Initiating adjunct low-dose hydroxyurea therapy for stroke prevention in children with SCA during the COVID-19 pandemic

Incidence and Risk Factors for New and Recurrent Infarcts in Adults With Sickle Cell Disease

BACKGROUND

Most adults with sickle cell disease will experience a silent cerebral infarction (SCI) or overt stroke. Identifying patient subgroups with increased stroke incidence is important for future clinical trials focused on stroke prevention. Our 3-center prospective cohort study tested the primary hypothesis that adults with sickle cell disease and SCIs have a greater incidence of new stroke or SCI compared with those without SCI. A secondary aim focused on identifying additional risk factors for progressive infarcts, particularly traditional risk factors for stroke in adults.

METHODS AND RESULTS

This observational study included adults with sickle cell disease and no history of stroke. Magnetic resonance imaging scans of the brain completed at baseline and >1 year later were reviewed by 3 radiologists for baseline SCIs and new or progressive infarcts on follow-up magnetic resonance imaging. Stroke risk factors were abstracted from the medical chart. Time-to-event analysis was utilized for progressive infarcts. Median age was 24.1 years; 45.3% of 95 participants had SCIs on baseline magnetic resonance imaging. Progressive infarcts were present in 17 participants (17.9%), and the median follow-up was 2.1 years. Incidence of new infarcts was 11.95 per 100 patient-years (6.17-20.88) versus 3.74 per 100 patient-years (1.21-8.73) in those with versus without prior SCI. Multivariable Cox regression showed that baseline SCI predicts progressive infarcts (hazard ratio, 3.46 [95% CI, 1.05-11.39]; P=0.041); baseline hypertension was also associated with progressive infarcts (hazard ratio, 3.23 [95% CI, 1.16-9.51]; P=0.025).

CONCLUSIONS

Selecting individuals with SCIs and hypertension for stroke prevention trials in sickle cell disease may enrich the study population with those at highest risk for infarct recurrence.

Provider prescription of hydroxyurea in youth and adults with sickle cell disease: A review of prescription barriers and facilitators

Sickle cell disease (SCD) is an inherited red blood cell disorder associated with frequent painful events and organ damage. Hydroxyurea (HU) is the recommended evidence-based treatment of SCD. However, among patients eligible for HU, prescription rates are low. Utilizing a scoping review approach, we summarized and synthesized relevant findings regarding provider barriers and facilitators to the prescription of HU in youth and adults with SCD and provided suggestions for future implementation strategies to improve prescription rates. Relevant databases were searched using specified search terms. Articles reporting provider barriers and/or facilitators to prescribing HU were included. A total of 10 studies met the inclusion criteria. Common barriers to the prescription of HU identified by providers included: doubts around patients' adherence to HU and their engaging in required testing, concerns about side effects, lack of knowledge, cost and patient concerns about side effects. Facilitators to the prescription of HU included beliefs in the effectiveness of HU, provider demographics and knowledge. Findings suggest significant provider biases exist, particularly in the form of negative perceptions towards patients' ability to adhere to taking HU and engaging in the required follow-up. Improving provider knowledge and attitudes towards HU and SCD may help improve low prescription rates.

Covid-19 impacts: Ethnic and regional inequalities in sickle cell disease patient care in Brazil

Brazil is a continental country with significant socioeconomic and ethnic inequalities. It is important to understand how these differences are reflected in health care, especially during the COVID-19 pandemic. We investigated the potential impacts of the reduced number Transcranial Doppler Ultrasound (TCD) tests performed in Brazil during the COVID-19 pandemic, and its reflections according to region and race/color for patients with Sickle Cell Disease (SCD). This study performed data queries from the Brazilian Ministry of Health, literature research, and quantitative analysis using descriptive statistical analysis. We found evidence for a decrease in the number of TCD tests performed during the pandemic (-83 %) relative to the same non-pandemic period, and disparities in tests given in five regions in Brazil. Our data show, that in absolute numbers, most people with SCD are brown, but the highest prevalence of cases was among blacks. We also found evidence for racial discrimination when performing TCD test, which leads us to believe that the Brazilian Unified Health System (SUS) may be susceptible to racism when treating this disease. The implications of these findings serve as a warning to other countries with high indices of mixed ancestry in formulating health care policies for patients with SCD.

Cerebrovascular disease in sickle cell disease

Sickle cell disease (SCD) is the most common type of hereditary anaemia and genetic disorder worldwide. Cerebrovascular disease is one of its most devastating complications, with consequent increased morbidity and mortality. Current guidelines suggest that children and adults with SCD who develop acute ischaemic stroke should be transfused without delay. Those with acute ischaemic stroke aged over 18 years who present within 4.5 hours of symptom onset should be considered for intravenous thrombolysis; older patients with conventional vascular risk factors are the most likely to benefit. Endovascular thrombectomy should be considered carefully in adults with SCD as there are few data to guide how the prevalence of cerebral vasculopathy may confound the expected benefits or risks of intervention. We present a practical approach to cerebrovascular disease in sickle cell patients based on the available evidence and our experience.

