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Dinah C, Balaskas K, Greystoke B, Awadzi R, Beke P, Ahern R, Talks J. Sickle Eye Project: a cross-sectional, non-interventional study of the prevalence of visual impairment due to sickle cell retinopathy and maculopathy in the UK. BMJ Open 2024; 14:e082471. [PMID: 38418238 PMCID: PMC10910489 DOI: 10.1136/bmjopen-2023-082471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/05/2024] [Indexed: 03/01/2024] Open
Abstract
INTRODUCTION Sickle cell disease (SCD) is one of the most common genetic disorders in the UK, with over 15 000 people affected. Proliferative sickle cell retinopathy (SCR) is a well-described complication of SCD and can result in significant sight loss, although the prevalence in the UK is not currently known. There are currently no national screening guidelines for SCR, with wide variations in the management of the condition across the UK. METHODS AND ANALYSIS The Sickle Eye Project is an epidemiological, cross-sectional, non-interventional study to determine the prevalence of visual impairment due to SCR and/or maculopathy in the UK. Haematologists in at least 16 geographically dispersed hospitals in the UK linked to participating eye clinics will offer study participation to consecutive patients meeting the inclusion criteria attending the sickle cell clinic. The following study procedures will be performed: (a) best corrected visual acuity with habitual correction and pinhole, (b) dilated slit lamp biomicroscopy and funduscopy, (c) optical coherence tomography (OCT), (d) OCT angiography where available, (e) ultrawide fundus photography, (f) National Eye Institute Visual Function Questionnaire-25 and (g) acceptability of retinal screening questionnaire. The primary outcome is the proportion of people with SCD with visual impairment defined as logarithm of the minimum angle of resolution ≥0.3 in at least one eye. Secondary outcomes include the prevalence of each stage of SCR and presence of maculopathy by age and genotype; correlation of stage of SCR and maculopathy to severity of SCD; the impact of SCR and presence of maculopathy on vision-related quality of life; and the acceptability to patients of routine retinal imaging for SCR and maculopathy. ETHICS AND DISSEMINATION Ethical approval was obtained from the South Central-Oxford A Research Ethics Committee (REC 23/SC/0363). Findings will be reported through academic journals in ophthalmology and haematology.
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Affiliation(s)
- Christiana Dinah
- Ophthalmology, London North West Healthcare NHS Trust, Harrow, UK
| | - Konstantinos Balaskas
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Institute of Ophthalmology, UCL, London, UK
| | | | - Rossby Awadzi
- London North West University Healthcare NHS Trust, Harrow, UK
| | | | | | - James Talks
- Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
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Conroy AL, Datta D, Hoffmann A, Wassmer SC. The brain-kidney-retinal axis in severe falciparum malaria. Trends Parasitol 2023; 39:412-413. [PMID: 37024317 DOI: 10.1016/j.pt.2023.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 04/08/2023]
Affiliation(s)
- Andrea L Conroy
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Dibyadyuti Datta
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Angelika Hoffmann
- University Institute of Diagnostic and Interventional Neuroradiology, University Hospital Bern, University of Bern, Switzerland
| | - Samuel C Wassmer
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
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Nwagha TU, Nweke M, Ezigbo ED. Contributions of von Willebrand factor to clinical severity of sickle cell disease: a systematic review and metanalysis. HEMATOLOGY (AMSTERDAM, NETHERLANDS) 2022; 27:860-866. [PMID: 35938970 DOI: 10.1080/16078454.2022.2107908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To evaluate the contributions of VWF to the clinical manifestation and severity of SCD. DESIGN A systematic review of peer-reviewed articles published in English. The review was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. METHODS The data sources for the review included MEDLINE, PubMed, CINAHL, and Academic Search Complete. Articles that applied a quantitative approach to the investigation of the relationship of vWF with clinical manifestations and severity indices were included. The risk of bias assessment was carried out with a mixed-method appraisal tool. We computed I 2 to estimate the degree of heterogeneity. RESULT There was a significantly higher level of VWF in SCD than in the control (d = 2.7, Z = 4.865, P < 0.001, I 2 = 96.41%). Significant positive correlations were obtained for the relationship of VWF with vasoocclusive crisis (r= 0.277, Z= 5.077, P < 0.001, 1 2 =15.62), rate of hemolysis (r=0.441; Z= 4.440, I 2 = <1%), extracellular haemoglobin (r=-0.397, Z=-4.155, I 2 =<1%) and CRP (r = 0.331, Z = 4.566, P < 0.001, I 2 < 1%).The VWF is important in determining the clinical severity of sickle cell disease, which constitutes a putative therapeutic target. More work is required to understand the causal direction underlying the association between VWF levels and the clinical severity of sickle cell disease and the potential role that VWF plays in the clinical manifestations of sickle cell disease. PROTOCOL REGISTRATION The protocol was registered with PROSPERO (CRD42021262625).
