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Gambari R, Waziri AD, Goonasekera H, Peprah E. Pharmacogenomics of Drugs Used in β-Thalassemia and Sickle-Cell Disease: From Basic Research to Clinical Applications. Int J Mol Sci 2024; 25:4263. [PMID: 38673849 PMCID: PMC11050010 DOI: 10.3390/ijms25084263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/30/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
In this short review we have presented and discussed studies on pharmacogenomics (also termed pharmacogenetics) of the drugs employed in the treatment of β-thalassemia or Sickle-cell disease (SCD). This field of investigation is relevant, since it is expected to help clinicians select the appropriate drug and the correct dosage for each patient. We first discussed the search for DNA polymorphisms associated with a high expression of γ-globin genes and identified this using GWAS studies and CRISPR-based gene editing approaches. We then presented validated DNA polymorphisms associated with a high HbF production (including, but not limited to the HBG2 XmnI polymorphism and those related to the BCL11A, MYB, KLF-1, and LYAR genes). The expression of microRNAs involved in the regulation of γ-globin genes was also presented in the context of pharmacomiRNomics. Then, the pharmacogenomics of validated fetal hemoglobin inducers (hydroxyurea, butyrate and butyrate analogues, thalidomide, and sirolimus), of iron chelators, and of analgesics in the pain management of SCD patients were considered. Finally, we discuss current clinical trials, as well as international research networks focusing on clinical issues related to pharmacogenomics in hematological diseases.
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Affiliation(s)
- Roberto Gambari
- Center “Chiara Gemmo and Elio Zago” for the Research on Thalassemia, Department of Life Sciences and Biotechnology, Ferrara University, 40124 Ferrara, Italy
| | - Aliyu Dahiru Waziri
- Department of Hematology and Blood Transfusion, Ahmadu Bello University Teaching Hospital Zaria, Kaduna 810001, Nigeria;
| | - Hemali Goonasekera
- Department of Anatomy, Genetics and Biomedical Informatics, Faculty of Medicine, University of Colombo, Colombo P.O. Box 271, Sri Lanka;
| | - Emmanuel Peprah
- Implementing Sustainable Evidence-Based Interventions through Engagement (ISEE) Lab, Department of Global and Environmental Health, School of Global Public Health, New York University, New York, NY 10003, USA;
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Gupta P, Kumar R. Nitric oxide: A potential etiological agent for vaso-occlusive crises in sickle cell disease. Nitric Oxide 2024; 144:40-46. [PMID: 38316197 DOI: 10.1016/j.niox.2024.01.008] [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: 10/06/2023] [Revised: 12/27/2023] [Accepted: 01/29/2024] [Indexed: 02/07/2024]
Abstract
Nitric oxide (NO), a vasodilator contributes to the vaso-occlusive crisis associated with the sickle cell disease (SCD). Vascular nitric oxide helps in vasodilation, controlled platelet aggregation, and preventing adhesion of sickled red blood cells to the endothelium. It decreases the expression of pro-inflammatory genes responsible for atherogenesis associated with SCD. Haemolysis and activated endothelium in SCD patients reduce the bioavailability of NO which promotes the severity of sickle cell disease mainly causes vaso-occlusive crises. Additionally, NO depletion can also contribute to the formation of thrombus, which can cause serious complications such as stroke, pulmonary embolism etc. Understanding the multifaceted role of NO provides valuable insights into its therapeutic potential for managing SCD and preventing associated complications. Various clinical trials and studies suggested the importance of artificially induced nitric oxide and its supplements in the reduction of severity. Further research on the mechanisms of NO depletion in SCD is needed to develop more effective treatment strategies and improve the management of this debilitating disease.
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Affiliation(s)
- Parul Gupta
- ICMR-National Institute of Research in Tribal Health, India
| | - Ravindra Kumar
- ICMR-National Institute of Research in Tribal Health, India.
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Aboursheid T, Albaroudi O, Alahdab F. Inhaled nitric oxide for treating pain crises in people with sickle cell disease. Cochrane Database Syst Rev 2022; 7:CD011808. [PMID: 35802341 PMCID: PMC9266993 DOI: 10.1002/14651858.cd011808.pub3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND In people with sickle cell disease, sickled red blood cells cause the occlusion of small blood vessels, which presents as episodes of severe pain known as pain crises or vaso-occlusive crises. The pain can occur in the bones, chest, or other parts of the body, and may last several hours to days. Pain relief during crises includes both pharmacologic and non-pharmacologic treatments. The efficacy of inhaled nitric oxide in pain crises has been a subject of controversy; hypotheses have been made suggesting a beneficial response due to its vasodilator properties, yet no conclusive evidence has been presented. This review aimed to evaluate the available randomised controlled studies addressing this topic. OBJECTIVES To capture the body of evidence evaluating the efficacy and safety of the use of inhaled nitric oxide in treating pain crises in people with sickle cell disease, and to assess the relevance, robustness, and validity of the treatment to better guide medical practice in the fields of haematology and palliative care (since the recent literature seems to favour the involvement of palliative care for such people). SEARCH METHODS We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register. We searched for unpublished work in the abstract books of the European Haematology Association conference, the American Society of Hematology conference, the British Society for Haematology Annual Scientific Meeting, the Caribbean Health Research Council Meetings, and the National Sickle Cell Disease Program Annual Meeting. The most recent search was conducted on 1 September 2021. We also searched ongoing study registries on 19 November 2021. SELECTION CRITERIA Randomised and quasi-randomised trials comparing inhaled nitric oxide with placebo for treating pain crises in people with sickle cell disease. DATA COLLECTION AND ANALYSIS Two review authors independently assessed trial quality and extracted data (including adverse event data), with any disagreements resolved by consulting a third review author. When the data were not reported in the text, we attempted to extract the data from available tables or figures. We contacted trial authors for additional information. We assessed the certainty of the evidence using the GRADE criteria. MAIN RESULTS We included three trials involving a total of 188 participants in the review. There were equal numbers of males and females. Most participants were adults, although one small trial was conducted in a children's hospital and recruited children over the age of 10 years. All three parallel trials compared inhaled nitric oxygen (80 parts per million (ppm)) to placebo (nitrogen gas mixed with oxygen or room air) for four hours; one trial continued administering nitric oxide (40 ppm) for a further four hours. This extended trial had an overall low risk of bias; however, we had concerns about risk of bias for the remaining two trials due to their small sample size, and additionally a high risk of bias due to financial conflicts of interest in one of these smaller trials. We were only able to analyse some limited data from the eight-hour trial, reporting the remaining results narratively. Evidence from one trial (150 participants) suggested that inhaled nitric oxide may not reduce the time to pain resolution: inhaled nitric oxide median 73.0 hours (95% confidence interval (CI) 46.0 to 91.0) and with placebo median 65.5 hours (95% CI 48.1 to 84.0) (low-certainty evidence). No trial reported on the duration of the initial pain crisis. Only one large trial reported on the frequency of pain crises in the follow-up period and found there may be little or no difference between the inhaled nitric oxide and placebo groups for return to the emergency department (risk ratio (RR) 0.73, 95% CI 0.31 to 1.71) and rehospitalisation (RR 0.53, 95% CI 0.25 to 1.11) (150 participants; low-certainty evidence). There may be little or no difference between treatment and placebo in terms of reduction in pain score at any time point up to eight hours (150 participants). The two smaller trials reported a beneficial effect of inhaled nitric oxide in reducing the visual analogue pain score after four hours of the intervention. Analgesic use was reported not to differ greatly between the inhaled nitric oxide group and placebo group in any of the three trials, but no analysable data were provided. Two trials reported the median duration of hospitalisation: in the largest trial the placebo group had the shorter duration, whilst in the second smaller (paediatric) trial hospitalisation was shorter in the treatment group. Only the largest trial (150 participants) reported serious adverse events, with no increase in the inhaled nitric oxide group during or after the intervention compared to the control group (acute chest syndrome occurred in 5 out of 75 participants from each group, pyrexia in 1 out of 75 participants from each group, and dysphagia and a drop in haemoglobin were each reported in 1 out of 75 participants in the inhaled nitric oxide group) (low-certainty evidence). AUTHORS' CONCLUSIONS The currently available evidence is insufficient to determine the effects (benefits or harms) of using inhaled nitric oxide to treat pain (vaso-occlusive) crises in people with sickle cell disease. Large-scale, long-term trials are needed to provide more robust data in this area. Patient-important outcomes (e.g. measures of pain and time to pain resolution and amounts of analgesics used), as well as use of healthcare services, should be measured and reported in a standardised manner.
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Affiliation(s)
| | - Omar Albaroudi
- Emergency Department, Hamad Medical Corporation, Doha, Qatar
| | - Fares Alahdab
- Evidence-based Practice Center, Mayo Clinic, Rochester, MN, USA
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PPARγ increases HUWE1 to attenuate NF-κB/p65 and sickle cell disease with pulmonary hypertension. Blood Adv 2021; 5:399-413. [PMID: 33496741 DOI: 10.1182/bloodadvances.2020002754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 12/07/2020] [Indexed: 12/17/2022] Open
Abstract
Sickle cell disease (SCD)-associated pulmonary hypertension (PH) causes significant morbidity and mortality. Here, we defined the role of endothelial specific peroxisome proliferator-activated receptor γ (PPARγ) function and novel PPARγ/HUWE1/miR-98 signaling pathways in the pathogenesis of SCD-PH. PH and right ventricular hypertrophy (RVH) were increased in chimeric Townes humanized sickle cell (SS) mice with endothelial-targeted PPARγ knockout (SSePPARγKO) compared with chimeric littermate control (SSLitCon). Lung levels of PPARγ, HUWE1, and miR-98 were reduced in SSePPARγKO mice compared with SSLitCon mice, whereas SSePPARγKO lungs were characterized by increased levels of p65, ET-1, and VCAM1. Collectively, these findings indicate that loss of endothelial PPARγ is sufficient to increase ET-1 and VCAM1 that contribute to endothelial dysfunction and SCD-PH pathogenesis. Levels of HUWE1 and miR-98 were decreased, and p65 levels were increased in the lungs of SS mice in vivo and in hemin-treated human pulmonary artery endothelial cells (HPAECs) in vitro. Although silencing of p65 does not regulate HUWE1 levels, the loss of HUWE1 increased p65 levels in HPAECs. Overexpression of PPARγ attenuated hemin-induced reductions of HUWE1 and miR-98 and increases in p65 and endothelial dysfunction. Similarly, PPARγ activation attenuated baseline PH and RVH and increased HUWE1 and miR-98 in SS lungs. In vitro, hemin treatment reduced PPARγ, HUWE1, and miR-98 levels and increased p65 expression, HPAEC monocyte adhesion, and proliferation. These derangements were attenuated by pharmacological PPARγ activation. Targeting these signaling pathways can favorably modulate a spectrum of pathobiological responses in SCD-PH pathogenesis, highlighting novel therapeutic targets in SCD pulmonary vascular dysfunction and PH.
