Trends in Sickle Cell Disease-Related Mortality in the United States, 1979 to 2017

Gene Therapy: A New Hope in Sickle Cell Disease Treatment

Sickle cell disease (SCD) is a lifelong disease requiring expensive treatment for management and limited curative options until the last few years. Gene therapy has emerged as a curative option for SCD, with two approved therapies available to SCD patients aged ≥ 12 years. Consideration must be considered regarding the ethics, efficacy, management requirements, education, and counseling needs of patients and their parents. Current and future practices will need to advocate for improved access and affordability of this specialized care and address the unknown and less defined areas of gene therapy pertaining to SCD through research.

Sickle cell anaemia therapy in 2025

New pharmacological therapies for sickle cell anaemia have not been as efficacious as hoped, while widespread application of curative stem cell and gene therapies is not likely to occur soon. This situation raises the question about whether more attention now be devoted to the use of hydroxyurea in this disease.

Practical guide for disease-modifying medication management of children and adolescents with sickle cell disease

Hydroxyurea has historically been the sole disease-modifying medication (DMM) for sickle cell disease (SCD). However, 3 newer DMMs, L-glutamine, voxelotor, and crizanlizumab, were approved for children and adolescents with SCD since 2017. Despite their emergence, treatment barriers, including access, affordability, and nonadherence, limit the optimization of DMMs in the clinical setting. Furthermore, there is limited work outlining real-world use and safety of the newer DMMs, and no published guidelines advise how best to select between DMMs or to use multiple in combination. Meanwhile, each DMM is associated with unique characteristics, such as tolerability, cost, and route of administration, which must be considered when weighing these options with patients and families. This article discusses DMMs for SCD and offers practical guidance on using the available DMMs in real-world settings based on published peer-reviewed studies and considering patient preferences. The recent withdrawal of one of these DMMs (voxelotor) from the market highlights the need for additional DMMs and evidence-based practices for adding DMMs and when to progress towards curative therapies.

End-of-life care for people with sickle cell disease: barriers to and facilitators of high-quality care

End-of-life (EOL) care is a critical part of sickle cell disease (SCD) management. However, barriers to high-quality EOL care remain, including (1) disease-related barriers (prior opioid exposure, risk of vaso-occlusive crises, chronic conditions with conflicting needs, and limitations of receiving disease-directed therapy on hospice); (2) communication-related barriers (challenges of identifying and responding to religious and spiritual concerns, limited health literacy, and previous health care system experience); (3) systemic issues (social determinants of health, structural racism, and mistrust of the medical system). However, palliative care and interdisciplinary collaboration can overcome many of these barriers. In addition, we can improve EOL care by accounting for opioid exposures, multimodal symptom management, and exploring (1) who people want involved in decision-making, (2) the role of religion and spirituality in decision-making, and (3) previous experiences with EOL. Systemic barriers can be addressed through the social determinants of health screening, minimizing financial burdens of care, and building longitudinal relationships with people with SCD. This requires the continued education of SCD providers about primary palliative care and palliative care providers about SCD. With such strategies, high-quality EOL care is possible for this vulnerable population.

Trends in Sickle Cell Disease Mortality: 1979-2020

BACKGROUND AND OBJECTIVES

Although sickle cell disease (SCD)-related childhood mortality in the United States significantly improved in the 1990s, unclear is the trend in SCD-related mortality more recently given the continued disparities faced by this minoritized population. In this analysis, we aimed to (1) compare the overall and age-specific mortality rates from 1999 to 2009 vs 2010 to 2020 with a particular focus on the age of transition and (2) determine the most common causes of death for the US SCD population for 2010 to 2020.

METHODS

We analyzed publicly available data from the Centers for Disease Control and Prevention WONDER database, a compilation of national-level mortality statistics from 1979 to 2020 derived from death certificates compiled by the National Center for Health Statistics. We searched by all individuals of all ethnicities, sexes, and ages using the underlying cause of death.

