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Cole MA, Ranjan N, Gerber GF, Pan XZ, Flores-Guerrero D, Chaturvedi S, Sperati CJ, McCrae KR, Brodsky RA. Complement Biosensors Identify a Classical Pathway Stimulus in Complement-Mediated Hemolytic Uremic Syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596475. [PMID: 38854038 PMCID: PMC11160691 DOI: 10.1101/2024.05.29.596475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Complement-mediated hemolytic uremic syndrome (CM-HUS) is a thrombotic microangiopathy characterized by germline variants or acquired antibodies to complement proteins and regulators. Building upon our prior experience with the modified Ham (mHam) assay for ex vivo diagnosis of complementopathies, we have developed an array of cell-based complement "biosensors'' by selective removal of complement regulatory proteins (CD55 and CD59, CD46, or a combination thereof) in an autonomously bioluminescent HEK293 cell line. These biosensors can be used as a sensitive method for diagnosing CM-HUS and monitoring therapeutic complement blockade. Using specific complement pathway inhibitors, this model identifies IgM-driven classical pathway stimulus during both acute disease and in many patients during clinical remission. This provides a potential explanation for ~50% of CM-HUS patients who lack an alternative pathway "driving" variant and suggests at least a subset of CM-HUS is characterized by a breakdown of IgM immunologic tolerance. Key Points CM-HUS has a CP stimulus driven by polyreactive IgM, addressing the mystery of why 40% of CM-HUS lack complement specific variantsComplement biosensors and the bioluminescent mHam can be used to aid in diagnosis of CM-HUS and monitor complement inhibitor therapy.
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Maruyama S, Ikeda Y, Kaname S, Kato N, Matsumoto M, Ishikawa Y, Shimono A, Miyakawa Y, Nangaku M, Shibagaki Y, Okada H. Eculizumab for adult patients with atypical haemolytic-uraemic syndrome: full dataset analysis of Japanese post-marketing surveillance. J Nephrol 2024:10.1007/s40620-024-01921-y. [PMID: 38809358 DOI: 10.1007/s40620-024-01921-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 02/10/2024] [Indexed: 05/30/2024]
Abstract
BACKGROUND Eculizumab has been approved for atypical haemolytic-uraemic syndrome (aHUS) in Japan since 2013. Post-marketing surveillance enrolled patients with aHUS who received ≥ 1 dose of eculizumab to assess eculizumab safety and effectiveness. METHODS We evaluated serious adverse events and effectiveness endpoints, i.e., haematologic normalization, a decrease of ≥ 25% in serum creatinine (sCr) levels, and complete thrombotic microangiopathy (TMA) response in adult patients with aHUS without other underlying diseases. In addition, the difference of baseline characteristics between patients who did and did not meet effectiveness endpoints was examined. RESULTS In this safety and effectiveness analysis, 79 adult patients were included; median age was 54.0 years, median treatment duration was 30 weeks. Total exposure time of eculizumab was 75.51 patient-years, and 94 serious adverse events were reported in 39 patients. No unexpected safety signals were identified in this population. Mean platelet count, lactate dehydrogenase and estimated glomerular filtration rate significantly improved after 7 days of treatment. Complete TMA response, haematologic normalization and the improvement of sCr levels were met by 35.3%, 40.4% and 51.3% of patients, respectively. Median treatment duration was shorter in patients who did not achieve complete TMA response (6 weeks) than in patients who did (114 weeks). Multivariate analysis suggested that the time from the most recent TMA episode to start of eculizumab treatment was negatively associated with kidney function improvement. CONCLUSIONS No unexpected safety signals of eculizumab were identified in Japanese patients with aHUS in a real-world setting. Renal outcomes were negatively associated with the time from the most recent TMA episode to the initiation of eculizumab treatment.