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Aboursheid T, Albaroudi O, Alahdab F. Inhaled nitric oxide for treating pain crises in people with sickle cell disease. Cochrane Database Syst Rev 2019; 10:CD011808. [PMID: 31603241 PMCID: PMC6788324 DOI: 10.1002/14651858.cd011808.pub2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND In people with sickle cell disease, sickled red blood cells cause the occlusion of small blood vessels which presents as episodes of severe pain known as pain crises or vaso-occlusive crises. The pain can occur in the bones, chest, or other parts of the body, and may last several hours to days. Pain relief during crises includes both pharmacologic and non-pharmacologic treatments. The efficacy of inhaled nitric oxide in pain crises has been a controversial issue and hypotheses have been made suggesting a beneficial response due to its vasodilator properties. Yet no conclusive evidence has been presented.This review aims to evaluate the available randomised controlled studies which address this topic. OBJECTIVES To capture the available body of evidence evaluating the efficacy and safety of the use of inhaled nitric oxide in treating pain crises in people with sickle cell disease; and to assess the treatment's relevance, robustness, and validity, in order to better guide medical practice in the fields of haematology and palliative care (since recent literature seems to favour the involvement of palliative care for those people). SEARCH METHODS We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. Unpublished work is identified by searching the abstract books of the European Haematology Association conference; the American Society of Hematology conference; the British Society for Haematology Annual Scientific Meeting; the Caribbean Health Research Council Meetings; and the National Sickle Cell Disease Program Annual Meeting.Date of most recent search: 19 September 2019.We also searched ongoing study registries, date of most recent search: 26 September 2019. SELECTION CRITERIA Randomised and quasi-randomised trials comparing inhaled nitric oxide with placebo, or standardized way of treatment of pain crises in people with sickle cell disease. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial quality and extracted data (including adverse event data). A third author helped clarify any disagreement. When the data were not reported in the text, we attempted to extract the data from any table or figure available. We contacted trial authors for additional information. We assessed the quality of the evidence using the GRADE criteria MAIN RESULTS: We identified six trials, three of which (188 participants) were eligible for inclusion in the review. There were equal numbers of males and females; and most participants were adults, although one small trial was conducted in a children's hospital and recruited children over the age of 10 years. All three parallel trials compared inhaled nitric oxygen (80 ppm) to placebo (room air) for four hours; one trial continued administering nitric oxide (40 ppm) for a further four hours. This extended trial had an overall low risk of bias; however, in the remaining two trials we had concerns about the risk of bias from the small sample size and additionally a high risk of bias due to financial conflicts of interest in one of these smaller trials. We were only able to analyse some limited data from the eight-hour trial and report the remaining results narratively.The time to pain resolution was only reported in one trial (150 participants), showing there may be little or no difference between the two groups: with inhaled nitric oxide median 73.0 hours (95% confidence interval (CI) 46.0 to 91.0) and with placebo median 65.5 hours (95% CI 48.1 to 84.0) (low-quality evidence). No trial reported on the duration of the initial pain crisis. Only one large trial reported on the frequency of pain crises in the follow-up period and found there may be little or no difference between the inhaled nitric oxide and placebo groups for a return to the ED, risk ratio 0.73 (95% CI 0.31 to 1.71) or for re-hospitalisation, risk ratio 0.53 (95% CI 0.25 to 1.11) (150 participants; low-quality evidence).There may be little or no difference between treatment and placebo in terms of reduction in pain score at any time point up to eight hours (150 participants). The two smaller trials reported a beneficial effect of inhaled nitric oxide in reducing the visual analogue pain score after four hours of the intervention, but these trials were small and limited compared to the first trial.Analgesic use was reported not to differ greatly between the inhaled nitric oxide group and placebo group in any of the three trials, but no analysable data were provided. The median duration of hospitalisation was reported by two trials, in the largest trial the placebo group had the shorter duration and in the second smaller (paediatric) trial hospitalisation was shorter in the treatment group.Only the largest trial (150 participants) reported serious adverse events, with no increase in the inhaled nitric oxide group during or after the intervention compared to the control group (acute chest syndrome occurred in 5 out of 75 participants from each group, pyrexia in 1 out of 75 participants from each group, dysphagia and a drop in haemoglobin were each reported in 1 out of 75 participants in the inhaled nitric oxide group, but not in the placebo group) (low-quality evidence). AUTHORS' CONCLUSIONS The currently available trials do not provide sufficient evidence to determine the effects (benefits or harms) of using inhaled nitric oxide to treat pain (vaso-occlusive) crises in people with sickle cell disease. Large-scale, long-term trials are needed to provide more robust data in this area. Patient-important outcomes (e.g. measures of pain and time to pain resolution and amounts of analgesics used), as well as use of healthcare services should be measured and reported in a standardized form.
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Affiliation(s)
| | | | - Fares Alahdab
- Mayo ClinicEvidence‐based Practice Center1919 3rd Ave NEApt 2RochesterMNUSA55906
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6
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Chen Y, Shi J, Xia TC, Xu R, He X, Xia Y. Preservation Solutions for Kidney Transplantation: History, Advances and Mechanisms. Cell Transplant 2019; 28:1472-1489. [PMID: 31450971 PMCID: PMC6923544 DOI: 10.1177/0963689719872699] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Solid organ transplantation was one of the greatest medical advances during the past few
decades. Organ preservation solutions have been applied to diminish ischemic/hypoxic
injury during cold storage and improve graft survival. In this article, we provide a
general review of the history and advances of preservation solutions for kidney
transplantation. Key components of commonly used solutions are listed, and effective
supplementations for current available preservation solutions are discussed. At cellular
and molecular levels, further insights were provided into the pathophysiological
mechanisms of effective ingredients against ischemic/hypoxic renal injury during cold
storage. We pay special attention to the cellular and molecular events during
transplantation, including ATP depletion, acidosis, mitochondrial dysfunction, oxidative
stress, inflammation, and other intracellular mechanisms.
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Affiliation(s)
- Yimeng Chen
- Department of Urology, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, China
| | - Jian Shi
- Department of Urology, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, China
| | - Terry C Xia
- The University of Connecticut, Storrs, CT, USA
| | - Renfang Xu
- Department of Urology, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, China
| | - Xiaozhou He
- Department of Urology, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, China
| | - Ying Xia
- Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Fudan University, Shanghai, China
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7
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Kang BY, Park K, Kleinhenz JM, Murphy TC, Sutliff RL, Archer D, Hart CM. Peroxisome Proliferator-Activated Receptor γ Regulates the V-Ets Avian Erythroblastosis Virus E26 Oncogene Homolog 1/microRNA-27a Axis to Reduce Endothelin-1 and Endothelial Dysfunction in the Sickle Cell Mouse Lung. Am J Respir Cell Mol Biol 2017; 56:131-144. [PMID: 27612006 DOI: 10.1165/rcmb.2016-0166oc] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pulmonary hypertension (PH), a serious complication of sickle cell disease (SCD), causes significant morbidity and mortality. Although a recent study determined that hemin release during hemolysis triggers endothelial dysfunction in SCD, the pathogenesis of SCD-PH remains incompletely defined. This study examines peroxisome proliferator-activated receptor γ (PPARγ) regulation in SCD-PH and endothelial dysfunction. PH and right ventricular hypertrophy were studied in Townes humanized sickle cell (SS) and littermate control (AA) mice. In parallel studies, SS or AA mice were gavaged with the PPARγ agonist, rosiglitazone (RSG), 10 mg/kg/day, or vehicle for 10 days. In vitro, human pulmonary artery endothelial cells (HPAECs) were treated with vehicle or hemin for 72 hours, and selected HPAECs were treated with RSG. SS mice developed PH and right ventricular hypertrophy associated with reduced lung levels of PPARγ and increased levels of microRNA-27a (miR-27a), v-ets avian erythroblastosis virus E26 oncogene homolog 1 (ETS1), endothelin-1 (ET-1), and markers of endothelial dysfunction (platelet/endothelial cell adhesion molecule 1 and E selectin). HPAECs treated with hemin had increased ETS1, miR-27a, ET-1, and endothelial dysfunction and decreased PPARγ levels. These derangements were attenuated by ETS1 knockdown, inhibition of miR-27a, or PPARγ overexpression. In SS mouse lung or in hemin-treated HPAECs, activation of PPARγ with RSG attenuated reductions in PPARγ and increases in miR-27a, ET-1, and markers of endothelial dysfunction. In SCD-PH pathogenesis, ETS1 stimulates increases in miR-27a levels that reduce PPARγ and increase ET-1 and endothelial dysfunction. PPARγ activation attenuated SCD-associated signaling derangements, suggesting a novel therapeutic approach to attenuate SCD-PH pathogenesis.
