Sickle Cell Disease in Children and Adolescents: A Review of the Historical, Clinical, and Public Health Perspective of Sub-Saharan Africa and Beyond

Burden of vaso-occlusive crisis, its management and impact on quality of life of Indian sickle cell disease patients

Sickle cell disease (SCD) with vaso-occlusive pain crisis (VOC) significantly impacts patient well-being and often results in extensive healthcare resource utilization. This study assessed the VOC burden, its management and its impact on patients' quality of life (QoL). A cross-sectional observational study was conducted between November 2021 and June 2022, including 1000 SCD patients from high-prevalence states in India. Data on demographics, clinical characteristics, VOC severity, management and QoL were collected. The study revealed that 33.5% of patients reported at least one VOC episode during the study period. In the year prior to their enrolment, 836 (83.60%) patients reported at least one VOC episode, with an equal proportion of 407/487 (83.6%) adults and 429/513 (83.6%) paediatric patients, reducing their QoL across all domains compared to patients without VOC. Of these, 469/1000 patients (46.9%) experienced ≥3 VOC episodes. Additionally, 764/1000 (76.40%) patients managed their VOCs at healthcare facilities, with 501/1000 (50.1%) requiring inpatient admissions. Further, 71.80% of patients received Hydroxyurea (HU) therapy. The study depicts the severity of the Arab-Indian haplotype in Indian SCD patients visiting healthcare settings based on high VOC burden. This highlights the urgent need for better management strategies and resource allocation for these patients.

Impacts of oxidative stress and anti-oxidants on the development, pathogenesis, and therapy of sickle cell disease: A comprehensive review

Sickle cell disease (SCD) is the most severe monogenic hemoglobinopathy caused by a single genetic mutation that leads to repeated polymerization and depolymerization of hemoglobin resulting in intravascular hemolysis, cell adhesion, vascular occlusion, and ischemia-reperfusion injury. Hemolysis causes oxidative damage indirectly by generating reactive oxygen species through various pathophysiological mechanisms, which include hemoglobin autoxidation, endothelial nitric oxide synthase uncoupling, reduced nitric oxide bioavailability, and elevated levels of asymmetric dimethylarginine. Red blood cells have a built-in anti-oxidant system that includes enzymes like sodium dismutase, catalase, and glutathione peroxidase, along with free radical scavenging molecules, such as vitamin C, vitamin E, and glutathione, which help them to fight oxidative damage. However, these anti-oxidants may not be sufficient to prevent the effects of oxidative stress in SCD patients. Therefore, in line with a recent FDA request that the focus to be placed on the development of innovative therapies for SCD that address the root cause of the disease, there is a need for therapies that target oxidative stress and restore redox balance in SCD patients. This review summarizes the current state of knowledge regarding the role of oxidative stress in SCD and the potential benefits of anti-oxidant therapies. It also discusses the challenges and limitations of these therapies and suggests future directions for research and development.

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020-2023)

Newborn bloodspot screening (NBS) began in the early 1960s based on the work of Dr. Robert "Bob" Guthrie in Buffalo, NY, USA. His development of a screening test for phenylketonuria on blood absorbed onto a special filter paper and transported to a remote testing laboratory began it all. Expansion of NBS to large numbers of asymptomatic congenital conditions flourishes in many settings while it has not yet been realized in others. The need for NBS as an efficient and effective public health prevention strategy that contributes to lowered morbidity and mortality wherever it is sustained is well known in the medical field but not necessarily by political policy makers. Acknowledging the value of national NBS reports published in 2007, the authors collaborated to create a worldwide NBS update in 2015. In a continuing attempt to review the progress of NBS globally, and to move towards a more harmonized and equitable screening system, we have updated our 2015 report with information available at the beginning of 2024. Reports on sub-Saharan Africa and the Caribbean, missing in 2015, have been included. Tables popular in the previous report have been updated with an eye towards harmonized comparisons. To emphasize areas needing attention globally, we have used regional tables containing similar listings of conditions screened, numbers of screening laboratories, and time at which specimen collection is recommended. Discussions are limited to bloodspot screening.

