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Chovanec J, Tunc I, Hughes J, Halstead J, Mateja A, Liu Y, O’Connell MP, Kim J, Park YH, Wang Q, Le Q, Pirooznia M, Trivedi NN, Bai Y, Yin Y, Hsu AP, McElwee J, Lassiter S, Nelson C, Bandoh J, DiMaggio T, Šelb J, Rijavec M, Carter MC, Komarow HD, Sabato V, Steinberg J, Hafer KM, Feuille E, Hourigan CS, Lack J, Khoury P, Maric I, Zanotti R, Bonadonna P, Schwartz LB, Milner JD, Glover SC, Ebo DG, Korošec P, Caughey GH, Brittain EH, Busby B, Metcalfe DD, Lyons JJ. Genetically defined individual reference ranges for tryptase limit unnecessary procedures and unmask myeloid neoplasms. Blood Adv 2023; 7:1796-1810. [PMID: 36170795 PMCID: PMC10164828 DOI: 10.1182/bloodadvances.2022007936] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/09/2022] [Accepted: 08/26/2022] [Indexed: 11/20/2022] Open
Abstract
Serum tryptase is a biomarker used to aid in the identification of certain myeloid neoplasms, most notably systemic mastocytosis, where basal serum tryptase (BST) levels >20 ng/mL are a minor criterion for diagnosis. Although clonal myeloid neoplasms are rare, the common cause for elevated BST levels is the genetic trait hereditary α-tryptasemia (HαT) caused by increased germline TPSAB1 copy number. To date, the precise structural variation and mechanism(s) underlying elevated BST in HαT and the general clinical utility of tryptase genotyping, remain undefined. Through cloning, long-read sequencing, and assembling of the human tryptase locus from an individual with HαT, and validating our findings in vitro and in silico, we demonstrate that BST elevations arise from overexpression of replicated TPSAB1 loci encoding canonical α-tryptase protein owing to coinheritance of a linked overactive promoter element. Modeling BST levels based on TPSAB1 replication number, we generate new individualized clinical reference values for the upper limit of normal. Using this personalized laboratory medicine approach, we demonstrate the clinical utility of tryptase genotyping, finding that in the absence of HαT, BST levels >11.4 ng/mL frequently identify indolent clonal mast cell disease. Moreover, substantial BST elevations (eg, >100 ng/mL), which would ordinarily prompt bone marrow biopsy, can result from TPSAB1 replications alone and thus be within normal limits for certain individuals with HαT.
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Affiliation(s)
- Jack Chovanec
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
| | - Ilker Tunc
- Bioinformatics and Computational Biology Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD
| | | | - Joseph Halstead
- Birmingham Women’s and Children’s NHS Foundation Trust, Birmingham, United Kingdom
| | - Allyson Mateja
- Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD
| | - Yihui Liu
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
| | - Michael P. O’Connell
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
| | - Jiwon Kim
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
| | - Young Hwan Park
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
| | - Qinlu Wang
- Bioinformatics and Computational Biosciences Branch, Office of Cyber Infrastructure and Computational Biology, NIAID, NIH, Bethesda, MD
| | - Quang Le
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA
| | - Mehdi Pirooznia
- Bioinformatics and Computational Biology Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD
| | - Neil N. Trivedi
- Cardiovascular Research Institute and Department of Medicine, University of California San Francisco, San Francisco, CA
- Veterans Affairs Medical Center, San Francisco, CA
| | - Yun Bai
- Mast Cell Biology Section, Laboratory of Allergic Diseases, NIAID, NIH, Bethesda, MD
| | - Yuzhi Yin
- Mast Cell Biology Section, Laboratory of Allergic Diseases, NIAID, NIH, Bethesda, MD
| | - Amy P. Hsu
- Immunopathogenesis Section, Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD
| | | | - Sheryce Lassiter
- Clinical Research Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD
| | - Celeste Nelson
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
| | - Judy Bandoh
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
| | - Thomas DiMaggio
- Fungal Pathogenesis Section, Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD
| | - Julij Šelb
- University Clinic of Respiratory and Allergic Diseases Golnik, Golnik, Slovenia
| | - Matija Rijavec
- University Clinic of Respiratory and Allergic Diseases Golnik, Golnik, Slovenia
| | - Melody C. Carter
- Mast Cell Biology Section, Laboratory of Allergic Diseases, NIAID, NIH, Bethesda, MD
| | - Hirsh D. Komarow
- Mast Cell Biology Section, Laboratory of Allergic Diseases, NIAID, NIH, Bethesda, MD
| | - Vito Sabato
- Department of Immunology, Allergology, and Rheumatology, Infla-Med Centre of Excellence, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Joshua Steinberg
- Division of Allergy and Clinical Immunology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI
| | - Kurt M. Hafer
- Department of Medicine, Stanford University, Stanford, CA
| | - Elizabeth Feuille
- Division of Allergy and Clinical Immunology, Department of Pediatrics, Weill Cornell Medical College, Cornell University, New York, NY
| | | | - Justin Lack
- NIAID Collaborative Bioinformatics Resource, NIAID, NIH, Bethesda, MD
| | - Paneez Khoury
- Human Eosinophil Section, Laboratory of Parasitic Diseases, NIAID, NIH, Bethesda, MD
| | - Irina Maric
- Hematology Service, Department of Laboratory Medicine, Clinical Center, NIH, Bethesda, MD
| | - Roberta Zanotti
- Department of Medicine, Section of Hematology, Verona University Hospital, Verona, Italy
| | | | | | - Joshua D. Milner
- Division of Allergy, Immunology and Rheumatology, Columbia University, New York, NY
| | - Sarah C. Glover
- Division of Digestive Diseases, Department of Medicine, University of Mississippi Medical Center, Jackson, MS
| | - Didier G. Ebo
- Department of Immunology, Allergology, and Rheumatology, Infla-Med Centre of Excellence, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Peter Korošec
- University Clinic of Respiratory and Allergic Diseases Golnik, Golnik, Slovenia
| | - George H. Caughey
- Cardiovascular Research Institute and Department of Medicine, University of California San Francisco, San Francisco, CA
- Veterans Affairs Medical Center, San Francisco, CA
| | | | - Ben Busby
- National Library of Medicine, National Center for Biotechnology Information, NIH, Bethesda, MD
| | - Dean D. Metcalfe
- Mast Cell Biology Section, Laboratory of Allergic Diseases, NIAID, NIH, Bethesda, MD
| | - Jonathan J. Lyons
- Translational Allergic Immunopathology Unit, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD
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Influence of Perinatal Factors on Blood Tryptase and Fecal Calprotectin Levels in Newborns. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10020345. [PMID: 36832475 PMCID: PMC9954950 DOI: 10.3390/children10020345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/31/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Abstract
BACKGROUND Blood tryptase and fecal calprotectin levels may serve as biomarkers of necrotizing enterocolitis. However, their interpretation may be hindered by the little-known effects of perinatal factors. The aim of this study was to compare the tryptase and calprotectin levels in newborns according to their term, trophicity, and sex. METHOD One hundred and fifty-seven premature newborns and 157 full-term newborns were included. Blood tryptase and fecal calprotectin were assayed. RESULTS Blood tryptase levels were higher in premature than in full-term newborns (6.4 vs. 5.2 µg/L; p < 0.001). In situations of antenatal use of corticosteroids (p = 0.007) and non-exclusive use of human milk (p = 0.02), these levels were also higher. However, in multiple linear regression analyses, only prematurity significantly influenced tryptase levels. Fecal calprotectin levels were extremely wide-ranging and were much higher in female than in male newborns (300.5 vs. 110.5 µg/g; p < 0.001). CONCLUSIONS The differences in tryptase levels according to term could be linked to early aggression of the still-immature digestive wall in premature newborns, in particular, by enteral feeding started early. The unexpected influence of sex on fecal calprotectin levels remains unexplained.
