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Abstract
“A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A biomarker may be used to see how well the body responds to a treatment for a disease or condition. Also called molecular marker or signature molecule” – Biomarker definition, National Institutes of Health, National Cancer Institute, Dictionary of Cancer Terms
Although this definition pertains to the field of cancer and cancer biology, it applies to many disciplines, including the field of pulmonary vascular disease. In the world of pulmonary hypertension (PH), biomarkers hold a special place. In the diagnosis of PH subtype, we are limited by the risk of lung biopsy1 and, further, in patients with pulmonary arterial hypertension (PAH) we are limited by the inability to frequently obtain our strongest predictors of mortality: invasive pulmonary hemodynamic assessment. Thus, biomarkers hold much promise for the field of PH. We are searching for markers of PH subtypes and endophenotypes. We are looking for predictors of mortality in all forms of PH and, critically, we are hoping to find peripheral blood markers that will help us discover which drugs are likely to benefit a particular patient. Although we have made inroads in all 3 areas, there are substantial opportunities for refinement of our current biomarkers and discovery of novel markers to improve the care of PH patients. This review will cover the state of current biomarkers in PH and discuss challenges and future directions.
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Affiliation(s)
- Anna R. Hemnes
- Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN
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2
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Austin ED, Loyd JE. Heritable forms of pulmonary arterial hypertension. Semin Respir Crit Care Med 2013; 34:568-80. [PMID: 24037626 DOI: 10.1055/s-0033-1355443] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Tremendous progress has been made in understanding the genetics of heritable pulmonary arterial hypertension (HPAH) since its description in the 1950s. Germline mutations in the gene coding bone morphogenetic receptor type 2 (BMPR2) are detectable in the majority of cases of HPAH, and in a small proportion of cases of idiopathic pulmonary arterial hypertension (IPAH). Recent advancements in gene sequencing methods have facilitated the discovery of additional genes with mutations among those with and without familial PAH (CAV1, KCNK3). HPAH is an autosomal dominant disease characterized by reduced penetrance, variable expressivity, and female predominance. These characteristics suggest that genetic and nongenetic factors modify disease expression, highlighting areas of active investigation. The reduced penetrance makes genetic counseling complex, as the majority of carriers of PAH-related mutations will never be diagnosed with the disease. This issue is increasingly important, as clinical testing for BMPR2 and other mutations is now available for the evaluation of patients and their at-risk kin. The possibilities to avoid mutation transmission, such as the rapidly advancing field of preimplantation genetic testing, highlight the need for all clinicians to understand the genetic features of PAH risk.
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Affiliation(s)
- Eric D Austin
- Division of Pulmonary, Allergy, and Immunology Medicine, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
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3
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Schuller D. Clinical Overview of Pulmonary Arterial Hypertension. Hosp Pharm 2013. [DOI: 10.1310/hpj48s4-s1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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4
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Arena R, Guazzi M, Myers J, Grinnen D, Forman DE, Lavie CJ. Cardiopulmonary exercise testing in the assessment of pulmonary hypertension. Expert Rev Respir Med 2011; 5:281-93. [PMID: 21510737 DOI: 10.1586/ers.11.4] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The assessment of patients with suspected or confirmed pulmonary arterial hypertension (PAH) and secondary pulmonary hypertension (PH) continues to evolve and, in recent years, evidence demonstrating that cardiopulmonary exercise testing (CPX) provides valuable information has grown at an impressive rate. The key premise supporting the use of CPX is that certain variables obtained provide insight into the degree of ventilation/perfusion mismatching secondary to altered pulmonary hemodynamics. In this article, we discuss the pathophysiology of PAH and secondary PH and its impact on cardiac function, review the clinical presentation of patients with elevated pulmonary pressures and outline a case for the use of CPX as an integral assessment technique, discuss CPX technology and testing procedures, and review the current state of available evidence and provide clinical recommendations for CPX in the setting of known or suspected PAH and secondary PH.
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Affiliation(s)
- Ross Arena
- Virginia Commonwealth University, Richmond, VA, USA.
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5
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Austin ED, Loyd JE, Phillips JA. Genetics of pulmonary arterial hypertension. Semin Respir Crit Care Med 2009; 30:386-98. [PMID: 19634078 DOI: 10.1055/s-0029-1233308] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Tremendous progress has been made in understanding the genetics of hereditable pulmonary arterial hypertension (HPAH) since its description in the 1950s. Germline mutations in the gene coding bone morphogenetic receptor type 2 ( BMPR2) are detectable in the majority of cases of HPAH, and in a small proportion of cases of idiopathic pulmonary arterial hypertension (IPAH). HPAH is an autosomal dominant disease characterized by reduced penetrance, variable expressivity, female predominance, and genetic anticipation. These characteristics suggest that endogenous and exogenous factors modify disease expression and areas of emphasis for future investigation. The variable clinical expression makes genetic counseling complex because the majority of carriers of a BMPR2 mutation will not be diagnosed with the disease. This issue will become increasingly important, as clinical testing for BMPR2 mutations is now available for the evaluation of patients and family members with HPAH and IPAH.