Blood Transfusion Vs. Hydroxyurea for Stroke Prevention in Children With Sickle Cell Anemia: A Systematic Review and Meta-Analysis

Sickle cell anemia (SCA) is a hereditary condition that can lead to severe complications in children such as acute coronary syndrome, splenic sequestration, renal failure, and stroke. Blood transfusion and hydroxyurea (HU) therapy are used to prevent stroke in children with sickle cell disease (SCD). Preliminary data show considerable variation and inconsistency in the use of these two therapeutic interventions. Therefore, this systematic review was carried out to compare the effects of blood transfusion to HU therapy in preventing stroke for children with sickle cell disease. There was an extensive literature search in reliable and authentic databases like PubMed, Medline, Scopus, Cochrane, and Science Direct to obtain relevant articles. This study used the standards and guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). During the systematic review, data were obtained focusing on the following parameters: the size of the sample in the study, the age of the subjects involved in the study, the type of Intervention, and the outcome. After an initial search of 163 papers, 25 studies were included. The results of the research give the first evidence that HU is effective in the treatment of cerebrovascular problems in children with SCD. However, it is unclear under what circumstances HU may prevent a second stroke. It can be concluded that children with SCA can effectively avoid primary strokes through chronic blood transfusions and HU.

Peculiar bony involvement of sinus pericranii in children: Extensive diploic erosion in three "karstic" variants

OBJECT

Sinus pericranii (SP) is a rare, benign, extradural venous anomaly whose extracranial connection consists in an enlarged subgaleal drainage composed of a network of thin-walled veins that form a varix on the external table of the skull. In the present series of three patients we present three variantesof SP which have never been described, characterized by an extensive diploic erosion causing a "karstic" effect.

METHODS

A systematic review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. A comprehensive search for relevant articles was performed on PubMed from 1992 to 2022 using the following search words: "sinus pericranii".

RESULTS

The search produced 77 articles with 137 patients. In all the cases analysed, there were not reported any patients with extensive diploic erosion, namely "karstic" variants. So, the authors present clinical history, neuroimages, treatment strategies and outcome of 3 patients with a "karstic" SP with the aim to describe this clinicradiological entity.

CONCLUSIONS

In this study, our group identified a peculiar variant of SP characterized by bony involvement with extensive diploic "karstic" erosion of diploe, with possible tendency to enlarge during time.

Revisiting anemia in sickle cell disease and finding the balance with therapeutic approaches

Chronic hemolytic anemia and intermittent acute pain episodes are the 2 hallmark characteristics of sickle cell disease (SCD). Anemia in SCD not only signals a reduction of red cell mass and oxygen delivery, but also ongoing red cell breakdown and release of cell-free hemoglobin, which together contribute to a number of pathophysiological responses and play a key role in the pathogenesis of cumulative multiorgan damage. However, although anemia is clearly associated with many detrimental outcomes, it may also have an advantage in SCD in lowering risks of potential viscosity-related complications. Until recently, clinical drug development for SCD has predominantly targeted a reduction in the frequency of vaso-occlusive crises as an endpoint, but increasingly, more attention is being directed toward addressing the contribution of chronic anemia to poor outcomes in SCD. This article aims to explore the complex pathophysiology and mechanisms of anemia in SCD, as well as the need to balance the benefits of raising hemoglobin levels with the potential risks of increasing blood viscosity, in the context of the current therapeutic landscape for anemia in SCD.

Pathogenic Basis of Thromboinflammation and Endothelial Injury in COVID-19: Current Findings and Therapeutic Implications

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic with a great impact on social and economic activities, as well as public health. In most patients, the symptoms of COVID-19 are a high-grade fever and a dry cough, and spontaneously resolve within ten days. However, in severe cases, COVID-19 leads to atypical bilateral interstitial pneumonia, acute respiratory distress syndrome, and systemic thromboembolism, resulting in multiple organ failure with high mortality and morbidity. SARS-CoV-2 has immune evasion mechanisms, including inhibition of interferon signaling and suppression of T cell and B cell responses. SARS-CoV-2 infection directly and indirectly causes dysregulated immune responses, platelet hyperactivation, and endothelial dysfunction, which interact with each other and are exacerbated by cardiovascular risk factors. In this review, we summarize current knowledge on the pathogenic basis of thromboinflammation and endothelial injury in COVID-19. We highlight the distinct contributions of dysregulated immune responses, platelet hyperactivation, and endothelial dysfunction to the pathogenesis of COVID-19. In addition, we discuss potential therapeutic strategies targeting these mechanisms.