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Affiliation(s)
- T U Nwagha
- Department of Haematology, Faculty of Medicine, University of Nigeria /University of Nigeria Teaching Hospital Ituku Ozalla, Nsukka, Nigeria
| | | | - E D Ezigbo
- Department of Medical Laboratory Science, Faculty of Health Sciences, University of Nigeria Enugu Campus, Nsukka, Nigeria
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Case Report: Peripheral Retinal Ischemia and Retinal Neovascularization in von Willebrand Disease. Optom Vis Sci 2021; 98:418-424. [PMID: 33828041 DOI: 10.1097/opx.0000000000001670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE Although von Willebrand disease is the most common inherited bleeding disorder, there are only a few published reports of ocular complications. To our knowledge, this is the first case of peripheral retinal ischemia and retinal neovascularization in a patient with von Willebrand disease. PURPOSE This study aimed to demonstrate the value of multispecialty care when exploring a diagnosis for bilateral retinopathy. CASE REPORT A 55-year-old African American woman presented with peripheral retinal hemorrhages on routine examination. She was asymptomatic and did not have any personal or family history of bleeding disorders. Blood work was ordered, and she was referred to a retinal specialist who found peripheral telangiectasia, retinal ischemia, and leakage on fluorescein angiography, consistent with retinal neovascularization. Laser photocoagulation was performed while numerous specialists were consulted to determine the cause for her retinopathy. Laboratory testing confirmed low-grade type 1 von Willebrand disease. She was monitored without systemic treatment. She remained stable and asymptomatic, but her retinal neovascularization did not regress fully, so laser treatment was repeated. CONCLUSIONS This case described a new finding of peripheral retinal ischemia and retinal neovascularization in von Willebrand disease. It was discovered in an asymptomatic patient who did not have a history of bleeding but presented with bilateral retinal hemorrhages. Diagnosis was challenging because of the high degree of variation in this bleeding disorder, requiring extensive testing and careful consideration of the individual's clinical profile. Most people with von Willebrand disease do not know they have the disease because symptoms are mild or absent, so most cases are unreported. The von Willebrand factor is poorly recognized in ocular disease, but given its role in angiogenesis, it may be a valuable target to consider in future research.
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Allali S, Taylor M, Brice J, Montalembert MD. Chronic organ injuries in children with sickle cell disease. Haematologica 2021; 106:1535-1544. [PMID: 33626864 PMCID: PMC8168494 DOI: 10.3324/haematol.2020.271353] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Indexed: 02/02/2023] Open
Abstract
Median life expectancy of patients with sickle cell disease has increased to up to 55 years but there are still frequent cases of premature death, mostly in patients with pre-existing organ failure such as pulmonary hypertension, kidney injury, and cerebral vasculopathy. Most organ injuries remain asymptomatic for a long time and can only be detected through early systematic screening. Protocols combining assessment of velocities on transcranial Doppler and regular transfusions in patients with abnormal velocities have been demonstrated to dramatically reduce the risk of stroke. In contrast, no consensus has been reached on systematic screening or therapy for silent cerebral infarcts. The prognostic significance of increased tricuspid regurgitant jet velocity on echocardiography has not yet been identified in children, whereas increased albuminuria is a good predictor of kidney injury. Finally, screening for hip and eye disorder is recommended; however, different countries adopt different screening strategies. Hydroxyurea is probably of potential benefit in preventing chronic organ damage but this requires further study in order to be fully demonstrated. Efficacy and safety of the other new drugs available are also under investigation.
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Affiliation(s)
- Slimane Allali
- Department of General Pediatrics and Pediatric Infectious Diseases, Reference Center for Sickle Cell Disease, Necker Hospital for Sick Children, Assistance Publique - Hôpitaux de Paris (AP-HP), Université de Paris, Paris; Laboratory of Cellular and Molecular Mechanisms of Hematological Disorders and Therapeutical Implications, Université de Paris, Imagine Institute, Inserm U1163, Paris; Laboratory of Excellence GR-Ex
| | - Melissa Taylor
- Department of General Pediatrics and Pediatric Infectious Diseases, Reference Center for Sickle Cell Disease, Necker Hospital for Sick Children, Assistance Publique - Hôpitaux de Paris (AP-HP), Université de Paris, Paris; Laboratory of Excellence GR-Ex, Paris; Paris-Cardiovascular Research Centre (PARCC), Université de Paris, Inserm U970
| | - Joséphine Brice
- Department of General Pediatrics and Pediatric Infectious Diseases, Reference Center for Sickle Cell Disease, Necker Hospital for Sick Children, Assistance Publique - Hôpitaux de Paris (AP-HP), Université de Paris, Paris; Laboratory of Excellence GR-Ex, Paris; Institut National de la Transfusion Sanguine (INTS), Université de Paris, Inserm U1134, Paris
| | - Mariane de Montalembert
- Department of General Pediatrics and Pediatric Infectious Diseases, Reference Center for Sickle Cell Disease, Necker Hospital for Sick Children, Assistance Publique - Hôpitaux de Paris (AP-HP), Université de Paris, Paris; Laboratory of Excellence GR-Ex, Paris; Institut National de la Transfusion Sanguine (INTS), Université de Paris, Inserm U1134, Paris.