RESULTS

The crude mortality rate for individuals with SCD for 2010 to 2020 was 1.6 per 1 000 000 individuals, which was significantly lower than the period 1999 to 2009 (crude rate 1.7 per 1 000 000, P < .0001). In addition, the mean age at mortality of those with SCD was older in 2010 to 2020 (43 years) versus 1999 to 2009 (39 years). However, there remains a significant increase in mortality rate in the 20 to 24 year age group versus 15 to 19 years (1.7 per 1 000 000 versus 0.7 per 1 000 000, P < .0001), corresponding with the age of transition from pediatric to adult centers. In addition, 39% of underlying causes of death were not caused by SCD, but rather primarily chronic conditions, including cardiovascular, cerebrovascular, malignancy, and renal disease. The study has several limitations mostly because of the imperfections of administrative data sources, including inaccuracies in diagnoses codes, risking over or undercounting.

CONCLUSIONS

Although the US SCD-related mortality rate continues to decrease, the age of transition to adult care is a particularly vulnerable time in the lives of this marginalized group. Innovative and expanded approaches to care are greatly needed.

PM2.5 exposure and household income are associated with lung function abnormalities in children with sickle cell disease

RATIONALE

Cardiopulmonary dysfunction is a major contributor to mortality among persons with sickle cell disease (pwSCD). Despite this, little is known regarding environmental drivers of lung function decline.

OBJECTIVE

We hypothesized that environmental and socioeconomic variables have a significant effect on lung function in pwSCD that can be detected by spirometry.

METHODS

We retrospectively analyzed all spirometry results from pwSCD followed in the Pediatric Pulmonology clinic at the Children's Hospital of Philadelphia since 1 January 2016.

RESULTS

The study included 349 spirometry tests from 128 patients, primarily "Black or African American" (88%) and male (61%). More frequent exposure to PM2.5 above 25 μg/m3 was associated with higher odds of obstruction. Specifically, when compared to incidence of exposure to PM2.5 above 25 μg/m3 <25th percentile, both pwSCD exposed to 25th-75th percentile and pwSCD >75th percentile had higher odds of obstruction on spirometry (25th-75th: odds ratio [OR]: 9.6, p = .017; >75th: OR: 31.85, p = .002) despite correction for potential confounders. Similarly, median household income below the mean was associated with higher odds of restriction (OR: 4.37; p = .009).

CONCLUSIONS

We report higher odds of obstruction in pwSCD frequently exposed to PM2.5 concentrations above 25 μg/m3 and higher odds of restriction in pwSCD with lower household income. Our findings link spirometry patterns to modifiable risk factors indicating that there may opportunities for early intervention in pwSCD that have been referred to a pulmonology clinic. Further research is needed to assess if these findings can be generalized to the wider population of pwSCD.

Expert consensus on the off-label use in China of drugs for rare hematologic diseases (2024 edition)

Drug package inserts are a crucial foundation for clinical medication practices and serve as the legal basis for guiding rational drug use and ensuring patient safety and efficacy. As rare disease treatments evolve, current package inserts often need to meet the clinical requirements for treating such conditions, frequently resulting in off-label drug use. This consensus is derived from discussions between Guangdong Pharmaceutical Association Hematologic Rare Diseases Group experts. The consensus aims to provide a framework and reference for the clinical application of off-label drug use in treating rare hematologic diseases.

Results of a healthcare transition learning collaborative for emerging adults with sickle cell disease: the ST3P-UP study transition quality improvement collaborative

BACKGROUND

Individuals with sickle cell disease (SCD) experience poor clinical outcomes while transitioning from paediatric to adult care. Standards for SCD transition are needed. We established a Quality Improvement (QI) Collaborative that aimed to improve the quality of care for all young adults with SCD by establishing a standardised SCD transition process. This study evaluates the implementation of the Six Core Elements (6CE) of Health Care Transition, which was a fundamental component of the cluster-randomised Sickle Cell Trevor Thompson Transition Project (ST3P-UP) study.

METHODS

A central QI team trained 14 ST3P-UP study sites on QI methodologies, 6CE and Got Transition's process measurement tool (PMT). Site-level QI teams included a transition coordinator, clinic physicians/staff, patients/parents with SCD and community representatives. Sites completed the PMT every 6 months for 54 months and monthly audits of 10 randomly-selected charts to verify readiness/self-care assessments and emergency care plans.