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Resolving the genetics of human tryptases: implications for health, disease, and clinical use as a biomarker. Curr Opin Allergy Clin Immunol 2022; 22:143-152. [PMID: 35197435 DOI: 10.1097/aci.0000000000000813] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW To discuss our evolving understanding of the genetic variation in human tryptases and recent advances in associated clinical phenotypes. RECENT FINDINGS Serum tryptase levels have long been used as biomarkers in clinical practice to diagnose mast cell-associated disorders and mast cell-mediated reactions but the contribution of specific secreted isoforms of human tryptases and their role(s) in health and disease has only recently begun to be illuminated. It is now recognized that hereditary alpha-tryptasemia (HαT) is a common genetic trait and the commonest cause for elevated basal serum tryptase (BST), where it can both contribute to mast cell-associated phenotypes, and potentially confound their correct diagnosis. Expression of different tryptase isoforms is now recognized to be associated with specific clinical phenotypes including clonal and nonclonal mast cell-associated disorders as well as certain asthma endotypes. These disparate impacts on clinical disorders may result from differences in enzymatic activities of mature α-tryptases and β-tryptases, and the unique substrate profile and stability of heterotetrameric mature α/β-tryptases recently described to naturally occur. SUMMARY Variable copy number and isoform expression of tryptases differentially impact diseases and reactions associated with mast cells in humans. Recent advances in understanding of genetics governing BST levels have refined our understanding and the clinical use of this biomarker. In the future, incorporation of tryptase genotyping will likely be integral to the work-up and trial design of patients with phenotypes impacted by mast cells ranging from asthma to mastocytosis.
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Mast cell tryptases in allergic inflammation and immediate hypersensitivity. Curr Opin Immunol 2021; 72:94-106. [PMID: 33932709 DOI: 10.1016/j.coi.2021.04.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/01/2021] [Accepted: 04/01/2021] [Indexed: 02/07/2023]
Abstract
Dysregulated mast cell-mediated inflammation and/or activation have been linked to a number of human diseases, including asthma, anaphylaxis, chronic spontaneous urticaria, and mast cell activation syndromes. As a major mast cell granule protein, tryptase is a biomarker commonly used in clinical practice to diagnose mast cell-associated disorders and -mediated reactions, but its mechanistic roles in disease pathogenesis remains incompletely understood. Here, we summarize recent advances in the understanding of human tryptase genetics and the effects that different genetic composition may have on the quaternary structure of tetrameric mature tryptases. We also discuss how these differences may impact clinical phenotypes including allergic inflammation, immediate hypersensitivity, and others seen in patients with mast cell-associated disorders. With the increased application of next-generation sequencing, we foresee that human genetic approaches will be a major focus of understanding human tryptase functions in various human mast cell disorders and in new therapeutic development.
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Ebo DG, De Puysseleyr LP, Van Gasse AL, Elst J, Poorten MLVD, Faber MA, Mertens C, Van Houdt M, Hagendorens MM, Sermeus L, Vitte J, Moise M, Garvey LH, Castells MC, Tacquard C, Mertes PM, Schwartz LB, Sabato V. Mast Cell Activation During Suspected Perioperative Hypersensitivity: A Need for Paired Samples Analysis. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2021; 9:3051-3059.e1. [PMID: 33862269 DOI: 10.1016/j.jaip.2021.03.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/12/2021] [Accepted: 03/27/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Perioperative hypersensitivity (POH) reactions constitute a significant clinical and diagnostic challenge. A transient increase in serum tryptase during POH reflects mast cell activation (MCA) and helps to recognize an underlying hypersensitivity mechanism. OBJECTIVE To determine the diagnostic performance of different tryptase decision thresholds based on single and paired measurements to document MCA in suspected POH. METHODS Acute serum tryptase (aST) and baseline serum tryptase (bST) samples were obtained from patients referred to our outpatients clinic because of clinical POH. Tryptase samples from controls were obtained before induction (Tt0) and 1.5 hours after induction (Tt1) in uneventful anesthesia. Different cutoff points for tryptase increase over bST and the percentage increase in tryptase (%T) were calculated and compared with existing thresholds: aST > [1.2 × (bST) + 2] (consensus formula), aST higher than 11.4 ng/mL, and aST higher than 14 ng/mL. RESULTS Patients with POH had higher bST and aST levels compared with controls (respectively 5.15 vs 2.28 ng/mL for bST and 20.30 vs 1.92 ng/mL for aST). The consensus formula and a tryptase increase over bST of greater than or equal to 3.2 ng/mL held the highest accuracies to document MCA in POH (respectively 81% and 82%). A bST of higher than 8 ng/mL was present in 4% of controls, 5% of patients with grade 1 POH, 24% of patients with grade 2 POH, 15% of patients with grade 3 POH, and 17% of patients with grade 4 POH. CONCLUSIONS Our data endorse the consensus formula for detection of MCA in POH. Furthermore, it shows that a bST of higher than 8 ng/mL was associated with occurrence of anaphylaxis.