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Angiopoietin-2 as a Marker of Retinopathy in Children and Adolescents With Sickle Cell Disease: Relation to Subclinical Atherosclerosis. J Pediatr Hematol Oncol 2019; 41:361-370. [PMID: 30994508 DOI: 10.1097/mph.0000000000001486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVES Angiopoietin-2 (Ang-2) is a multifaceted cytokine that functions in both angiogenesis and inflammation. A proangiogenic state has been found in adults with sickle cell disease (SCD), mainly because of elevated Ang-2 levels. We determined Ang-2 level in 40 children and adolescents with SCD compared with 40 healthy controls and assessed its relation to retinopathy as well as carotid intimamedia thickness (CIMT). METHODS Hematologic profile, serum ferritin, and serum Ang-2 were measured. CIMT was assessed using high-resolution ultrasound. Fundus examination was performed followed by fundus fluorescein angiography. Optical coherence tomography angiography (OCTA) was used to find small vascular changes not clinically manifested. RESULTS Ang-2 levels and CIMT were significantly higher in SCD patients compared with controls. The incidence of nonproliferative retinopathy was 45%. SCD patients with retinopathy were older in age with a history of sickling crisis of >3 attacks per year and had a higher incidence of sickle cell anemia than sickle β-thalassemia. Ang-2 cutoff value 9000 pg/mL could significantly detect the presence of retinopathy among SCD patients with 100% sensitivity and specificity. Serum Ang-2 levels were positively correlated with HbS and CIMT. Logistic regression analysis revealed that Ang-2 and HbS significantly contribute to retinopathy among patients with SCD. CONCLUSIONS Elevated Ang-2 highlights the role of angiogenesis in the pathophysiology of SCD and may be considered a promising marker for screening of patients at risk of sickle retinopathy and vascular dysfunction.
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Antwi-Boasiako C, Dzudzor B, Kudzi W, Doku A, Dale CA, Sey F, Otu KH, Boatemaa GD, Ekem I, Ahenkorah J, Achel DG, Aboagye ET, Donkor ES. Association between eNOS Gene Polymorphism (T786C and VNTR) and Sickle Cell Disease Patients in Ghana. Diseases 2018; 6:E90. [PMID: 30274269 PMCID: PMC6313677 DOI: 10.3390/diseases6040090] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 09/21/2018] [Accepted: 09/27/2018] [Indexed: 01/01/2023] Open
Abstract
Endothelial nitric oxide synthase (eNOS) variants have been found to be associated with several vascular disorders as well as the pathogenesis of sickle cell disease (SCD) complications such as vaso-occlusive crises (VOC). Studies on eNOS gene variants among SCD patients are rare in Ghana and several other African countries. The current study aimed to determine a possible association between variants of the eNOS gene (variable number of tandem repeats in intron 4 and T786C) in SCD complications among Ghanaian patients. This was a cross-sectional study involving 89 HbSS patients with complications and 46 HbSS patients without complications. Genomic DNA was extracted from leukocytes in the buffy coat and separated from collected whole blood samples of the study participants. PCR amplification, followed by restriction fragment length polymorphism (RFLP) was used to genotype T786C (rs2070744) variants. Variable number of tandem repeats (VNTR) in intron 4 was genotyped by PCR and direct electrophoresis. There was a significant difference in the genotype frequency of the T786C variant between HbSS patients with complications and those without complications (p = 0.0165). However, there was no significant difference in the VNTR intron 4 variant of the eNOS gene between patients with complications and those without complications (p > 0.05). The study shows an association between the eNOS gene variant (T786C) and complications in SCD.
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Affiliation(s)
- Charles Antwi-Boasiako
- Department of Physiology, School of Biomedical and Allied Health Sciences, University of Ghana, Accra +233, Ghana.
| | - Bartholomew Dzudzor
- Department of Medical Biochemistry, School of Biomedical and Allied Health Sciences, University of Ghana, Accra +233, Ghana.
| | - William Kudzi
- Centre for Tropical Clinical Pharmacology and Therapeutics School of Biomedical and Allied Health Sciences, University of Ghana, Accra +233, Ghana.
| | - Alfred Doku
- Department of Internal Medicine, School of Medicine and Dentistry, University of Ghana, Accra +233, Ghana.
| | - Campbell Andrew Dale
- Center for Cancer and Blood Disorders Children's National Medical Center George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA.
| | - Fredericka Sey
- Center for Clinical Genetics, Korle-Bu Teaching Hospital, Accra +233, Ghana.
| | - Kate Hgar Otu
- Department of Nursing and Midwifery, Greenhills School of Health Sciences, Accra +233, Ghana.
| | - Gifty Dankwah Boatemaa
- Department of Physiology, School of Biomedical and Allied Health Sciences, University of Ghana, Accra +233, Ghana.
| | - Ivy Ekem
- Department of Haematology, School of Medical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast +233, Ghana.
| | - John Ahenkorah
- Department of Anatomy, School of Biomedical and Allied Health Sciences, University of Ghana, Accra +233, Ghana.
| | - Daniel Gyingiri Achel
- Applied Radiation Biology Center, Radiological and Medical Sciences Research, Ghana Atomic Energy Commission, Accra +233, Ghana.
| | - Elvis Twumasi Aboagye
- Centre for Tropical Clinical Pharmacology and Therapeutics School of Biomedical and Allied Health Sciences, University of Ghana, Accra +233, Ghana.
| | - Eric S Donkor
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences, University of Ghana, Accra +233, Ghana.
