tokyo Hospital
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, the University of Tokyo Hospital
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Pouw RB, Gómez Delgado I, López Lera A, Rodríguez de Córdoba S, Wouters D, Kuijpers TW, Sánchez-Corral P. High Complement Factor H-Related (FHR)-3 Levels Are Associated With the Atypical Hemolytic-Uremic Syndrome-Risk Allele CFHR3*B. Front Immunol 2018; 9:848. [PMID: 29740447 PMCID: PMC5928496 DOI: 10.3389/fimmu.2018.00848] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/05/2018] [Indexed: 02/05/2023] Open
Abstract
Dysregulation of the complement alternative pathway (AP) is a major pathogenic mechanism in atypical hemolytic-uremic syndrome (aHUS). Genetic or acquired defects in factor H (FH), the main AP regulator, are major aHUS drivers that associate with a poor prognosis. FH activity has been suggested to be downregulated by homologous FH-related (FHR) proteins, including FHR-3 and FHR-1. Hence, their relative levels in plasma could be disease-relevant. The genes coding for FH, FHR-3, and FHR-1 (CFH, CFHR3, and CFHR1, respectively) are polymorphic and located adjacent to each other on human chromosome 1q31.3. We have previously shown that haplotype CFH(H3)-CFHR3*B-CFHR1*B associates with aHUS and reduced FH levels. In this study, we used a specific enzyme-linked immunosorbent assay to quantify FHR-3 in plasma samples from controls and patients with aHUS genotyped for the three known CFHR3 alleles (CFHR3*A, CFHR3*B, and CFHR3*Del). In the 218 patients carrying at least one copy of CFHR3, significant differences between CFHR3 genotype groups were found, with CFHR3*A/Del patients having the lowest FHR-3 concentration (0.684-1.032 µg/mL), CFHR3*B/Del and CFHR3*A/A patients presenting intermediate levels (1.437-2.201 µg/mL), and CFHR3*A/B and CFHR3*B/B patients showing the highest concentration (2.330-4.056 µg/mL) (p < 0.001). These data indicate that CFHR3*A is a low-expression allele, whereas CFHR3*B, associated with increased risk of aHUS, is a high-expression allele. Our study reveals that the aHUS-risk haplotype CFH(H3)-CFHR3*B-CFHR1*B generates twofold more FHR-3 than the non-risk CFH(H1)-CFHR3*A-CFHR1*A haplotype. In addition, FHR-3 levels were higher in patients with aHUS than in control individuals with the same CFHR3 genotype. These data suggest that increased plasma levels of FHR-3, altering the balance between FH and FHR-3, likely impact the FH regulatory functions and contribute to the development of aHUS.
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Affiliation(s)
- Richard B. Pouw
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
- Department of Pediatric Hematology, Immunology and Infectious Diseases, Emma Children’s Hospital, Academic Medical Center, Amsterdam, Netherlands
| | - Irene Gómez Delgado
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Alberto López Lera
- Immunology Unit, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Santiago Rodríguez de Córdoba
- Biological Research Center (CIB)-CSIC, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Diana Wouters
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Taco W. Kuijpers
- Department of Pediatric Hematology, Immunology and Infectious Diseases, Emma Children’s Hospital, Academic Medical Center, Amsterdam, Netherlands
- Department of Blood Cell Research, Sanquin Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Pilar Sánchez-Corral
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
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Durey MAD, Sinha A, Togarsimalemath SK, Bagga A. Anti-complement-factor H-associated glomerulopathies. Nat Rev Nephrol 2016; 12:563-78. [PMID: 27452363 DOI: 10.1038/nrneph.2016.99] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Atypical haemolytic uraemic syndrome (aHUS), an important cause of acute kidney injury, is characterized by dysregulation of the complement pathway, frequent need for dialysis, and progression to end-stage renal disease. Autoantibodies against complement factor H (FH), the main plasma regulatory protein of the alternative pathway of the complement system, account for a considerable proportion of children with aHUS. The autoantibodies are usually associated with the occurrence of a homozygous deletion in the genes encoding the FH-related proteins FHR1 and FHR3. High levels of autoantibodies, noted at the onset of disease and during relapses, induce functional deficiency of FH, whereas their decline, in response to plasma exchanges and/or immunosuppressive therapy, is associated with disease remission. Management with plasma exchange and immunosuppression is remarkably effective in inducing and maintaining remission in aHUS associated with FH autoantibodies, whereas terminal complement blockade with eculizumab is considered the most effective therapy in other forms of aHUS. Anti-FH autoantibodies are also detected in a small proportion of patients with C3 glomerulopathies, which are characterized by chronic glomerular injury mediated by activation of the alternative complement pathway and predominant C3 deposits on renal histology.