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Affiliation(s)
- Didier G Ebo
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium; AZ Jan Palfijn Gent, Department of Immunology and Allergology, Ghent, Belgium.
| | - Leander P De Puysseleyr
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium
| | - Athina L Van Gasse
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium; Faculty of Medicine and Health Sciences, Department of Paediatrics and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Paediatrics, Antwerp University Hospital, Antwerp, Belgium
| | - Jessy Elst
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium
| | - Marie-Line van der Poorten
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium; Faculty of Medicine and Health Sciences, Department of Paediatrics and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Paediatrics, Antwerp University Hospital, Antwerp, Belgium
| | - Margaretha A Faber
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium
| | - Christel Mertens
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium
| | - Michel Van Houdt
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium
| | - Margo M Hagendorens
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium; Faculty of Medicine and Health Sciences, Department of Paediatrics and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Paediatrics, Antwerp University Hospital, Antwerp, Belgium
| | - Luc Sermeus
- Department of Anaesthesia, Antwerp University Hospital, Antwerp, Belgium
| | - Joana Vitte
- Aix-Marseille University, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France; IDESP, INSERM, University of Montpellier, Montpellier, France; Laboratoire d'Immunologie, CHU de Nîmes, Nîmes, France
| | - Michel Moise
- Aix-Marseille University, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille, France; Laboratoire d'Immunologie, CHU de Nîmes, Nîmes, France
| | - Lene H Garvey
- Allergy Clinic, Department of Dermatology and Allergy, Gentofte Hospital, Gentofte, Denmark; Department of Clinical Medicine, Ha, Denmark
| | - Mariana C Castells
- Division of Allergy and Clinical Immunology, Brigham and Women's Hospital, Boston, Mass; Harvard Medical School, Boston, Mass
| | - Charles Tacquard
- Nouvel Hôpital Civil, hôpitaux universitaires de Strasbourg, service d'anesthésie-réanimation chirurgicale, Strasbourg, France
| | - Paul-Michel Mertes
- Nouvel Hôpital Civil, hôpitaux universitaires de Strasbourg, service d'anesthésie-réanimation chirurgicale, Strasbourg, France
| | - Lawrence B Schwartz
- Department of Internal Medicine, Division of Rheumatology, Allergy & Immunologie, Virginia Commonwealth University, Richmond, Va
| | - Vito Sabato
- Faculty of Medicine and Health Sciences, Department of Immunology, Allergology, Rheumatology and the Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium; Department of Immunology, Allergology, Rheumatology, Antwerp University Hospital, Antwerp, Belgium; AZ Jan Palfijn Gent, Department of Immunology and Allergology, Ghent, Belgium
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Luskin KT, White AA, Lyons JJ. The Genetic Basis and Clinical Impact of Hereditary Alpha-Tryptasemia. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2021; 9:2235-2242. [PMID: 33744473 DOI: 10.1016/j.jaip.2021.03.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/21/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022]
Abstract
Hereditary alpha-tryptasemia (HαT) is an autosomal dominant genetic trait found in 4% to 6% of the general population and defined by excess copies of alpha-tryptase at TPSAB1. Elevated basal serum tryptase (sBT >8 ng/mL) is a defining feature of HαT and appears to result from increased pro-alpha-tryptase synthesis and secretion rather than mast cell activation. It is estimated that approximately one-third of individuals with HαT have associated symptoms, including cutaneous, gastrointestinal, atopic, musculoskeletal, autonomic, and neuropsychiatric manifestations. HαT is found at a disproportionately high rate in systemic mastocytosis and idiopathic anaphylaxis, and is a modifying factor that independently increases the incidence and severity of anaphylaxis. The varied phenotypes associated with HαT may, in part, result from coinheritance of other genetic variants, increased expression of α-/ß-tryptase heterotetramers, and/or overexpression of pro-alpha-tryptase, although further studies are needed. There is an accurate diagnostic test available to confirm HαT in patients that can be used in combination with sBT to help risk-stratify individuals in whom bone marrow biopsy is being considered. There is no specific treatment for symptoms associated with HαT, and management is focused on controlling clinical manifestations with mast cell mediator antagonists, aspirin, inhalers, epinephrine, omalizumab, and involvement of other specialists.
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Affiliation(s)
- Kathleen T Luskin
- Division of Allergy, Asthma and Immunology, Scripps Clinic, La Jolla, Calif.
| | - Andrew A White
- Division of Allergy, Asthma and Immunology, Scripps Clinic, La Jolla, Calif
| | - Jonathan J Lyons
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md.
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Genetic Regulation of Tryptase Production and Clinical Impact: Hereditary Alpha Tryptasemia, Mastocytosis and Beyond. Int J Mol Sci 2021; 22:ijms22052458. [PMID: 33671092 PMCID: PMC7957558 DOI: 10.3390/ijms22052458] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/20/2021] [Accepted: 02/25/2021] [Indexed: 12/12/2022] Open
Abstract
Tryptase is a serine protease that is predominantly produced by tissue mast cells (MCs) and stored in secretory granules together with other pre-formed mediators. MC activation, degranulation and mediator release contribute to various immunological processes, but also to several specific diseases, such as IgE-dependent allergies and clonal MC disorders. Biologically active tryptase tetramers primarily derive from the two genes TPSB2 (encoding β-tryptase) and TPSAB1 (encoding either α- or β-tryptase). Based on the most common gene copy numbers, three genotypes, 0α:4β, 1α:3β and 2α:2β, were defined as “canonical”. About 4–6% of the general population carry germline TPSAB1-α copy number gains (2α:3β, 3α:2β or more α-extra-copies), resulting in elevated basal serum tryptase levels. This condition has recently been termed hereditary alpha tryptasemia (HαT). Although many carriers of HαT appear to be asymptomatic, a number of more or less specific symptoms have been associated with HαT. Recent studies have revealed a significantly higher HαT prevalence in patients with systemic mastocytosis (SM) and an association with concomitant severe Hymenoptera venom-induced anaphylaxis. Moreover, HαT seems to be more common in idiopathic anaphylaxis and MC activation syndromes (MCAS). Therefore, TPSAB1 genotyping should be included in the diagnostic algorithm in patients with symptomatic SM, severe anaphylaxis or MCAS.