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Affiliation(s)
- Bum-Yong Kang
- 1 Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia; and
| | - Kathy Park
- 1 Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia; and
| | - Jennifer M Kleinhenz
- 1 Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia; and
| | - Tamara C Murphy
- 1 Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia; and
| | - Roy L Sutliff
- 1 Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia; and
| | - David Archer
- 2 Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia
| | - C Michael Hart
- 1 Department of Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Atlanta, Georgia; and
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Morris CR. New strategies for the treatment of pulmonary hypertension in sickle cell disease : the rationale for arginine therapy. ACTA ACUST UNITED AC 2016; 5:31-45. [PMID: 16409014 DOI: 10.2165/00151829-200605010-00003] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nitric oxide (NO) is inactivated in sickle cell disease (SCD), while bioavailability of arginine, the substrate for NO synthesis, is diminished. Impaired NO bioavailability represents the central feature of endothelial dysfunction, and is a key factor in the pathophysiology of SCD. Inactivation of NO correlates with the hemolytic rate and is associated with erythrocyte release of cell-free hemoglobin and arginase during hemolysis. Accelerated consumption of NO is enhanced further by the inflammatory environment of oxidative stress that exists in SCD. Based upon its critical role in mediating vasodilation and cell growth, decreased NO bioavailability has also been implicated in the pathogenesis of pulmonary arterial hypertension (PHT). Secondary PHT is a common life-threatening complication of SCD that also occurs in most hereditary and chronic hemolytic disorders. Aberrant arginine metabolism contributes to endothelial dysfunction and PHT in SCD, and is strongly associated with prospective patient mortality. The central mechanism responsible for this metabolic disorder is enhanced arginine turnover, occurring secondary to enhanced plasma arginase activity. This is consistent with a growing appreciation of the role of excessive arginase activity in human diseases, including asthma and PHT. Decompartmentalization of hemoglobin into plasma consumes endothelial NO and thus drives a metabolic requirement for arginine, whose bioavailability is further limited by arginase activity. New treatments aimed at maximizing both arginine and NO bioavailability through arginase inhibition, suppression of hemolytic rate, or oral arginine supplementation may represent novel therapeutic strategies.
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Affiliation(s)
- Claudia R Morris
- Department of Emergency Medicine, Children’s Hospital and Research Center at Oakland, Oakland, California, USA
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9
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Altawashi A, Albaroudi O, Aboursheid T, Alahdab F. Inhaled nitric oxide for treating pain crises in people with sickle cell disease. Hippokratia 2015. [DOI: 10.1002/14651858.cd011808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Abdulkareem Altawashi
- Klinikum Oberberg; Department of Internal Medicine; Wilhelm-Breckow-Allee 20 Gummersbach Nordrhein Westfalen Germany 51643
| | - Omar Albaroudi
- Damascus University; Faculty of Medicine; Almazzah Jabal Damascus Syrian Arab Republic
| | - Tarek Aboursheid
- Damascus University; Faculty of Medicine; Almazzah Jabal Damascus Syrian Arab Republic
| | - Fares Alahdab
- Mayo Clinic; Evidence-based Practice Center; 1919 3rd Ave NE Apt 2 Rochester MN USA 55906
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Idzko M, Ferrari D, Riegel AK, Eltzschig HK. Extracellular nucleotide and nucleoside signaling in vascular and blood disease. Blood 2014; 124:1029-37. [PMID: 25001468 PMCID: PMC4133480 DOI: 10.1182/blood-2013-09-402560] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 06/16/2014] [Indexed: 12/17/2022] Open
Abstract
Nucleotides and nucleosides-such as adenosine triphosphate (ATP) and adenosine-are famous for their intracellular roles as building blocks for the genetic code or cellular energy currencies. In contrast, their function in the extracellular space is different. Here, they are primarily known as signaling molecules via activation of purinergic receptors, classified as P1 receptors for adenosine or P2 receptors for ATP. Because extracellular ATP is rapidly converted to adenosine by ectonucleotidase, nucleotide-phosphohydrolysis is important for controlling the balance between P2 and P1 signaling. Gene-targeted mice for P1, P2 receptors, or ectonucleotidase exhibit only very mild phenotypic manifestations at baseline. However, they demonstrate alterations in disease susceptibilities when exposed to a variety of vascular or blood diseases. Examples of phenotypic manifestations include vascular barrier dysfunction, graft-vs-host disease, platelet activation, ischemia, and reperfusion injury or sickle cell disease. Many of these studies highlight that purinergic signaling events can be targeted therapeutically.
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Affiliation(s)
- Marco Idzko
- Department of Pneumology, Freiburg University Medical Center, Albert-Ludwigs-University, Freiburg, Germany
| | - Davide Ferrari
- Department of Morphology, Surgery and Experimental Medicine, Section of General Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy; and
| | - Ann-Kathrin Riegel
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO
| | - Holger K Eltzschig
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO
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Santos FKDS, Maia CN. Patients with sickle cell disease taking hydroxyurea in the Hemocentro Regional de Montes Claros. Rev Bras Hematol Hemoter 2013; 33:105-9. [PMID: 23284256 PMCID: PMC3520633 DOI: 10.5581/1516-8484.20110029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 10/25/2010] [Indexed: 11/27/2022] Open
Abstract
Background The development of therapies for sickle cell disease has received special attention, particularly those that reduce the polymerization of hemoglobin S. Hydroxyurea is a commonly used medication because it has the ability to raise levels of fetal hemoglobin, decrease the frequency of vaso-occlusive episodes and thus improve the clinical course of sickle cell disease patients. Objective To study hematological data and the clinical profile of sickle cell disease patients taking hydroxyurea in a regional blood center. Methods From the charts of 20 patients with sickle cell anemia, the clinical outcomes and a number of hematological variables were analyzed before and during treatment with hydroxyurea. Results The patients' ages ranged from 6 to 41 years old, most were dark skinned and there was a predominance of women. The main symptom that defined whether patients were prescribed hydroxyurea was painful crises followed by hospitalizations. During treatment with hydroxyurea there were significant increases in hemoglobin, fetal hemoglobin, mean corpuscular volume and mean corpuscular hemoglobin. The reticulocyte and white blood cell counts dropped significantly with treatment. A positive correlation was found between fetal hemoglobin and mean corpuscular volume before and during treatment. Additionally, a correlation was found between the white blood cell and reticulocyte counts before treatment with hydroxyurea. Conclusion Most patients showed improvements with treatment as demonstrated by increases in hemoglobin, fetal hemoglobin and mean corpuscular volume, as well as by reductions in the reticulocyte and white blood cell counts. Clinically, more than 50% of patients had a significant reduction of events.
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12
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Sałdyka M. Photodecomposition of N-hydroxyurea in argon matrices. FTIR and theoretical studies. RSC Adv 2013. [DOI: 10.1039/c2ra22694d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Abstract
Ischemia and reperfusion-elicited tissue injury contributes to morbidity and mortality in a wide range of pathologies, including myocardial infarction, ischemic stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease and sleep apnea. Ischemia-reperfusion injury is also a major challenge during organ transplantation and cardiothoracic, vascular and general surgery. An imbalance in metabolic supply and demand within the ischemic organ results in profound tissue hypoxia and microvascular dysfunction. Subsequent reperfusion further enhances the activation of innate and adaptive immune responses and cell death programs. Recent advances in understanding the molecular and immunological consequences of ischemia and reperfusion may lead to innovative therapeutic strategies for treating patients with ischemia and reperfusion-associated tissue inflammation and organ dysfunction.
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Affiliation(s)
- Holger K Eltzschig
- Department of Anesthesiology, Mucosal Inflammation Program, University of Colorado, Aurora, Colorado, USA.
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Distribution of coronary artery calcium scores by Framingham 10-year risk strata in the MESA (Multi-Ethnic Study of Atherosclerosis) potential implications for coronary risk assessment. J Am Coll Cardiol 2011; 57:1838-45. [PMID: 21527159 DOI: 10.1016/j.jacc.2010.11.053] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/18/2010] [Accepted: 11/01/2010] [Indexed: 11/20/2022]
Abstract
OBJECTIVES By examining the distribution of coronary artery calcium (CAC) levels across Framingham risk score (FRS) strata in a large, multiethnic, community-based sample of men and women, we sought to determine if lower-risk persons could benefit from CAC screening. BACKGROUND The 10-year FRS and CAC levels are predictors of coronary heart disease. A CAC level of 300 or more is associated with the highest risk for coronary heart disease even in low-risk persons (FRS, <10%); however, expert groups have suggested CAC screening only in intermediate-risk groups (FRS, 10% to 20%). METHODS We included 5,660 Multi-Ethnic Study of Atherosclerosis participants. The number needed to screen (number of people that need to be screened to detect 1 person with CAC level above the specified cutoff point) was used to assess the yield of screening for CAC. CAC prevalence was compared across FRS strata using chi-square tests. RESULTS CAC levels of more than 0, of 100 or more, and of 300 or more were present in 46.4%, 20.6%, and 10.1% of participants, respectively. The prevalence and amount of CAC increased with higher FRS. A CAC level of 300 or more was observed in 1.7% and 4.4% of those with FRS of 0% to 2.5% and of 2.6% to 5%, respectively (number needed to screen, 59.7 and 22.7, respectively). Likewise, a CAC level of 300 or more was observed in 24% and 30% of those with FRS of 15.1% to 20% and more than 20%, respectively (number needed to screen, 4.2 and 3.3, respectively). Trends were similar when stratified by age, sex, and race or ethnicity. CONCLUSIONS Our study suggests that in very low-risk individuals (FRS ≤5%), the yield of screening and probability of identifying persons with clinically significant levels of CAC is low, but becomes greater in low- and intermediate-risk persons (FRS 5.1% to 20%).
