scholarly journals Downregulation of Cytoskeletal Protein Kazrin in Lung Endothelial Cells of Preclinical Sickle Cell Disease Mouse Model - Essential Role of Endothelial Barrier Function

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2258-2258
Author(s):  
Umapathy N Siddaramappa ◽  
Niren Patel ◽  
Betty S. Pace ◽  
Abdullah Kutlar
Keyword(s):  
Sickle Cell ◽  
Barrier Function ◽  
Research Funding ◽  
Blue Dye ◽  
Cell Disease ◽  
Barrier Dysfunction ◽  
Transwell Filter ◽  
Filter Assay ◽  
First Time

Background: Lung capillary barrier dysfunction is common to all causes of acute chest syndrome (ACS), a leading cause of morbidity and mortality in individuals with sickle cell disease (SCD). Our published data (Haematologica 2017, 102, e26-e29) demonstrated, for the first time, an impaired barrier function in freshly isolated endothelial cells (EC) from the lungs of Townes transgenic sickle cell anemia (SS) mice, compared to heterozygote (AS) or control (AA) mice. In addition, we showed a sub-stimulatory dose (0.05 mg/kg) of bacterial toxin lipopolysaccharide, which did not cause prominent acute lung injury in control AS/AA mice, was fatal to SS mice suggesting an enhanced hypersensitivity of sickle EC to infection. Hemolysis is a fundamental feature of SCD that contributes to its pathophysiology. Hemolysis results in the leakage of vast amounts of hemoglobin, and subsequently, heme into the plasma. Although, previous studies have demonstrated the detrimental effect of heme in SCD, the mechanisms of heme-mediated lung EC barrier dysfunction have not been studied. Recently, Kazrin was identified as a widely expressed protein influencing intercellular adhesion and co-localizes with the cortical actin ring to stabilize cell-cell junctions. In this study, we investigated the mechanisms of heme-induced EC barrier dysfunction related to Kazrin function, using primary EC isolated from the lungs of SCD mice and controls. Methods: Primary EC from the lungs of SS, AS, and AA mice (6-8 weeks old) were isolated according to methods described in our recent publication. The EC barrier function was measured using electrical cell-substrate impedance sensing (ECIS) and Evans blue dye transendothelial permeability was done using a transwell filter assay system. Western blot was performed to measure total and phosphorylated expression levels of protein involved in the regulation of EC barrier function. Immunocytochemistry was performed using specific antibodies and actin cytoskeleton was identified using a known F-actin binding fluorescent marker Phalloidin. Results: Our data demonstrated a significantly reduced basal expression of the Kazrin mRNA and protein in freshly isolated SS-EC compared to AS-EC or AA-EC. To determine the effects of Kazrin downregulation on the EC barrier function, we depleted the Kazrin protein in AS-EC using Kazrin specific siRNA and scrambled control siRNA. Kazrin depleted cells demonstrate an attenuated EC barrier function as evidenced by reduced trans-endothelial electrical resistance by ECIS and increased Evans blue dye leak by transwell filter assay (p<0.05). By contrast, control siRNA treated AS-EC displayed normal barrier function. Therefore, our data, for the first time, suggest that Kazrin is essential for the EC barrier function. Given the crucial role of hemolysis in SCD, we detected that clinically relevant dose of heme (5 µM; 60 min) significantly decreases the AS-EC barrier function (p<0.05) and the heme-mediated decrease of barrier function is dose-dependent. Moreover prolonged treatment of AS-EC with heme (5 µM; 24-48 hrs) downregulated the Kazrin protein levels. These results are intriguing since the SS-EC inherently show downregulated Kazrin when compared with AS-EC. Therefore, it is possible that impaired barrier function in SS-EC that we recently published could be an effect of Kazrin downregulation since hemolysis is a constant process in SCD. We also found that incubation of AS-EC with heme upregulated the efficacy of barrier disruption agent RhoA. Previous studies have indicated that activated RhoA promotes the actin stress fibers by stimulating actin-myosin contractility and increased endothelial permeability. Our immunocytochemistry data reveal that heme incubated AS-EC develop severe actin stress fibers. Studies in progress to determine the mechanistic link between Kazrin downregulation, RhoA activation and impaired EC barrier function in SS-EC. Conclusions and Future Direction: Our findings support the notion that Kazrin participates in the EC barrier function and its downregulation cause an impaired EC barrier function. Our future studies will focus on to identify protective mechanisms of lung EC barrier function in SCD. Disclosures Kutlar: Bluebird Bio: Other: DSMB Member; Novo Nordisk: Research Funding; Novartis: Consultancy; Micelle Biopharma: Other: DSMB Chair; Global Blood Therapeutics, Inc. (GBT): Research Funding.