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Abstract
PURPOSE OF REVIEW Is sexual dimorphism also true in anaphylaxis as described in other allergic diseases? Possible gender differences in the epidemiology, triggers, severity, outcomes of anaphylaxis as well as in the pathogenesis of the disease are discussed. RECENT FINDINGS Hormonal status and the X-chromosome-coded factors deeply involved in the regulation of T-cell and B-cell responses may influence the gender difference noticed in allergic diseases, such as asthma and rhinitis. Little is known if sex is also relevant for anaphylaxis, although the description of catamenial anaphylaxis is intriguing. However, epidemiologic bias, lack of reliable animal models for the human disease, differences into diagnostic codes and not harmonized clinical grading unfortunately represent hurdles to obtain meaningful information on this topic. SUMMARY The female sex predisposes to a dysregulation of the immune response as suggested by the increased prevalence of autoimmunity and atopy. In anaphylaxis, pathomechanisms are not fully disclosed, triggers are numerous and IgE-dependent mast cell degranulation only represents a part of the story. Improvement into the definition of the disease including a more careful coding system and better investigations about triggers seem the only way to allow a more precise assessment of the possible different risk for women to develop anaphylaxis.
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Abstract
The evolutionary conservation of the catalytically inactive α-tryptase gene has remained a mystery. In this issue of JEM, Le et al. unveil the existence of a novel but natural tryptase, heteromeric α/β-tryptase, a critical mediator of α-tryptase–associated diseases. The evolutionary conservation of the catalytically inactive α-tryptase gene has remained a mystery. In this issue of JEM, Le et al. (2019. J. Exp. Med.https://doi.org/10.1084/jem.20190701) unveil the existence of a novel but natural tryptase, heteromeric α/β-tryptase, a critical mediator of α-tryptase–associated diseases.
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Affiliation(s)
- Michelle Shuling Ong
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology, and Research), Singapore
| | - Vinay Tergaonkar
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology, and Research), Singapore .,Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Faculty of Health Sciences, University of Macau, Macau, China
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Hunter J, Naguib M. Sugammadex-induced bradycardia and asystole: how great is the risk? Br J Anaesth 2018; 121:8-12. [DOI: 10.1016/j.bja.2018.03.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/03/2018] [Accepted: 03/05/2018] [Indexed: 12/17/2022] Open
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Vasquez Velasquez C, Roman AD, Lan NTP, Huy NT, Mercado ES, Espino FE, Perez MLM, Huong VTQ, Thuy TT, Tham VD, Nga CTP, Ha TTN, Bilar JM, Bajaro JDP, Baello BQ, Kikuchi M, Yasunami M, Morita K, Watanabe N, Karbwang J, Hirayama K. Alpha tryptase allele of Tryptase 1 (TPSAB1) gene associated with Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS) in Vietnam and Philippines. Hum Immunol 2015; 76:318-23. [DOI: 10.1016/j.humimm.2015.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 03/03/2015] [Accepted: 03/11/2015] [Indexed: 01/19/2023]
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Abdelmotelb AM, Rose-Zerilli MJ, Barton SJ, Holgate ST, Walls AF, Holloway JW. Alpha-tryptase gene variation is associated with levels of circulating IgE and lung function in asthma. Clin Exp Allergy 2015; 44:822-30. [PMID: 24372627 PMCID: PMC4282335 DOI: 10.1111/cea.12259] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 11/20/2013] [Accepted: 11/27/2013] [Indexed: 12/31/2022]
Abstract
Background Tryptase, a major secretory product of human mast cells has been implicated as a key mediator of allergic inflammation. Genetic variation in the tryptases is extensive, and α-tryptase, an allelic variant of the more extensively studied β-tryptase, is absent in substantial numbers of the general population. The degree to which α-tryptase expression may be associated with asthma has not been studied. We have investigated the α-tryptase gene copy number variation and its potential associations with phenotypes of asthma. Objectives Caucasian families (n = 341) with at least two asthmatic siblings (n = 1350) were genotyped for the α-tryptase alleles, using high-resolution melting assays. Standards for the possible α-/β-tryptase ratios were constructed by cloning α-and β-tryptase PCR products to generate artificial templates. Association analysis of asthma affection status and related phenotypes [total and allergen-specific serum IgE, bronchial hyperresponsiveness to methacholine, forced expiratory volume in 1s (FEV1) and atopy and asthma severity scores] was undertaken using family-based association tests (FBAT). Results Four consistent melting patterns for the α-tryptase genotype were identified with alleles carrying null, one or two copies of the α-tryptase allele. Possessing one copy of α-tryptase was significantly associated with lower serum levels of total and dust mite-specific IgE levels and higher FEV1 measurements, while two copies were related to higher serum concentrations of total and dust mite-specific IgE and greater atopy severity scores. Conclusions and Clinical Relevance Associations of α-tryptase copy number with serum IgE levels, atopy scores and bronchial function may reflect roles for tryptases in regulating IgE production and other processes in asthma.
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Affiliation(s)
- A M Abdelmotelb
- Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, UK; Faculty of Medicine, Tanta University, Tanta, Egypt
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Vitte J. Human mast cell tryptase in biology and medicine. Mol Immunol 2015; 63:18-24. [DOI: 10.1016/j.molimm.2014.04.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 04/01/2014] [Accepted: 04/02/2014] [Indexed: 12/25/2022]
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14
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Le QT, Lotfi-Emran S, Min HK, Schwartz LB. A simple, sensitive and safe method to determine the human α/β-tryptase genotype. PLoS One 2014; 9:e114944. [PMID: 25545679 PMCID: PMC4278853 DOI: 10.1371/journal.pone.0114944] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/16/2014] [Indexed: 11/18/2022] Open
Abstract
The human tryptase locus on chromosome 16 contains one gene encoding only β-tryptase and another encoding either β-tryptase or the homologous α-tryptase, providing α:β gene ratios of 0:4, 1:3 or 2:2 in the diploid genome, these genotypes being of potential clinical relevance in severe atopy. Using an EcoRV restriction site in α- but not β-tryptase, PCR products, spanning intron 1 to exon 5, were used to determine α/β-tryptase gene ratios using non-radioactive labels, including ethidium bromide labeling of all PCR products, and either digoxigenin-primer or DY682-primer labeling of only the final PCR cycle products. Sensitivity increased ∼60-fold with each final PCR cycle labeling technique. Ethidium bromide labeling underestimated amounts of α-tryptase, presumably because heteroduplexes of α/β-tryptase amplimers, formed during annealing, were EcoRV resistant. In contrast, both final PCR cycle labeling techniques precisely quantified these gene ratios, because only homoduplexes were labeled. Using the DY682-primer was most efficient, because PCR/EcoRV products could be analyzed directly in the gel; while digoxigenin-labeled products required transfer to a nitrocellulose membrane followed by immunoblotting. This technique for determining the α/β-tryptase genotype is sensitive, accurate, simple and safe, and should permit high-throughput screening to detect potential phenotype-genotype relations for α/β-tryptases, and for other closely related alleles.
