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Schmidt DE, Truedsson Å, Strålfors A, Hojbjerg JA, Soutari N, Holmström M, Ranta S, Letelier A, Bowyer A, Ljung R, Antovic J, Bruzelius M. Clinical Implications of Discrepancy between One-Stage Clotting and Chromogenic Factor IX Activity in Hemophilia B. Thromb Haemost 2024; 124:32-39. [PMID: 37494968 DOI: 10.1055/a-2142-0262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
BACKGROUND Discrepancy in factor IX activity (FIX:C) between one-stage assay (OSA) and chromogenic substrate assay (CSA) in patients with hemophilia B (PwHB) introduces challenges for clinical management. AIM To study the differences in FIX:C using OSA and CSA in moderate and mild hemophilia B (HB), their impact on classification of severity, and correlation with genotype. METHODS Single-center study including 21 genotyped and clinically characterized PwHB. FIX:C by OSA was measured using ActinFSL (Siemens) and CSA by Biophen (Hyphen). In addition, in vitro experiments with wild-type FIX were performed. Reproducibility of CSA was assessed between three European coagulation laboratories. RESULTS FIX:C by CSA was consistently lower than by OSA, with 10/17 PwHB having a more severe hemophilia type by CSA. OSA displayed a more accurate description of the clinical bleeding severity, compared with CSA. A twofold difference between OSA:CSA FIX:C was present in 12/17 PwHB; all patients had genetic missense variants in the FIX serine protease domain. Discrepancy was also observed with diluted normal plasma, most significant for values below 0.10 IU/mL. Assessment of samples with low FIX:C showed excellent reproducibility of the CSA results between the laboratories. CONCLUSION FIX:C was consistently higher by OSA compared with the CSA. Assessing FIX:C by CSA alone would have led to diagnosis of a more severe hemophilia type in a significant proportion of patients. Our study suggests using both OSA and CSA FIX:C together with genotyping to classify HB severity and provide essential information for clinical management.
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Affiliation(s)
- David E Schmidt
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
- Paediatric Coagulation, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Åsa Truedsson
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
| | - Annelie Strålfors
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Johanne Andersen Hojbjerg
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Nida Soutari
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Margareta Holmström
- Coagulation Unit, Department of Hematology, Karolinska University Hospital, Stockholm, Sweden
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Susanna Ranta
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
- Paediatric Coagulation, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Letelier
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Annette Bowyer
- Department of Coagulation, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Rolf Ljung
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Jovan Antovic
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Maria Bruzelius
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Coagulation Unit, Department of Hematology, Karolinska University Hospital, Stockholm, Sweden
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Labarque V, Mancuso ME, Kartal-Kaess M, Ljung R, Mikkelsen TS, Andersson NG. F8/F9 variants in the population-based PedNet Registry cohort compared with locus-specific genetic databases of the European Association for Haemophilia and Allied Disorders and the Centers for Disease Control and Prevention Hemophilia A or Hemophilia B Mutation Project. Res Pract Thromb Haemost 2023; 7:100036. [PMID: 36798899 PMCID: PMC9926204 DOI: 10.1016/j.rpth.2023.100036] [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: 08/31/2022] [Revised: 11/11/2022] [Accepted: 12/17/2022] [Indexed: 01/11/2023] Open
Abstract
Background Hemophilia A and B are caused by variants in the factor (F) VIII or FIX gene. Selective reporting may influence the distribution of variants reported in genetic databases. Objectives To compare the spectrum of F8 and F9 variants in an international population-based pediatric cohort (PedNet Registry) with the spectrum found in the European Association for Haemophilia and Allied Disorders (EAHAD) and the Centers for Disease Control and Prevention Hemophilia A or Hemophilia B Mutation Project (CHAMP/CHBMP) databases. Methods All patients registered in the PedNet Registry on January 1, 2021 were included in this study. As comparators, data from patients with severe hemophilia included in the CHAMP/CHBMP registry (US center data) and EAHAD were used. Results Genetic information was available for 1941 patients. Intron 22 inversion was present in 52% of patients with severe hemophilia A; frameshift (36%), missense (28%), and nonsense (20%) were the most frequent variants in patients with severe hemophilia A who were inversion-negative. The most frequent variants in severe hemophilia B were missense (48%). In nonsevere disease, most variants were missense variants (moderate hemophilia A: 91%; mild hemophilia A: 95%, moderate and mild hemophilia B: 86% each). Comparison with the databases demonstrated a higher proportion of missense variants associated with severe hemophilia B in EAHAD (68%) than in PedNet (48%) and CHBMP (46%). Conclusion The PedNet population-based cohort provides an alternative to the established databases, which collect data by selective reporting, as it is a well-maintained database covering the full spectrum of pathogenic F8 and F9 variants, and indicates the number of patients affected by each particular variant.