RESULTS

Of a possible 100, the aggregate mean (±SD) PMT score for paediatric clinics was 23.9 (±13.8) at baseline, 95.9 (±6.0) at 24 months and 98.9 (±2.1) at 54 months. The aggregate mean PMT score for adult clinics was 15.0 (±13.5) at baseline, 88.4 (±11.8) at 24 months and 95.8 (±6.8) at 54 months. The overall QI Collaborative PMT score improved by 402%. At baseline, readiness/self-care assessments were current for 38% of paediatric and 20% of adult patients; emergency care plans were current for 20% of paediatric and 3% of adult patients. Paediatric clinics had one median readiness assessment shift (76%) and four median emergency care plan shifts (65%, 77%, 79%, 84%). Adult clinics experienced three median self-care assessment shifts (58%, 63%, 70%) and two median emergency care plan shifts (57%, 70%).

CONCLUSIONS

The ST3P-UP QI Collaborative successfully embedded the 6CE of Health Care Transition into routine care and increased administration of assessments and emergency care plans for transition-aged patients with SCD.

Identification of small molecule agonists of fetal hemoglobin expression for the treatment of sickle cell disease

Induction of fetal hemoglobin (HbF) has been shown to be a viable therapeutic approach to treating sickle cell disease and potentially other β-hemoglobinopathies. To identify targets and target-modulating small molecules that enhance HbF expression, we engineered a human umbilical-derived erythroid progenitor reporter cell line (HUDEP2_HBG1_HiBiT) by genetically tagging a HiBiT peptide to the carboxyl (C)-terminus of the endogenous HBG1 gene locus, which codes for γ-globin protein, a component of HbF. Employing this reporter cell line, we performed a chemogenomic screen of approximately 5000 compounds annotated with known targets or mechanisms that have achieved clinical stage or approval by the US Food and Drug Administration (FDA). Among them, 10 compounds were confirmed for their ability to induce HbF in the HUDEP2 cell line. These include several known HbF inducers, such as pomalidomide, lenalidomide, decitabine, idoxuridine, and azacytidine, which validate the translational nature of this screening platform. We identified avadomide, autophinib, triciribine, and R574 as novel HbF inducers from these screens. We orthogonally confirmed HbF induction activities of the top hits in both parental HUDEP2 cells as well as in human primary CD34+ hematopoietic stem and progenitor cells (HSPCs). Further, we demonstrated that pomalidomide and avadomide, but not idoxuridine, induced HbF expression through downregulation of several transcriptional repressors such as BCL11A, ZBTB7A, and IKZF1. These studies demonstrate a robust phenotypic screening workflow that can be applied to large-scale small molecule profiling campaigns for the discovery of targets and pathways, as well as novel therapeutics for sickle cell disease and other β-hemoglobinopathies.

Impact of Neighborhood Disadvantage on Preventive and Acute Care Utilization in Sickle Cell Disease

BACKGROUND

Individuals with sickle cell disease (SCD) experience significant healthcare disparities; however, there is little known on the impact of psychosocial stressors and neighborhood disadvantage on preventive and acute care utilization in this population.

PROCEDURE

A retrospective data collection was performed for all patients cared for at a comprehensive pediatric sickle cell center in the Midwest who had also completed the Psychosocial Assessment Tool (PAT), a validated caregiver-reported measurement of family psychosocial risk, from September 2021 through December 2022. Patient age, payor, primary language, frequency of acute and missed preventive care visits, as well as Area Deprivation Index (ADI) and Childhood Opportunity Index (COI) scores were collected for 256 patients.

RESULTS

The average state ADI was 6.3 (±2.9), and the majority of patients were in the Very Low or Low COI categories. Total PAT score (p = 0.003), state ADI (p < 0.001), and state COI (p < 0.001) were all significantly correlated with missed SCD clinic visits, with increased odds of a missed visit with increasing neighborhood disadvantage (OR 1.22, p < 0.001). The odds of acute care were also increased in those with higher family psychosocial risk (OR 1.76, p < 0.011), though this was not seen with ADI or COI, suggesting an additional effect of family stressors and resilience on acute care utilization.

CONCLUSIONS

This highlights the importance of regular, universal social and psychological risk screening, as well as inclusion of psychosocial team members in SCD programs to identify and readily address risk factors that impact child outcomes in a minoritized chronic disease population.