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Ikuta T, Thatte HS, Tang JX, Mukerji I, Knee K, Bridges KR, Wang S, Montero-Huerta P, Joshi RM, Head CA. Nitric oxide reduces sickle hemoglobin polymerization: potential role of nitric oxide-induced charge alteration in depolymerization. Arch Biochem Biophys 2011; 510:53-61. [PMID: 21457702 DOI: 10.1016/j.abb.2011.03.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 03/25/2011] [Accepted: 03/27/2011] [Indexed: 11/30/2022]
Abstract
We previously demonstrated that inhaling nitric oxide (NO) increases the oxygen affinity of sickle red blood cells (RBCs) in patients with sickle cell disease (SCD). Our recent studies found that NO lowered the P(50) values of sickle hemoglobin (HbS) hemolysates but did not increase methemoglobin (metHb) levels, supporting the role of NO, but not metHb, in the oxygen affinity of HbS. Here we examine the mechanism by which NO increases HbS oxygen affinity. Because anti-sickling agents increase sickle RBC oxygen affinity, we first determined whether NO exhibits anti-sickling properties. The viscosity of HbS hemolysates, measured by falling ball assays, increased upon deoxygenation; NO treatment reduced the increment. Multiphoton microscopic analyses showed smaller HbS polymers in deoxygenated sickle RBCs and HbS hemolysates exposed to NO. These results suggest that NO inhibits HbS polymer formation and has anti-sickling properties. Furthermore, we found that HbS treated with NO exhibits an isoelectric point similar to that of HbA, suggesting that NO alters the electric charge of HbS. NO-HbS adducts had the same elution time as HbA upon high performance liquid chromatography analysis. This study demonstrates that NO may disrupt HbS polymers by abolishing the excess positive charge of HbS, resulting in increased oxygen affinity.
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Affiliation(s)
- Tohru Ikuta
- Department of Anesthesiology and Perioperative Medicine, Georgia Health Sciences University, Augusta, 30912, United States
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Baldanzi G, Traina F, Marques Neto JF, Santos AO, Ramos CD, Saad STO. Low bone mass density is associated with hemolysis in Brazilian patients with sickle cell disease. Clinics (Sao Paulo) 2011; 66:801-5. [PMID: 21789383 PMCID: PMC3109378 DOI: 10.1590/s1807-59322011000500015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 01/11/2011] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVES To determine whether kidney disease and hemolysis are associated with bone mass density in a population of adult Brazilian patients with sickle cell disease. INTRODUCTION Bone involvement is a frequent clinical manifestation of sickle cell disease, and it has multiple causes; however, there are few consistent clinical associations between bone involvement and sickle cell disease. METHODS Patients over 20 years of age with sickle cell disease who were regularly followed at the Hematology and Hemotherapy Center of Campinas, Brazil, were sorted into three groups, including those with normal bone mass density, those with osteopenia, and those with osteoporosis, according to the World Health Organization criteria. The clinical data of the patients were compared using statistical analyses. RESULTS In total, 65 patients were included in this study: 12 (18.5%) with normal bone mass density, 37 (57%) with osteopenia and 16 (24.5%) with osteoporosis. Overall, 53 patients (81.5%) had bone mass densities below normal standards. Osteopenia and osteoporosis patients had increased lactate dehydrogenase levels and reticulocyte counts compared to patients with normal bone mass density (p<0.05). Osteoporosis patients also had decreased hemoglobin levels (p<0.05). Hemolysis was significantly increased in patients with osteoporosis compared with patients with osteopenia, as indicated by increased lactate dehydrogenase levels and reticulocyte counts as well as decreased hemoglobin levels. Osteoporosis patients were older, with lower glomerular filtration rates than patients with osteopenia. There was no significant difference between the groups with regard to gender, body mass index, serum creatinine levels, estimated creatinine clearance, or microalbuminuria. CONCLUSION A high prevalence of reduced bone mass density that was associated with hemolysis was found in this population, as indicated by the high lactate dehydrogenase levels, increased reticulocyte counts and low hemoglobin levels.
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Affiliation(s)
- Gabriel Baldanzi
- Hematology and Hemotherapy Center/Instituto Nacional de Ciência e Tecnologia do Sangue, University of Campinas-UNICAMP, Campinas, SP, Brazil
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Cho CS, Kato GJ, Yang SH, Bae SW, Lee JS, Gladwin MT, Rhee SG. Hydroxyurea-induced expression of glutathione peroxidase 1 in red blood cells of individuals with sickle cell anemia. Antioxid Redox Signal 2010; 13:1-11. [PMID: 19951064 PMCID: PMC2935334 DOI: 10.1089/ars.2009.2978] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Chronic redox imbalance in erythrocytes of individuals with sickle cell disease (SCD) contributes to oxidative stress and likely underlies common etiologies of hemolysis. We measured the amounts of six antioxidant enzymes-SOD1, catalase, glutathione peroxidase 1 (GPx1), as well as peroxiredoxins (Prxs) I, II, and VI-in red blood cells (RBCs) of SCD patients and control subjects. The amounts of SOD1 and Prx VI were reduced by about 17% and 20%, respectively, in SCD RBCs compared with control cells. The amounts of Prx II and GPx1 did not differ between SCD and normal RBCs. However, about 18% of Prx II was inactivated in SCD RBCs as a result of oxidation to sulfinic Prx II, whereas inactive Prx II was virtually undetectable in control cells. Furthermore, GPx1 activity was reduced by about 33% in SCD RBCs, and the loss of activity was correlated with hemolysis in SCD patients. RBCs from SCD patients taking hydroxyurea demonstrated 90% higher GPx1 activity than did those from untreated SCD patients, with no differences seen for the other catalytic antioxidants. Hydroxyurea induced GPx1 expression in multiple cultured cell lines in a manner dependent on both p53 and NO-cGMP signaling pathways. GPx1 expression represents a previously unrecognized potential benefit of hydroxyurea treatment in SCD patients.
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Affiliation(s)
- Chun-Seok Cho
- Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seodaemun-gu, Seoul, Korea
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Barst RJ, Mubarak KK, Machado RF, Ataga KI, Benza RL, Castro O, Naeije R, Sood N, Swerdlow PS, Hildesheim M, Gladwin MT. Exercise capacity and haemodynamics in patients with sickle cell disease with pulmonary hypertension treated with bosentan: results of the ASSET studies. Br J Haematol 2010; 149:426-35. [PMID: 20175775 DOI: 10.1111/j.1365-2141.2010.08097.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Doppler-defined pulmonary hypertension (PH) in sickle cell disease (SCD) is associated with 40% mortality at 40 months. To assess the effect of bosentan in SCD-PH, two randomized, double-blind, placebo-controlled, 16-week studies were initiated. Safety concerns are particularly relevant in SCD due to comorbid conditions. ASSET-1 and -2 enrolled patients with pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PH), respectively. Haemodynamics and 6-min walk distance (6MWD) were obtained at baseline and week 16. The studies were terminated due to slow site initiation and patient enrolment (n = 26). Bosentan appeared to be well tolerated. Although sample sizes were limited, in ASSET-1 at baseline, 6MWD correlated with cardiac output (CO; P = 0.006) with non-significant inverse correlations between 6MWD and pulmonary vascular resistance (PVR; P = 0.07) and between 6MWD and right atrial pressure (P = 0.08). In ASSET-2 at baseline, there was a non-significant correlation between 6MWD and CO (P = 0.06). Due to limited sample sizes, efficacy endpoints were not analysed. However, in both studies, non-significant increases in CO were observed with bosentan compared to placebo. Similarly, non-significant decreases in PVR were observed with bosentan. Limited data in SCD-PH suggest that a low 6MWD predicts a low CO. Standard-dose bosentan appears to be well tolerated. Further investigation is warranted. Clinicaltrials.gov registration numbers NCT00310830, NCT00313196, NCT00360087.
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Affiliation(s)
- Robyn J Barst
- Department of Pediatric Cardiology, Columbia University, New York, NY, USA.
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Sałdyka M. Isomerical and structural determination of N-hydroxyurea: a matrix isolation and theoretical study. Phys Chem Chem Phys 2010; 12:15111-8. [DOI: 10.1039/c0cp00709a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Creagh-Brown BC, Griffiths MJD, Evans TW. Bench-to-bedside review: Inhaled nitric oxide therapy in adults. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2009; 13:221. [PMID: 19519946 PMCID: PMC2717403 DOI: 10.1186/cc7734] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nitric oxide (NO) is an endogenous mediator of vascular tone and host defence. Inhaled nitric oxide (iNO) results in preferential pulmonary vasodilatation and lowers pulmonary vascular resistance. The route of administration delivers NO selectively to ventilated lung units so that its effect augments that of hypoxic pulmonary vasoconstriction and improves oxygenation. This 'Bench-to-bedside' review focuses on the mechanisms of action of iNO and its clinical applications, with emphasis on acute lung injury and the acute respiratory distress syndrome. Developments in our understanding of the cellular and molecular actions of NO may help to explain the hitherto disappointing results of randomised controlled trials of iNO.
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Brewer CJ, Coates TD, Wood JC. Spleen R2 and R2* in iron-overloaded patients with sickle cell disease and thalassemia major. J Magn Reson Imaging 2009; 29:357-64. [PMID: 19161188 DOI: 10.1002/jmri.21666] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To evaluate the magnetic properties of the spleen in chronically transfused, iron-overloaded patients with sickle cell disease (SCD) and thalassemia major (TM) and to compare splenic iron burdens to those in the liver, heart, pancreas, and kidneys. MATERIALS AND METHODS A retrospective analysis of 63 TM and 46 SCD patients was performed. Spleen R2 and R2* values were calculated from spin-echo and gradient-echo images collected between April 2004 and September 2007. RESULTS The spleen showed a different R2-R2* relationship than that previously established for the liver. At high iron concentrations (R2* > 300 Hz), spleen R2 was lower than predicted for liver. The proportion of splenic to hepatic iron content was greater in SCD patients compared with TM patients (23.8% vs. 13.8%). A weak association was found between splenic and liver iron-this association was stronger in SCD patients. Little correlation was found between splenic iron and extrahepatic R2* values. CONCLUSION For spleen and liver tissue with the same R2* value, splenic R2 was significantly lower than hepatic R2, particularly for R2* > approximately 300 Hz. Splenic iron levels have little predictive value for R2* values of heart, pancreas, and kidney.