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Affiliation(s)
- Marie-Agnes Dragon Durey
- INSERM UMRS1138, Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, 15 rue de l'ecole de medecine, 75006 Paris, France.,Université Paris Descartes, Paris, France.,Service d'Immunologie Biologique, Hôpital Européen Georges Pompidou, APHP, 20 rue Leblanc, 75015 Paris, France
| | - Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Shambhuprasad Kotresh Togarsimalemath
- INSERM UMRS1138, Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, 15 rue de l'ecole de medecine, 75006 Paris, France.,Université Paris Descartes, Paris, France
| | - Arvind Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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Buhlmann D, Eberhardt HU, Medyukhina A, Prodinger WM, Figge MT, Zipfel PF, Skerka C. FHR3 Blocks C3d-Mediated Coactivation of Human B Cells. THE JOURNAL OF IMMUNOLOGY 2016; 197:620-9. [PMID: 27279373 DOI: 10.4049/jimmunol.1600053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 05/05/2016] [Indexed: 01/27/2023]
Abstract
The autoimmune renal disease deficient for complement factor H-related (CFHR) genes and autoantibody-positive form of hemolytic uremic syndrome is characterized by the presence of autoantibodies specific for the central complement regulator, factor H, combined with a homozygous deficiency, mostly in CFHR3 and CFHR1 Because FHR3 and FHR1 bind to C3d and inactivated C3b, which are ligands for complement receptor type 2 (CR2/CD21), the aim of the current study was to examine whether FHR3-C3d or FHR1-C3d complexes modulate B cell activation. Laser-scanning microscopy and automated image-based analysis showed that FHR3, but not FHR1 or factor H, blocked B cell activation by the BCR coreceptor complex (CD19/CD21/CD81). FHR3 bound to C3d, thereby inhibiting the interaction between C3d and CD21 and preventing colocalization of the coreceptor complex with the BCR. FHR3 neutralized the adjuvant effect of C3d on B cells, as shown by inhibited intracellular CD19 and Akt phosphorylation in Raji cells, as well as Ca(2+) release in peripheral B cells. In cases of CFHR3/CFHR1 deficiency, the FHR3 binding sites on C3d are occupied by factor H, which lacks B cell-inhibitory functions. These data provide evidence that FHR3, which is absent in patients with the autoimmune form of hemolytic uremic syndrome, is involved in B cell regulation.
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Affiliation(s)
- Denise Buhlmann
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Hannes U Eberhardt
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Anna Medyukhina
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Wolfgang M Prodinger
- Department of Hygiene and Medical Microbiology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; and
| | - Marc Thilo Figge
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany; Friedrich Schiller University, 07743 Jena, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany; Friedrich Schiller University, 07743 Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany;
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7
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Muff-Luett M, Nester CM. The Genetics of Ultra-Rare Renal Disease. J Pediatr Genet 2016; 5:33-42. [PMID: 27617140 DOI: 10.1055/s-0036-1572515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/02/2015] [Indexed: 12/14/2022]
Abstract
The complement-mediated renal diseases are a group of ultra-rare renal diseases that disproportionately affect children and young adults and frequently lead to irreversible renal failure. Genetic mutations in alternate pathway of complement genes are pathomechanistically involved in a significant number of these unique diseases. Here, we review our current understanding of the role of genetics in the primary complement-mediated renal diseases affecting children, with a focus on atypical hemolytic uremic syndrome and C3 glomerulopathy. Also, included is a brief discussion of the related diseases whose relationship to complement abnormality has been suspected but not yet confirmed. Advances in genetics have transformed both treatment and outcomes in these historically difficult to treat, highly morbid diseases.