Impact of an individualized pain plan to treat sickle cell disease vaso-occlusive episodes in the emergency department

ABSTRACT

To address acute vaso-occlusive episodes (VOEs), the leading cause of emergency department (ED) visits among individuals with sickle cell disease (SCD), we conducted the clinical study, ALIGN (An Individualized Pain Plan with Patient and Provider Access for Emergency Department care of SCD), across 8 sites. We hypothesized an improvement of 0.5 standard deviations in perceived quality of ED pain treatment of a VOE after implementing individualized pain plans (IPPs) accessible to both patients and providers. Patients with SCD were aged 18 to 45 years, owned a cell phone, and had an ED VOE visit within 90 days prior. Patients completed the perceived quality of care surveys at baseline and within 96 hours after an ED VOE visit. Providers completed surveys regarding comfort managing VOEs at baseline and after managing an enrolled patient. Most of the 153 patients were African American (95.4%), female (64.7%), and had Hb SS/Sβ0 genotype (71.9%). The perceived quality of ED pain treatment was high at both baseline and after implementation of IPPs; our primary outcome hypothesis was not met, because no statistically significant change in the patient-perceived quality of ED treatment occurred. A total of 135 providers completed baseline and follow-up surveys. On a scale of 1 to 7, with 7 being extremely comfortable managing VOEs, 60.5% reported a score ≥6 after IPP implementation vs 57.8% at baseline. Almost all (97.6%) ordered the recommended medication, and 94.7% intended to use IPPs. In this implementation protocol, all sites successfully implemented IPPs. Patients and ED providers both endorsed the use of IPPs. This trial was registered at www.ClinicalTrials.gov as # NCT04584528.

Microbiome in sickle cell disease: Pathophysiology and therapeutic insights

Sickle cell disease (SCD) is a complex genetic blood disorder characterized by abnormal haemoglobin, resulting in sickle-shaped red blood cells. While extensive research has concentrated on the genetic and physiological aspects of SCD, recent studies suggest a potential role of the human microbiome in SCD pathophysiology, adding new dimensions to its understanding. This review synthesizes current knowledge on the microbiome's involvement in SCD, focusing on alterations in the gut microbiome composition and diversity compared to healthy individuals, and their implications for disease pathogenesis. We explore how microbiome changes may contribute to vaso-occlusive crises and other complications, along with the possible associations of specific microbial taxa or markers with disease crises and clinical outcomes. Additionally, we discuss the potential of microbiome-targeted interventions, including probiotics, dietary modifications, and faecal microbiota transplantation, in managing SCD complications and improving patient outcomes. Understanding the intricate relationship between the microbiome and SCD could lead to innovative therapeutic strategies and personalized interventions for better managing the disease. This review underscores the importance of further microbiome research and its integration into holistic SCD care.

Targeted therapeutic management based on phytoconstituents for sickle cell anemia focusing on molecular mechanisms: Current trends and future perspectives

The global epidemic of Sickle cell anemia (SCA) is causing thousands of children to die. SCA, a genetic disorder affecting the hemoglobin-globin chain, affects millions globally. The primary physiological issue in these patients is the polymerization of sickle hemoglobin within their red blood cells (RBCs) during their deoxygenating state. The RBC undergoes a sickle shape due to the polymerization of mutant hemoglobin within it and membrane deformation during anoxic conditions. To prevent complications, it is essential to effectively stop the sickling of RBCs of the patients. Various medications have been studied for treating SCA patients, focusing on antisickling, γ-globulin induction, and antiplatelet action. Natural and synthetic anti-sickling agents can potentially reduce patient clinical morbidity. Numerous clinical trials focused on using natural remedies for the symptomatic therapy of SCA. Medicinal plants and phytochemical agents have antisickling properties. Recent studies on plant extracts' natural compounds have primarily focused on in vitro RBCs sickling studies, with limited data on in vivo studies. This review discussed the potential role of phytoconstituents in the management of SCA.

Sexually transmitted infection testing and diagnosis in adolescents and young adults with sickle cell disease

BACKGROUND

Sexually transmitted infections (STIs) are common and disproportionately affect Black adolescents and young adults (AYAs). Less is known about STIs among Black AYAs with chronic conditions, such as sickle cell disease (AYAs-SCD). This study compared STI testing and diagnosis between AYAs-SCD and their peers, overall and among STI-related encounters.