Malnutrition in sickle cell anemia: Prevalence, impact, and interventions: A Review

Sickle Cell Anemia (SCA) is a hereditary hemoglobinopathy characterized by chronic hemolytic anemia, vaso-occlusive events, and a wide range of clinical complications. Malnutrition, often an underexplored aspect of this complex condition, plays a critical role in disease management and overall patient well-being. This publication provides a comprehensive review of the prevalence, impact, and interventions related to malnutrition in individuals with SCA. A thorough literature review reveals the multifaceted challenges faced by SCA patients in maintaining adequate nutrition. The pathophysiology of SCA, involving chronic inflammation, oxidative stress, and hypermetabolism, contributes to increased nutritional requirements and altered dietary patterns. Factors such as reduced appetite, nutrient malabsorption, dietary restrictions, and socioeconomic disparities further exacerbate the risk of malnutrition. Malnutrition is a prevalent issue among individuals with SCA, affecting patients of different age groups and disease severities. Nutritional deficiencies, including vitamins, minerals, and essential nutrients, are common in this population. The impact of malnutrition on disease outcomes is significant, with associations between nutrient status and complications such as pain crises, infections, and impaired quality of life. This paper also reviews nutritional interventions aimed at addressing malnutrition in SCA patients. While dietary counseling, supplementation, and personalized nutrition plans have shown promise in improving nutritional status, challenges such as patient adherence and access to healthcare must be addressed to optimize their effectiveness.

Managing gastrointestinal challenges: Diarrhea in sickle cell anemia

Sickle cell anemia (SCA), a hereditary hemoglobinopathy, is characterized by the presence of abnormal hemoglobin and has long been associated with a wide range of complications. While much attention has been given to the condition hematological aspects, gastrointestinal complications, particularly diarrhea, have been relatively understudied and often overlooked. This publication delves into the management of gastrointestinal challenges, with a focus on diarrhea, in individuals living with SCA. The pathophysiology of SCA is intrinsically linked to gastrointestinal complications, and diarrhea is a common manifestation of this condition. This abstract publication outlines the key elements discussed in the full-length work, which includes the clinical presentation of diarrhea in these patients, the diagnostic tools used to evaluate the condition, and various management strategies to alleviate symptoms and enhance the overall quality of life for affected individuals. The paper emphasizes the importance of patient education, offering healthcare professionals valuable insights into how to inform and support patients in managing their conditions effectively. It also highlights the need for continued research to further our understanding of gastrointestinal challenges in SCA and to identify potential areas for future therapeutic interventions. Ultimately, the comprehensive management of diarrhea in individuals with SCA is vital for their overall well-being. This publication serves as a valuable resource for healthcare providers, researchers, and caregivers in addressing the gastrointestinal challenges that accompany SCA, ultimately working toward a better quality of life for those affected by this condition.

Unraveling the Complexity of Vaso-Occlusive Crises in Sickle Cell Disease: Insights from a Resource-Limited Setting

Background/Objectives: This study investigated vaso-occlusive crises (VOCs) in sickle cell disease in Lubumbashi, Democratic Republic of Congo, aiming to understand the disease complexities amidst limited resources. With sickle cell hemoglobinopathies on the rise in sub-Saharan Africa, this nine-year study explored factors associated with VOCs and hematological components. Methods: This study comprised 838 patients, analyzing VOCs and hematological changes over time. Demographic characteristics and blood composition changes were carefully categorized. A total of 2910 crises were observed and managed, with analyses conducted on severity, localization, and age groups using statistical methods. Results: The majority of crises were mild or moderate, primarily affecting osteoarticular regions. Statistical analysis revealed significant disparities in crisis intensity based on location and age. The association between blood samples and the number of comorbidities was investigated. Significant positive associations were found for all parameters, except monocytes, indicating a potential link between blood variables and complication burden. Survival analysis using Cox regression was performed to predict the probability of experiencing a second crisis. No significant effects of medication or localization were observed. However, intensity (p < 0.001), age (p < 0.001), and gender (p < 0.001) showed significant effects. Adjusted Hazard Ratios indicated increased risk with age and male gender and reduced risk with mild or severe crisis intensity compared to light. Conclusions: This research sheds light on the complexities of VOCs in resource-limited settings where sickle cell disease is prevalent. The intricate interplay between clinical, laboratory, and treatment factors is highlighted, offering insights for improved patient care. It aims to raise awareness of patient challenges and provide valuable information for targeted interventions to alleviate their burden.