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Affiliation(s)
- Melissa Muff-Luett
- Division of Pediatric Nephrology, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Carla M Nester
- Division of Pediatric Nephrology, Dialysis and Transplantation, Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States; Molecular Otolaryngology and Renal Research Laboratory, University of Iowa, Iowa City, Iowa, United States
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8
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Nester CM, Barbour T, de Cordoba SR, Dragon-Durey MA, Fremeaux-Bacchi V, Goodship THJ, Kavanagh D, Noris M, Pickering M, Sanchez-Corral P, Skerka C, Zipfel P, Smith RJH. Atypical aHUS: State of the art. Mol Immunol 2015; 67:31-42. [PMID: 25843230 DOI: 10.1016/j.molimm.2015.03.246] [Citation(s) in RCA: 194] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/11/2015] [Accepted: 03/12/2015] [Indexed: 12/12/2022]
Abstract
Tremendous advances in our understanding of the thrombotic microangiopathies (TMAs) have revealed distinct disease mechanisms within this heterogeneous group of diseases. As a direct result of this knowledge, both children and adults with complement-mediated TMA now enjoy higher expectations for long-term health. In this update on atypical hemolytic uremic syndrome, we review the clinical characteristics; the genetic and acquired drivers of disease; the broad spectrum of environmental triggers; and current diagnosis and treatment options. Many questions remain to be addressed if additional improvements in patient care and outcome are to be achieved in the coming decade.
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Affiliation(s)
- Carla M Nester
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Division of Nephrology, Stead Family Department of Pediatrics, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Thomas Barbour
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, UK
| | | | - Marie Agnes Dragon-Durey
- Assistance Publique - Hopitaux de Paris, Service d'Immunologie Biologique, Hopital Europeen Georges Pompidou, Paris, France
| | - Veronique Fremeaux-Bacchi
- Assistance Publique - Hopitaux de Paris, Service d'Immunologie Biologique, Hopital Europeen Georges Pompidou, Paris, France
| | - Tim H J Goodship
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - David Kavanagh
- Assistance Publique - Hopitaux de Paris, Service d'Immunologie Biologique, Hopital Europeen Georges Pompidou, Paris, France
| | - Marina Noris
- IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", Ranica, Bergamo, Italy
| | - Matthew Pickering
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, UK
| | - Pilar Sanchez-Corral
- Unidad de Investigación and Ciber de Enfermedades Raras, Hospital Universitario de La Paz_IdiPAZ, Paseo de la Castellana 261, 28046 Madrid, Spain
| | - Christine Skerka
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Peter Zipfel
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany; Friedrich Schiller University, Jena, Germany
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Division of Nephrology, Stead Family Department of Pediatrics, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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9
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Kim S, Swaminathan S, Inlow M, Risacher SL, Nho K, Shen L, Foroud TM, Petersen RC, Aisen PS, Soares H, Toledo JB, Shaw LM, Trojanowski JQ, Weiner MW, McDonald BC, Farlow MR, Ghetti B, Saykin AJ. Influence of genetic variation on plasma protein levels in older adults using a multi-analyte panel. PLoS One 2013; 8:e70269. [PMID: 23894628 PMCID: PMC3720913 DOI: 10.1371/journal.pone.0070269] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 06/17/2013] [Indexed: 12/24/2022] Open
Abstract
Proteins, widely studied as potential biomarkers, play important roles in numerous physiological functions and diseases. Genetic variation may modulate corresponding protein levels and point to the role of these variants in disease pathophysiology. Effects of individual single nucleotide polymorphisms (SNPs) within a gene were analyzed for corresponding plasma protein levels using genome-wide association study (GWAS) genotype data and proteomic panel data with 132 quality-controlled analytes from 521 Caucasian participants in the Alzheimer’s Disease Neuroimaging Initiative (ADNI) cohort. Linear regression analysis detected 112 significant (Bonferroni threshold p = 2.44×10−5) associations between 27 analytes and 112 SNPs. 107 out of these 112 associations were tested in the Indiana Memory and Aging Study (IMAS) cohort for replication and 50 associations were replicated at uncorrected p<0.05 in the same direction of effect as those in the ADNI. We identified multiple novel associations including the association of rs7517126 with plasma complement factor H-related protein 1 (CFHR1) level at p<1.46×10−60, accounting for 40 percent of total variation of the protein level. We serendipitously found the association of rs6677604 with the same protein at p<9.29×10−112. Although these two SNPs were not in the strong linkage disequilibrium, 61 percent of total variation of CFHR1 was accounted for by rs6677604 without additional variation by rs7517126 when both SNPs were tested together. 78 other SNP-protein associations in the ADNI sample exceeded genome-wide significance (5×10−8). Our results confirmed previously identified gene-protein associations for interleukin-6 receptor, chemokine CC-4, angiotensin-converting enzyme, and angiotensinogen, although the direction of effect was reversed in some cases. This study is among the first analyses of gene-protein product relationships integrating multiplex-panel proteomics and targeted genes extracted from a GWAS array. With intensive searches taking place for proteomic biomarkers for many diseases, the role of genetic variation takes on new importance and should be considered in interpretation of proteomic results.
