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Byrnes JR, Lee T, Sharaby S, Campbell RA, Dobson DA, Holle LA, Luo M, Kangro K, Homeister JW, Aleman MM, Luyendyk JP, Kerlin BA, Dumond JB, Wolberg AS. Reciprocal stabilization of coagulation factor XIII-A and -B subunits is a determinant of plasma FXIII concentration. Blood 2024; 143:444-455. [PMID: 37883802 PMCID: PMC10862369 DOI: 10.1182/blood.2023022042] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/28/2023] [Accepted: 10/15/2023] [Indexed: 10/28/2023] Open
Abstract
ABSTRACT Transglutaminase factor XIII (FXIII) is essential for hemostasis, wound healing, and pregnancy maintenance. Plasma FXIII is composed of A and B subunit dimers synthesized in cells of hematopoietic origin and hepatocytes, respectively. The subunits associate tightly in circulation as FXIII-A2B2. FXIII-B2 stabilizes the (pro)active site-containing FXIII-A subunits. Interestingly, people with genetic FXIII-A deficiency have decreased FXIII-B2, and therapeutic infusion of recombinant FXIII-A2 (rFXIII-A2) increases FXIII-B2, suggesting FXIII-A regulates FXIII-B secretion, production, and/or clearance. We analyzed humans and mice with genetic FXIII-A deficiency and developed a mouse model of rFXIII-A2 infusion to define mechanisms mediating plasma FXIII-B levels. Like humans with FXIII-A deficiency, mice with genetic FXIII-A deficiency had reduced circulating FXIII-B2, and infusion of FXIII-A2 increased FXIII-B2. FXIII-A-deficient mice had normal hepatic function and did not store FXIII-B in liver, indicating FXIII-A does not mediate FXIII-B secretion. Transcriptional analysis and polysome profiling indicated similar F13b levels and ribosome occupancy in FXIII-A-sufficient and -deficient mice and in FXIII-A-deficient mice infused with rFXIII-A2, indicating FXIII-A does not induce de novo FXIII-B synthesis. Unexpectedly, pharmacokinetic/pharmacodynamic modeling of FXIII-B antigen after rFXIII-A2 infusion in humans and mice suggested FXIII-A2 slows FXIII-B2 loss from plasma. Accordingly, comparison of free FXIII-B2 vs FXIII-A2-complexed FXIII-B2 (FXIII-A2B2) infused into mice revealed faster clearance of free FXIII-B2. These data show FXIII-A2 prevents FXIII-B2 loss from circulation and establish the mechanism underlying FXIII-B2 behavior in FXIII-A deficiency and during rFXIII-A2 therapy. Our findings reveal a unique, reciprocal relationship between independently synthesized subunits that mediate an essential hemostatic protein in circulation. This trial was registered at www.ClinicalTrials.com as #NCT00978380.
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Affiliation(s)
- James R. Byrnes
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Taek Lee
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Sherif Sharaby
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Robert A. Campbell
- Molecular Medicine Program, Department of Internal Medicine, The University of Utah, Salt Lake City, UT
| | - Dre’Von A. Dobson
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Lori A. Holle
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Michelle Luo
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Kadri Kangro
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Jonathon W. Homeister
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Maria M. Aleman
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - James P. Luyendyk
- Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI
| | - Bryce A. Kerlin
- Center for Clinical and Translational Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio
- Division of Pediatric Hematology/Oncology/Blood & Marrow Transplantation, Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio
| | - Julie B. Dumond
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Alisa S. Wolberg
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC
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Singh S, Pezeshkpoor B, Jamil MA, Dodt J, Sharma A, Ramar V, Ivaskevicius V, Hethershaw E, Philippou H, Pavlova A, Oldenburg J, Biswas A. Heterozygosity in factor XIII genes and the manifestation of mild inherited factor XIII deficiency. J Thromb Haemost 2024; 22:379-393. [PMID: 37832789 DOI: 10.1016/j.jtha.2023.09.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/15/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023]