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Affiliation(s)
- Quang Trong Le
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Sahar Lotfi-Emran
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Hae-Ki Min
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Lawrence B. Schwartz
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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Neale MC. Latent classiness and other mixtures. Behav Genet 2014; 44:205-11. [PMID: 24477932 DOI: 10.1007/s10519-013-9637-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Abstract
The aim of this article is to laud Lindon Eaves' role in the development of mixture modeling in genetic studies. The specification of models for mixture distributions was very much in its infancy when Professor Eaves implemented it in his own FORTRAN programs, and extended it to data collected from relatives such as twins. It was his collaboration with the author of this article which led to the first implementation of mixture distribution modeling in a general-purpose structural equation modeling program, Mx, resulting in a 1996 article on linkage analysis in Behavior Genetics. Today, the popularity of these methods continues to grow, encompassing methods for genetic association, latent class analysis, growth curve mixture modeling, factor mixture modeling, regime switching, marginal maximum likelihood, genotype by environment interaction, variance component twin modeling in the absence of zygosity information, and many others. This primarily historical article concludes with some consideration of some possible future developments.
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Affiliation(s)
- Michael C Neale
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Box 980126, Richmond, VA, 23298-0126, USA,
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16
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Genetic factors account for most of the variation in serum tryptase--a twin study. Ann Allergy Asthma Immunol 2013; 111:286-9. [PMID: 24054365 DOI: 10.1016/j.anai.2013.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 07/08/2013] [Accepted: 07/11/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Mast cells are involved in a number of diseases, including inflammatory diseases such as asthma. Tryptase is a known marker of mast cell burden and activity. However, little is known about the genetic influence on serum tryptase variation. Also, only few and conflicting data exist on serum tryptase in asthma. OBJECTIVE To estimate the overall contribution of genetic and environmental factors to the variation in serum tryptase and to examine the correlation between serum tryptase and asthma, rhinitis, markers of allergy, airway inflammation, and airway hyperresponsiveness (AHR) in a sample of Danish twins. METHODS A total of 575 twins underwent a skin prick test and had lung function, AHR to methacholine, exhaled nitric oxide and serum tryptase measured. Multiple regression and variance components models (using the statistical package SOLAR) were computed. RESULTS Serum tryptase values were available in 569 subjects. Intraclass correlations of serum tryptase in monozygotic and dizygotic twin pairs were 0.84 and 0.42 (P < .001). Variance decomposition showed that genetic factors accounted for 82% (95% confidence interval 74-90, P < .001) of the variation in serum tryptase. Body mass index and sex, but not asthma, rhinitis, or AHR, were correlated to serum tryptase. CONCLUSION As much as 82% of the variation in serum tryptase is due to genetic factors. Body mass index and sex, but not asthma or AHR to methacholine, correlate to serum tryptase. A genetic overlap may exist between serum tryptase and body mass index.
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Fenger RV, Linneberg A, Vidal C, Vizcaino L, Husemoen LL, Aadahl M, Gonzalez-Quintela A. Determinants of serum tryptase in a general population: the relationship of serum tryptase to obesity and asthma. Int Arch Allergy Immunol 2011; 157:151-8. [PMID: 21985913 DOI: 10.1159/000327535] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 02/21/2011] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Recent studies indicate that mast cells are more abundant in the obese state. Total serum tryptase (ST) is a marker of mast cell numbers or activity. Since obesity and asthma have been consistently linked in epidemiological studies, a possible higher mast cell activity in obesity could be a factor between the two conditions. The aim of this study was to investigate determinants of ST and whether a potential association between obesity and allergic respiratory disease would be influenced by levels of ST in obese persons. METHODS Measurements of ST (ImmunoCAP Tryptase assay), atopy (skin prick test reactivity), methacholine bronchial hyperresponsiveness (BHR), body mass index (BMI) and serum lipids were performed in a general population of 1,216 persons aged 15-69 years. RESULTS ST increased significantly with increasing BMI. The median ST level increased from 3.3 μg/l in persons with BMI <25 to 4.4 μg/l in persons with BMI >30, p < 0.0001. Age (p < 0.0001), male sex (p = 0.0009) and smoking (p = 0.022) were positively associated with ST, whereas alcohol consumption (p = 0.005) was inversely associated with ST. ST was not associated with atopy, symptoms of allergic respiratory disease or BHR. A positive association between symptoms of allergic respiratory disease and obesity (OR = 1.98, 95% CI = 1.25-3.14) was not influenced by obesity-related differences in ST. CONCLUSIONS Increasing BMI was significantly associated with increasing ST and the prevalence of symptoms of allergic respiratory disease. However, mast cell activity/burden (assessed by ST levels) did not influence the association between BMI and asthma/rhinitis symptoms.
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Affiliation(s)
- R V Fenger
- Research Center for Prevention and Health, Glostrup University Hospital, Copenhagen, Denmark.
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Le QT, Min HK, Xia HZ, Fukuoka Y, Katunuma N, Schwartz LB. Promiscuous processing of human alphabeta-protryptases by cathepsins L, B, and C. THE JOURNAL OF IMMUNOLOGY 2011; 186:7136-43. [PMID: 21562164 DOI: 10.4049/jimmunol.1001804] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Human α- and β-protryptase zymogens are abundantly and selectively produced by mast cells, but the mechanism(s) by which they are processed is uncertain. β-Protryptase is sequentially processed in vitro by autocatalysis at R(-3) followed by cathepsin (CTS) C proteolysis to the mature enzyme. However, mast cells from CTSC-deficient mice successfully convert protryptase (pro-murine mast cell protease-6) to mature murine mast cell protease-6. α-Protryptase processing cannot occur by trypsin-like enzymes due to an R(-3)Q substitution. Thus, biological mechanisms for processing these zymogens are uncertain. β-Tryptase processing activity(ies) distinct from CTSC were partially purified from human HMC-1 cells and identified by mass spectroscopy to include CTSB and CTSL. Importantly, CTSB and CTSL also directly process α-protryptase (Q(-3)) and mutated β-protryptase (R(-3)Q) as well as wild-type β-protryptase to maturity, indicating no need for autocatalysis, unlike the CTSC pathway. Heparin promoted tryptase tetramer formation and protected tryptase from degradation by CTSB and CTSL. Thus, CTSL and CTSB are capable of directly processing both α- and β-protryptases from human mast cells to their mature enzymatically active products.