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Antwi-Boasiako C, Frimpong E, Gyan B, Kyei-Baafour E, Sey F, Dzudzor B, Abdul-Rahman M, Dankwah GB, Otu KH, Ndanu TA, Campbell AD, Ekem I, Donkor ES. Elevated Proangiogenic Markers are Associated with Vascular Complications within Ghanaian Sickle Cell Disease Patients. Med Sci (Basel) 2018; 6:E53. [PMID: 29954157 PMCID: PMC6164085 DOI: 10.3390/medsci6030053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/22/2018] [Accepted: 06/22/2018] [Indexed: 01/19/2023] Open
Abstract
: Sickle cell disease (SCD) is an inherited blood disorder that can result in vasculopathy and end organ damage. Angiogenesis has been implicated as a key contributing factor to vascular mediated tissue injury in SCD. The relative plasma levels of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and vascular endothelial growth factor (VEGF) greatly influence angiogenesis. Dysregulation of these growth factors, leading to a pro-angiogenic state in SCD patients, has been documented in the developed world but there is very little data in Africa. There is the need, therefore, for studies in Ghanaian SCD patients. The aim of this study was to assess plasma levels of Ang-1, Ang-2, and VEGF in homozygous (HbSS) SCD patients with or without complications and healthy controls (HbAA) in Ghana. The study was a case-control study involving 544 participants: 396 HbSS SCD patients and 148 HbAA healthy controls. The study was conducted at the Center for Clinical Genetics (Sickle Cell Clinic) and Accra Area Blood Centre for National Blood transfusion at the Korle-Bu Teaching Hospital, Accra, Ghana. The plasma levels of Ang-1, Ang-2, and VEGF of study participants were measured with a double sandwich enzyme-linked immunosorbent assay (ELISA) technique. Complete blood count (CBC) was measured with an autoanalyser. The mean plasma Ang-1, Ang-2, and VEGF were significantly higher in HbSS SCD patients with or without complications than healthy controls (p < 0.001). The Ang-2/Ang-1 ratio was significantly lower in the controls than the HbSS patients (p < 0.001). The Ang-2/Ang-1 ratio was higher in the HbSS patients with leg ulcers as compared with patients with other complications and healthy controls (p < 0.001). There were higher leucocyte counts in HbSS patients than healthy controls. Overall, there was elevated plasma levels of Ang-1, Ang-2, and VEGF in SCD patients. The higher Ang-2/Ang-1 plasma levels in patients with leg ulcers suggests a possible ongoing angiogenesis and response to inflammatory stimuli. The study provides a first report on plasma levels of angiopoietin-1, angiopoietin-2, and vascular endothelial growth factors in homozygous sickle cell disease patients in Ghana.
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Affiliation(s)
| | - Emmanuel Frimpong
- School of Medical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana.
| | - Ben Gyan
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
| | - Eric Kyei-Baafour
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
| | - Fredericka Sey
- Sickle Cell Clinic, Korle-Bu Teaching Hospital, Accra, Ghana.
| | - Bartholomew Dzudzor
- School of Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana.
| | - Mubarak Abdul-Rahman
- School of Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana.
| | - Gifty B Dankwah
- School of Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana.
| | - Kate H Otu
- Department of Nursing and Midwifery, Greenhills School of Health Sciences, Accra, Ghana.
| | - Tom A Ndanu
- School of Medicine and Dentistry, University of Ghana, Accra, Ghana.
| | - Andrew D Campbell
- Center for Cancer and Blood Disorder, Hematology Children's National Medical Center, George Washington School of Medicine and Health Sciences, Washington, DC 20052, USA.
| | - Ivy Ekem
- School of Medical Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana.
| | - Eric S Donkor
- School of Biomedical and Allied Health Sciences, University of Ghana, Accra, Ghana.