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Affiliation(s)
- Shoichi Maruyama
- Department of Nephrology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
| | - Yoichiro Ikeda
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Shinya Kaname
- Department of Nephrology and Rheumatology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka-City, Tokyo, 181-8611, Japan
| | - Noritoshi Kato
- Department of Nephrology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
| | - Masanori Matsumoto
- Department of Blood Transfusion Medicine, Nara Medical University, 840 Shijyo-cho, Kashihara City, Nara, 634-8522, Japan
| | - Yumiko Ishikawa
- Alexion Pharma GK, 3-1-1 Shibaura, Minato-Ku, Tokyo, 108-0023, Japan
| | - Akihiko Shimono
- Alexion Pharma GK, 3-1-1 Shibaura, Minato-Ku, Tokyo, 108-0023, Japan
| | - Yoshitaka Miyakawa
- Department of Haematology, Saitama Medical University, 38 Moroyama, Iruma-gun, Saitama, 350-0495, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Yugo Shibagaki
- Division of Nephrology and Hypertension, Department of Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa, 216-8511, Japan
| | - Hirokazu Okada
- Department of Nephrology, Saitama Medical University, 38 Moroyama, Iruma-Gun, Saitama, 350-0495, Japan
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Jefferis J, Mallett AJ. Exploring the impact and utility of genomic sequencing in established CKD. Clin Kidney J 2024; 17:sfae043. [PMID: 38464959 PMCID: PMC10921391 DOI: 10.1093/ckj/sfae043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Indexed: 03/12/2024] Open
Abstract
Clinical genetics is increasingly recognized as an important area within nephrology care. Clinicians require awareness of genetic kidney disease to recognize clinical phenotypes, consider use of genomics to aid diagnosis, and inform treatment decisions. Understanding the broad spectrum of clinical phenotypes and principles of genomic sequencing is becoming increasingly required in clinical nephrology, with nephrologists requiring education and support to achieve meaningful patient outcomes. Establishment of effective clinical resources, multi-disciplinary teams and education is important to increase application of genomics in clinical care, for the benefit of patients and their families. Novel applications of genomics in chronic kidney disease include pharmacogenomics and clinical translation of polygenic risk scores. This review explores established and emerging impacts and utility of genomics in kidney disease.
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Affiliation(s)
- Julia Jefferis
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Brisbane, Australia
- Faculty of Medicine, The University of Queensland, Brisbane, Australia
- Kidney Health Service, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Andrew J Mallett
- Faculty of Medicine, The University of Queensland, Brisbane, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
- Department of Renal Medicine, Townsville University Hospital, Douglas, Australia
- College of Medicine and Dentistry, James Cook University, Douglas, Australia
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Golshayan D, Schwotzer N, Fakhouri F, Zuber J. Targeting the Complement Pathway in Kidney Transplantation. J Am Soc Nephrol 2023; 34:1776-1792. [PMID: 37439664 PMCID: PMC10631604 DOI: 10.1681/asn.0000000000000192] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/02/2023] [Indexed: 07/14/2023] Open
Abstract
The complement system is paramount in the clearance of pathogens and cell debris, yet is increasingly recognized as a key component in several pathways leading to allograft injury. There is thus a growing interest in new biomarkers to assess complement activation and guide tailored therapies after kidney transplantation (KTx). C5 blockade has revolutionized post-transplant management of atypical hemolytic uremic syndrome, a paradigm of complement-driven disease. Similarly, new drugs targeting the complement amplification loop hold much promise in the treatment and prevention of recurrence of C3 glomerulopathy. Although unduly activation of the complement pathway has been described after brain death and ischemia reperfusion, any clinical attempts to mitigate the ensuing renal insults have so far provided mixed results. However, the intervention timing, strategy, and type of complement blocker need to be optimized in these settings. Furthermore, the fast-moving field of ex vivo organ perfusion technology opens new avenues to deliver complement-targeted drugs to kidney allografts with limited iatrogenic risks. Complement plays also a key role in the pathogenesis of donor-specific ABO- and HLA-targeted alloantibodies. However, C5 blockade failed overall to improve outcomes in highly sensitized patients and prevent the progression to chronic antibody-mediated rejection (ABMR). Similarly, well-conducted studies with C1 inhibitors in sensitized recipients yielded disappointing results so far, in part, because of subtherapeutic dosage used in clinical studies. The emergence of new complement blockers raises hope to significantly reduce the negative effect of ischemia reperfusion, ABMR, and nephropathy recurrence on outcomes after KTx.