Folic Acid in the Treatment of Sickle Cell Disease: A Systematic Review

Sickle cell disease (SCD) is a group of inherited genetic disorders that is caused by a mutation in the gene that codes for hemoglobin subunit β. This systematic review aimed to evaluate the effect of folic acid in the treatment of SCD patients. We retrieved 3730 articles from PubMed, PubMed Central, Google Scholar, and ScienceDirect databases. We employed a search technique that involved framing keywords, such as folic acid, folate, and sickle cell illness, and the Medical Subject Headings (MeSH) strategy in PubMed. We chose research articles that had been published during the last 10 years, as well as case reports, systematic reviews and meta-analyses, literature reviews, randomized controlled trials, and observational studies. Exclusion criteria included paid full-text articles, abstracts, non-English studies, and patients who do not have SCD. The 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria were used in the design of our systematic review. It was found that the majority of SCD patients were receiving regular folic acid supplements and that their plasma folate levels were either increased or within normal range, with no discernible impact on other clinical outcomes such as hemoglobin levels, infections, or pain crises. SCD patients produce more red blood cells than healthy individuals, and nearly all SCD patients receive daily folic acid supplements. On the other hand, not enough information is available on folic acid's potential benefits in the management of SCD; thus, there is a need for more large clinical trials.

Maximizing longevity: erythropoietin's impact on sickle cell anaemia survival rates

Sickle cell anaemia (SCA) stands as a hereditary blood disorder characterized by mutated haemoglobin, causing red blood cells to adopt a sickle shape, leading to complications like vaso-occlusive crises, anaemia, and organ damage. Despite advancements in treatment, managing SCA remains challenging, with limited options to increase life expectancy and improve quality of life for affected individuals. This paper reviews the potential impact of erythropoietin (EPO) therapy in enhancing life expectancy and ameliorating complications in individuals with SCA. EPO, primarily recognized for its role in stimulating red blood cell production, holds promise in mitigating anaemia, reducing transfusion dependence, and possibly diminishing the frequency and severity of vaso-occlusive crises in SCA patients. Moreover, by stimulating red blood cell production, EPO therapy might alleviate the vaso-occlusive process, thus reducing the frequency of painful crises and associated complications. Additionally, considering the potential side effects and the need for continuous monitoring, the use of EPO in SCA treatment requires cautious consideration. The potential of EPO therapy in SCA offers a glimpse into novel strategies aimed at improving the quality of life and extending the life expectancy of affected individuals. In conclusion, while the application of EPO in SCA treatment holds promise, additional research is indispensable to comprehend its precise role, optimize dosing strategies, and ensure safety, thereby paving the way for enhanced life expectancy and improved outcomes for individuals living with SCA.

Sickle Cell Disease Update: New Treatments and Challenging Nutritional Interventions

Sickle cell disease (SCD), a distinctive and often overlooked illness in the 21st century, is a congenital blood disorder characterized by considerable phenotypic diversity. It comprises a group of disorders, with sickle cell anemia (SCA) being the most prevalent and serious genotype. Although there have been some systematic reviews of global data, worldwide statistics regarding SCD prevalence, morbidity, and mortality remain scarce. In developed countries with a lower number of sickle cell patients, cutting-edge technologies have led to the development of new treatments. However, in developing settings where sickle cell disease (SCD) is more prevalent, medical management, rather than a cure, still relies on the use of hydroxyurea, blood transfusions, and analgesics. This is a disease that affects red blood cells, consequently affecting most organs in diverse manners. We discuss its etiology and the advent of new technologies, but the aim of this study is to understand the various types of nutrition-related studies involving individuals suffering from SCD, particularly in Africa. The interplay of the environment, food, gut microbiota, along with their respective genomes collectively known as the gut microbiome, and host metabolism is responsible for mediating host metabolic phenotypes and modulating gut microbiota. In addition, it serves the purpose of providing essential nutrients. Moreover, it engages in direct interactions with host homeostasis and the immune system, as well as indirect interactions via metabolites. Nutrition interventions and nutritional care are mechanisms for addressing increased nutrient expenditures and are important aspects of supportive management for patients with SCD. Underprivileged areas in Sub-Saharan Africa should be accompanied by efforts to define and promote of the nutritional aspects of SCD. Their importance is key to maintaining well-being and quality of life, especially because new technologies and products remain limited, while the use of native medicinal plant resources is acknowledged.