Philadelphia-Negative Chronic Myeloproliferative Neoplasms during the COVID-19 Pandemic: Challenges and Future Scenarios

An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) started in December 2019 in China and then become pandemic in February 2020. Several publications investigated the possible increased rate of COVID-19 infection in hematological malignancies. Based on the published data, strategies for the management of chronic Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are provided. The risk of severe COVID-19 seems high in MPN, particularly in patients with essential thrombocythemia, but not negligible in myelofibrosis. MPN patients are at high risk of both thrombotic and hemorrhagic complications and this must be accounted in the case of COVID-19 deciding on a case-by-case basis. There are currently no data to suggest that hydroxyurea or interferon may influence the risk or severity of COVID-19 infection. Conversely, while the immunosuppressive activity of ruxolitinib might pose increased risk of infection, its abrupt discontinuation during COVID-19 syndrome is associated with worse outcome. All MPN patients should receive vaccine against COVID-19; reassuring data are available on efficacy of mRNA vaccines in MPNs.

Educational technology on COVID-19 for families of children and adolescents with sickle cell disease

OBJECTIVE

to construct and validate educational technology on COVID-19 and essential care for families of children/adolescents with sickle cell disease.

METHODS

this is a methodological study, in three stages: 1) elaborated educational technology, using the Doak, Doak and Root theoretical-methodological model; 2) content and appearance validation by the content validity coefficient. Delphi technique was applied in two rounds (Delphi I [12 judges]/Delphi II [11 judges]); 3) conducting a pilot test with six families.

RESULTS

"Sickle cell disease and COVID-19: essential care" included: consequences of COVID-19 in sickle cell disease, guidelines for reducing the risks of contracting the virus and having complications, signs and symptoms of COVID-19, guidelines in case of child/adolescent with suspicion or symptoms of COVID-19. Global content validity coefficient (Delphi II): 0.98.

CONCLUSION

educational technology presented content and appearance validity for families of children/adolescents with sickle cell disease, related to COVID-19.

A comprehensive review of hydroxyurea for β-haemoglobinopathies: the role revisited during COVID-19 pandemic

Background

Hydroxyurea is one of the earliest drugs that showed promise in the management of haemoglobinopathies that include β-thalassaemia and sickle cell disease. Despite this, many aspects of hydroxyurea are either unknown or understudied; specifically, its usefulness in β-thalassaemia major and haemoglobin E β-thalassaemia is unclear. However, during COVID-19 pandemic, it has become a valuable adjunct to transfusion therapy in patients with β-haemoglobinopathies. In this review, we aim to explore the available in vitro and in vivo mechanistic data and the clinical utility of hydroxyurea in β-haemoglobinopathies with a special emphasis on its usefulness during the COVID-19 pandemic.

Main body

Hydroxyurea is an S-phase-specific drug that reversibly inhibits ribonucleoside diphosphate reductase enzyme which catalyses an essential step in the DNA biosynthesis. In human erythroid cells, it induces the expression of γ-globin, a fetal globin gene that is suppressed after birth. Through several molecular pathways described in this review, hydroxyurea exerts many favourable effects on the haemoglobin content, red blood cell indices, ineffective erythropoiesis, and blood rheology in patients with β-haemoglobinopathies. Currently, it is recommended for sickle cell disease and non-transfusion dependent β-thalassaemia. A number of clinical trials are ongoing to evaluate its usefulness in transfusion dependent β-thalassaemia. During the COVID-19 pandemic, it was widely used as an adjunct to transfusion therapy due to limitations in the availability of blood and logistical disturbances. Thus, it has become clear that hydroxyurea could play a remarkable role in reducing transfusion requirements of patients with haemoglobinopathies, especially when donor blood is a limited resource.

Conclusion

Hydroxyurea is a well-tolerated oral drug which has been in use for many decades. Through its actions of reversible inhibition of ribonucleoside diphosphate reductase enzyme and fetal haemoglobin induction, it exerts many favourable effects on patients with β-haemoglobinopathies. It is currently approved for the treatment of sickle cell disease and non-transfusion dependent β-thalassaemia. Also, there are various observations to suggest that hydroxyurea is an important adjunct in the treatment of transfusion dependent β-thalassaemia which should be confirmed by randomised clinical trials.