Abstract
BACKGROUND The characterization of inherited mild factor XIII deficiency is more imprecise than its rare, inherited severe forms. It is known that heterozygosity at FXIII genetic loci results in mild FXIII deficiency, characterized by circulating FXIII activity levels ranging from 20% to 60%. There exists a gap in information on 1) how genetic heterozygosity renders clinical bleeding manifestations among these individuals and 2) the reversal of unexplained bleeding upon FXIII administration in mild FXIII-deficient individuals. OBJECTIVES To assess the prevalence and burden of mild FXIII deficiency among the apparently healthy German-Caucasian population and correlate it with genetic heterozygosity at FXIII and fibrinogen gene loci. METHODS Peripheral blood was collected from 752 donors selected from the general population with essentially no bleeding complications to ensure asymptomatic predisposition. These were assessed for FXIII and fibrinogen activity, and FXIII and fibrinogen genes were resequenced using next-generation sequencing. For comparison, a retrospective analysis was performed on a cohort of mild inherited FXIII deficiency patients referred to us. RESULTS The prevalence of mild FXIII deficiency was high (∼0.8%) among the screened German-Caucasian population compared with its rare-severe forms. Although no new heterozygous missense variants were found, certain combinations were relatively dominant/prevalent among the mild FXIII-deficient individuals. CONCLUSION This extensive, population-based quasi-experimental approach revealed that the burden of heterozygosity in FXIII and fibrinogen gene loci causes the clinical manifestation of inherited mild FXIII deficiency, resulting in ''unexplained bleeding'' upon provocation.
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Affiliation(s)
- Sneha Singh
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany
| | - Behnaz Pezeshkpoor
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany
| | - Muhammad Ahmer Jamil
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany
| | | | - Amit Sharma
- Department of Hematology, All India Institute of Medical Sciences, New Delhi, India
| | - Vasanth Ramar
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany
| | - Vytautas Ivaskevicius
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany
| | - Emma Hethershaw
- Division of Cardiovascular and Diabetes Research, School of Medicine, University of Leeds, Leeds, United Kingdom
| | - Helen Philippou
- Division of Cardiovascular and Diabetes Research, School of Medicine, University of Leeds, Leeds, United Kingdom
| | - Anna Pavlova
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany
| | - Johannes Oldenburg
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany
| | - Arijit Biswas
- Institute for Experimental Hematology and Transfusion Medicine, University Hospital of Bonn, Bonn, North-Rheine Westfalen, Germany.
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Javed H, Singh S, Urs SUR, Oldenburg J, Biswas A. Genetic landscape in coagulation factor XIII associated defects – Advances in coagulation and beyond. Blood Rev 2022; 59:101032. [PMID: 36372609 DOI: 10.1016/j.blre.2022.101032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022]
Abstract
Coagulation factor XIII (FXIII) acts as a fine fulcrum in blood plasma that maintains the balance between bleeding and thrombosis by covalently crosslinking the pre-formed fibrin clot into an insoluble one that is resistant to premature fibrinolysis. In plasma, FXIII circulates as a pro-transglutaminase complex composed of the dimeric catalytic FXIII-A encoded by the F13A1 gene and dimeric carrier/regulatory FXIII-B subunits encoded by the F13B gene. Growing evidence accumulated over decades of exhaustive research shows that not only does FXIII play major roles in both pathological extremes of hemostasis i.e. bleeding and thrombosis, but that it is, in fact, a pleiotropic protein with physiological roles beyond coagulation. However, the current FXIII genetic-epidemiological literature is overwhelmingly derived from the bleeding pathology associated with its deficiency. In this article we review the current clinical, functional, and molecular understanding of this fascinating multifaceted protein, especially putting into the same perspective its genetic landscape.