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Affiliation(s)
- Quang T Le
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA
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Dugas-Breit S, Przybilla B, Dugas M, Arnold A, Pfundstein G, Küchenhoff H, Ruëff F. Serum concentration of baseline mast cell tryptase: evidence for a decline during long-term immunotherapy for Hymenoptera venom allergy. Clin Exp Allergy 2010; 40:643-9. [PMID: 20100187 DOI: 10.1111/j.1365-2222.2009.03436.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Baseline serum mast cell tryptase concentration (BTC) is thought to reflect the constitutive mast cell load or activity of an individual patient. Little is known about the individual stability of BTC during long-term venom immunotherapy (VIT). OBJECTIVE To investigate the intra-individual stability of BTC over time in patients with Hymenoptera venom allergy. METHODS Three hundred and two patients were studied. BTC was measured before and at least twice during VIT. At least 4 weeks lay between BTC measurements and the most recent field sting, in-hospital sting, or preceding venom injection. Multifactorial mixed linear models were used to analyse BTC changes over time. RESULTS Median observation time was 4.2 years (range 2-12 years). Before VIT, the median BTC was 6.8 microg/L (range 1.14-177 microg/L). The median coefficient of variation (CV) over time was 15.3% (range 1.9-63.8%). The median CV was significantly smaller in patients presenting with an elevated BTC (>11.4 microg/L) than in patients with a normal BTC (11.4%, range 2.6-39.5%; vs. 17.6%, range 1.9- 63.8%; P<0.001). During VIT and after adjusting for age and gender, we found a slight but significant decrease of BTC over time (2.5% per year, 95% confidence interval 2.0-3.0%, P<0.001). CONCLUSION Individual variation of BTC during VIT does not rise when BTC is increased before therapy. VIT is associated with a small, but continuous decrease of BTC over time possibly indicating a dampened mast cell function or a decline in mast cell burden.
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Affiliation(s)
- S Dugas-Breit
- AllergieZentrum, Klinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität, München, Germany
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Gonzalez-Quintela A, Vizcaino L, Gude F, Rey J, Meijide L, Fernandez-Merino C, Linneberg A, Vidal C. Factors influencing serum total tryptase concentrations in a general adult population. Clin Chem Lab Med 2010; 48:701-6. [DOI: 10.1515/cclm.2010.124] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Sperr WR, El-Samahi A, Kundi M, Girschikofsky M, Winkler S, Lutz D, Endler G, Rumpold H, Agis H, Sillaber C, Jäger U, Valent P. Elevated tryptase levels selectively cluster in myeloid neoplasms: a novel diagnostic approach and screen marker in clinical haematology. Eur J Clin Invest 2009; 39:914-23. [PMID: 19522836 DOI: 10.1111/j.1365-2362.2009.02184.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Recent data suggest that tryptase, a mast cell enzyme, is expressed in neoplastic cells in myeloid leukaemias. In several of these patients, increased serum tryptase levels are detectable. MATERIALS AND METHODS We have determined serum tryptase levels in 914 patients with haematological malignancies, including myeloproliferative disorders (n = 156), myelodysplastic syndromes (MDS, n = 241), acute myeloid leukaemia (AML, n = 317), systemic mastocytosis (SM, n = 81), non-Hodgkin's lymphoma (n = 59) and acute lymphoblastic leukaemia (n = 26). Moreover, tryptase was measured in 136 patients with non-neoplastic haematological disorders, 102 with non-haematological disorders and 164 healthy subjects. RESULTS In healthy subjects, the median serum tryptase was 5.2 ng mL(-1). Elevated serum tryptase levels were found to cluster in myeloid neoplasm, whereas almost all patients with lymphoid neoplasms exhibited normal tryptase. Among myeloid neoplasms, elevated tryptase levels (> 15 ng mL(-1)) were recorded in > 90% of patients with SM, 38% with AML, 34% with CML and 25% with MDS. The highest tryptase levels, often > 1000 ng mL(-1), were found in advanced SM and core-binding-factor leukaemias. In most patients with non-neoplastic haematological disorders and non-haematological disorders analysed in our study, tryptase levels were normal, the exception being a few patients with end-stage kidney disease and helminth infections, in whom a slightly elevated tryptase was found. CONCLUSIONS In summary, tryptase is a new diagnostic marker of myeloid neoplasms and a useful test in clinical haematology.
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Affiliation(s)
- W R Sperr
- Medical University of Vienna, A-1090 Vienna, Austria.
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Trivedi NN, Tamraz B, Chu C, Kwok PY, Caughey GH. Human subjects are protected from mast cell tryptase deficiency despite frequent inheritance of loss-of-function mutations. J Allergy Clin Immunol 2009; 124:1099-105.e1-4. [PMID: 19748655 DOI: 10.1016/j.jaci.2009.07.026] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 07/13/2009] [Accepted: 07/16/2009] [Indexed: 12/29/2022]
Abstract
BACKGROUND Mast cell tryptases have proposed roles in allergic inflammation and host defense against infection. Tryptase gene loci TPSAB1 and TPSB2 are known to be polymorphic, but the nature and extent of diversity at these loci have not been fully explored. OBJECTIVE We sought to compare functional and nonfunctional tryptase allele frequencies and establish haplotypes in human populations. METHODS Tryptase allele frequencies were determined by means of direct sequencing in 270 individuals from HapMap populations of European, African, Chinese, and Japanese ancestry. Haplotypes were predicted, validated in parent-child trios, and compared between populations. RESULTS We identify a new frame-shifted tryptase allele (betaIII(FS)) carried by 23% and 19% of individuals of European and African ancestry but 0% of Asian subjects. Homology models predict that betaIII(FS) is functionless. Our genotyping assay shows that allele and haplotype distributions in each population are unique. Strong linkage disequilibrium between TPSAB1 and TPSB2 (r(2)=0.83, D'=0.85) yields 2 major and 5 minor tryptase haplotypes. CONCLUSIONS Tryptase deficiency alleles (alpha and the newly discovered betaIII(FS)) are common, causing the number of inherited active genes to range from a minimum of 2 to a maximum of 4, with major differences between populations in the proportion of individuals inheriting 2 versus 4 active alleles. African and Asian populations are especially enriched in genes encoding functional and nonfunctional tryptases, respectively. Strong linkage of TPSAB1 and TPSB2 and pairing of deficiency alleles with functional alleles in observed haplotypes protect human subjects from "knockout" genomes and indeed from inheritance of fewer than 2 active alleles.