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Affiliation(s)
- Eric D Austin
- Department of Pediatrics, Division of Pulmonary, Allergy, and Immunology Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2578, USA
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6
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Abstract
Pulmonary arterial hypertension (PAH) is an uncommon disorder of the pulmonary vasculature characterized by remodeling of the smallest pulmonary arteries, leading to a progressive increase in pulmonary vascular resistance. Various forms of PAH exist, including familial (FPAH) and idiopathic (IPAH) forms and associated conditions. FPAH transmits as an autosomal dominant trait that exhibits genetic anticipation but also markedly reduced penetrance (20%). The primary genetic defect of FPAH, identifiable in more than 70% of cases of FPAH, is a mutation in the gene encoding bone morphogenetic protein receptor type 2 (BMPR2), a member of the transforming growth factor beta superfamily. The true prevalence of BMPR2 mutations in IPAH is unknown, with reports ranging from 10% to 40% of patients. The cause of the variable phenotypic expression of PAH among carriers of mutated BMPR2 genes and patients is unclear, and likely related to environmental and genetic modifiers of disease not yet fully elucidated. Although BMPR2-related pathways seem to be pivotal, many other mediator pathways participate in the pathogenesis of different forms of PAH and are being actively investigated, both independently and in combination. As understanding of the molecular basis of this devastating disease improves, opportunities for earlier diagnosis, additional therapeutic regimens, and perhaps disease prevention will emerge.
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Affiliation(s)
- Eric D Austin
- Division of Pediatric Pulmonary Medicine, Department of Pediatrics, Vanderbilt University Medical Center, T-1217 Medical Center North, Nashville, TN 37232-2650, USA.
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7
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Michelakis ED, Archer SL. Pulmonary Arterial Hypertension. CARDIOVASCULAR MEDICINE 2007. [PMCID: PMC7123519 DOI: 10.1007/978-1-84628-715-2_108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The first description of the circulation of blood through the lungs has been attributed to Ibn Nafis (1210–1288).1 The concept was rediscovered by Michael Servetus, a Spanish physician during the Renaissance (1511–1553) and recorded, oddly enough, in two pages of his religious treatise, Christianismi Restitutio (1553).2 The definitive exposition of the pulmonary circulation was made by William Harvey in DeMotu Cordis (1628).3 The first observation of the pulmonary capillaries was first reported by Marcellus Malpighi (1661).4 Heart catheterization in humans, driven by a desire to obtain the perfect mixed venous specimen and measure cardiac output, was first performed in 1929 by the German urologist Forssmann,5 using a ureteral catheter to access his own right atrium. Over a decade later, Cournand and Richards at Columbia University in New York subsequently used right heart catheterization to record pulmonary artery pressure (PAP) in patients with shock and secondary forms of pulmonary hypertension (PHT). For these accomplishments, which were inspired by an interest in the pulmonary circulation and PHT related to mitral stenosis, Forssmann, Cournand, and Richards received the Nobel Prize in 1956.
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8
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Abstract
Despite advances in drug therapy, severe sustained pulmonary arterial hypertension can be a fatal disease. When medical therapy is exhausted, transplantation may be an option. The most common approaches are heart-lung transplantation or double-lung transplantation, with repair of the cardiac defect if necessary. Single-lung transplantation optimises the use of scarce donors but leads to particular management problems. Heterotopic cardiac transplantation has occasionally been employed in subjects with pulmonary vascular disease secondary to cardiac disease. Timing of transplantation is a difficult decision and depends largely on the aetiology of pulmonary arterial hypertension and the rate of decline. Outcomes following transplantation are steadily improving but remain poorer than for other solid organ transplants, mainly because of the high incidence of post-transplant bronchiolitis obliterans syndrome.