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Affiliation(s)
- Casey J Brewer
- Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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22
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Pulmonary hypertension associated with sickle cell disease: pathophysiology and rationale for treatment. Lung 2008; 186:247-254. [PMID: 18470553 DOI: 10.1007/s00408-008-9092-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2007] [Accepted: 04/04/2008] [Indexed: 01/23/2023]
Abstract
Approximately one third of patients with sickle cell disease (SCD) have pulmonary hypertension (PH), which increases their risk of death. Endothelin (ET)-1 is elevated in SCD and appears to play a key role in many of the pathologic processes in this disease, including PH, suggesting that endothelin receptor antagonists such as bosentan may be effective in treating patients with SCD, particularly those with PH. Other possible treatments include sildenafil, epoprostenol, and oral arginine. Data from controlled clinical trials are needed to establish the most effective treatment of patients with PH associated with SCD.
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Aliyu ZY, Kato GJ, Taylor J, Babadoko A, Mamman AI, Gordeuk VR, Gladwin MT. Sickle cell disease and pulmonary hypertension in Africa: a global perspective and review of epidemiology, pathophysiology, and management. Am J Hematol 2008; 83:63-70. [PMID: 17910044 DOI: 10.1002/ajh.21057] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Secondary pulmonary hypertension (PAH) has been shown to have a prevalence of 30% in patients with sickle cell disease (SCD) with mortality rates of 40% at 40 months after diagnosis in the United States. The burden of SCD is highest in sub-Saharan Africa, especially in Nigeria (West Africa), where approximately 6 million people are afflicted. The true global incidence, prevalence, and burden of SCD and its associated end organ complications however remain unknown. Chronic hemolysis represents a prominent mechanistic pathway in the pathogenesis of SCD-associated pulmonary hypertension via a nitric oxide (NO) scavenging and abrogation of NO salutatory effects on vascular function, including smooth muscle relaxation, downregulation of endothelial adhesion molecules and inhibition of platelet activation. Many known infectious risk factors for PAH are also hyperendemic in Africa, including Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS), chronic hepatitis B and C, and possibly malaria. Interactions between these infectious complications and SCD-related hemolysis could yield an even higher prevalence of pulmonary hypertension and compound the existing global health systems challenges in managing SCD. Indeed, our preliminary analysis of African immigrants currently in the United States suggests that pulmonary hypertension represents a significant complication of SCD in the African subcontinent. There is clearly a need to include Africa and other parts of the world with high SCD prevalence in future comprehensive studies on the epidemiology and treatment of end organ complications of an aging SCD population world-wide.
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Affiliation(s)
- Zakari Y Aliyu
- Vascular Medicine Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1662, USA.
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Ambrusko SJ, Gunawardena S, Sakara A, Windsor B, Lanford L, Michelson P, Krishnamurti L. Elevation of tricuspid regurgitant jet velocity, a marker for pulmonary hypertension in children with sickle cell disease. Pediatr Blood Cancer 2006; 47:907-13. [PMID: 16496290 DOI: 10.1002/pbc.20791] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Pulmonary hypertension (PHTN) is a potentially life-threatening complication, detected by echocardiographic evidence of elevated tricuspid regurgitant velocity (TRV). This condition has been described in adults with sickle cell disease (SCD) and other hemolytic disorders; however, there is little information on the occurrence of this condition in pediatric patients. METHODS Records for pediatric SCD patients were retrospectively reviewed to determine clinical characteristics and co-morbidities of patients with elevated TRV on echocardiograms obtained under steady state conditions as an outpatient. Correlation of TRV > or =2.5 m/sec with age, sex, type of SCD, number of outpatient echocardiograms per patient, episodes of vasoocclusive crisis (VOC) and acute chest syndrome (ACS), mean hemoglobin and reticulocyte count, asthma, obstructive sleep apnea, cerebrovascular disease (CVD), and hydroxyurea therapy was determined. RESULTS Of 224 SCD patients, 44 had outpatient echocardiographic measurement of TRV. Patients (11 of 44) (26.2%) with TRV > or =2.5 m/sec were compared to 31 patients without elevated TRV. Significant differences were noted for percent with HbSS disease (P = 0.041), CVD (P = 0.021), hemoglobin (P = 0.003), % reticulocytes (P = 0.037), and number of echocardiograms performed (P < 0.001). No significant differences were observed for gender, age, asthma, or frequency of VOC and ACS. CONCLUSIONS Elevated TRV, a surrogate marker for PHTN, occurs in children with SCD and is associated with low hemoglobin, elevated reticulocyte count, and cerebral vasculopathy. Appropriate screening by echocardiography can lead to detection and treatment that may reduce TRV and potentially reverse the disease process, prevent the increased morbidity and mortality associated with PHTN.
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Affiliation(s)
- Steven J Ambrusko
- Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center Health System, Pittsburgh, Pennsylvania 15213, USA
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MESH Headings
- Acute Disease
- Adolescent
- Adult
- Age Factors
- Analgesics, Non-Narcotic/administration & dosage
- Analgesics, Non-Narcotic/therapeutic use
- Analgesics, Opioid/administration & dosage
- Analgesics, Opioid/therapeutic use
- Anemia, Sickle Cell/complications
- Anemia, Sickle Cell/diagnosis
- Anemia, Sickle Cell/drug therapy
- Anemia, Sickle Cell/epidemiology
- Anemia, Sickle Cell/genetics
- Anemia, Sickle Cell/physiopathology
- Anemia, Sickle Cell/therapy
- Antibiotic Prophylaxis
- Antisickling Agents/administration & dosage
- Antisickling Agents/therapeutic use
- Blood Transfusion
- Child
- Child, Preschool
- Diagnosis, Differential
- Female
- Genotype
- Hematopoietic Stem Cell Transplantation
- Hospitalization
- Humans
- Hydroxyurea/administration & dosage
- Hydroxyurea/therapeutic use
- Ibuprofen/administration & dosage
- Ibuprofen/therapeutic use
- Immunization
- Infant
- Infant, Newborn
- Male
- Morphine/administration & dosage
- Morphine/therapeutic use
- Pain/diagnosis
- Pain/drug therapy
- Pain/etiology
- Pain Measurement
- Penicillins/administration & dosage
- Penicillins/therapeutic use
- Risk Factors
- Stroke/epidemiology
- Stroke/prevention & control
- Time Factors
- Treatment Outcome
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Affiliation(s)
- Rupa Redding-Lallinger
- Division of Hematology/Oncology, Department of Pediatrics, University of North Carolina, Chapel Hill, NC, USA
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Belcher JD, Mahaseth H, Welch TE, Otterbein LE, Hebbel RP, Vercellotti GM. Heme oxygenase-1 is a modulator of inflammation and vaso-occlusion in transgenic sickle mice. J Clin Invest 2006; 116:808-16. [PMID: 16485041 PMCID: PMC1366501 DOI: 10.1172/jci26857] [Citation(s) in RCA: 204] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Accepted: 12/13/2005] [Indexed: 01/29/2023] Open
Abstract
Transgenic sickle mice expressing betaS hemoglobin have activated vascular endothelium that exhibits enhanced expression of NF-kappaB and adhesion molecules that promote vascular stasis in sickle, but not in normal, mice in response to hypoxia/reoxygenation. Sickle mice hemolyze rbcs in vivo as demonstrated by increased reticulocyte counts, plasma hemoglobin and bilirubin, and reduced plasma haptoglobin. The heme content is elevated in sickle organs, which promotes vascular inflammation and heme oxygenase-1 expression. Treatment of sickle mice with hemin further increases heme oxygenase-1 expression and inhibits hypoxia/reoxygenation-induced stasis, leukocyte-endothelium interactions, and NF-kappaB, VCAM-1, and ICAM-1 expression. Heme oxygenase inhibition by tin protoporphyrin exacerbates stasis in sickle mice. Furthermore, treatment of sickle mice with the heme oxygenase enzymatic product carbon monoxide or biliverdin inhibits stasis and NF-kappaB, VCAM-1, and ICAM-1 expression. Local administration of heme oxygenase-1 adenovirus to subcutaneous skin increases heme oxygenase-1 and inhibits hypoxia/reoxygenation-induced stasis in the skin of sickle mice. Heme oxygenase-1 plays a vital role in the inhibition of vaso-occlusion in transgenic sickle mice.
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Affiliation(s)
- John D Belcher
- Division of Hematology, Oncology, and Transplantation, Department of Medicine and Vascular Biology Center, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Suell MN, Bezold LI, Okcu MF, Mahoney DH, Shardonofsky F, Mueller BU. Increased pulmonary artery pressures among adolescents with sickle cell disease. J Pediatr Hematol Oncol 2005; 27:654-8. [PMID: 16344670 DOI: 10.1097/01.mph.0000194022.17968.bf] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The prevalence of pulmonary hypertension (PHT) among adolescents with sickle cell disease (SCD) is unknown. A tricuspid regurgitant (TR) jet peak velocity of 2.5 m/s or more is a screening test for PHT. The authors retrospectively reviewed echocardiograms and clinical data of adolescents followed at the Texas Children's Sickle Cell Center. Of 80 evaluable adolescents with SCD and echocardiogram data, 21 (26%) had a TR jet velocity of 2.5 m/s or more. Of these 21 patients with PHT, 12 (57%) had an echocardiogram performed during an inpatient stay for vaso-occlusive crisis (n = 6), acute chest syndrome (n = 4), fever (n = 1), or seizures (n = 1), and 9 (43%) had an echocardiogram performed as an outpatient in a baseline state of health. Elevation of pulmonary artery pressures was common in this adolescent cohort, but clinical symptoms were rare. Prospective study is warranted to determine the prevalence and course of elevated pulmonary artery pressures in this age group.
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Affiliation(s)
- Mary Nell Suell
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA.