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Abstract
The primary β-globin gene mutation that causes sickle cell disease (SCD) has significant pathophysiological consequences that result in hemolytic events and the induction of the inflammatory processes that ultimately lead to vaso-occlusion. In addition to their role in the initiation of the acute painful vaso-occlusive episodes that are characteristic of SCD, inflammatory processes are also key components of many of the complications of the disease including autosplenectomy, acute chest syndrome, pulmonary hypertension, leg ulcers, nephropathy and stroke. We, herein, discuss the events that trigger inflammation in the disease, as well as the mechanisms, inflammatory molecules and cells that propagate these inflammatory processes. Given the central role that inflammation plays in SCD pathophysiology, many of the therapeutic approaches currently under pre-clinical and clinical development for the treatment of SCD endeavor to counter aspects or specific molecules of these inflammatory processes and it is possible that, in the future, we will see anti-inflammatory drugs being used either together with, or in place of, hydroxyurea in those SCD patients for whom hematopoietic stem cell transplants and evolving gene therapies are not a viable option.
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Affiliation(s)
- Nicola Conran
- Hematology Center, University of Campinas - UNICAMP, Cidade Universitária, Campinas-SP, Brazil
| | - John D Belcher
- Department of Medicine, Division of Hematology, Oncology and Transplantation, Vascular Biology Center, University of Minnesota, Minneapolis, MN, USA
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Abstract
Sickle retinopathy reflects disease-related vascular injury of the eye, which can potentially result in visual loss from vitreous hemorrhage or retinal detachment. Here we review sickle retinopathy among children with sickle cell disease, describe the epidemiology, pediatric risk factors, pathophysiology, ocular findings, and treatment. Newer, more sensitive ophthalmological imaging modalities are available for retinal imaging, including ultra-widefield fluorescein angiography, spectral-domain optical coherence tomography, and optical coherence tomography angiography. Optical coherence tomography angiography provides a noninvasive view of retinal vascular layers that could previously not be imaged and can be quantified for comparative or prospective analyses. Ultra-widefield fluorescein angiography provides a more comprehensive view of the peripheral retina than traditional imaging techniques. Screening for retinopathy by standard fundoscopic imaging modalities detects a prevalence of approximately 10%. In contrast, these more sensitive methods allow for more sensitive examination that includes the retina perimeter where sickle retinopathy is often first detectable. Use of these new imaging modalities may detect a higher prevalence of early sickle pathology among children than has previously been reported. Earlier detection may help in better understanding the pathogenesis of sickle retinopathy and guide future screening and treatment paradigms.
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Tantawy AAG, Adly AAM, Ismail EAR, Youssef OI, Ali ME. Soluble fms-Like Tyrosine Kinase 1 as a Link Between Angiogenesis and Endothelial Dysfunction in Pediatric Patients With β-Thalassemia Intermedia. Clin Appl Thromb Hemost 2017; 23:943-950. [DOI: 10.1177/1076029617692879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Endothelial damage has been implicated in the pathogenesis of vascular complications in β-thalassemia intermedia (β-TI). Soluble fms-like tyrosine kinase 1 (sFLT-1) is a member of the vascular endothelial growth factor receptor (VEGFR) family. Soluble fms-like tyrosine kinase 1 is an antiangiogenic protein that induces endothelial dysfunction by adhering to and inhibiting VEGF and placenta growth factor. The aim of this study was to assess the level of sFLT-1 in 35 children and adolescents with β-TI, correlating it with markers of hemolysis and iron overload as well as cardiopulmonary complications. Patients were studied focusing on the history of cardiac disease, splenectomy, transfusion, chelation/hydroxyurea therapy, serum ferritin, and sFLT-1 levels. Echocardiography and measurement of carotid intima–media thickness (CIMT) were done for all participants. Soluble fms-like tyrosine kinase 1 was significantly higher in TI patients compared to the control group (median [interquartile range], 110 [80-155] pg/mL versus 70 [60-90] pg/mL; P < .001). Splenectomized patients and those who had pulmonary hypertension risk or heart disease had higher sFLT-1 levels than those without ( P < .001). The sFLT-1 cutoff value that differentiates patients with and without pulmonary hypertension risk or heart disease was determined. Soluble fms-like tyrosine kinase 1 was lower among patients who received chelation therapy and/or hydroxyurea. Significant positive relations were observed between sFLT-1 and lactate dehydrogenase, serum ferritin, liver iron concentration, tricuspid regurgitant jet velocity, and CIMT. We suggest that sFLT-1 represents a link between angiogenesis, endothelial dysfunction, and subclinical atherosclerosis. Measurement of sFLT-1 as a marker of vascular dysfunction in β-TI may provide utility for early identification of patients at increased risk of cardiopulmonary complications.