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Affiliation(s)
- Dela Golshayan
- Transplantation Center, Department of Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Nora Schwotzer
- Service of Nephrology and Hypertension, Department of Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Fadi Fakhouri
- Service of Nephrology and Hypertension, Department of Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Julien Zuber
- Service de Transplantation rénale adulte, Assistance Publique-Hôpitaux de Paris, Hôpital Necker, Paris, France
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Hallam TM, Sharp SJ, Andreadi A, Kavanagh D. Complement factor I: Regulatory nexus, driver of immunopathology, and therapeutic. Immunobiology 2023; 228:152410. [PMID: 37478687 DOI: 10.1016/j.imbio.2023.152410] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/23/2023] [Accepted: 06/01/2023] [Indexed: 07/23/2023]
Abstract
Complement factor I (FI) is the nexus for classical, lectin and alternative pathway complement regulation. FI is an 88 kDa plasma protein that circulates in an inactive configuration until it forms a trimolecular complex with its cofactor and substrate whereupon a structural reorganization allows the catalytic triad to cleave its substrates, C3b and C4b. In keeping with its role as the master complement regulatory enzyme, deficiency has been linked to immunopathology. In the setting of complete FI deficiency, a consumptive C3 deficiency results in recurrent infections with encapsulated microorganisms. Aseptic cerebral inflammation and vasculitic presentations are also less commonly observed. Heterozygous mutations in the factor I gene (CFI) have been demonstrated to be enriched in atypical haemolytic uraemic syndrome, albeit with a very low penetrance. Haploinsufficiency of CFI has also been associated with decreased retinal thickness and is a strong risk factor for the development of age-related macular degeneration. Supplementation of FI using plasma purified or recombinant protein has long been postulated, however, technical difficulties prevented progression into clinical trials. It is only using gene therapy that CFI supplementation has reached the clinic with GT005 in phase I/II clinical trials for geographic atrophy.
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Affiliation(s)
- T M Hallam
- Gyroscope Therapeutics Limited, A Novartis Company, Rolling Stock Yard, London N7 9AS, UK; Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK; National Renal Complement Therapeutics Centre, Building 26, Royal Victoria Infirmary, UK
| | - S J Sharp
- Gyroscope Therapeutics Limited, A Novartis Company, Rolling Stock Yard, London N7 9AS, UK
| | - A Andreadi
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK; National Renal Complement Therapeutics Centre, Building 26, Royal Victoria Infirmary, UK
| | - D Kavanagh
- Translational and Clinical Research Institute, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK; National Renal Complement Therapeutics Centre, Building 26, Royal Victoria Infirmary, UK; NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK.
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Connaughton DM, Bhai P, Isenring P, Mahdi M, Sadikovic B, Schenkel LC. Genotypic analysis of a large cohort of patients with suspected atypical hemolytic uremic syndrome. J Mol Med (Berl) 2023; 101:1029-1040. [PMID: 37466676 PMCID: PMC10400659 DOI: 10.1007/s00109-023-02341-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 07/20/2023]
Abstract
Atypical hemolytic uremic syndrome (aHUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and renal impairment. Complement and coagulation gene variants have been associated with aHUS susceptibility. We assessed the diagnostic yield of a next-generation sequencing (NGS) panel in a large cohort of Canadian patients with suspected aHUS. Molecular testing was performed on peripheral blood DNA samples from 167 patients, collected between May 2019 and December 2021, using a clinically validated NGS pipeline. Coding exons with 20 base pairs of flanking intronic regions for 21 aHUS-associated or candidate genes were enriched using a custom hybridization protocol. All sequence and copy number variants were assessed and classified following American College of Medical Genetics guidelines. Molecular diagnostic results were reported for four variants in three individuals (1.8%). Twenty-seven variants of unknown significance were identified in 25 (15%) patients, and 34 unique variants in candidate genes were identified in 28 individuals. An illustrative patient case describing two genetic alterations in complement genes is presented, highlighting that variable expressivity and incomplete penetrance must be considered when interpreting genetic data in patients with complement-mediated disease, alongside the potential additive effects of genetic variants on aHUS pathophysiology. In this cohort of patients with suspected aHUS, using clinical pipelines for genetic testing and variant classification, pathogenic/likely pathogenic variants occurred in a very small percentage of patients. Our results highlight the ongoing challenges in variant classification following NGS panel testing in patients with suspected aHUS, alongside the need for clear testing guidance in the clinical setting. KEY MESSAGES: • Clinical molecular testing for disease associated genes in aHUS is challenging. • Challenges include patient selection criteria, test validation, and interpretation. • Most variants were of uncertain significance (31.7% of patients; VUS + candidates). • Their clinical significance may be elucidated as more evidence becomes available. • Low molecular diagnostic rate (1.8%), perhaps due to strict classification criteria. • Case study identified two likely pathogenic variants; one each in MCP/CD46 and CFI.