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Affiliation(s)
- R Radley-Smith
- Formerly Harefield Hospital, Middlesex, and Great Ormond Street Hospital for Children, London, UK
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Bartyik K, Bede O, Tiszlavicz L, Onozo B, Virag I, Turi S. Pulmonary capillary haemangiomatosis in children and adolescents: report of a new case and a review of the literature. Eur J Pediatr 2004; 163:731-7. [PMID: 15365825 DOI: 10.1007/s00431-004-1527-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Pulmonary capillary haemangiomatosis (PCH) in childhood is a rarity, characterised by the uncontrolled proliferation of pulmonary microvessels which may invade pulmonary, bronchial and vascular structures, resulting in diffuse alveolar haemorrhage, manifesting clinically in haemoptysis, dyspnoea and symptoms of pulmonary hypertension (PH). A 14-year-old boy with some particular features (pericardial effusion and thrombocytopenia) is presented and 14 paediatric/adolescent cases from the literature are surveyed. The diagnostic problems and difficulties are discussed, including the importance of imaging (high-resolution CT) and histopathological studies, with the aim of providing a clear-cut distinction of PCH from other conditions such as primary PH (PPH). The literature data can be regarded as ambiguous: both similarities and relatively sharp distinctions between PCH and PPH are to be found. New developments in the field of genetics are also discussed. The early coexistence of PCH and other (vascular) disorders and associations, involving focal or diffuse, disseminated forms is summarised briefly. Conclusion. The diagnosis of this progressive disorder may lead to effective therapy. Treatment possibilities include the rapidly evolving field of anti-angiogenic therapy, but at present lung transplantation is universally accepted as the final definitive treatment for pulmonary capillary haemangiomatosis.
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Affiliation(s)
- Katalin Bartyik
- Department of Paediatrics, Albert Szent-Györgyi Medical and Pharmaceutical Centre, Faculty of Medicine, University of Szeged, 14-15 Koranyi fasor, 6720 Szeged, Hungary.
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10
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Harrison RE, Flanagan JA, Sankelo M, Abdalla SA, Rowell J, Machado RD, Elliott CG, Robbins IM, Olschewski H, McLaughlin V, Gruenig E, Kermeen F, Halme M, Räisänen-Sokolowski A, Laitinen T, Morrell NW, Trembath RC. Molecular and functional analysis identifies ALK-1 as the predominant cause of pulmonary hypertension related to hereditary haemorrhagic telangiectasia. J Med Genet 2004; 40:865-71. [PMID: 14684682 PMCID: PMC1735342 DOI: 10.1136/jmg.40.12.865] [Citation(s) in RCA: 222] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Mutations of the transforming growth factor beta (TGFbeta) receptor components ENDOGLIN and ALK-1 cause the autosomal dominant vascular disorder hereditary haemorrhagic telangiectasia (HHT). Heterozygous mutations of the type II receptor BMPR2 underlie familial primary pulmonary hypertension. OBJECTIVE To investigate kindreds presenting with both pulmonary hypertension and HHT. METHODS Probands and families were identified by specialist pulmonary hypertension centres in five countries. DNA sequence analysis of ALK-1, ENDOGLIN, and BMPR2 was undertaken. Cellular localisation was investigated by heterologous overexpression of mutant constructs in both BAEC and HeLa cells. The impact of a novel sequence variant was assessed through comparative analysis and computer modelling. RESULTS Molecular analysis of 11 probands identified eight missense mutations of ALK-1, one of which was observed in two families. Mutations were located within exons 5 to 10 of the ALK-1 gene. The majority of ALK-1 mutant constructs appeared to be retained within the cell cytoplasm, in the endoplasmic reticulum. A novel GS domain mutation, when overexpressed, reached the cell surface but is predicted to disrupt conformational changes owing to loss of a critical hydrogen bond. Two novel missense mutations were identified in ENDOGLIN. CONCLUSIONS The association of pulmonary arterial hypertension and HHT identifies an important disease complication and appears most common among subjects with defects in ALK-1 receptor signalling. Future studies should focus on detailed molecular analysis of the common cellular pathways disrupted by mutations of ALK-1 and BMPR2 that cause inherited pulmonary vascular disease.