Overview of the Association Between the Pathophysiology, Types, and Management of Sickle Cell Disease and Stroke

Sickle cell disease (SCD) is a genetic blood disorder that affects hemoglobin and increases stroke risk, particularly in childhood. This review examines the pathophysiological association between SCD and stroke, the classification of stroke types, risk factors, diagnosis, management, prevention, and prognosis. A comprehensive literature search was conducted via PubMed, Scopus, and Cochrane databases. Relevant studies on SCD and stroke pathophysiology, classification, epidemiology, diagnosis, treatment, and prevention were identified. Sickle cell disease causes red blood cells to become rigid and sickle-shaped, obstructing blood vessels. Recurrent sickling alters cerebral blood flow and damages vessel walls, often leading to ischemic or hemorrhagic strokes (HS). These occur most frequently in childhood, with ischemic strokes (IS) being more common. Key risk factors include a prior transient ischemic attack (TIA), low hemoglobin, and a high leukocyte count. Neuroimaging is essential for diagnosis and determining stroke type. Primary prevention centers on blood transfusions and hydroxyurea for those at high risk. Acute treatment involves promptly restoring blood flow and managing complications. However, significant knowledge gaps remain regarding stroke mechanisms, optimizing screening protocols, and improving long-term outcomes. This review synthesizes current evidence on SCD and stroke to highlight opportunities for further research and standardizing care protocols across institutions. Ultimately, a holistic perspective is critical for mitigating the high risk of debilitating strokes in this vulnerable patient population.

Infertility and treatment-seeking practices among females and males with sickle cell disease in the Sickle Cell Disease Implementation Consortium registry

OBJECTIVE

To describe the prevalence of infertility and infertility treatment seeking among people enrolled in the Sickle Cell Disease Implementation Consortium (SCDIC) registry and identify sociodemographic and clinical correlates of infertility.

DESIGN

Cross-sectional.

PARTICIPANTS

The study population included 2108 women and men (≥18 years of age) enrolled in the SCDIC registry who completed the fertility questionnaire.

RESULTS

All participants who completed the infertility-specific questions were included in the analysis (1224 females; 884 males). Of these, 16.9% of males and 23.7% of females reported infertility, in contrast to rates in the general population (12% of males; 11% of females). Only 22.8% of this subgroup had sought a fertility consultation; of these, 41% received infertility testing and 58% received advice, yet only a few received specific treatment: ovulation medication (19.1%), fallopian tubal surgery (4.8%), other female treatment (17.5%), varicocelectomy (8.1%), or other male treatment (10.8%). Increasing age, employment status, and interaction between gender and single marital status are associated with reported infertility. We did not observe differences between groups relative to sickle cell disease (SCD) genotype, a broad category of self-reported hydroxyurea use any time during life, type of medical insurance, income, or education.

CONCLUSION

To our knowledge, this is the first study to examine self-reported identification of and treatment for infertility among a large sample of people with SCD. These findings suggest that (a) infertility occurs at a higher rate, but fertility care treatment seeking is less frequent than in the general public; and (b) sociodemographic and clinical differences between individuals who report experiencing infertility and those who do not did not emerge in this study.

Global, regional, and national prevalence and mortality burden of sickle cell disease, 2000-2021: a systematic analysis from the Global Burden of Disease Study 2021

BACKGROUND

Previous global analyses, with known underdiagnosis and single cause per death attribution systems, provide only a small insight into the suspected high population health effect of sickle cell disease. Completed as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021, this study delivers a comprehensive global assessment of prevalence of sickle cell disease and mortality burden by age and sex for 204 countries and territories from 2000 to 2021.