Thrombocytopathy and endotheliopathy: crucial contributors to COVID-19 thromboinflammation

The core pathology of coronavirus disease 2019 (COVID-19) is infection of airway cells by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that results in excessive inflammation and respiratory disease, with cytokine storm and acute respiratory distress syndrome implicated in the most severe cases. Thrombotic complications are a major cause of morbidity and mortality in patients with COVID-19. Patients with pre-existing cardiovascular disease and/or traditional cardiovascular risk factors, including obesity, diabetes mellitus, hypertension and advanced age, are at the highest risk of death from COVID-19. In this Review, we summarize new lines of evidence that point to both platelet and endothelial dysfunction as essential components of COVID-19 pathology and describe the mechanisms that might account for the contribution of cardiovascular risk factors to the most severe outcomes in COVID-19. We highlight the distinct contributions of coagulopathy, thrombocytopathy and endotheliopathy to the pathogenesis of COVID-19 and discuss potential therapeutic strategies in the management of patients with COVD-19. Harnessing the expertise of the biomedical and clinical communities is imperative to expand the available therapeutics beyond anticoagulants and to target both thrombocytopathy and endotheliopathy. Only with such collaborative efforts can we better prepare for further waves and for future coronavirus-related pandemics.

The dynamic association between COVID-19 and chronic disorders: An updated insight into prevalence, mechanisms and therapeutic modalities

The devastating pandemic of coronavirus disease 2019 (COVID-19) has caused thousands of deaths and left millions of restless patients suffering from its complications. Increasing data indicate that the disease presents in a severe form in patients with pre-existing chronic conditions like cardiovascular diseases, diabetes, respiratory system diseases, and renal diseases. This denotes that these patients are more susceptible to COVID-19 and have higher mortality rates compared to patients with no comorbid conditions. Several factors can explain the heightened susceptibility and fatal presentation of COVID-19 in these patients, for example, the enhanced expression of the angiotensin-converting enzyme-2 (ACE2) in specific organs, cytokine storm, and drug interactions contribute to the increased morbidity and mortality. Adding to the findings that individuals with pre-existing conditions may be more susceptible to COVID-19, it has also been shown that COVID-19 can induce chronic diseases in previously healthy patients. Therefore, understanding the interlinked relationship between COVID-19 and chronic diseases helps in optimizing the management of susceptible patients. This review comprehensively described the molecular mechanisms that contribute to worse COVID-19 prognosis in patients with pre-existing comorbidities such as diabetes, cardiovascular diseases, respiratory diseases, gastrointestinal and renal diseases, blood disorders, autoimmune diseases, and finally, obesity. It also focused on how COVID-19 could, in some cases, lead to chronic conditions as a result of long-term multi-organ damage. Lastly, this work carefully discussed the tailored management plans for each specific patient population, aiming to achieve the best therapeutic outcome with minimum complications.

COVID-19 pandemic and transfusion medicine: the worldwide challenge and its implications

COVID-19 pandemic has imposed worldwide challenge and has significantly affected transfusion medicine. Shortage in blood products along with concerns regarding the safety of blood products have emerged. Measures to overcome these challenges have been implemented in order to decrease the demand on blood products and to encourage blood donations while taking full precautions to minimize risk of COVID-19 transmission mainly at blood banks and medical centers. Several countries have been successful in facing these new challenges. In addition, the role of plasma therapy in the treatment of COVID-19 patients, especially in severe cases, has been proposed and current studies are being conducted to determine its efficacy. Other therapeutic options are currently being explored. So far, the use of convalescent plasma is considered a promising rescue treatment to be looked at.

Combination dose-escalated hydroxyurea and transfusion: an approach to conserve blood during the COVID-19 pandemic

Nickel et al describe a single-arm trial using dose-escalated hydroxyurea and regular transfusions to prevent complications of sickle cell anemia. Preliminary results suggest that a reduction in volume of red cell requirements may be achievable.

Management of Hemoglobin Disorders During the COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) is an emerging infectious disease that has become a global public health concern after being first reported in China and has subsequently spread worldwide. It causes mild to severe respiratory illness with some flu-like symptoms. The causal virus behind this disease, SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), conceivably attacks the receptors of the respiratory system of the human body but has no strict evidence of attacking the blood cells yet. However, patients with hemoglobin disorders (e.g., sickle cell anemia, thalassemia) are vulnerable to this global health situation due to their clinical complications. Such patients are generally more prone to viral and bacterial infections, which can worsen their physical condition. Some of these patients present immunocompromised conditions, e.g., splenectomized or post-transplant patients. Therefore, they should follow some preventive steps such as shielding as well as the general guidelines for the COVID-19 pandemic. Transfusion dependent patients require regular monitoring for iron overload, and iron chelation therapy may be stopped by the physician depending on the situation. This article reviews the management strategies and provides some crucial recommendations for people in the corner with hemoglobin disorders.