scholarly journals Use of Thromboprophylaxis for Central Venous Access Devices in Patients with Sickle Cell Disease: A Survey of Canadian Providers

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4173-4173
Author(s):  
Kristine Matusiak ◽  
Stephanie Forte ◽  
Jameel Abdulrehman ◽  
Madeleine Verhovsek ◽  
Kevin H.M. Kuo
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Research Funding ◽  
Central Venous Access ◽  
Venous Access ◽  
Cell Disease ◽  
Central Venous ◽  
Advisory Committees ◽  
History Of

Abstract Background: Sickle cell disease (SCD) induces a chronic prothrombotic state, with a cumulative incidence of venous thromboembolism (VTE) reported to be 11% by age 40. Central venous access devices (CVAD) are commonly used for chronic transfusions and iron chelation in this patient population.The presence of a CVAD is an additional risk factor for venous thromboembolism (VTE), with a catheter related thrombosis rate of 24%. Despite this high risk of VTE, the role of thromboprophylaxis in this setting is uncertain due to a lack of high quality data. Methods: A survey was administered in March 2021 to physicians caring for adult sickle cell disease patients via the Canadian Haemoglobinopathy Association (CanHaem), covering nine SCD comprehensive care centers in Canada. One reminder email was distributed after 3 weeks to encourage participation. Questions were directed at characterizing the practice size, number of patients with CVADs, and the role of thromboprophylaxis for CVADs. Physicians were also surveyed about their willingness to enroll their SCD patients with CVADs in a randomized trial of thromboprophylaxis versus placebo. Items were generated and selected based on face and content validity. Results are reported in medians and percentages, where applicable. Results: Responses were collected from 14 physicians who care for a median of 100 (IQR 185) adult sickle cell disease patients in practices across Canada. Physicians reported approximately 5% of their patients currently require a CVAD, and physicians estimated no CVAD patients are lost to follow up. Respondents use a variety of CVADs, including port-a-caths (75%), followed by PICC lines (58%), tunneled (25%) and non-tunneled CVCs (25%) (Figure 1). Duration of venous access was reported to be &lt;1 month (17%), 1-3 months (8%), 3-6 months (0%), 6-12 months (8%), and &gt;12 months (67%). Fifty percent of respondents indicated they do not use thromboprophylaxis for CVADs. Responses varied with respect to choice and dose of antiplatelet or anticoagulant in cases where thromboprophylaxis is used (Figure 2). Forty-two percent of physicians indicated they were not very confident or not at all confident in choice of prophylaxis. Past history of VTE was the most cited factor influencing the choice to use thromboprophylaxis. Physicians were generally in favour of enrolling patients in an RCT using thromboprophylaxis for CVADs. The exception was that 69% answered "No" when asked about enrolling patients with a prior history of VTE who are not currently on anticoagulation. One-hundred percent of physicians agreed that an RCT would improve their confidence in decision-making around thromboprophylaxis in their patients with CVADs. Conclusions: While there is evidence for an increased risk of VTE for SCD patients with CVADs, our results suggest there remains clinical equipoise with respect to the use of thromboprophylaxis. Thromboprophylaxis options were variable when physicians chose to use them, as there is no evidence to support specific antithrombotic regimens. All physicians surveyed are supportive of an RCT to clarify this management approach, and many would enroll their patients. As a result of this survey, a Canadian multicenter pilot RCT addressing this question is currently underway. Figure 1 Figure 1. Disclosures Forte: Pfizer: Research Funding; Canadian Hematology Society: Research Funding; Novartis: Honoraria. Verhovsek: Vertex: Consultancy. Kuo: Alexion: Consultancy, Honoraria; Celgene: Consultancy; Bluebird Bio: Consultancy; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Research Funding; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria; Apellis: Consultancy. OffLabel Disclosure: This survey explored the use of LMWH, direct oral anticoagulants, warfarin and ASA for prophylaxis among patients with sickle cell disease using a central venous access device.

scholarly journals Phase-I Study of ETA Receptor Antagonist Ambrisentan in Sickle Cell Disease