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Abdulmalik O, Obeng D, Asakura T. Sickle cell disease: current therapeutic approaches. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.15.11.1497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Azizi F, Kielbasa JE, Adeyiga AM, Maree RD, Frazier M, Yakubu M, Shields H, King SB, Kim-Shapiro DB. Rates of nitric oxide dissociation from hemoglobin. Free Radic Biol Med 2005; 39:145-51. [PMID: 15964506 DOI: 10.1016/j.freeradbiomed.2005.03.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2004] [Revised: 02/28/2005] [Accepted: 03/01/2005] [Indexed: 11/15/2022]
Abstract
Nitric oxide (NO) plays a major role in human physiology and in many pathological states. Although oxyhemoglobin is known to destroy NO activity, NO activity can, in principle, be conserved through iron nitrosylation at vacant hemes. In order for this NO activity to be delivered, the NO must dissociate from the heme. Despite its study over the past few decades, our understanding of NO dissociation from hemoglobin is incomplete. In principle, there are at least four NO dissociation rates: kR(alpha), kR(beta), kT(alpha), and kT(beta), where the subscript refers to the quaternary state and the superscript to the hemoglobin chain. In the T-state, a proportion of the proximal histidine bonds break forming pentacoordinate alpha-nitrosyl hemoglobin. In vivo, alpha-nitrosyl hemoglobin predominates over beta-nitrosyl hemoglobin. In this study we have used a fast NO trap, Fe(II)-proline-dithiocarbamate, to measure NO dissociation rates from hemoglobin. We have varied solution conditions so the rate of dissociation from pentacoordinate alpha-nitrosyl hemoglobin could be definitively measured for the first time; kT(alpha) = 4.2 +/- 1.5 x 10(-4) s(-1). We have also found that the fastest NO dissociation rate is on the order of 10(-3) s(-1) and that NO dissociation from sickle cell hemoglobin is the same as that from normal adult hemoglobin.
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Affiliation(s)
- Fouad Azizi
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109-7507, USA
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Abstract
Sickle cell disease is characterized by chronic hemolytic anemia and vaso-occlusive painful crises. The vascular occlusion in sickle cell disease is a complex process and accounts for the majority of the clinical manifestation of the disease. Abdominal pain is an important component of vaso-occlusive painful crises. It often represents a substantial diagnostic challenge in this population of patients. These episodes are often attributed to micro-vessel occlusion and infarcts of mesentery and abdominal viscera. Abdominal pain due to sickle cell vaso-occlusive crisis is often indistinguishable from an acute intra-abdominal disease process such as acute cholecystitis, acute pancreatitis, hepatic infarction, ischemic colitis and acute appendicitis. In the majority of cases, however, no specific cause is identified and spontaneous resolution occurs. This chapter will focus on etiologies, pathophysiology and management of abdominal pain in patients with sickle cell disease.
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Affiliation(s)
- Shahid Ahmed
- Saskatoon Cancer Center, University of Saskatchewan, University of Saskatchewan Campus, 20 Campus Drive, Saskatoon, Sask., Canada S7N4H4.
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Weatherall D, Hofman K, Rodgers G, Ruffin J, Hrynkow S. A case for developing North-South partnerships for research in sickle cell disease. Blood 2005; 105:921-3. [PMID: 15466925 DOI: 10.1182/blood-2004-06-2404] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
For a better understanding of the pathophysiology and mechanisms of phenotypic diversity of sickle cell disease, and for the improvement of its management globally, there is a strong case for developing sustainable research partnerships between rich and poor countries.
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Affiliation(s)
- David Weatherall
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, United Kingdom
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Crawford JH, Chacko BK, Kevil CG, Patel RP. The red blood cell and vascular function in health and disease. Antioxid Redox Signal 2004; 6:992-9. [PMID: 15548896 DOI: 10.1089/ars.2004.6.992] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Nitric oxide (NO) is widely accepted as a central regulator of vascular tone and a vast array of other cardiovascular signaling mechanisms. An emerging player in these mechanisms is hemoglobin (Hb), an erythrocytic protein that serves as the archetypical model for an allosteric protein. Specifically, red blood cells (RBC) are suggested to be integral in matching blood flow to tissue oxygen demands. The mechanisms proposed involve the ability of Hb to sense changes in oxygen concentrations and coupling this process to modulating vascular NO levels. The molecular basis of these mechanisms remains under investigation, but is clearly diverse and discussed in this article from the basis of the blood flow responses to hypoxia. Another emerging theme in RBC biology is the role of these cells during inflammatory disease in which disease processes promote the interaction of vascular NO and the RBC. This is exemplified in hemolytic diseases, in which released Hb has drastic affects on vascular homeostasis mechanisms. Additionally, it is becoming evident that RBC express numerous molecules that mediate interactions with the extracellular matrix and cellular mediators of inflammation. The functional implications for such interactions remain unclear but highlight potential roles of the RBC in modulating inflammatory disease.
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Affiliation(s)
- Jack H Crawford
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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35
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Abstract
With the global scope of sickle-cell disease, knowledge of the countless clinical presentations and treatment of this disorder need to be familiar to generalists, haematologists, internists, and paediatricians alike. Additionally, an underlying grasp of sickle-cell pathophysiology, which has rapidly accrued new knowledge in areas related to erythrocyte and extra-erythrocyte events, is crucial to an understanding of the complexity of this molecular disease with protean manifestations. We highlight studies from past decades related to such translational research as the use of hydroxyurea in treatment, as well as the therapeutic promise of red-cell ion-channel blockers, and antiadhesion and anti-inflammatory therapy. The novel role of nitric oxide in sickle-cell pathophysiology and the range of its potential use in treatment are also reviewed. Understanding of disease as the result of a continuing interaction between basic scientists and clinical researchers is best exemplified by this entity.
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Affiliation(s)
- Marie J Stuart
- Department of Pediatrics, Division of Hematology, the Marian Anderson Sickle Cell Anemia Research Hematology Laboratories, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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36
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Abstract
Hydroxyurea is a relatively new treatment for sickle cell disease. A portion of hydroxyurea's beneficial effects may be mediated by nitric oxide, which has also drawn considerable interest as a sickle cell disease treatment. Patients taking hydroxyurea show a significant increase in iron nitrosyl hemoglobin and plasma nitrite and nitrate within 2 h of ingestion, providing evidence for the in vivo conversion of hydroxyurea to nitric oxide. Hydroxyurea reacts with hemoglobin to produce iron nitrosyl hemoglobin, nitrite, and nitrate, but these reactions do not occur fast enough to account for the observed increases in these species in patients taking hydroxyurea. This report reviews recent in vitro studies directed at better understanding the in vivo nitric oxide release from hydroxyurea in patients. Specifically, this report covers: (1) peroxidase-mediated formation of nitric oxide from hydroxyurea; (2) nitric oxide production after hydrolysis of hydroxyurea to hydroxylamine; and (3) the nitric oxide-producing structure-activity relationships of hydroxyurea. Results from these studies should provide a better understanding of the nitric oxide donor properties of hydroxyurea and guide the development of new hydroxyurea-derived nitric oxide donors as potential sickle cell disease therapies.
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Affiliation(s)
- S Bruce King
- Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA.
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Saad STO, Lajolo C, Gilli S, Marques Júnior JFC, Lima CS, Costa FF, Arruda VR. Follow-up of sickle cell disease patients with priapism treated by hydroxyurea. Am J Hematol 2004; 77:45-9. [PMID: 15307105 DOI: 10.1002/ajh.20142] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hydroxyurea is one of the most successfully used therapies for sickle cell disease. Results of many clinical trials point to hydroxyurea administration for patients with frequent painful crises and acute chest syndrome. Priapism is one of the complications that could be prevented by hydroxyurea, but there are few reports demonstrating the results. Since November 1993, hydroxyurea has been used in our clinic for preventing priapism in patients with stuttering or major attacks who are still capable of achieving intercourse on demand. Five patients were enrolled in the study, and 4 cases benefited by this treatment. After the initial treatment for the acute attack, all five patients developed stuttering priapism. Hydroxyurea was then introduced at the initial dose of 10 mg/kg, and as the hydroxyurea dosage increased, the number or length of priapism episodes decreased. One to two months after the maximal dose (20-35 mg/kg) was introduced, the episodes disappeared. In two patients, we were forced to administer over 30 mg hydroxyurea/kg to abort the episodes, and, in another patient, 25 mg/kg was necessary. All patients present normal sexual activity. Hydroxyurea was discontinued in two patients, but stuttering priapism reappeared. Hydroxyurea was then re-introduced, and priapism disappeared. One patient, using 20 mg hydroxyurea/kg, had a 6-year remission of priapism after hydroxyurea administration; however, he experienced stuttering priapism, 1 month before a major attack, that progressed to impotence. During that month, he did not seek medical attention. In conclusion, the data here presented suggests that hydroxyurea may prevent priapism attacks in sickle cell disease, probably at higher doses than usually prescribed for painful crisis prevention.
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Affiliation(s)
- Sara T O Saad
- Hematology and Hemotherapy Center of the State University of Campinas, Campinas, São Paulo, Brazil.
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Conran N, Fattori A, Saad STO, Costa FF. Increased levels of soluble ICAM-1 in the plasma of sickle cell patients are reversed by hydroxyurea. Am J Hematol 2004; 76:343-7. [PMID: 15282666 DOI: 10.1002/ajh.20129] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Increased adhesive events between the blood vessel endothelium and red and white cells play a central role in the initiation of vasoocclusive crisis in sickle cell disease (SCD). Soluble VCAM-1 levels are increased in the plasma of sickle cell patients and may be reduced during hydroxyurea (HU) therapy. Reports regarding any changes in soluble ICAM-1 (sICAM-1) levels in sickle cell patients, however, are conflicting, and as yet no beneficial effect of HU upon levels has been observed. Thus, we sought to thoroughly investigate changes in sICAM-1 levels in SCD patients and the effect of HU therapy (20-30 mg/kg/day). Plasma sVCAM-1 levels were significantly higher in steady-state SCD patients than in normal controls (766 +/- 86 ng/mL vs. 325 +/- 38 ng/mL, respectively, P < 0.0001). sVCAM-1 levels were decreased in patients on HU therapy (543 +/- 69 ng/mL) compared to those not taking HU; however, this difference was not significant. Plasma sICAM-1 levels were significantly increased in steady-state SCD patients compared to normal individuals (285 +/- 20 ng/mL vs. 202 +/- 16 ng/mL, respectively, P = 0.002), and HU therapy significantly reduced sICAM-1 levels in patients (217 +/- 12, P = 0.027) to levels approaching those of healthy individuals. sVCAM-1 levels inversely correlated with fetal hemoglobin levels in SCD patients, while a nonsignificant inverse trend was observed between sICAM-1 levels and fetal hemoglobin. In conclusion, plasma sICAM-1 levels were significantly increased in SCD patients, and this increase was reversed by hydroxyurea therapy, possibly reflecting reduced endothelial activation in patients taking HU. Such an event may benefit patients by reducing adhesive interactions between white cells and the endothelium.