METHODS

We estimated cause-specific sickle cell disease mortality using standardised GBD approaches, in which each death is assigned to a single underlying cause, to estimate mortality rates from the International Classification of Diseases (ICD)-coded vital registration, surveillance, and verbal autopsy data. In parallel, our goal was to estimate a more accurate account of sickle cell disease health burden using four types of epidemiological data on sickle cell disease: birth incidence, age-specific prevalence, with-condition mortality (total deaths), and excess mortality (excess deaths). Systematic reviews, supplemented with ICD-coded hospital discharge and insurance claims data, informed this modelling approach. We employed DisMod-MR 2.1 to triangulate between these measures-borrowing strength from predictive covariates and across age, time, and geography-and generated internally consistent estimates of incidence, prevalence, and mortality for three distinct genotypes of sickle cell disease: homozygous sickle cell disease and severe sickle cell β-thalassaemia, sickle-haemoglobin C disease, and mild sickle cell β-thalassaemia. Summing the three models yielded final estimates of incidence at birth, prevalence by age and sex, and total sickle cell disease mortality, the latter of which was compared directly against cause-specific mortality estimates to evaluate differences in mortality burden assessment and implications for the Sustainable Development Goals (SDGs).

FINDINGS

Between 2000 and 2021, national incidence rates of sickle cell disease were relatively stable, but total births of babies with sickle cell disease increased globally by 13·7% (95% uncertainty interval 11·1-16·5), to 515 000 (425 000-614 000), primarily due to population growth in the Caribbean and western and central sub-Saharan Africa. The number of people living with sickle cell disease globally increased by 41·4% (38·3-44·9), from 5·46 million (4·62-6·45) in 2000 to 7·74 million (6·51-9·2) in 2021. We estimated 34 400 (25 000-45 200) cause-specific all-age deaths globally in 2021, but total sickle cell disease mortality burden was nearly 11-times higher at 376 000 (303 000-467 000). In children younger than 5 years, there were 81 100 (58 800-108 000) deaths, ranking total sickle cell disease mortality as 12th (compared to 40th for cause-specific sickle cell disease mortality) across all causes estimated by the GBD in 2021.

INTERPRETATION

Our findings show a strikingly high contribution of sickle cell disease to all-cause mortality that is not apparent when each death is assigned to only a single cause. Sickle cell disease mortality burden is highest in children, especially in countries with the greatest under-5 mortality rates. Without comprehensive strategies to address morbidity and mortality associated with sickle cell disease, attainment of SDG 3.1, 3.2, and 3.4 is uncertain. Widespread data gaps and correspondingly high uncertainty in the estimates highlight the urgent need for routine and sustained surveillance efforts, further research to assess the contribution of conditions associated with sickle cell disease, and widespread deployment of evidence-based prevention and treatment for those with sickle cell disease.

FUNDING

Bill & Melinda Gates Foundation.

Cerebral artery conditional blood velocity in sickle cell disease: a multicentre study and evidence for active treatment

OBJECTIVE

To obtain multicentre data on the prevalence of normal, high or conditional (intermediate) blood velocity in the cerebral arteries among children with sickle cell disease (SCD) in Nigeria.

DESIGN

A prospective observational study in five tertiary healthcare institutions. By transcranial Doppler (TCD) ultrasonography, cerebral artery peak systolic blood velocity (PSV) was determined in 193 children with SCD and time averaged mean of the maximum blood velocity (TAMMV) in a different cohort of 115 children. This design was to make the findings relevant to hospitals with TCD equipment that measure either PSV or TAMMV.

SETTING

Nigeria.

PARTICIPANTS

308 children (126 girls, 182 boys; age 2-16 years).

MAIN OUTCOME MEASURES

Percentage of children with SCD who have normal, high or intermediate (often termed conditional) PSV or TAMMV.

RESULTS

In the cohort of 193 children, PSV was normal in 150 (77.7%), high in 7 (3.6%) and conditional in 36 (18.7%). In the cohort of 115 children, TAMMV was normal in 96 (84%), high in 7 (6%) and conditional in 12 (10%). There were no significant differences in gender or age distribution between the PSV and TAMMV cohorts. Altogether, cerebral artery blood velocity was normal in 246/308 children (80%), high in 14 (4.5%) and conditional in 48 (15.5%).

CONCLUSION

Since conditional blood velocity in cerebral arteries can progress to high values and predispose to stroke, the proportion of children with SCD who are affected (15.5%) raises the question of whether regular monitoring and proactive intervention ought to be the standard of care.