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The Plasma Factor XIII Heterotetrameric Complex Structure: Unexpected Unequal Pairing within a Symmetric Complex. Biomolecules 2019; 9:biom9120765. [PMID: 31766577 PMCID: PMC6995596 DOI: 10.3390/biom9120765] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/15/2019] [Accepted: 11/19/2019] [Indexed: 02/07/2023] Open
Abstract
Factor XIII (FXIII) is a predominant determinant of clot stability, strength, and composition. Plasma FXIII circulates as a pro-transglutaminase with two catalytic A subunits and two carrier-protective B subunits in a heterotetramer (FXIII-A2B2). FXIII-A2 and -B2 subunits are synthesized separately and then assembled in plasma. Following proteolytic activation by thrombin and calcium-mediated dissociation of the B subunits, activated FXIII (FXIIIa) covalently cross links fibrin, promoting clot stability. The zymogen and active states of the FXIII-A subunits have been structurally characterized; however, the structure of FXIII-B subunits and the FXIII-A2B2 complex have remained elusive. Using integrative hybrid approaches including atomic force microscopy, cross-linking mass spectrometry, and computational approaches, we have constructed the first all-atom model of the FXIII-A2B2 complex. We also used molecular dynamics simulations in combination with isothermal titration calorimetry to characterize FXIII-A2B2 assembly, activation, and dissociation. Our data reveal unequal pairing of individual subunit monomers in an otherwise symmetric complex, and suggest this unusual structure is critical for both assembly and activation of this complex. Our findings enhance understanding of mechanisms associating FXIII-A2B2 mutations with disease and have important implications for the rational design of molecules to alter FXIII assembly or activity to reduce bleeding and thrombotic complications.
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Singh S, Akhter MS, Dodt J, Volkers P, Reuter A, Reinhart C, Krettler C, Oldenburg J, Biswas A. Identification of Potential Novel Interacting Partners for Coagulation Factor XIII B (FXIII-B) Subunit, a Protein Associated with a Rare Bleeding Disorder. Int J Mol Sci 2019; 20:ijms20112682. [PMID: 31159152 PMCID: PMC6600159 DOI: 10.3390/ijms20112682] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 12/28/2022] Open
Abstract
Coagulation factor XIII (FXIII) is a plasma-circulating heterotetrameric pro-transglutaminase complex that is composed of two catalytic FXIII-A and two protective/regulatory FXIII-B subunits. FXIII acts by forming covalent cross-links within a preformed fibrin clots to prevent its premature fibrinolysis. The FXIII-A subunit is known to have pleiotropic roles outside coagulation, but the FXIII-B subunit is a relatively unexplored entity, both structurally as well as functionally. Its discovered roles so far are limited to that of the carrier/regulatory protein of its partner FXIII-A subunit. In the present study, we have explored the co-presence of protein excipients in commercial FXIII plasma concentrate FibrogamminP by combination of protein purification and mass spectrometry-based verification. Complement factor H was one of the co-excipients observed in this analysis. This was followed by performing pull down assays from plasma in order to detect the putative novel interacting partners for the FXIII-B subunit. Complement system proteins, like complement C3 and complement C1q, were amongst the proteins that were pulled down. The only protein that was observed in both experimental set ups was alpha-2-macroglobulin, which might therefore be a putative interacting partner of the FXIII/FXIII-B subunit. Future functional investigations will be needed to understand the physiological significance of this association.
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Affiliation(s)
- Sneha Singh
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, 53127 Bonn, Germany.
| | - Mohammad Suhail Akhter
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, 53127 Bonn, Germany.
- College of Applied Medical Sciences, Jazan University, 82911 Jazan, Saudi Arabia.
| | | | | | | | - Christoph Reinhart
- Department of Molecular Membrane Biology, Max-Planck Institute for Biophysics, Max-Von Laue Str 3, 60438 Frankfurt am Main, Germany.
| | - Christoph Krettler
- Department of Molecular Membrane Biology, Max-Planck Institute for Biophysics, Max-Von Laue Str 3, 60438 Frankfurt am Main, Germany.
| | - Johannes Oldenburg
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, 53127 Bonn, Germany.
| | - Arijit Biswas
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, 53127 Bonn, Germany.