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 617-617
Author(s):  
Abdullah Kutlar ◽  
Jennifer Pollock ◽  
Steffen E. Meiler ◽  
Ryan Harris ◽  
Xu Hongyan ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Inflammatory Cytokines ◽  
Sickle Cell ◽  
Research Funding ◽  
Receptor Blockade ◽  
Tubular Injury ◽  
Cell Disease ◽  
Pressure Pain ◽  
Eta Receptor

Endothelin-1 (ET1) is a potent vasoconstrictor, mitogen, proinflammatory mediator and a mediator of nociception. Its synthesis is increased by hypoxia, ischemia, shear stress, oxidative stress and reduced nitric oxide (NO) bioavailability, all of which are well documented mechanisms in the pathophysiology of sickle cell disease. Two distinct receptors, ETA and ETB mediate opposing actions of ET1; while ETA mediates vasoconstriction, inflammation, cellular adhesion and vascular remodeling, ETB stimulation leads to increased NO production, vasodilatation, anticoagulation and anti-adhesion. We studied the role of ET1 in SCD in transgenic mouse models, and showed that selective ETA receptor blockade with ambrisentan provides renal protection by preventing the development of glomerular hyperfiltration, and preventing proteinuria (Kasztan et al, 2017; Taylor et al, 2019; Kasztan & Pollock, 2019).Additionaly, ETA receptor blockade was shown to decrease pulmonary inflammation in response to different stimuli, including hypoxia/reoxygenation and LPS (Meiler et al). Lutz et al (2018) showed that pharmacologic inhibition, or neuron specific knockdown of ETA receptor in primary sensory neurons of dorsal root ganglia in Berk mice alleviated basal and post-hypoxia evoked pain hypersensitivity. We then conducted a Phase 1, double blind, placebo controlled study to elucidate the role of ET-1 in 26 patients with SCD (SS or Sb0thal); patients were randomized to either ambrisentan 5 mg/day (N=13) or placebo (N=13) for 12 weeks. The primary end point was safety and tolerability. We also measured microalbuminuria, pressure pain threshold, transcranial doppler (TCD), echocardiograms (TR jet velocity), vascular endothelial function by flow mediated dilation (FMD), and inflammatory cytokines. Urine specimens were collected for measurement of markers of glomerular and tubular injury (NGAL, KIM-1, netrin and nephrin) at baseline and at the end of study (Day 85). Ambrisentan was well tolerated without any adverse events or fluid retention. No change in systolic and diastolic blood pressures were observed in either group (p=0.88, and p=049, respectively). No significant change in weight or serum creatinine was observed in the ambrisentan group (69.1→68.6 Kg, p=0.99, and 0.74→0.69 mg/dl, p=0.43). In the ambrisentan group, there was a tendency toward reduced microalbuminuria, (-36.6 mg/g Cr, vs +91.6), especially in the subgroup of patients who had been on a stable dose of ACE or ARB for 6 months (n=6, 286.1 mg/g Cr at baseline to 197.7 mg/g on day 85, p=0.06). FMD measurements showed increased arterial diameter, and improved microvascular function. Data collected for secondary end points including, TCD, TRV, inflammatory cytokines, markers of glomerular and tubular injury, quantitative sensory testing (QST) with pressure pain measurements, and von Frey monofilament readings, as well as quality of life measures (ASCQMe) are in the process of being analyzed. These data suggest that ETA receptor blockade is safe, well tolerated and has the potential to impact various aspects of disease pathophysiology in SCD. Disclosures Kutlar: Novartis: Consultancy; Global Blood Therapeutics, Inc. (GBT): Research Funding; Bluebird Bio: Other: DSMB Member; Novo Nordisk: Research Funding; Micelle Biopharma: Other: DSMB Chair. OffLabel Disclosure: Ambrisentan is an approved FDA drug used for treatment of another condition but it is expected that it will also help improve and/or prevent kidney damage that can be caused by sickle cell disease.