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Affiliation(s)
- Dervla M Connaughton
- Schulich School of Medicine & Dentistry, University of Western, London, ON, Canada
- Department of Medicine, Division of Nephrology, London Health Sciences Centre, 339 Windermere Road, London, ON, Canada
| | - Pratibha Bhai
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre (LHSC), London, ON, Canada
| | - Paul Isenring
- Faculty of Medicine, Université Laval, Quebec City, QC, Canada
| | | | - Bekim Sadikovic
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre (LHSC), London, ON, Canada
- Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Laila C Schenkel
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre (LHSC), London, ON, Canada.
- Pathology and Laboratory Medicine, Western University, London, ON, Canada.
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Caliskan Y, Safak S, Oto OA, Velioglu A, Yelken B, Mirioglu S, Dirim AB, Yildiz A, Guller N, Yazici H, Ersoy A, Turkmen A, Lentine KL. Propensity score-matched analysis of long-term outcomes for living kidney donation in alternative complement pathway diseases: a pilot study. J Nephrol 2023; 36:979-986. [PMID: 36808609 DOI: 10.1007/s40620-023-01588-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 01/15/2023] [Indexed: 02/23/2023]
Abstract
BACKGROUND Atypical hemolytic syndrome (aHUS) and C3 glomerulopathy (C3G) are complement-mediated rare diseases with excessive activation of the alternative pathway. Data to guide the evaluation of living-donor candidates for aHUS and C3G are very limited. The outcomes of living donors to recipients with aHUS and C3G (Complement disease-living donor group) were compared with a control group to improve our understanding of the clinical course and outcomes of living donation in this context. METHODS Complement disease-living donor group [n = 28; aHUS(53.6%), C3G(46.4%)] and propensity score-matched control-living donor group (n = 28) were retrospectively identified from 4 centers (2003-2021) and followed for major cardiac events (MACE), de novo hypertension, thrombotic microangiopathy (TMA), cancer, death, estimated glomerular filtration rate (eGFR) and proteinuria after donation. RESULTS None of the donors for recipients with complement-related kidney diseases experienced MACE or TMA whereas two donors in the control group developed MACE (7.1%) after 8 (IQR, 2.6-12.8) years (p = 0.15). New-onset hypertension was similar between complement disease and control donor groups (21.4% vs 25%, respectively, p = 0.75). There were no differences between study groups regarding last eGFR and proteinuria levels (p = 0.11 and p = 0.70, respectively). One related donor for a recipient with complement-related kidney disease developed gastric cancer and another related donor developed a brain tumor and died in the 4th year after donation (2, 7.1% vs none, p = 0.15). No recipient had donor-specific human leukocyte antigen antibodies at the time of transplantation. Median follow-up period of transplant recipients was 5 years (IQR, 3-7). Eleven (39.3%) recipients [aHUS (n = 3) and C3G (n = 8)] lost their allografts during the follow-up period. Causes of allograft loss were chronic antibody-mediated rejection in 6 recipients and recurrence of C3G in 5. Last serum creatinine and last eGFR of the remaining patients on follow up were 1.03 ± 038 mg/dL and 73.2 ± 19.9 m/min/1.73 m2 for aHUS patients and 1.30 ± 0.23 mg/dL and 56.4 ± 5.5 m/min/1.73 m2 for C3G patients. CONCLUSION The present study highlights the importance and complexity of living related-donor kidney transplant for patients with complement-related kidney disorders and motivates the need for further research to determine the optimal risk-assessment for living donor candidates to recipients with aHUS and C3G.
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Affiliation(s)
- Yasar Caliskan
- Saint Louis University Transplant Center, SSM-Saint Louis University Hospital, 1201 S. Grand Blvd., St. Louis, MO, 63104, USA. .,Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey.