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Affiliation(s)
| | | | | | | | - Mohamed ElSayed Ali
- Pediatrics Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
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Visual and Oculomotor Disorders in Internal Diseases. Neuroophthalmology 2016. [DOI: 10.1007/978-3-319-28956-4_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Lopes FCM, Traina F, Almeida CB, Leonardo FC, Franco-Penteado CF, Garrido VT, Colella MP, Soares R, Olalla-Saad ST, Costa FF, Conran N. Key endothelial cell angiogenic mechanisms are stimulated by the circulating milieu in sickle cell disease and attenuated by hydroxyurea. Haematologica 2015; 100:730-9. [PMID: 25769545 DOI: 10.3324/haematol.2014.119727] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 03/05/2015] [Indexed: 01/05/2023] Open
Abstract
As hypoxia-induced inflammatory angiogenesis may contribute to the manifestations of sickle cell disease, we compared the angiogenic molecular profiles of plasma from sickle cell disease individuals and correlated these with in vitro endothelial cell-mediated angiogenesis-stimulating activity and in vivo neovascularization. Bioplex demonstrated that plasma from patients with steady-state sickle cell anemia contained elevated concentrations of pro-angiogenic factors (angiopoietin-1, basic fibroblast growth factor, vascular endothelial growth factor, vascular endothelial growth factor-D and placental growth factor) and displayed potent pro-angiogenic activity, significantly increasing endothelial cell proliferation, migration and capillary-like structure formation. In vivo neovascularization of Matrigel plugs was significantly greater in sickle cell disease mice than in non-sickle cell disease mice, consistent with an up-regulation of angiogenesis in the disease. In plasma from patients with hemoglobin SC disease without proliferative retinopathy, anti-angiogenic endostatin and thrombospondin-2 were significantly elevated. In contrast, plasma from hemoglobin SC individuals with proliferative retinopathy had a pro-angiogenic profile and more significant effects on endothelial cell proliferation and capillary formation than plasma from patients without retinopathy. Hydroxyurea therapy was associated with significant reductions in plasma angiogenic factors and inhibition of endothelial cell-mediated angiogenic mechanisms and neovascularization. Thus, individuals with sickle cell anemia or hemoglobin SC disease with retinopathy present a highly angiogenic circulating milieu, capable of stimulating key endothelial cell-mediated angiogenic mechanisms. Combination anti-angiogenic therapy to prevent the progression of unregulated neovascularization and associated manifestations in sickle cell disease, such as pulmonary hypertension, may be indicated; furthermore, the benefits and drawbacks of the potent anti-angiogenic effects of hydroxyurea should be clarified.
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Affiliation(s)
- Flavia C M Lopes
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Fabiola Traina
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil Department of Internal Medicine, University of São Paulo at Riberão Preto Medical School, Riberão Preto, Brazil
| | - Camila B Almeida
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Flavia C Leonardo
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Carla F Franco-Penteado
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Vanessa T Garrido
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Marina P Colella
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Raquel Soares
- Department of Biochemistry (I3S), Faculty of Medicine, University of Porto, Portugal
| | - Sara T Olalla-Saad
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Fernando F Costa
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
| | - Nicola Conran
- INCT de Sangue, Hematology Center, School of Medical Science, University of Campinas - UNICAMP, São Paulo, Brazil
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Increased circulating PEDF and low sICAM-1 are associated with sickle cell retinopathy. Blood Cells Mol Dis 2014; 54:33-7. [PMID: 25172543 DOI: 10.1016/j.bcmd.2014.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 08/06/2014] [Indexed: 11/21/2022]
Abstract
Sickle cell retinopathy (SCR) develops in up to 30% of sickle cell disease patients (SCD) during the second decade of life. Treatment for this affection remains palliative, so studies on its pathophysiology may contribute to the future development of novel therapies. SCR is more frequently observed in hemoglobin SC disease and derives from vaso-occlusion in the microvasculature of the retina leading to neovascularization and, eventually, to blindness. Circulating inflammatory cytokines, angiogenic factors, and their interaction may contribute to the pathophysiology of this complication. Angiopoietin (Ang)-1, Ang-2, soluble vascular cell adhesion molecule-1, intercellular adhesion molecule (ICAM)-1, E-selectin, P-selectin, IL1-β, TNF-α, pigment epithelium derived factor (PEDF) and vascular endothelial growth factor plasmatic levels were determined in 37 SCD patients with retinopathy, 34 without retinopathy, and healthy controls. We observed that sICAM-1 is significantly decreased, whereas PEDF is elevated in HbSC patients with retinopathy (P=0.012 and P=0.031, respectively). Ang-1, Ang-2 and IL1-β levels were elevated in SCD patients (P=0.001, P<0.001 and P=0.001, respectively), compared to controls, and HbSS patients presented higher levels of Ang-2 compared to HbSC (P<0.001). Our study supports the possible influence of sICAM-1 and PEDF on the pathophysiology of retinal neovascularization in SCD patients.