Computer Vision and Deep Learning Assisted Microchip Electrophoresis for Integrated Anemia and Sickle Cell Disease Screening

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 46-47
Author(s):  
Ran An ◽  
Yuncheng Man ◽  
Shamreen Iram ◽  
Erdem Kucukal ◽  
Muhammad Noman Hasan ◽  
...  
Keyword(s):  
Computer Vision ◽  
Deep Learning ◽  
Sickle Cell ◽  
Research Funding ◽  
High Morbidity ◽  
Cell Disease ◽  
The World ◽  
Hb Variant ◽  
First Time ◽  
Variant Identification

Introduction: Anemia affects a third of the world's population with the heaviest burden borne by women and children. Anemia leads to preventable impaired development in children, as well as high morbidity and early mortality among sufferers. Inherited hemoglobin (Hb) disorders, such as sickle cell disease (SCD), are associated with chronic hemolytic anemia causing high morbidity and mortality. Anemia and SCD are inherently associated and are both prevalent in the same regions of the world including sub-Saharan Africa, India, and south-east Asia. Anemia and SCD-related complications can be mitigated by screening, early diagnosis followed by timely intervention. Anemia treatment depends on the accurate characterization of the cause, such as inherited Hb disorders. Meanwhile, Hb disorders or SCD treatments, such as hydroxyurea therapy, requires close monitoring of blood Hb level and the patient's anemia status over time. As a result, it is crucially important to perform integrated detection and monitoring of blood Hb level, anemia status, and Hb variants, especially in areas where anemia and inherited Hb disorders are the most prevalent. Blood Hb level (in g/dL) is used as the main indicator of anemia, while the presence of Hb variants (e.g., sickle Hb or HbS) in blood is the primary indicator of an inherited disorder. The current clinical standards for anemia testing and Hb variant identification are complete blood count (CBC) and High-Performance Liquid Chromatography (HPLC), respectively. State-of-the-art laboratory infrastructure and trained personnel are required for these laboratory tests. However, these resources are typically scarce in low- and middle-income countries, where anemia and Hb disorders are the most prevalent. As a result, there is a dire need for high accuracy portable point-of-care (POC) devices to perform integrated anemia and Hb variant tests with affordable cost and high throughput. Methods: In 2019, the World Health Organization (WHO) listed Hb electrophoresis as an essential in vitro diagnostic (IVD) technology for diagnosing SCD and sickle cell trait. We have leveraged the common Hb electrophoresis method and developed a POC microchip electrophoresis test, Hemoglobin Variant/Anemia (HbVA). This technology is being commercialized under the product name "Gazelle" by Hemex Health Inc. for Hb variant identification with integrated anemia detection (Fig. 1A&B). We hypothesized that computer vision and deep learning will enhance the accuracy and reproducibility of blood Hb level prediction and anemia detection in cellulose acetate based Hb electrophoresis, which is a clinical standard test for Hb variant screening and diagnosis worldwide (Fig. 1C). To test this hypothesis, we integrated, for the first time, a new, computer vision and artificial neural network (ANN) based deep learning imaging and data analysis algorithm, to Hb electrophoresis. Here, we show the feasibility of this new, computer vision and deep learning enabled diagnostic approach via testing of 46 subjects, including individuals with anemia and homozygous (HbSS) or heterozygous (HbSC or Sβ-thalassemia) SCD. Results and Discussion: HbVA computer vision tracked the electrophoresis process real-time and the deep learning neural network algorithm determined Hb levels which demonstrated significant correlation with a Pearson Correlation Coefficient of 0.95 compared to the results of reference standard CBC (Fig.1D). Furthermore, HbVA demonstrated high reproducibly with a mean absolute error of 0.55 g/dL and a bias of -0.10 g/dL (95% limits of agreement: 1.5 g/dL) according to Bland-Altman analysis (Fig. 1E). Anemia determination was achieved with 100% sensitivity and 92.3% specificity with a receiver operating characteristic area under the curve (AUC) of 0.99 (Fig. 1F). Within the same test, subjects with SCD were identified with 100% sensitivity and specificity (Fig. 1G). Overall, the results suggested that computer vision and deep learning methods can be used to extract new information from Hb electrophoresis, enabling, for the first time, reproducible, accurate, and integrated blood Hb level prediction, anemia detection, and Hb variant identification in a single affordable test at the POC. Disclosures An: Hemex Health, Inc.: Patents & Royalties. Hasan:Hemex Health, Inc.: Patents & Royalties. Ahuja:Genentech: Consultancy; Sanofi-Genzyme: Consultancy; XaTec Inc.: Consultancy; XaTec Inc.: Research Funding; XaTec Inc.: Divested equity in a private or publicly-traded company in the past 24 months; Genentech: Honoraria; Sanofi-Genzyme: Honoraria. Little:GBT: Research Funding; Bluebird Bio: Research Funding; BioChip Labs: Patents & Royalties: SCD Biochip (patent, no royalties); Hemex Health, Inc.: Patents & Royalties: Microfluidic electropheresis (patent, no royalties); NHLBI: Research Funding; GBT: Membership on an entity's Board of Directors or advisory committees. Gurkan:Hemex Health, Inc.: Consultancy, Current Employment, Patents & Royalties, Research Funding; BioChip Labs: Patents & Royalties; Xatek Inc.: Patents & Royalties; Dx Now Inc.: Patents & Royalties.