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Affiliation(s)
- Nicola Conran
- The Hematology and Hemotherapy Center, State University of Campinas-UNICAMP, Campinas, Brazil.
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39
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Abstract
Hydroxyurea reduces the incidence of painful crises in patients with sickle cell disease and has recently been approved for the treatment of this condition. A number of in vitro studies show that the oxidation of hydroxyurea results in the formation of nitric oxide, which also has drawn considerable interest as a sickle cell disease therapy. While patients on hydroxyurea demonstrate elevated levels of nitric oxide-derived metabolites, little information regarding the site or mechanism of the in vivo conversion of hydroxyurea to nitric oxide exists. Chemiluminescence detection experiments show the ability of catalase to catalyze the formation of nitrite and nitrate from hydroxyurea. Spectroscopic studies show that the reaction of hydroxyurea and catalase in the presence of a hydrogen peroxide generating system produces a ferrous-NO catalase complex. Trapping studies indicate the intermediacy of a nitroso species during this reaction. The proposed mechanism for this conversion includes initial hydrogen peroxide-dependent oxidation of hydroxyurea by catalase to form the nitroso species, hydrolysis of this nitroso species to produce nitroxyl, and reductive nitrosylation of the ferric heme of catalase by nitroxyl to yield the ferrous-NO catalase complex. Addition of Angeli's salt, a nitroxyl donor, to ferric catalase also produces the ferrous-NO catalase complex. Spectroscopic studies show that the ferrous-NO catalase complex releases nitric oxide as judged by the oxyhemoglobin assay and an NO specific EPR specific trap. These results demonstrate nitric oxide production from the ferric catalase oxidation of nitroxyl and identify a catalase-mediated pathway as a potential source of nitric oxide production from hydroxyurea.
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Affiliation(s)
- Jinming Huang
- Departments of Chemistry and Physics, Wake Forest University, Winston Salem, NC 27109, USA
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40
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Conran N, Oresco-Santos C, Acosta HC, Fattori A, Saad STO, Costa FF. Increased soluble guanylate cyclase activity in the red blood cells of sickle cell patients. Br J Haematol 2004; 124:547-54. [PMID: 14984506 DOI: 10.1111/j.1365-2141.2004.04810.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Activation of soluble guanylate cyclase (sGC) has been reported to up-regulate gamma-globin gene transcription in erythroid cell lines and primary erythroblasts. sGC is activated by nitric oxide (NO), subsequently catalysing the conversion of guanosine triphosphate to cyclic guanosine monophosphate (cGMP), which mediates various physiological responses. To study the importance of this mechanism in the erythroid cells of sickle cell patients, cGMP levels were measured in the red blood cells (RBC) of normal individuals, steady-state sickle cell patients (SS) and SS patients on hydroxyurea (HU) therapy (SS + HU). cGMP levels were found to be significantly higher in RBC of SS patients (SS RBC) than in RBC of normal individuals, and were further increased in RBC of SS + HU patients. cGMP levels correlated with fetal haemoglobin (HbF) levels in SS/SS + HU patients, but not with reticulocyte count. Furthermore, NO-stimulated sGC activity, following incubation of cells with a NO donor, was significantly greater in SS RBC than in normal RBC. These results demonstrate, for the first time, an increased metabolism of NO mediated by sGC in the SS RBC, which is further increased by hydroxyurea. Augmentation of cGMP levels by NO in erythroid cells may constitute a mechanism for induction of HbF and other erythrocyte functions and represent a possible therapeutic target for treatment of sickle cell disease.
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Affiliation(s)
- Nicola Conran
- The Haematology and Haemotherapy Centre, State University of Campinas - UNICAMP, Campinas, Brazil.
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41
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Zuzak KJ, Gladwin MT, Cannon RO, Levin IW. Imaging hemoglobin oxygen saturation in sickle cell disease patients using noninvasive visible reflectance hyperspectral techniques: effects of nitric oxide. Am J Physiol Heart Circ Physiol 2003; 285:H1183-9. [PMID: 12791593 DOI: 10.1152/ajpheart.00243.2003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sickle cell disease is characterized by microvascular occlusion and hemolytic anemia, factors that impair tissue oxygen delivery. We use visible reflectance hyperspectral imaging to quantitate skin tissue hemoglobin oxygen saturation (HbO2) and to determine whether changes in blood flow during nitric oxide (NO) stimulation or gas administration (therapies proposed for this disease) improve skin tissue oxygen saturation in five patients with sickle cell disease. Compared with six healthy African-American subjects, sickle cell patients exhibited higher forearm blood flows (7.4 +/- 1.8 vs. 3.2 +/- 0.4 ml.min-1.100 ml tissue-1, P = 0.037) but significantly reduced percentages of skin HbO2 (61.0 +/- 0.2 vs. 77.5 +/- 0.2%, P < 0.001). Administration of acetylcholine to patients increased blood flow by 15.1 +/- 3.8 ml.min-1.100 ml tissue-1 and the percentage of skin HbO2 by 4.1 +/- 0.3% (P = 0.02, P < 0.001, respectively, from baseline values). Sodium nitroprusside, a direct NO donor, increased blood flow by 3.9 +/- 1.1 ml/min and the percentage of skin HbO2 by 2.9 +/- 0.3% (P = 0.02, P < 0.001, respectively). NO inhalation had no effect on forearm blood flow, yet increased the percentage of skin HbO2 by 2.3 +/- 0.3% (P < 0.001). Percentages of skin HbO2 were exponentially related to blood flow (R = 0.97, P < 0.001), indicating a limit to skin tissue oxygen saturation at high blood flows. Thus, for acetylcholine infusion leading to blood flows sevenfold greater than those of healthy resting African-American subjects, patients still exhibited lower percentages of skin HbO2 (65.2 +/- 0.2 vs. 77.5 +/- 0.2%, P < 0.001). Visible reflectance hyperspectral imaging demonstrates that either the stimulation or the administration of NO pharmacologically or by gas inhalation improves, but does not normalize, skin tissue oxygen saturation in patients with sickle cell disease.
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Affiliation(s)
- Karel J Zuzak
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases/NIH, 9000 Rockville Pike, Bethesda, MD 20892-0510, USA
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42
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Huang J, Zou Z, Kim-Shapiro DB, Ballas SK, King SB. Hydroxyurea analogues as kinetic and mechanistic probes of the nitric oxide producing reactions of hydroxyurea and oxyhemoglobin. J Med Chem 2003; 46:3748-53. [PMID: 12904079 DOI: 10.1021/jm0301538] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Derivatives of N-hydroxyurea that contain an N-hydroxy group react with oxyhemoglobin to form methemoglobin and variable amounts of nitrite/nitrate. Compounds with an unsubstituted -NHOH group produce the most nitrite/nitrate, which provides evidence for nitric oxide formation. The rate of reaction of these N-hydroxyurea derivatives with oxyhemoglobin correlates well with that compound's oxidation potential. Aromatic N-hydroxyureas react 25-80-fold faster with oxyhemoglobin than with N-hydroxyurea, suggesting other N-hydroxyurea analogues may be superior nitric oxide donors. Electron paramagnetic resonance spectroscopy shows that the formation of a low-spin methemoglobin-hydroxyurea complex is critical for iron nitrosyl hemoglobin formation. These results show that iron nitrosyl hemoglobin formation from the reaction of hydroxyureas and hemoglobin requires an unsubstituted -NHOH group and that the nitrogen atom of the non-N-hydroxy group must contain at least a single hydrogen atom. These results should guide the development of new hydroxyurea-based nitric oxide donors and sickle cell disease therapies.
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Affiliation(s)
- Jinming Huang
- Departments of Chemistry and Physics, Wake Forest University, Winston-Salem, NC 27109, USA
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43
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Morris CR, Vichinsky EP, van Warmerdam J, Machado L, Kepka-Lenhart D, Morris SM, Kuypers FA. Hydroxyurea and arginine therapy: impact on nitric oxide production in sickle cell disease. J Pediatr Hematol Oncol 2003; 25:629-34. [PMID: 12902916 DOI: 10.1097/00043426-200308000-00008] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE Recent data suggest that hydroxyurea (HU) increases the production of nitric oxide (NO), a potent vasodilator. NO is normally metabolized from l-Arginine (Arg). However, in vitro and animal experiments suggest that HU is the NO donor itself. In contrast, a recent study indicates that nitric oxide synthase (NOS) may play a role. Since adults with sickle cell disease (SCD) are Arg-deficient, Arg availability may limit the ability of HU to maximally impact NO production if an NOS mechanism is involved. The authors have previously shown that Arg supplementation alone induces a paradoxical decrease in NO metabolite (NO(x)) production. METHODS The authors studied the effects of HU and Arg supplementation on NO(x) production. HU alone or HU + Arg was administered to patients with SCD at steady state, and sequential levels of Arg, serum NO(x) and exhaled NO were followed over 4 hours. RESULTS After HU + Arg, all patients demonstrated a significant increase in serum NO(x) production within 2 hours. When the same patients were treated with HU alone (5.1 +/- 2 micromol/L), a mixed response occurred. NO(x) levels increased in four patients and decreased in one patient (-23.3 micromol/L). CONCLUSIONS While Arg alone does not increase serum NO(x) production in SCD patients at steady state, it does when given together with HU. Hence, co-administration of Arg with HU may augment the NO(x) response in SCD and improve utilization of Arg in patients at steady state.