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Vascular endothelial growth factor in children with thalassemia major. Mediterr J Hematol Infect Dis 2013; 5:e2013044. [PMID: 23795282 PMCID: PMC3684348 DOI: 10.4084/mjhid.2013.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 05/28/2013] [Indexed: 11/25/2022] Open
Abstract
Background The β-Thalassemia syndromes are the most common hereditary chronic hemolytic anemia due to impaired globin chain synthesis. Vascular endothelial growth factor (VEGF) plays several roles in angiogenesis which is a crucial process in the pathogenesis of several inflammatory, autoimmune and malignant diseases. Endothelial damage and inflammation make a significant contribution to the pathophysiology of β-thalassemia. Purpose : The aim of the study was to assess serum VEGF level in children with beta-thalassemia major as a marker of angiogenesis. Methods A total of 50 children entered the study, 40 patients with thalassemia major and 10 healthy controls. We used enzyme-linked immunosorbent assay for quantitative evaluation of VEGF. Results VEGF level was significantly higher in patients with β-thalassemia major than healthy controls (p=0.001). VEGF level was also higher in splenectomised thalassemic patients than non splenectomised ones (p=0.001). There were a positive correlation between VEGF and chelation starting age (p=0.008), and a negative correlation between VEGF and frequency of blood transfusion (p=0.002). Conclusion Thalassemia patients, especially splenectomized, have elevated serum levels of VEGF. Early chelation and regular blood transfusion help to decrease serum VEGF and the risk of angiogenesis.
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Abstract
Sickle cell disease (SCD) is caused by a mutation in both beta globin genes, resulting in chronic hemolysis and multiorgan disease that ultimately leads to premature death. Although hemoglobin S (HbS) polymerization and vaso-occlusion are central to the pathogenesis of SCD, overlapping pathways implicated in SCD-related endothelial dysfunction include hemolysis, defects in nitric oxide metabolism, ischemia-reperfusion injury, oxidative stress, increased cell-to-cell adhesion, and proinflammatory and coagulation mediators. Progression of organ-specific vasculopathy often precedes organ dysfunction and may provide targets for therapeutic intervention. SCD-related vasculopathies include, but are not limited to, moyamoya that often precedes cerebral infarcts or hemorrhage, proliferative retinopathy prior to loss of eyesight, pulmonary vasculopathy associated with pulmonary hypertension, and renal vasculopathy prior to the onset of chronic renal disease. This review evaluates evidence that SCD vasculopathy is a harbinger for organ dysfunction and reviews the potential for targeted antivasculopathy therapies.
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Affiliation(s)
- Adetola A Kassim
- Department of Medicine, Hematology/Stem Cell Transplant, Vanderbilt and Meharry Center for Excellence in Sickle Cell Disease, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
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The rate of hemolysis in sickle cell disease correlates with the quantity of active von Willebrand factor in the plasma. Blood 2011; 117:3680-3. [PMID: 21300978 DOI: 10.1182/blood-2010-08-302539] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Vaso-occlusion, hemolysis, and oxidative stress are hallmarks of sickle cell disease (SCD). This pathology is accompanied by systemic endothelial activation, rendering the endothelium more adhesive for blood cells, including sickle erythrocytes. Activated endothelial cells display or secrete several adhesive molecules, including von Willebrand factor (VWF). We assessed several VWF parameters in SCD patients at baseline: multimer pattern, antigen concentration (VWF:Ag), activation factor (VWF:AF), and total active VWF (VWF:TA). VWF:AF was determined using a llama nanobody (AU/VWFa-11) that detects a platelet-binding conformation of the A1 domain; VWF:TA was calculated by multiplying VWF:Ag by VWF:AF. SCD plasma contained elevated VWF:Ag and ultralarge VWF multimers. VWF:TA, a measure of total VWF reactivity, correlated closely with hemolysis, as determined by serum lactate dehydrogenase. ADAMTS13 activity and antigen were normal in all patients. These findings suggest an important role for hyperreactive VWF in SCD pathology and connect SCD to other microangiopathies, particularly thrombotic thrombocytopenic purpura.
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Elagouz M, Jyothi S, Gupta B, Sivaprasad S. Sickle Cell Disease and the Eye: Old and New Concepts. Surv Ophthalmol 2010; 55:359-77. [DOI: 10.1016/j.survophthal.2009.11.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 11/15/2009] [Accepted: 11/17/2009] [Indexed: 10/19/2022]
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van Beem RT, Nur E, Zwaginga JJ, Landburg PP, van Beers EJ, Duits AJ, Brandjes DP, Lommerse I, de Boer HC, van der Schoot CE, Schnog JJB, Biemond BJ. Elevated endothelial progenitor cells during painful sickle cell crisis. Exp Hematol 2009; 37:1054-9. [PMID: 19539689 DOI: 10.1016/j.exphem.2009.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 05/06/2009] [Accepted: 06/09/2009] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Circulating endothelial progenitor cells (EPCs) counts were determined in patients with sickle cell disease (SCD) to elucidate their role in SCD-related ischemia-induced angiogenesis and reendothelialization. MATERIALS AND METHODS Circulating EPC counts (KDR(+)/CD34(+)/Cd45(dim) cells) and their relation to serum levels of EPC mobilizing growth factors erythropoietin, vascular endothelial growth factor, and interleukin-8 were investigated in SCD patients during asymptomatic state (n=66) and painful crisis (n=36) and compared to healthy controls (n=13). RESULTS EPC counts were comparable between controls (0; range, 0-1.1 cells/mL) and patients (0; range, 0-0 cells/mL) in asymptomatic state, but were significantly higher during painful crisis (41.7; range, 0-186 cells/mL; p<0.05). Also in a paired analysis of 12 patients who were included both during asymptomatic state and painful crisis, EPC counts increased significantly during painful crisis (from 0 [range, 0-0] to 26 [range, 0-149 cell/mL; p<0.05). EPC counts were not related to any of the measured growth factors. CONCLUSION The higher EPC counts during painful crisis might indicate a role for EPC mobilization in reendothelialization. As a relationship of EPCs with the established mobilizing growth factors, measured in this study was not observed, the mechanism of EPC mobilization in SCD remains to be elucidated.