| | - Seda Safak
- Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey
| | - Ozgur Akin Oto
- Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey
| | - Arzu Velioglu
- Division of Nephrology, Marmara University School of Medicine, Istanbul, Turkey
| | - Berna Yelken
- Organ Transplantation Center, Koc University Hospital, Istanbul, Turkey
| | - Safak Mirioglu
- Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey.,Division of Nephrology, Bezmialem Vakif University School of Medicine, Istanbul, Turkey
| | - Ahmet Burak Dirim
- Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey
| | - Abdulmecit Yildiz
- Division of Nephrology, Bursa Uludag University School of Medicine, Bursa, Turkey
| | - Nurana Guller
- Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey
| | - Halil Yazici
- Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey
| | - Alparslan Ersoy
- Division of Nephrology, Bursa Uludag University School of Medicine, Bursa, Turkey
| | - Aydin Turkmen
- Division of Nephrology, Istanbul University Istanbul School of Medicine, Istanbul, Turkey
| | - Krista L Lentine
- Saint Louis University Transplant Center, SSM-Saint Louis University Hospital, 1201 S. Grand Blvd., St. Louis, MO, 63104, USA
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CFH-CFHR1 hybrid genes in two cases of atypical hemolytic uremic syndrome. J Hum Genet 2023; 68:427-430. [PMID: 36755127 DOI: 10.1038/s10038-023-01129-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/10/2023]
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a rare complement-mediated disease that manifests as the triad of thrombotic microangiopathy. We identified two aHUS patients with neither anti-complement factor H (CFH) antibodies nor causative variants of seven aHUS-related genes (CFH, CFI, CFB, C3, MCP, THBD, and DGKE); however, their plasma showed increased levels of hemolysis by hemolytic assay, which strongly suggests CFH-related abnormalities. Using a copy number variation (CNV) analysis of the CFH/CFHR gene cluster, we identified CFH-CFHR1 hybrid genes in these patients. We verified the absence of aHUS-related abnormal CNVs of the CFH gene in control genomes of 2036 individuals in the general population, which suggests that pathogenicity is related to these hybrid genes. Our study emphasizes that, for patients suspected of having aHUS, it is important to perform an integrated analysis based on a clinical examination, functional analysis, and detailed genetic investigation.
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Gastoldi S, Aiello S, Galbusera M, Breno M, Alberti M, Bresin E, Mele C, Piras R, Liguori L, Santarsiero D, Benigni A, Remuzzi G, Noris M. An ex vivo test to investigate genetic factors conferring susceptibility to atypical haemolytic uremic syndrome. Front Immunol 2023; 14:1112257. [PMID: 36845135 PMCID: PMC9949374 DOI: 10.3389/fimmu.2023.1112257] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/20/2023] [Indexed: 02/11/2023] Open
Abstract
Introduction Comprehensive genetic analysis is essential to clinical care of patients with atypical haemolytic uremic syndrome (aHUS) to reinforce diagnosis, and to guide treatment. However, the characterization of complement gene variants remains challenging owing to the complexity of functional studies with mutant proteins. This study was designed: 1) To identify a tool for rapid functional determination of complement gene variants; 2) To uncover inherited complement dysregulation in aHUS patients who do not carry identified gene variants. Methods To address the above goals, we employed an ex-vivo assay of serum-induced C5b-9 formation on ADP-activated endothelial cells in 223 subjects from 60 aHUS pedigrees (66 patients and 157 unaffected relatives). Results Sera taken from all aHUS patients in remission induced more C5b-9 deposition than control sera, independently from the presence of complement gene abnormalities. To avoid the possible confounding effects of chronic complement dysregulation related to aHUS status, and considering the incomplete penetrance for all aHUS-associated genes, we used serum from unaffected relatives. In control studies, 92.7% of unaffected relatives with known pathogenic variants exhibited positive serum-induced C5b-9 formation test, documenting a high sensitivity of the assay to identify functional variants. The test was also specific, indeed it was negative in all non-carrier relatives and in relatives with variants non-segregating with aHUS. All but one variants in aHUS-associated genes predicted in-silico as likely pathogenic or of uncertain significance (VUS) or likely benign resulted as pathogenic in the C5b-9 assay. At variance, variants in putative candidate genes did not exhibit a functional effect, with the exception of a CFHR5 variant. The C5b-9 assay in relatives was helpful in defining the relative functional effect of rare variants in 6 pedigrees in which the proband carried more than one genetic abnormality. Finally, for 12 patients without identified rare variants, the C5b-9 test in parents unmasked a genetic liability inherited from an unaffected parent. Discussion In conclusion, the serum-induced C5b-9 formation test in unaffected relatives of aHUS patients may be a tool for rapid functional evaluation of rare complement gene variants. When combined with exome sequencing the assay might be of help in variant selection, to identify new aHUS-associated genetic factors.