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Affiliation(s)
- Neil N Trivedi
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, Calif, USA
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Raymond WW, Su S, Makarova A, Wilson TM, Carter MC, Metcalfe DD, Caughey GH. Alpha 2-macroglobulin capture allows detection of mast cell chymase in serum and creates a reservoir of angiotensin II-generating activity. THE JOURNAL OF IMMUNOLOGY 2009; 182:5770-7. [PMID: 19380825 DOI: 10.4049/jimmunol.0900127] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human chymase is a highly efficient angiotensin II-generating serine peptidase expressed by mast cells. When secreted from degranulating cells, it can interact with a variety of circulating antipeptidases, but is mostly captured by alpha(2)-macroglobulin, which sequesters peptidases in a cage-like structure that precludes interactions with large protein substrates and inhibitors, like serpins. The present work shows that alpha(2)-macroglobulin-bound chymase remains accessible to small substrates, including angiotensin I, with activity in serum that is stable with prolonged incubation. We used alpha(2)-macroglobulin capture to develop a sensitive, microtiter plate-based assay for serum chymase, assisted by a novel substrate synthesized based on results of combinatorial screening of peptide substrates. The substrate has low background hydrolysis in serum and is chymase-selective, with minimal cleavage by the chymotryptic peptidases cathepsin G and chymotrypsin. The assay detects activity in chymase-spiked serum with a threshold of approximately 1 pM (30 pg/ml), and reveals native chymase activity in serum of most subjects with systemic mastocytosis. alpha(2)-Macroglobulin-bound chymase generates angiotensin II in chymase-spiked serum, and it appears in native serum as chymostatin-inhibited activity, which can exceed activity of captopril-sensitive angiotensin-converting enzyme. These findings suggest that chymase bound to alpha(2)-macroglobulin is active, that the complex is an angiotensin-converting enzyme inhibitor-resistant reservoir of angiotensin II-generating activity, and that alpha(2)-macroglobulin capture may be exploited in assessing systemic release of secreted peptidases.
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Affiliation(s)
- Wilfred W Raymond
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94143, USA
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Wesseldijk F, van Toorenenbergen AW, van Wijk RG, Huygen FJ, Zijlstra FJ. IgE-mediated hypersensitivity: patients with complex regional pain syndrome type 1 (CRPS1) vs the Dutch population. A retrospective study. PAIN MEDICINE 2008; 10:172-8. [PMID: 18721169 DOI: 10.1111/j.1526-4637.2008.00496.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To investigate whether hypersensitivity is more common in Complex Regional Pain Syndrome type 1 (CRPS1) patients than in the general population. In a recent study, the level of tryptase, a specific marker for mast cells, was significantly higher in blister fluid from the involved extremity of CRPS1 patients. This suggested that mast cells may play a role in the pathophysiology of CRPS1. Mast cells are major effectors in allergic reactions, and are also involved in a variety of noninfectious inflammatory diseases. Patients. Sixty-six Dutch patients with CRPS1 in one extremity were included. OUTCOME MEASURES Allergy information was obtained from the medical history and a modified questionnaire based on the Europees Luchtweg Onderzoek Nederland 1 study. Total IgE and allergen-specific IgE were measured from blood samples. Also tryptase, as a marker for mast cells, was measured. The data from the questionnaire were compared with that of the general Dutch population, and the plasma levels were compared with reference values and data in the literature. RESULTS The medical history did not differ from information provided in the questionnaire by the CRPS1 group. There was no significant difference between the answers to the questionnaire between the CRPS1 patients and the general population. The total IgE levels were elevated in 30% of the CRPS1 patients compared with 15-24% of the general population, and allergen-specific IgE and tryptase levels were comparable with the reference values. CONCLUSIONS Based on the medical history, an allergy questionnaire, and objective laboratory findings we conclude that IgE-mediated hypersensitivity is not more common in CRPS1 patients than in the general population.
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Affiliation(s)
- Feikje Wesseldijk
- Department of Anesthesiology, Pain Treatment Center, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands.
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Trivedi NN, Raymond WW, Caughey GH. Chimerism, point mutation, and truncation dramatically transformed mast cell δ-tryptases during primate evolution. J Allergy Clin Immunol 2008; 121:1262-8. [DOI: 10.1016/j.jaci.2008.01.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 01/03/2008] [Accepted: 01/16/2008] [Indexed: 11/24/2022]
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Trivedi NN, Tong Q, Raman K, Bhagwandin VJ, Caughey GH. Mast cell alpha and beta tryptases changed rapidly during primate speciation and evolved from gamma-like transmembrane peptidases in ancestral vertebrates. THE JOURNAL OF IMMUNOLOGY 2007; 179:6072-9. [PMID: 17947681 DOI: 10.4049/jimmunol.179.9.6072] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Human mast cell tryptases vary strikingly in secretion, catalytic competence, and inheritance. To explore the basis of variation, we compared genes from a range of primates, including humans, great apes (chimpanzee, gorilla, orangutan), Old- and New-World monkeys (macaque and marmoset), and a prosimian (galago), tracking key changes. Our analysis reveals that extant soluble tryptase-like proteins, including alpha- and beta-like tryptases, mastins, and implantation serine proteases, likely evolved from membrane-anchored ancestors because their more deeply rooted relatives (gamma tryptases, pancreasins, prostasins) are type I transmembrane peptidases. Function-altering mutations appeared at widely separated times during primate speciation, with tryptases evolving by duplication, gene conversion, and point mutation. The alpha-tryptase Gly(216)Asp catalytic domain mutation, which diminishes activity, is present in macaque tryptases, and thus arose before great apes and Old World monkeys shared an ancestor, and before the alphabeta split. However, the Arg(-3)Gln processing mutation appeared recently, affecting only human alpha. By comparison, the transmembrane gamma-tryptase gene, which anchors the telomeric end of the multigene tryptase locus, changed little during primate evolution. Related transmembrane peptidase genes were found in reptiles, amphibians, and fish. We identified soluble tryptase-like genes in the full spectrum of mammals, including marsupial (opossum) and monotreme (platypus), but not in nonmammalian vertebrates. Overall, our analysis suggests that soluble tryptases evolved rapidly from membrane-anchored, two-chain peptidases in ancestral vertebrates into soluble, single-chain, self-compartmentalizing, inhibitor-resistant oligomers expressed primarily by mast cells, and that much of present numerical, behavioral, and genetic diversity of alpha- and beta-like tryptases was acquired during primate evolution.