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Disruption of Structural Disulfides of Coagulation FXIII-B Subunit; Functional Implications for a Rare Bleeding Disorder. Int J Mol Sci 2019; 20:ijms20081956. [PMID: 31013569 PMCID: PMC6514982 DOI: 10.3390/ijms20081956] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/18/2019] [Accepted: 04/18/2019] [Indexed: 12/13/2022] Open
Abstract
Congenital FXIII deficiency is a rare bleeding disorder in which mutations are detected in F13A1 and F13B genes that express the two subunits of coagulation FXIII, the catalytic FXIII-A, and protective FXIII-B. Mutations in FXIII-B subunit are considerably rarer compared to FXIII-A. Three mutations in the F13B gene have been reported on its structural disulfide bonds. In the present study, we investigate the structural and functional importance of all 20 structural disulfide bonds in FXIII-B subunit. All disulfide bonds were ablated by individually mutating one of its contributory cysteine’s, and these variants were transiently expressed in HEK293t cell lines. The expression products were studied for stability, secretion, the effect on oligomeric state, and on FXIII-A activation. The structural flexibility of these disulfide bonds was studied using classical MD simulation performed on a FXIII-B subunit monomer model. All 20 FXIII-B were found to be important for the secretion and stability of the protein since ablation of any of these led to a secretion deficit. However, the degree of effect that the disruption of disulfide bond had on the protein differed between individual disulfide bonds reflecting a functional hierarchy/diversity within these disulfide bonds.
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Akhter MS, Singh S, Yadegari H, Ivaskevicius V, Oldenburg J, Biswas A. Exploring the structural similarity yet functional distinction between coagulation factor XIII-B and complement factor H sushi domains. J Thromb Thrombolysis 2019; 48:95-102. [PMID: 30915671 DOI: 10.1007/s11239-019-01841-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Coagulation factor XIII (FXIII) covalently crosslinks pre-formed fibrin clots preventing their premature fibrinolysis. In plasma, FXIII circulates as a zymogenic heterotetramer composed of catalytic FXIII-A subunits, and carrier/regulatory FXIII-B subunits. FXIII-A is a well characterized component of this complex, and has been associated with several pleiotropic roles outside coagulation as well. In comparison only protective/regulatory roles towards the FXIII-A subunit have been identified for FXIII-B. Strong homology between FXIII-B and complement regulator Complement factor H suggests a putative role of FXIII-B in complement activation. In the current study we have analyzed the similarities and yet functional divergence of these two proteins using in silico sequence alignment and structural analysis. We have evaluated complement activation post reconstitution of FXIII components into FXIII deficient and CFH deficient plasma. We have also transiently expressed FXIII-B in SH-SY5Y cell lines and evaluated its effect on the endogenous complement activation. Our investigations show no effect of FXIII-B subunit on the rate of complement activation. Therefore we conclude that at a physiological level, FXIII-B subunit plays no role in the complement system, although a vestigial function in altered pathological states might still exist.
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Affiliation(s)
- Mohammad Suhail Akhter
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Sigmund Freud Str. 25, 53127, Bonn, Germany
- College of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
| | - Sneha Singh
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Sigmund Freud Str. 25, 53127, Bonn, Germany
| | - Hamideh Yadegari
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Sigmund Freud Str. 25, 53127, Bonn, Germany
| | - Vytautas Ivaskevicius
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Sigmund Freud Str. 25, 53127, Bonn, Germany
| | - Johannes Oldenburg
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Sigmund Freud Str. 25, 53127, Bonn, Germany
| | - Arijit Biswas
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Sigmund Freud Str. 25, 53127, Bonn, Germany.
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Thomas A, Biswas A, Dodt J, Philippou H, Hethershaw E, Ensikat HJ, Ivaskevicius V, Oldenburg J. Coagulation Factor XIIIA Subunit Missense Mutations Affect Structure and Function at the Various Steps of Factor XIII Action. Hum Mutat 2016; 37:1030-41. [PMID: 27363989 DOI: 10.1002/humu.23041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 06/06/2016] [Accepted: 06/17/2016] [Indexed: 11/06/2022]
Abstract
Inherited defects of coagulation Factor XIII (FXIII) can be categorized into severe and mild forms based on their genotype and phenotype. Heterozygous mutations occurring in F13A1 and F13B genes causing mild FXIII deficiency have been reported only in the last few years primarily because the mild FXIII deficiency patients are often asymptomatic unless exposed to some kind of a physical trauma. However, unlike mutations causing severe FXIII deficiency, many of these mutations have not been comprehensively characterized based on expression studies. In our current article, we have transiently expressed 16 previously reported missense mutations detected in the F13A1 gene of patients with mild FXIII deficiency and analyzed their respective expression phenotype. Complimentary to expression analysis, we have used in silico analysis to understand and explain some of the in vitro findings. The expression phenotype has been evaluated with a number of expression phenotype determining assays. We observe that the mutations influence different aspects of FXIII function and can be functionally categorized on the basis of their expression phenotype. We identified mutations which even in heterozygous form would have strong impact on the functional status of the protein (namely mutations p.Arg716Gly, p.Arg704Gln, p.Gln602Lys, p.Leu530Pro, p.His343Tyr, p.Pro290Arg, and p.Arg172Gln).