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Affiliation(s)
- Sara Gastoldi
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Sistiana Aiello
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Miriam Galbusera
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Matteo Breno
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marta Alberti
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elena Bresin
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Caterina Mele
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Rossella Piras
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Lucia Liguori
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Donata Santarsiero
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Ariela Benigni
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
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Boyer O, Niaudet P. Hemolytic-Uremic Syndrome in Children. Pediatr Clin North Am 2022; 69:1181-1197. [PMID: 36880929 DOI: 10.1016/j.pcl.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hemolytic uremic syndrome is characterized by a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney failure. Most cases are caused by Shiga-toxin-producing bacteria, especially Escherichia coli. Transmission occurs through ground beef and unpasteurized milk. STEC-HUS is the main cause of acute renal failure in children. Management remains supportive. Immediate outcome is most often. Atypical HUS represents about 5% of cases, has a relapsing course with more than half of the patients progressing to end-stage kidney failure. Most cases are due to variants in complement regulators of the alternative pathway. Complement inhibitors, such as eculizumab, have considerably improved the prognosis.
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Affiliation(s)
- Olivia Boyer
- Pediatric Nephrology, Necker Enfants Malades Hospital, Université Paris Cité, France; Néphrologie Pédiatrique, Hôpital Necker, 149 Rue de Sèvres, Paris 75015, France
| | - Patrick Niaudet
- Pediatric Nephrology, Necker Enfants Malades Hospital, Université Paris Cité, France.
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Ito S, Hataya H, Ashida A, Hamada R, Ishikawa T, Ishikawa Y, Shimono A, Konomoto T, Miyazawa T, Ogura M, Tanaka K, Kagami S. Eculizumab for paediatric patients with atypical haemolytic uraemic syndrome: full dataset analysis of post-marketing surveillance in Japan. Nephrol Dial Transplant 2022; 38:414-424. [PMID: 35438790 PMCID: PMC9923705 DOI: 10.1093/ndt/gfac150] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Eculizumab was approved for atypical haemolytic uraemic syndrome (aHUS) in Japan in 2013. Post-marketing surveillance (PMS) was mandated by regulatory authorities to assess the safety and effectiveness of eculizumab in patients with aHUS in a real-world setting. METHODS Paediatric patients in the PMS cohort who were <18 years of age at the first administration of eculizumab and diagnosed with aHUS [excluding Shiga toxin-producing Escherichia coli HUS, thrombotic thrombocytopaenic purpura and secondary thrombotic microangiopathy (TMA)] were included in the effectiveness and safety analysis. Clinical endpoints of effectiveness [complete TMA response, TMA event-free status, platelet (PLT) count and lactate dehydrogenase (LDH) normalization, serum creatinine (sCr) decrease and estimated glomerular filtration rate (eGFR) improvement] were analysed in patients treated with at least one dose of eculizumab. Serious adverse events (SAEs) were also evaluated. RESULTS A total of 40 paediatric patients (median age 5 years) were included. The median eculizumab treatment duration was 66 weeks. PLT count, LDH and eGFR significantly improved at 10 days post-treatment. Complete TMA response, haematologic normalization, sCr decrease, eGFR improvement and TMA event-free status were achieved by 73.3%, 73.3%, 70.0%, 78.3% and 77.5% of patients, respectively. Discontinuation criteria were met by 18 patients: 13 patients maintained treatment discontinuation at the end of observation and 5 patients, including 1 patient with aHUS relapse, continued the treatment but extended the treatment interval. During eculizumab treatment, 59 SAEs (0.66/person-year) were reported. Although four deaths were reported, none of them were related to eculizumab. CONCLUSION Eculizumab was well tolerated and effective for paediatric patients with aHUS in the real-world setting in Japan.