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Affiliation(s)
- Sungeun Kim
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Shanker Swaminathan
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Mark Inlow
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Mathematics, Rose-Hulman Institute of Technology, Terre Haute, Indiana, United States of America
| | - Shannon L. Risacher
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Kwangsik Nho
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Li Shen
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Tatiana M. Foroud
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Ronald C. Petersen
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Paul S. Aisen
- Department of Neurology, University of California San Diego, San Diego, California, United States of America
| | - Holly Soares
- Bristol Myers Squibb Co, Wallingford, Connecticut, United States of America
| | - Jon B. Toledo
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Leslie M. Shaw
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - John Q. Trojanowski
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Michael W. Weiner
- Departments of Radiology, Medicine and Psychiatry, University of California, San Francisco, San Francisco, California, United States of America
- Department of Veterans Affairs Medical Center, San Francisco, California, United States of America
| | - Brenna C. McDonald
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Martin R. Farlow
- Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Andrew J. Saykin
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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10
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Skerka C, Chen Q, Fremeaux-Bacchi V, Roumenina LT. Complement factor H related proteins (CFHRs). Mol Immunol 2013; 56:170-80. [PMID: 23830046 DOI: 10.1016/j.molimm.2013.06.001] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 05/08/2013] [Indexed: 02/06/2023]
Abstract
Factor H related proteins comprise a group of five plasma proteins: CFHR1, CFHR2, CFHR3, CFHR4 and CFHR5, and each member of this group binds to the central complement component C3b. Mutations, genetic deletions, duplications or rearrangements in the individual CFHR genes are associated with a number of diseases including atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathies (C3 glomerulonephritis (C3GN), dense deposit disease (DDD) and CFHR5 nephropathy), IgA nephropathy, age related macular degeneration (AMD) and systemic lupus erythematosus (SLE). Although complement regulatory functions were attributed to most of the members of the CFHR protein family, the precise role of each CFHR protein in complement activation and the exact contribution to disease pathology is still unclear. Recent publications show that CFHR proteins form homo- as well as heterodimers. Genetic abnormalities within the CFHR gene locus can result in hybrid proteins with affected dimerization or recognition domains which cause defective functions. Here we summarize the recent data about CFHR genes and proteins in order to better understand the role of CFHR proteins in complement activation and in complement associated diseases.
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Affiliation(s)
- Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.
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Determining the population frequency of the CFHR3/CFHR1 deletion at 1q32. PLoS One 2013; 8:e60352. [PMID: 23613724 PMCID: PMC3629053 DOI: 10.1371/journal.pone.0060352] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 02/25/2013] [Indexed: 01/04/2023] Open
Abstract
In this study we have used multiplex ligation-dependent probe amplification (MLPA) to measure the copy number of CFHR3 and CFHR1 in DNA samples from 238 individuals from the UK and 439 individuals from the HGDP-CEPH Human Genome Diversity Cell Line Panel. We have then calculated the allele frequency and frequency of homozygosity for the copy number polymorphism represented by the CFHR3/CFHR1 deletion. There was a highly significant difference between geographical locations in both the allele frequency (X2 = 127.7, DF = 11, P-value = 4.97x10-22) and frequency of homozygosity (X2 = 142.3, DF = 22, P-value = 1.33x10-19). The highest frequency for the deleted allele (54.7%) was seen in DNA samples from Nigeria and the lowest (0%) in samples from South America and Japan. The observed frequencies in conjunction with the known association of the deletion with AMD, SLE and IgA nephropathy is in keeping with differences in the prevalence of these diseases in African and European Americans. This emphasises the importance of identifying copy number polymorphism in disease.
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