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Affiliation(s)
- Veerle Labarque
- Department of Paediatrics, Paediatric Haematology and Oncology, University Hospitals Leuven, Leuven, Belgium,Correspondence Veerle Labarque, Department of Paediatrics, Paediatric Haematology and Oncology, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
| | - Maria Elisa Mancuso
- Center for Thrombosis and Hemorrhagic Diseases, IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy,Humanitas University, Rozzano, Milan, Italy
| | - Mutlu Kartal-Kaess
- Division of Pediatric Hematology and Oncology, Department of Pediatrics, Inselspital, University Hospital, University of Bern, Bern, Switzerland
| | - Rolf Ljung
- Department of Clinical Sciences and Paediatrics, Lund University, Lund, Sweden
| | - Torben S. Mikkelsen
- Department of Paediatric Oncology and Haematology, University Hospital, Aarhus, Denmark
| | - Nadine G. Andersson
- Department of Clinical Sciences and Paediatrics, Lund University, Lund, Sweden,Centre for Thrombosis and Haemostasis, Skåne University Hospital, Lund, Sweden
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Meireles MR, Stelmach LH, Bandinelli E, Vieira GF. Unveiling the influence of factor VIII physicochemical properties on hemophilia A phenotype through an in silico methodology. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 219:106768. [PMID: 35367915 DOI: 10.1016/j.cmpb.2022.106768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 01/24/2022] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVES Hemophilia A (HA) is an X-linked blood disorder. It is caused by pathogenic F8 gene variants, among which missense mutations are the most prevalent. The resulting amino acid substitutions may have different impacts on physicochemical properties and, consequently, on protein functionality. Regular prediction tools do not include structural elements and their physiological significance, which hampers our ability to functionally link variants to disease phenotype, opening an ample field for investigation. The present study aims to elucidate how physicochemical changes generated by substitutions in different protein domains relate to HA, and which of these features are more consequential to protein function and its impact on HA phenotype. METHODS An in silico evaluation of 71 F8 variants found in patients with different HA phenotypes (mild, moderate, severe) was performed to understand protein modifications and functional impact. Homology modeling was used for the structural analysis of physicochemical changes including electrostatic potential, hydrophobicity, solvent-accessible/excluded surface areas, disulfide disruptions, and substitutions indexes. These variants and properties were analyzed by hierarchical clustering analysis (HCA) and principal component analysis (PCA), independently and in combination, to investigate their relative contribution. RESULTS About 69% of variants show electrostatic changes, and almost all show hydrophobicity and surface area modifications. HCA combining all physicochemical properties analyzed was better in reflecting the impact of different variants in disease severity, more so than the single feature analysis. On the other hand, PCA led to the identification of prominent properties involved in the clustering results for variants of different domains. CONCLUSIONS The methodology developed here enables the assessment of structural features not available in other prediction tools (e.g., surface distribution of electrostatic potential), evaluating what kind of physicochemical changes are involved in FVIII functional disruption. HCA results allow distinguishing substitutions according to their properties, and yielded clusters which were more homogeneous in phenotype. All evaluated properties are involved in determining disease severity. The nature, as well as the position of the variants in the protein, were shown to be relevant for physicochemical changes, demonstrating that all these aspects must be collectively considered to fine-tune an approach to predict HA severity.
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Affiliation(s)
- Mariana R Meireles
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, Porto Alegre 91501-970, RS, Brasil
| | - Lara H Stelmach
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, Porto Alegre 91501-970, RS, Brasil
| | - Eliane Bandinelli
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, Porto Alegre 91501-970, RS, Brasil
| | - Gustavo F Vieira
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, Porto Alegre 91501-970, RS, Brasil; Universidade La Salle, Canoas, RS, Brasil.