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Affiliation(s)
| | - Hiroshi Hataya
- Department of General Paediatrics, Department of Nephrology, Tokyo Metropolitan Children's Medical Centre, Tokyo, Japan
| | - Akira Ashida
- Department of Paediatrics, Osaka Medical and Pharmaceutical University, Osaka, Japan
| | - Riku Hamada
- Department of Nephrology, Tokyo Metropolitan Children's Medical Centre, Tokyo, Japan
| | | | | | | | - Takao Konomoto
- Division of Pediatrics, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | | | - Masao Ogura
- Division of Nephrology and Rheumatology, Department of Medical Subspecialties, National Centre for Child Health and Development, Tokyo, Japan
| | - Kazuki Tanaka
- Department of Nephrology, Aichi Children's Health and Medical Centre, Aichi, Japan
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Rodrigues EM, Ardissino G, Pintarelli G, Capone V, Mariotti J, Verna M, Bernardo ME, Faraci M, Tozzi M, Bucalossi A, Schiavello E, Biassoni V, Guidetti A, Carotti A, Facchini L, Terruzzi E, Giglio F, Zecca M, Onida F, Caroti L, Cesaro S, Consonni D, Cugno M, Porcaro L. Gene Abnormalities in Transplant Associated-Thrombotic Microangiopathy: Comparison between Recipient and Donor's DNA. Thromb Haemost 2021; 122:1247-1250. [PMID: 34965590 DOI: 10.1055/s-0041-1740498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Evangeline Millicent Rodrigues
- Center for HUS Control, Prevention and Management, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Gianluigi Ardissino
- Center for HUS Control, Prevention and Management, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Giulia Pintarelli
- Laboratory of Medical Genetics, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Valentina Capone
- Center for HUS Control, Prevention and Management, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Jacopo Mariotti
- Bone Marrow Transplant Unit, Hematology-Oncology Department, Humanitas Cancer Center, Rozzano, Italy
| | - Marta Verna
- Paediatric Foundation MBBM, San Gerardo Hospital, Monza, Italy
| | - Maria Ester Bernardo
- Paediatric Immunohaematology and Bone Marrow Transplantation Unit, San Raffaele Scientific Institute, Vita Salute San Raffaele University, Milan, Italy
| | - Maura Faraci
- Hematopoietic Stem Cell Unit, Department of Hematology-Oncology, IRCCS Istituto G. Gaslini, Genova, Italy
| | - Monica Tozzi
- Cellular Therapy Unit, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | | | - Elisabetta Schiavello
- Paediatric Oncology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Veronica Biassoni
- Paediatric Oncology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Anna Guidetti
- Hematology Division, Hemato-Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Alessandra Carotti
- HST Program, Hematology Immunology Department, University Hospital, Perugia, Italy
| | - Luca Facchini
- Haematology Department, Azienda USL IRCCS, Reggio Emilia, Italy
| | | | - Fabio Giglio
- Hematology and Bone Marrow Transplantation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marco Zecca
- Paediatric Hematoloy/Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Francesco Onida
- Hematology-BMT Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Leonardo Caroti
- Nephrology and Dialysis Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Simone Cesaro
- Oncoematologia Pediatrica, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Dario Consonni
- Unit of Epidemiology in Public Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Massimo Cugno
- Internal Medicine and Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Luigi Porcaro
- Laboratory of Medical Genetics, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
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13
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Filippone EJ, Newman ED, Li L, Gulati R, Farber JL. Thrombotic Microangiopathy, an Unusual Form of Monoclonal Gammopathy of Renal Significance: Report of 3 Cases and Literature Review. Front Immunol 2021; 12:780107. [PMID: 34858436 PMCID: PMC8631422 DOI: 10.3389/fimmu.2021.780107] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/22/2021] [Indexed: 12/25/2022] Open
Abstract
Monoclonal gammopathies result from neoplastic clones of the B-cell lineage and may cause kidney disease by various mechanisms. When the underlying clone does not meet criteria for a malignancy requiring treatment, the paraprotein is called a monoclonal gammopathy of renal significance (MGRS). One rarely reported kidney lesion associated with benign paraproteins is thrombotic microangiopathy (TMA), provisionally considered as a combination signifying MGRS. Such cases may lack systemic features of TMA, such as a microangiopathic hemolytic anemia, and the disease may be kidney limited. There is no direct deposition of the paraprotein in the kidney, and the presumed mechanism is disordered complement regulation. We report three cases of kidney limited TMA associated with benign paraproteins that had no other detectable cause for the TMA, representing cases of MGRS. Two of the cases are receiving clone directed therapy, and none are receiving eculizumab. We discuss in detail the pathophysiological basis for this possible association. Our approach to therapy involves first ruling out other causes of TMA as well as an underlying B-cell malignancy that would necessitate direct treatment. Otherwise, clone directed therapy should be considered. If refractory to such therapy or the disease is severe and multisystemic, C5 inhibition (eculizumab or ravulizumab) may be indicated as well.
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Affiliation(s)
- Edward J Filippone
- Divsion of Nephrology, Department of Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
| | - Eric D Newman
- Divsion of Nephrology, Department of Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
| | - Li Li
- Department of Pathology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
| | - Rakesh Gulati
- Divsion of Nephrology, Department of Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
| | - John L Farber
- Department of Pathology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
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