PROCEDURE

This retrospective, cross-sectional study used diagnosis and billing codes in the Pediatric Health Information System (PHIS) to identify inpatient and emergency department encounters from January 1, 2022 to May 31, 2023 among all AYAs 15-24 years and those with STI-related diagnoses (e.g., "cystitis"). STI testing and diagnosis rates were compared between AYAs-SCD, non-Black AYAs, and Black AYAs, controlling for age, sex, and encounter setting.

RESULTS

We identified 3602 AYAs-SCD, 177,783 Black AYAs, and 534,495 non-Black AYAs. AYAs-SCD were less likely to be tested for STIs than non-Black AYAs (odds ratio [OR] = 0.26; adj. p < .001) and Black AYAs (OR = 0.53; adj. p < .001). When tested, AYAs-SCD were more likely to be diagnosed with an STI than non-Black AYAs (OR = 2.39; adj. p = .006) and as likely as Black AYAs (OR = 0.67; adj. p = .15). Among STI-related encounters, AYAs-SCD were less likely to be tested than non-Black AYAs (OR = 0.18; adj. p < .001) and Black AYAs (OR = 0.44; adj. p < .001). No significant differences in STI diagnoses were found in this subset between AYAs-SCD and non-Black AYAs (OR = 0.32; adj. p = .28) or Black AYAs (OR = 1.07; adj. p = .99).

CONCLUSIONS

STI care gaps may disproportionately affect AYAs-SCD. STIs should be considered when evaluating symptomatic AYAs-SCD in acute settings. More research is needed to further contextualize STI care for AYAs-SCD.

Social Vulnerability and Sickle Cell Disease Mortality in the US

Importance

Social determinants of health (SDOH) influence health outcomes, including those of sickle cell disease (SCD), despite advancements in treatments like disease-modifying therapies.

Objective

To investigate the association of SDOH with SCD mortality rates from 2016 to 2020.

Design, Setting, and Participants

This cross-sectional study combined county-level data from the Centers for Disease Control and Prevention and Agency for Toxic Substances and Disease Registry Social Vulnerability Index (SVI) with SCD mortality data from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research database from January 1, 2016, to December 31, 2020. US counties were divided into 4 quartile (Q) models according to their SVI scores. Deaths from SCD in the US among patients of all ages were included. Data analysis occurred from March to April 2024.

Exposure

SVI score.

Main Outcomes and Measures

Age-adjusted mortality rates (AAMRs) per 1 000 000 individuals were measured. Rate ratios (RRs) were obtained by comparing county-specific AAMRs of SVI-Q4 with SVI-Q1.

Results

From 2016 to 2020, among a total population of 1 633 737 771 individuals, there were 2635 deaths from SCD (1289 male [49.1%] and 1336 female [50.9%]). There were 1480 deaths in Q4, 687 deaths in Q3, 344 deaths in Q2, and 114 deaths in Q1. Higher SVI was associated with 2.11 excess deaths per 1 000 000 individuals (RR, 4.90; 95% CI, 4.81-5.00). Similar trends were seen for both males (RR, 4.56; 95% CI, 4.44-4.69) and females (RR, 5.85; 95% CI, 5.68-6.03). Middle-aged patients with SCD had the highest mortality rate in Q4, with 3.45 excess deaths per 1 000 000 individuals (RR, 4.97; 95% CI, 4.85-5.09). Higher SVI was associated with 2.29 excess deaths per 1 000 000 individuals in African American individuals with SCD (RR, 1.24; 95% CI, 1.22-1.27]). In White individuals with SCD, higher SVI was associated with 0.12 excess deaths per 1 000 000 individuals (RR not available due to unreliable data in Q1). When stratifying by census region, the highest level of SCD-related mortality was in the Northeast, with higher SVI associated with 3.16 excess deaths per 1 000 000 individuals (RR, 8.02; 95% CI, 7.66-8.40).

Conclusions

In this cross-sectional study of the association of SVI with SCD mortality rates, higher SVI was associated with higher SCD mortality across US counties. These findings underscore the importance of addressing social determinants of health to improve mortality outcomes among patients with SCD.