scholarly journals STAT3 Signalling via the IL-6ST/gp130 Cytokine Receptor Promotes Epithelial Integrity and Intestinal Barrier Function during DSS-Induced Colitis

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 187
Author(s):  
Lokman Pang ◽  
Jennifer Huynh ◽  
Mariah G. Alorro ◽  
Xia Li ◽  
Matthias Ernst ◽  
...  
Keyword(s):  
Barrier Function ◽  
Intestinal Barrier ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Integrity ◽  
Barrier Integrity ◽  
Gp130 Receptor ◽  
Stat3 Signalling

The intestinal epithelium provides a barrier against commensal and pathogenic microorganisms. Barrier dysfunction promotes chronic inflammation, which can drive the pathogenesis of inflammatory bowel disease (IBD) and colorectal cancer (CRC). Although the Signal Transducer and Activator of Transcription-3 (STAT3) is overexpressed in both intestinal epithelial cells and immune cells in IBD patients, the role of the interleukin (IL)-6 family of cytokines through the shared IL-6ST/gp130 receptor and its associated STAT3 signalling in intestinal barrier integrity is unclear. We therefore investigated the role of STAT3 in retaining epithelial barrier integrity using dextran sulfate sodium (DSS)-induced colitis in two genetically modified mouse models, to either reduce STAT1/3 activation in response to IL-6 family cytokines with a truncated gp130∆STAT allele (GP130∆STAT/+), or by inducing short hairpin-mediated knockdown of Stat3 (shStat3). Here, we show that mice with reduced STAT3 activity are highly susceptible to DSS-induced colitis. Mechanistically, the IL-6/gp130/STAT3 signalling cascade orchestrates intestinal barrier function by modulating cytokine secretion and promoting epithelial integrity to maintain a defence against bacteria. Our study also identifies a crucial role of STAT3 in controlling intestinal permeability through tight junction proteins. Thus, therapeutically targeting the IL-6/gp130/STAT3 signalling axis to promote barrier function may serve as a treatment strategy for IBD patients.

scholarly journals Antiphospholipid Antibodies in Sickle Cell Disease: A Systematic Review and Exploratory Meta-Analysis

2021 ◽  
Vol 27 ◽  
pp. 107602962110029
Author(s):  
Mira Merashli ◽  
Alessia Arcaro ◽  
Maria Graf ◽  
Matilde Caruso ◽  
Paul R. J. Ames ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Antiphospholipid Antibodies ◽  
Meta Analysis ◽  
Age Groups ◽  
Anticardiolipin Antibodies ◽  
Cell Disease ◽  
Pooled Prevalence ◽  
The Relationship

The relationship between antiphospholipid antibodies (aPL) and sickle cell disease (SCD) has never been systematically addressed. Our aim was to evaluate potential links between SCD and aPL in all age groups. EMBASE/PubMed was screened from inception to May 2020 and Peto odds ratios for rare events were calculated. The pooled prevalence (PP) of IgG anticardiolipin antibodies (aCL) was higher in individuals with SCD than in controls (27.9% vs 8.7%, P < 0.0001), that of IgM aCL was similar in the two groups (2.9% vs 2.7%); only individuals with SCD were positive for lupus anticoagulant (LA) (7.7% vs 0%, P < 0.0001). The PP of leg ulcers was similar between aPL positive and negative individuals (44% vs 53%) and between patients in acute crisis and stable patients (5.6% vs 7.3%). Reporting of aPL as a binary outcome and not as a titer precluded further interpretation. The results indicate that a prospective case-control study with serial measurements of a panel of aPL in SCD patients might be warranted, in order to understand further the possible pathogenic role of aPL in SCD.

scholarly journals Sickle Cell Disease: Role of Oxidative Stress and Antioxidant Therapy