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MESH Headings
- Activin Receptors, Type I/analysis
- Activin Receptors, Type I/chemistry
- Activin Receptors, Type I/genetics
- Activin Receptors, Type II
- Adolescent
- Adult
- Aged
- Amino Acid Sequence
- Antigens, CD
- Bone Morphogenetic Protein Receptors, Type II
- DNA Mutational Analysis
- Endoglin
- Endoplasmic Reticulum/chemistry
- Female
- Genetic Predisposition to Disease
- Humans
- Hypertension, Pulmonary/diagnosis
- Hypertension, Pulmonary/genetics
- Male
- Middle Aged
- Models, Molecular
- Mutation, Missense
- Protein Serine-Threonine Kinases/genetics
- Receptors, Cell Surface
- Structural Homology, Protein
- Telangiectasia, Hereditary Hemorrhagic/complications
- Telangiectasia, Hereditary Hemorrhagic/diagnosis
- Telangiectasia, Hereditary Hemorrhagic/genetics
- Vascular Cell Adhesion Molecule-1/genetics
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Affiliation(s)
- R E Harrison
- Division of Medical Genetics, University of Leicester, Leicester, UK
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11
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Christie JD, Kotloff RM, Pochettino A, Arcasoy SM, Rosengard BR, Landis JR, Kimmel SE. Clinical risk factors for primary graft failure following lung transplantation. Chest 2003; 124:1232-41. [PMID: 14555551 DOI: 10.1378/chest.124.4.1232] [Citation(s) in RCA: 201] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
STUDY OBJECTIVE s: Primary graft failure (PGF) is a devastating acute lung injury syndrome following lung transplantation. We sought to identify donor, recipient, and operative risk factors for its development. DESIGN We conducted a cohort study of 255 consecutive lung transplant procedures performed between October 1991 and July 2000. We defined PGF as follows: (1) diffuse alveolar opacities exclusively involving allograft(s) and developing within 72 h of transplant, (2) a ratio of PaO(2) to fraction of inspired oxygen < 200 beyond 48 h postoperatively, and (3) no other secondary cause of graft dysfunction identified. Risk factors were assessed individually and adjusted for confounding using multivariable logistic regression models. SETTING Tertiary-care academic medical center. RESULTS The overall incidence was 11.8% (95% confidence interval [CI], 7.9 to 15.9). Following multivariable analysis, the risk factors independently associated with development of PGF were as follows: a recipient diagnosis of primary pulmonary hypertension (PPH; adjusted odds ratio [OR], 4.52; 95% CI, 1.29 to 15.9; p = 0.018), donor female gender (adjusted OR, 4.11; 95% CI, 1.17 to 14.4; p = 0.027), donor African-American race (adjusted OR, 5.56; 95% CI, 1.57 to 19.8; p = 0.008), and donor age < 21 years (adjusted OR, 4.06; 95% CI, 1.34 to 12.3; p = 0.013) and > 45 years (adjusted OR, 6.79; 95% CI, 1.61 to 28.5; p = 0.009). CONCLUSIONS Recipient diagnosis of PPH, donor African-American race, donor female gender, and donor age are independently and strongly associated with development of PGF.
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Affiliation(s)
- Jason D Christie
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Philadelhia, 19104, USA.
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12
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Abstract
Pulmonary involvement is common in patients with portal hypertension and can manifest in diverse manners. Changes in pulmonary arterial resistance, manifesting either as the hepatopulmonary syndrome or portopulmonary hypertension (PPHTN), have been increasingly recognized in these patients in recent years. This review summarizes the clinicopathologic features, diagnostic criteria, as well as the latest concepts in the pathogenesis and management of PPHTN, which is defined as an elevated pulmonary artery pressure in the setting of an increased pulmonary vascular resistance and a normal wedge pressure in a patient with portal hypertension.
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Affiliation(s)
- Rohit Budhiraja
- Pulmonary and Critical Care Division, Department of Medicine, Tufts-New England Medical Center, Tufts University School of Medicine, Boston, MA, USA
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13
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Michelakis ED, McMurtry MS, Sonnenberg B, Archer SL. The NO − K+ Channel Axis in Pulmonary Arterial Hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 543:293-322. [PMID: 14713130 DOI: 10.1007/978-1-4419-8997-0_21] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The prognosis of patients with pulmonary arterial hypertension (PAH) is poor. Available therapies (Ca(++)-channel blockers, epoprostenol, bosentan) have limited efficacy or are expensive and associated with significant complications. PAH is characterized by vasoconstriction, thrombosis in-situ and vascular remodeling. Endothelial-derived nitric oxide (NO) activity is decreased, promoting vasoconstriction and thrombosis. Voltage-gated K+ channels (Kv) are downregulated, causing depolarization, Ca(++)-overload and PA smooth muscle cell (PASMC) contraction and proliferation. Augmenting the NO and Kv pathways should cause pulmonary vasodilatation and regression of PA remodeling. Several inexpensive oral treatments may be able to enhance the NO axis and/or K+ channel expression/function and selectively decrease pulmonary vascular resistance (PVR). Oral L-Arginine, NOS' substrate, improves NO synthesis and functional capacity in humans with PAH. Most of NO's effects are mediated by cyclic guanosine-monophosphate (c-GMP). cGMP causes vasodilatation by activating K+ channels and lowering cytosolic Ca++. Sildenafil elevates c-GMP levels by inhibiting type-5 phosphodiesterase, thereby opening BK(Ca). channels and relaxing PAs. In PAH, sildenafil (50 mg-po) is as effective and selective a pulmonary vasodilator as inhaled NO. These benefits persist after months of therapy leading to improved functional capacity. 3) Oral Dichloroacetate (DCA), a metabolic modulator, increases expression/function of Kv2.1 channels and decreases remodeling and PVR in rats with chronic-hypoxic pulmonary hypertension, partially via a tyrosine-kinase-dependent mechanism. These drugs appear safe in humans and may be useful PAH therapies, alone or in combination.
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Affiliation(s)
- Evangelos D Michelakis
- University of Alberta Hospitals, 2C2 Walker C McKenzie Health Sciences, Centre, Edmonton, Canada
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