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Affiliation(s)
- Neil N Trivedi
- Cardiovascular Research Institute and Department of Medicine, University of California, San Francisco, CA 94143, USA
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Valent P, Akin C, Escribano L, Födinger M, Hartmann K, Brockow K, Castells M, Sperr WR, Kluin-Nelemans HC, Hamdy NAT, Lortholary O, Robyn J, van Doormaal J, Sotlar K, Hauswirth AW, Arock M, Hermine O, Hellmann A, Triggiani M, Niedoszytko M, Schwartz LB, Orfao A, Horny HP, Metcalfe DD. Standards and standardization in mastocytosis: consensus statements on diagnostics, treatment recommendations and response criteria. Eur J Clin Invest 2007; 37:435-53. [PMID: 17537151 DOI: 10.1111/j.1365-2362.2007.01807.x] [Citation(s) in RCA: 515] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Although a classification for mastocytosis and diagnostic criteria are available, there remains a need to define standards for the application of diagnostic tests, clinical evaluations, and treatment responses. To address these demands, leading experts discussed current issues and standards in mastocytosis in a Working Conference. The present article provides the resulting outcome with consensus statements, which focus on the appropriate application of clinical and laboratory tests, patient selection for interventional therapy, and the selection of appropriate drugs. In addition, treatment response criteria for the various clinical conditions, disease-specific symptoms, and specific pathologies are provided. Resulting recommendations and algorithms should greatly facilitate the management of patients with mastocytosis in clinical practice, selection of patients for therapies, and the conduct of clinical trials.
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Affiliation(s)
- P Valent
- Department of Internal Medicine I, Division of Haematology and Haemostaseology, Medical University of Vienna, Vienna, Austria.
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Akin C, Soto D, Brittain E, Chhabra A, Schwartz LB, Caughey GH, Metcalfe DD. Tryptase haplotype in mastocytosis: relationship to disease variant and diagnostic utility of total tryptase levels. Clin Immunol 2007; 123:268-71. [PMID: 17449330 PMCID: PMC1949411 DOI: 10.1016/j.clim.2007.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 02/20/2007] [Accepted: 02/26/2007] [Indexed: 01/08/2023]
Abstract
Serum mast cell tryptase levels are used as a diagnostic criterion and surrogate marker of disease severity in mastocytosis. Approximately 29% of the healthy population lacks alpha tryptase genes; however, it is not known whether lack of alpha tryptase genes leads to variability in tryptase levels or impacts on disease severity in mastocytosis. We have thus analyzed tryptase haplotype in patients with mastocytosis, computing correlations between haplotype and plasma total and mature tryptase levels; and disease category. We found: (1) the distribution of tryptase haplotype in patients with mastocytosis appeared consistent with Hardy-Weinberg equilibrium and the distribution in the general population; (2) the disease severity and plasma tryptase levels were not affected by the number of alpha or beta tryptase alleles in this study; and (3) information about the tryptase haplotype did not provide any prognostic value about the severity of disease. Total and mature tryptase levels positively correlated with disease severity, as well as prothrombin time and partial thromboplastin time, and negatively correlated with the hemoglobin concentration.
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Affiliation(s)
- Cem Akin
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA.
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Yuan J, Beltman J, Gjerstad E, Nguyen MT, Sampang J, Chan H, Janc JW, Clark JM. Expression and characterization of recombinant γ-tryptase. Protein Expr Purif 2006; 49:47-54. [PMID: 16815034 DOI: 10.1016/j.pep.2006.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 04/06/2006] [Accepted: 04/08/2006] [Indexed: 10/24/2022]
Abstract
Tryptases are trypsin-like serine proteases whose expression is restricted to cells of hematopoietic origin, notably mast cells. gamma-Tryptase, a recently described member of the family also known as transmembrane tryptase (TMT), is a membrane-bound serine protease found in the secretory granules or on the surface of degranulated mast cells. The 321 amino acid protein contains an 18 amino acid propeptide linked to the catalytic domain (cd), followed by a single-span transmembrane domain. gamma-Tryptase is distinguished from other human mast cell tryptases by the presence of two unique cysteine residues, Cys(26) and Cys(145), that are predicted to form an intra-molecular disulfide bond linking the propeptide to the catalytic domain to form the mature, membrane-anchored two-chain enzyme. We expressed gamma-tryptase as either a soluble, single-chain enzyme with a C-terminal His tag (cd gamma-tryptase) or as a soluble pseudozymogen activated by enterokinase cleavage to form a two-chain protein with an N-terminal His tag (tc gamma-tryptase). Both recombinant proteins were expressed at high levels in Pichia pastoris and purified by affinity chromatography. The two forms of gamma-tryptase exhibit comparable kinetic parameters, indicating the propeptide does not contribute significantly to the substrate affinity or activity of the protease. Substrate and inhibitor library screening indicate that gamma-tryptase possesses a substrate preference and inhibitor profile distinct from that of beta-tryptase. Although the role of gamma-tryptase in mast cell function is unknown, our results suggest that it is likely to be distinct from that of beta-tryptase.
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Affiliation(s)
- Jing Yuan
- Department of Molecular Biology, Celera Genomics, 180 Kimball Way, South San Francisco, CA 4080, USA
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Abstract
Serum (or plasma) levels of total and mature tryptase measurements are recommended in the diagnostic evaluation of systemic anaphylaxis and systemic mastocytosis, but their interpretation must be considered in the context of a complete workup of each patient. Total tryptase levels generally reflect the increased burden of mast cells in patients with all forms of systemic mastocytosis (indolent systemic mastocytosis, smoldering systemic mastocytosis, systemic mastocytosis associated with a hematologic clonal non-mast cell disorder, aggressive systemic mastocytosis, and mast cell leukemia) and the decreased burden of mast cells associated with cytoreductive therapies in these disorders. Causes of an elevated total tryptase level other than systemic mastocytosis must be considered, however, and include systemic anaphylaxis, acute myelocytic leukemia, various myelodysplastic syndromes, hypereosinophilic syndrome associated with the FLP1L1-PDGFRA mutation, end-stage renal failure, and treatment of onchocerciasis. Mature (beta) tryptase levels generally reflect the magnitude of mast cell activation and are elevated during most cases of systemic anaphylaxis, particularly with parenteral exposure to the inciting agent.
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Affiliation(s)
- Lawrence B Schwartz
- Division of Rheumatology, Allergy, and Immunology, Department of Internal Medicine, Virginia Commonwealth University, PO Box 980263, McGuire Hall 4-110, Richmond, VA 23298, USA.
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