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 296
Author(s):  
Rosa Vona ◽  
Nadia Maria Sposi ◽  
Lorenza Mattia ◽  
Lucrezia Gambardella ◽  
Elisabetta Straface ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Globin Gene ◽  
Organ Damage ◽  
Cell Disease ◽  
Vessel Occlusion ◽  
Antioxidant Agents ◽  
Oxidant Status

Sickle cell disease (SCD) is the most common hereditary disorder of hemoglobin (Hb), which affects approximately a million people worldwide. It is characterized by a single nucleotide substitution in the β-globin gene, leading to the production of abnormal sickle hemoglobin (HbS) with multi-system consequences. HbS polymerization is the primary event in SCD. Repeated polymerization and depolymerization of Hb causes oxidative stress that plays a key role in the pathophysiology of hemolysis, vessel occlusion and the following organ damage in sickle cell patients. For this reason, reactive oxidizing species and the (end)-products of their oxidative reactions have been proposed as markers of both tissue pro-oxidant status and disease severity. Although more studies are needed to clarify their role, antioxidant agents have been shown to be effective in reducing pathological consequences of the disease by preventing oxidative damage in SCD, i.e., by decreasing the oxidant formation or repairing the induced damage. An improved understanding of oxidative stress will lead to targeted antioxidant therapies that should prevent or delay the development of organ complications in this patient population.

Role of Adhesion Molecules and Vascular Endothelium in the Pathogenesis of Sickle Cell Disease

Hematology ◽  
2007 ◽  
Vol 2007 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Marilyn J. Telen
Keyword(s):  
Sickle Cell Disease ◽  
Red Blood Cells ◽  
Adhesion Molecules ◽  
Sickle Cell ◽  
Vascular Endothelium ◽  
Blood Cells ◽  
Cell Disease ◽  
Adhesive Interactions ◽  
Lines Of Evidence

AbstractA number of lines of evidence now support the hypothesis that vaso-occlusion and several of the sequelae of sickle cell disease (SCD) arise, at least in part, from adhesive interactions of sickle red blood cells, leukocytes, and the endothelium. Both experimental and genetic evidence provide support for the importance of these interactions. It is likely that future therapies for SCD might target one or more of these interactions.

Vaso-occlusion in sickle cell disease: pathophysiology and novel targeted therapies

Hematology ◽  
2013 ◽  
Vol 2013 (1) ◽  
pp. 362-369 ◽  
Author(s):  
Deepa Manwani ◽  
Paul S. Frenette
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Targeted Therapies ◽  
Therapeutic Intervention ◽  
Fetal Hemoglobin ◽  
Cell Disease ◽  
The Past ◽  
Symptomatic Management

Abstract Recurrent and unpredictable episodes of vaso-occlusion are the hallmark of sickle cell disease. Symptomatic management and prevention of these events using the fetal hemoglobin–reactivating agent hydroxyurea are currently the mainstay of treatment. Discoveries over the past 2 decades have highlighted the important contributions of various cellular and soluble participants in the vaso-occlusive cascade. The role of these elements and the opportunities for therapeutic intervention are summarized in this review.

scholarly journals Influence of Haptoglobin Polymorphism on Stroke in Sickle Cell Disease Patients

Genes ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 144
Author(s):  
Olivia Edwards ◽  
Alicia Burris ◽  
Josh Lua ◽  
Diana J. Wilkie ◽  
Miriam O. Ezenwa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Blood Cells ◽  
Cell Disease ◽  
Free Hemoglobin ◽  
Cerebral Tissue ◽  
Sickle Hemoglobin ◽  
Haptoglobin Polymorphism

This review outlines the current clinical research investigating how the haptoglobin (Hp) genetic polymorphism and stroke occurrence are implicated in sickle cell disease (SCD) pathophysiology. Hp is a blood serum glycoprotein responsible for binding and removing toxic free hemoglobin from the vasculature. The role of Hp in patients with SCD is critical in combating blood toxicity, inflammation, oxidative stress, and even stroke. Ischemic stroke occurs when a blocked vessel decreases oxygen delivery in the blood to cerebral tissue and is commonly associated with SCD. Due to the malformed red blood cells of sickle hemoglobin S, blockage of blood flow is much more prevalent in patients with SCD. This review is the first to evaluate the role of the Hp polymorphism in the incidence of stroke in patients with SCD. Overall, the data compiled in this review suggest that further studies should be conducted to reveal and evaluate potential clinical advancements for gene therapy and Hp infusions.

Sign in / Sign up

Export Citation Format

Share Document