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Affiliation(s)
- Rachel T van Beem
- Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Amsterdam, The Netherlands
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Abstract
PURPOSE OF REVIEW Plasma cytokines and related factors represent a burgeoning area of inquiry related to the pathogenesis in sickle cell disease. Cytokines derived from platelets, white blood cells and endothelial cells have all been implicated in the development of several sequelae of this disease. In this review, we seek to provide an overview of the noted and potentially novel roles for several key plasma factors in sickle cell disease. We also consider the putative role for those cytokines implicated by genetic analysis in sickle cell disease, but where the pathogenic, or ameliorative, role has yet to be determined. RECENT FINDINGS New roles for the platelet as a key mediator in the release of cytokines in sickle cell disease have recently been demonstrated. Angiogenic and inflammatory factors are also being explored in this illness. Members of the vascular endothelial growth factor and transforming growth factor-beta superfamilies have been suggested to contribute to several key events in pathogenesis of sickle cell disease, but with the promise of nitrous oxide therapy in this disorder, these cytokines merit a fresh perspective in the context of sickle cell disease. SUMMARY Increased understanding of the origin and pathology of cytokine levels in sickle cell disease may provide novel therapeutic approaches in the management of the disease.
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Li B, Tang SB, Hu J, Gao Y, Zhang G, Lin SF, Chen JH, Li BJ. Protective effects of transcription factor HESR1 on retinal vasculature. Microvasc Res 2006; 72:146-52. [PMID: 17028039 DOI: 10.1016/j.mvr.2006.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 07/14/2006] [Accepted: 07/19/2006] [Indexed: 11/17/2022]
Abstract
HESR1 is a basic helix-loop-helix transcription factors regulated by the Notch signaling pathway in vertebrate and Drosophila embryos, and is related to the HES/Hairy/E (sp1) family. HESR1 is a downstream target of Notch in endothelial cells and could be an effector of Notch signaling in these cells. HESR1 is necessary for the induction of a tubular network and for continued maintenance of mature and quiescent blood vessels. To examine the role of HESR1 in retinal neovascularization, we transfected retinal vascular endothelial cells (HRCECs) with the HESR1 gene and studied its effects on the expression of angiogenic factors, on the proliferation and migration of endothelial cells, and on the formation of tube-like structures (TLSs). Overexpression of HESR1 downregulated VEGFR-2 expression, upregulated occludin expression, inhibited the migration and proliferation of HRCECs, and inhibited the formation of TLSs. Thus, HESR1 plays a key role in the finely tuned network of molecules involved in the regulation of retinal vascular homeostasis. HESR1 seems to inhibit the vessel-promoting effects of VEGF, shift endothelial cells from a proliferative state to a quiescent state, and restore normal vessel structures. Expression of the HESR1 gene in retinal vascular endothelial cells may protect retinal blood vessels and may be useful in the treatment of diseases involving damage to the retinal vasculature, including diabetic retinopathy, age-related macular degeneration, and retinal vein occlusion.
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Affiliation(s)
- Bin Li
- State Key Laboratory of Ophthalmology, Zhongshan Opthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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Duits AJ, Rodriguez T, Schnog JJB. Serum levels of angiogenic factors indicate a pro-angiogenic state in adults with sickle cell disease. Br J Haematol 2006; 134:116-9. [PMID: 16803577 DOI: 10.1111/j.1365-2141.2006.06103.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hypoxia-induced angiogenesis may play an important role in the pathophysiology of sickle cell disease (SCD). Serum levels of angiopoietin (Ang)-1, Ang-2, vascular endothelial growth factor, placenta growth factor (PlGF), soluble tunica intima endothelial kinase 2 (sTIE2), erythropoietin (EPO) and endothelial activation markers (soluble vascular adhesion molecule-1, soluble intercellular adhesion molecule-1) were determined in controls, HbSS (n = 35) and HbSC (n = 23) patients. In the asymptomatic phase, serum Ang-2 (P < 0.001), EPO (P < 0.001) and sTIE2 (P = 0.03) were elevated in patients. During painful crises, increased Ang-2 (P < 0.001) and PlGF (P = 0.04) occurred in HbSS and Ang-2 (P = 0.05) in HbSC patients. These results indicate a pro-angiogenic state in SCD, mainly because of elevated Ang-2 levels.
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Affiliation(s)
- Ashley J Duits
- Immunology Laboratory Department, Red Cross Blood Bank Foundation, Curaçao, Netherlands Antilles.
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