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Affiliation(s)
- Claudia R Morris
- Department of Emergency Medicine, Children's Hospital and Research Center at Oakland, Oakland, California 94609, USA.
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44
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Lockamy VL, Huang J, Shields H, Ballas SK, King SB, Kim-Shapiro DB. Urease enhances the formation of iron nitrosyl hemoglobin in the presence of hydroxyurea. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1622:109-16. [PMID: 12880948 DOI: 10.1016/s0304-4165(03)00132-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although it has been shown that hydroxyurea (HU) therapy produces measurable amounts of nitric oxide (NO) metabolites, including iron nitrosyl hemoglobin (HbNO) in patients with sickle cell disease, the in vivo mechanism for formation of these is not known. Much in vitro data and some in vivo data indicates that HU is the NO donor, but other studies suggest a role for nitric oxide synthase (NOS). In this study, we confirm that the NO-forming reactions of HU with hemoglobin (Hb) or other blood constituents is too slow to account for NO production measured in vivo. We hypothesize that, in vivo, HU is partially metabolized to hydroxylamine (HA), which quickly reacts with Hb to form methemoglobin (metHb) and HbNO. We show that addition of urease, which converts HU to HA, to a mixture of blood and HU, greatly enhances HbNO formation.
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Affiliation(s)
- Virginia L Lockamy
- Department of Physics, Wake Forest University, Winston-Salem, NC 27109-7507, USA
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45
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Abstract
Pulmonary complications account for significant morbidity and mortality in patients with sickle cell disease. Clinical lung involvement manifests in two major forms: the acute chest syndrome and sickle cell chronic lung disease. Acute chest syndrome is characterised by fever, chest pain, and appearance of a new infiltrate on chest radiograph. Sickle cell chronic lung disease, on the other hand, manifests as radiographic interstitial abnormalities, impaired pulmonary function, and, in its most severe form, by the evidence of pulmonary hypertension. Progress has been made in understanding the pathophysiology and management of these complications. In this review the current knowledge of the mechanism, diagnosis, and treatment of pulmonary complications of sickle cell disease are discussed.
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Affiliation(s)
- A K Siddiqui
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Long Island Jewish Medical Center, New Hyde Park, USA
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46
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Morris CR, Morris SM, Hagar W, Van Warmerdam J, Claster S, Kepka-Lenhart D, Machado L, Kuypers FA, Vichinsky EP. Arginine therapy: a new treatment for pulmonary hypertension in sickle cell disease? Am J Respir Crit Care Med 2003; 168:63-9. [PMID: 12626350 DOI: 10.1164/rccm.200208-967oc] [Citation(s) in RCA: 237] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Pulmonary hypertension is a life-threatening complication of sickle cell disease. L-Arginine is the nitrogen donor for synthesis of nitric oxide, a potent vasodilator that is deficient during times of sickle cell crisis. This deficiency may play a role in pulmonary hypertension. The enzyme arginase hydrolyzes arginine to ornithine and urea, and thus, it may compete with nitric oxide synthase, leading to decreased nitric oxide production. Nitric oxide therapy by inhalation has improved pulmonary hypertension associated with acute chest syndrome in sickle cell disease, and several studies demonstrate therapeutic benefits of arginine therapy for primary and secondary pulmonary hypertension. We sought to determine the effects of arginine therapy on pulmonary hypertension in patients with sickle cell disease. Arginase activity was also determined. Oral arginine produced a 15.2% mean reduction in estimated pulmonary artery systolic pressure (63.9 +/- 13 to 54.2 +/- 12 mm Hg, p = 0.002) after 5 days of therapy in 10 patients. Arginase activity was elevated almost twofold (p = 0.07) in patients with pulmonary hypertension and may limit arginine bioavailability. With limited treatment options and a high mortality rate for patients with sickle cell disease who develop pulmonary hypertension, arginine is a promising new therapy that warrants further investigation.
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Affiliation(s)
- Claudia R Morris
- Department of Emergency Medicine, Children's Hospital Oakland, 747 52nd Street, Oakland, CA 94609, USA.
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47
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Weiner DL, Hibberd PL, Betit P, Cooper AB, Botelho CA, Brugnara C. Preliminary assessment of inhaled nitric oxide for acute vaso-occlusive crisis in pediatric patients with sickle cell disease. JAMA 2003; 289:1136-42. [PMID: 12622584 DOI: 10.1001/jama.289.9.1136] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
CONTEXT Vaso-occlusion is central to the painful crises and acute and chronic organ damage in sickle cell disease. Abnormal nitric oxide-dependent regulation of vascular tone, adhesion, platelet activation, and inflammation contributes to the pathophysiology of vaso-occlusion. Nitric oxide may have promise as a mechanism-of-disease-based therapy for treatment of vaso-occlusion. OBJECTIVE To explore the efficacy and safety of inhaled nitric oxide (INO) for treatment of vaso-occlusive crisis in pediatric patients. DESIGN Prospective, double-blind, placebo-controlled, randomized clinical trial with enrollment between September 1999 and October 2001. SETTING Urban, tertiary care children's hospital in the United States. PARTICIPANTS Twenty patients aged 10 to 21 years with sickle cell disease and severe acute vaso-occlusive crisis. INTERVENTION Patients were randomly assigned to receive INO (80 ppm with 21% final concentration of inspired oxygen; n = 10), or placebo (21% inspired oxygen; n = 10) for 4 hours. MAIN OUTCOME MEASURES Change in pain at 4 hours of inhalation compared with preinhalation pain, measured on a 10-cm visual analog scale (VAS); secondary outcome measures were pain over 6 hours, parenteral narcotic use over 24 hours, duration of hospitalization, blood pressure, oxygen saturation, and methemoglobin concentration. RESULTS Preinhalation VAS pain scores were similar in the INO and placebo groups (P =.80). The decrease in VAS pain scores at 4 hours was 2.0 cm in the INO group and 1.2 cm in the placebo group (P =.37). Repeated-measures analysis of variance for hourly pain scores showed a 1-cm/h greater reduction in the INO group than the placebo group (P =.02). Morphine use over 6 hours was significantly less in the INO group (mean cumulative use, 0.29 vs 0.44 mg/kg; P =.03) but was not different over 4 hours (0.26 vs 0.32 mg/kg; P =.21) or 24 hours (0.63 vs 0.91 mg/kg; P =.15). Duration of hospitalization was 78 and 100 hours in the INO and placebo groups, respectively (P =.19). No INO toxicity was observed. CONCLUSIONS Results of this exploratory study suggest that INO may be beneficial for acute vaso-occlusive crisis. These preliminary results warrant further investigation.
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Affiliation(s)
- Debra L Weiner
- Pediatric Emergency, Children's Hospital Boston, 300 Longwood Ave, Boston, MA 02115, USA.
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48
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Girgis RE, Qureshi MA, Abrams J, Swerdlow P. Decreased exhaled nitric oxide in sickle cell disease: relationship with chronic lung involvement. Am J Hematol 2003; 72:177-84. [PMID: 12605389 DOI: 10.1002/ajh.10284] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A deficiency in airway nitric oxide (NO) could contribute to pulmonary vaso-occlusion in sickle cell disease (SCD). We measured the fractional expired concentration of NO (FE(NO)) by chemiluminescence during a slow vital capacity maneuver against a positive pressure of 16 cm H(2)O at an expiratory flow rate of 50 mL/sec in 44 stable ambulatory adults with SCD and 30 healthy controls. A history of acute chest syndrome was present in 29 patients, and 22 complained of dyspnea. Mean +/- SD FE(NO) was significantly reduced in the SCD group compared with controls (14.8 +/- 8.4 vs. 24.9 +/- 13.5 ppb, P < 0.001). SCD patients with dyspnea had lower FE(NO) than those without dyspnea (10.1 +/- 5.7 vs. 19.6 +/- 8 ppb, P < 0.001) and those with a history of ACS had lower values than those no episodes of ACS (13.0 +/- 8.3 vs. 18.4 +/- 7.6 ppb, P < 0.05). There was a weak correlation between FE(NO) and percent-predicted DLCO (r = 0.4, P = 0.02) among the SCD patients. We conclude that exhaled NO is reduced in adults with SCD, and this may play a role in the pathogenesis of acute chest syndrome and chronic sickle cell lung disease.
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Affiliation(s)
- Reda E Girgis
- Division of Pulmonary, Critical Care and Sleep Medicine, Wayne State University School of Medicine, Detroit, Michigan, USA.
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49
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Lopez BL, Kreshak AA, Morris CR, Davis-Moon L, Ballas SK, Ma XL. L-arginine levels are diminished in adult acute vaso-occlusive sickle cell crisis in the emergency department. Br J Haematol 2003; 120:532-4. [PMID: 12580975 DOI: 10.1046/j.1365-2141.2003.04109.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Paediatric studies have demonstrated that l-arginine (l-arg), the precursor to nitric oxide, is diminished in vaso-occlusive crisis (VOC). This study aimed to determine whether l-arginine levels are altered in adult VOC in the emergency department. Plasma l-arg and nitric oxide metabolite (NOx) levels were obtained in adult VOC patients presenting to the emergency department. Fifty patients had significantly low plasma l-arg (29.78 micromol/l +/- 11.21, P < 0.05 vs steady-state control = 41.16 micromol/l +/- 5.04) and significantly low plasma NOx (12.33 micromol/l +/- 10.28, P < 0.05 vs steady-state control = 25.2 +/- 2.6 micro mol/l). Neither l-arg nor NOx levels could predict VOC clinical course.
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Affiliation(s)
- Bernard L Lopez
- Department of Emergency Medicine, Jefferson Medical College, Philadelphia, PA, USA.
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50
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King SB. A role for nitric oxide in hydroxyurea-mediated fetal hemoglobin induction. J Clin Invest 2003; 111:171-2. [PMID: 12531869 PMCID: PMC151883 DOI: 10.1172/jci17597] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- S Bruce King
- Department of Chemistry, Wake Forest University, Winston-Salem, North Carolina 27109, USA.
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