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Affiliation(s)
- Anne Thomas
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - Arijit Biswas
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany.
| | | | - Helen Philippou
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Emma Hethershaw
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | | | - Vytautas Ivaskevicius
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - Johannes Oldenburg
- Institute of Experimental Haematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany.
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Effects of Factor XIII Deficiency on Thromboelastography. Thromboelastography with Calcium and Streptokinase Addition is more Sensitive than Solubility Tests. Mediterr J Hematol Infect Dis 2016; 8:e2016037. [PMID: 27648200 PMCID: PMC5016016 DOI: 10.4084/mjhid.2016.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 07/05/2016] [Indexed: 11/29/2022] Open
Abstract
Background Homozygous or double heterozygous factor XIII (FXIII) deficiency is characterized by soft tissue hematomas, intracranial and delayed spontaneous bleeding. Alterations of thromboelastography (TEG) parameters in these patients have been reported. The aim of the study was to show results of TEG, TEG Lysis (Lys 60) induced by subthreshold concentrations of streptokinase (SK), and to compare them to the clot solubility studies results in samples of a 1-year-old girl with homozygous or double heterozygous FXIII deficiency. Case A year one girl with a history of bleeding from the umbilical cord. During her first year of life, several hematomas appeared in soft upper limb tissue after punctures for vaccination and a gluteal hematoma. One additional sample of a heterozygous patient and three samples of acquired FXIII deficiency were also evaluated. Materials and Methods Clotting tests, von Willebrand factor (vWF) antigen and activity, plasma FXIII-A subunit (pFXIII-A) were measured by an immunoturbidimetric assay in a photo-optical coagulometer. Solubility tests were performed with Ca2+-5 M urea and thrombin-2% acetic acid. Basal and post-FXIII concentrate infusion samples were studied. TEG was performed with CaCl2 or CaCl2 + SK (3.2 U/mL) in a Thromboelastograph. Results Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, fibrinogen, factor VIIIc, vWF, and platelet aggregation were normal. Antigenic pFXIII-A subunit was < 2%. TEG, evaluated at diagnosis and post FXIII concentrate infusion (pFXIII-A= 37%), presented a normal reaction time (R), 8 min, prolonged k (14 and 11min respectively), a low Maximum-Amplitude (MA) ( 39 and 52 mm respectively), and Clot Lysis (Lys60) slightly increased (23 and 30% respectively). In the sample at diagnosis, clot solubility was abnormal, 50 and 45 min with Ca-Urea and thrombin-acetic acid, respectively, but normal (>16 hours) 1-day post-FXIII infusion. Analysis of FXIII deficient and normal plasma mixtures (< 2–102% of pFXIII-A), showed that Ca-urea solubility was abnormal at pFXIII-A < 9%, thrombin-acetic acid at pFXIII-A<18%, but TEG MA and elasticity at 23% and Lys60 with SK at pFXIII-A< 40%. Conclusions TEG parameters MA and elasticity, and Lys 60 in TEG either with Ca2+ or Ca2+ and SK are more sensitive to low levels of pFXIII than solubility tests. The increased Lys60 induced by a subthreshold concentration of SK could probably reflect the clot characteristics “in vivo” in many patients with pFXIII levels between 5–40% and could be potentially considered as screening test.
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de Moerloose P, Schved JF, Nugent D. Rare coagulation disorders: fibrinogen, factor VII and factor XIII. Haemophilia 2016; 22 Suppl 5:61-5. [DOI: 10.1111/hae.12965] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2016] [Indexed: 12/17/2022]
Affiliation(s)
- P. de Moerloose
- Division of Angiology and Haemostasis; University Hospitals and Faculty of Medicine; Geneva Switzerland
| | | | - D. Nugent
- Department of Hematology; Children's Hospital of Orange County; Orange CA USA
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