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Shen G, Gao M, Cao Q, Li W. The Molecular Basis of FIX Deficiency in Hemophilia B. Int J Mol Sci 2022; 23:2762. [PMID: 35269902 PMCID: PMC8911121 DOI: 10.3390/ijms23052762] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/23/2022] [Accepted: 02/27/2022] [Indexed: 12/15/2022] Open
Abstract
Coagulation factor IX (FIX) is a vitamin K dependent protein and its deficiency causes hemophilia B, an X-linked recessive bleeding disorder. More than 1000 mutations in the F9 gene have been identified in hemophilia B patients. Here, we systematically summarize the structural and functional characteristics of FIX and the pathogenic mechanisms of the mutations that have been identified to date. The mechanisms of FIX deficiency are diverse in these mutations. Deletions, insertions, duplications, and indels generally lead to severe hemophilia B. Those in the exon regions generate either frame shift or inframe mutations, and those in the introns usually cause aberrant splicing. Regarding point mutations, the bleeding phenotypes vary from severe to mild in hemophilia B patients. Generally speaking, point mutations in the F9 promoter region result in hemophilia B Leyden, and those in the introns cause aberrant splicing. Point mutations in the coding sequence can be missense, nonsense, or silent mutations. Nonsense mutations generate truncated FIX that usually loses function, causing severe hemophilia B. Silent mutations may lead to aberrant splicing or affect FIX translation. The mechanisms of missense mutation, however, have not been fully understood. They lead to FIX deficiency, often by affecting FIX's translation, protein folding, protein stability, posttranslational modifications, activation to FIXa, or the ability to form functional Xase complex. Understanding the molecular mechanisms of FIX deficiency will provide significant insight for patient diagnosis and treatment.
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Affiliation(s)
- Guomin Shen
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang 471023, China; (M.G.); (Q.C.)
- School of Basic Medical Science, Henan University of Science and Technology, Luoyang 471023, China
| | - Meng Gao
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang 471023, China; (M.G.); (Q.C.)
- School of Basic Medical Science, Henan University of Science and Technology, Luoyang 471023, China
| | - Qing Cao
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang 471023, China; (M.G.); (Q.C.)
- School of Basic Medical Science, Henan University of Science and Technology, Luoyang 471023, China
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
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Sousa Bomfim A, Corrêa de Freitas MC, Picanço Castro V, Abreu Soares Neto M, Pádua R, Covas DT, Sousa Russo EM. Generation of hyperfunctional recombinant human factor IX variants expressed in human cell line SK-Hep-1. Biotechnol Lett 2020; 43:143-152. [PMID: 33130980 DOI: 10.1007/s10529-020-03040-7] [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: 12/05/2019] [Accepted: 10/27/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To develop recombinant factor IX (FIX) variants with augmented clotting activity. RESULTS We generated three new variants, FIX-YKALW, FIX-ALL and FIX-LLW, expressed in SK-Hep-1 cells and characterized in vitro and in vivo. FIX-YKALW showed the highest antigen expression level among the variants (2.17 µg-mL), followed by FIX-LLW (1.5 µg-mL) and FIX-ALL (0.9 µg-mL). The expression level of FIX variants was two-five fold lower than FIX-wild-type (FIX-WT) (4.37 µg-mL). However, the biological activities of FIX variants were 15-31 times greater than FIX-WT in the chromogenic assay. Moreover, the new variants FIX-YKALW, FIX-LLW and FIX-ALL also presented higher specific activity than FIX-WT (17, 20 and 29-fold higher, respectively). FIX variants demonstrated a better clotting time than FIX-WT. In hemophilia B mice, we observed that FIX-YKALW promoted hemostatic protection. CONCLUSION We have developed three improved FIX proteins with potential for use in protein replacement therapy for hemophilia B.
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Affiliation(s)
- Aline Sousa Bomfim
- Department of Clinical, Toxicological and Food Science Analysis, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo, Brazil. .,Laboratory of Biotechnology, Center for Cell-Based Therapy and Regional Blood Center, University of São Paulo, São Paulo, Brazil. .,Department of Clinical, Toxicological and Food Science Analysis, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Café Avenue, Block R, Room 7, Ribeirão Preto, SP, ZIP 14040-903, Brazil.
| | | | - Virgínia Picanço Castro
- Laboratory of Biotechnology, Center for Cell-Based Therapy and Regional Blood Center, University of São Paulo, São Paulo, Brazil
| | - Mario Abreu Soares Neto
- Laboratory of Biotechnology, Center for Cell-Based Therapy and Regional Blood Center, University of São Paulo, São Paulo, Brazil
| | - Ricardo Pádua
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Dimas Tadeu Covas
- Laboratory of Biotechnology, Center for Cell-Based Therapy and Regional Blood Center, University of São Paulo, São Paulo, Brazil.,Department of Medical Clinic, Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Elisa Maria Sousa Russo
- Department of Clinical, Toxicological and Food Science Analysis, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.,Laboratory of Biotechnology, Center for Cell-Based Therapy and Regional Blood Center, University of São Paulo, São Paulo, Brazil
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