Standardization of coding definitions for sickle cell disease complications: A systematic literature review

PURPOSE

Sickle cell disease (SCD) affects all organ systems and is characterized by numerous acute and chronic complications and comorbidities. Standardized codes are needed for complications/comorbidities used in real-world evidence (RWE) studies that rely on administrative and medical coding. This systematic literature review was conducted to produce a comprehensive list of complications/comorbidities associated with SCD, along with their diagnosis codes used in RWE studies.

METHODS

A search in MEDLINE and Embase identified studies published from 2016 to 2023. Studies were included if they were conducted in US SCD populations and reported complications/comorbidities and respective International Classification of Diseases, Clinical Modification (ICD-CM) codes. All identified complications/comorbidities and codes were reviewed by a certified medical coding expert and hematologist.

RESULTS

Of 1851 identified studies, 39 studies were included. The most reported complications/comorbidities were stroke, acute chest syndrome, pulmonary embolism, venous thromboembolism, and vaso-occlusive crisis. Most of the studies used ICD-9-CM codes (n = 21), while some studies used ICD-10-CM codes (n = 3) or both (n = 15), depending on the study period. Most codes reported in literature were heterogeneous across complications/comorbidities. The medical coding expert and hematologist recommended modifications for several conditions.

CONCLUSION

While many studies we identified did not report their codes and were excluded from this review, the studies with codes exhibited diverse coding definitions. By providing a standardized set of diagnosis codes that were reported by studies and reviewed by a coding expert and hematologist, our review can serve as a foundation for accurately identifying complications/comorbidities in future research, and may reduce heterogeneity, enhance transparency, and improve reproducibility. Future efforts focused on validating these code lists are needed.

Revolutionary breakthrough: FDA approves CASGEVY, the first CRISPR/Cas9 gene therapy for sickle cell disease

Sickle cell disease (SCD) is a hereditary hemoglobinopathy resulting from a β-globin chain mutation that causes abnormal hemoglobin (HbS) polymerization and leads to severe complications. Current treatment options primarily focus on symptom management, with limited curative potential. Recently, Casgevy, the first CRISPR/Cas9-based gene therapy for SCD, has received breakthrough FDA approval. Clinical trials have shown that Casgevy administered to patients aged older than or equal to 12 years enables precise modifications in hematopoietic stem cells, resulting in elevated fetal hemoglobin (HbF) levels and a significant reduction in vaso-occlusive events. Unlike conventional treatments, this therapy offers a curative approach and eliminates the need for recurrent transfusions and transplants, thereby improving the quality of life of patients with SCD. Casgevy has emerged as a beacon of hope for SCD patients and signifies a potential paradigm shift in SCD management due to its safety, curative potential, and transformative impact, positioning it as a groundbreaking intervention. Nevertheless, ethical considerations surrounding CRISPR technology and regulatory frameworks must be addressed to ensure responsible application and equitable access to this one-time gene editing therapy. As the authors celebrate this scientific advancement, sustained interdisciplinary collaboration and ethical scrutiny are essential to navigating the evolving landscape of CRISPR technology in medicine. This review aims to provide a detailed insight into the application of Casgevy, challenges associated with its application, future prospects of this therapy, and its comparison with existing treatment options for SCD.

Synthetic datasets for open software development in rare disease research

BACKGROUND

Globally, researchers are working on projects aiming to enhance the availability of data for rare disease research. While data sharing remains critical, developing suitable methods is challenging due to the specific sensitivity and uniqueness of rare disease data. This creates a dilemma, as there is a lack of both methods and necessary data to create appropriate approaches initially. This work contributes to bridging this gap by providing synthetic datasets that can form the foundation for such developments.

METHODS

Using a hierarchical data generation approach parameterised with publicly available statistics, we generated datasets reflecting a random sample of rare disease patients from the United States (US) population. General demographics were obtained from the US Census Bureau, while information on disease prevalence, initial diagnosis, survival rates as well as race and sex ratios were obtained from the information provided by the US Centers for Disease Control and Prevention as well as the scientific literature. The software, which we have named SynthMD, was implemented in Python as open source using libraries such as Faker for generating individual data points.

RESULTS

We generated three datasets focusing on three specific rare diseases with broad impact on US citizens, as well as differences in affected genders and racial groups: Sickle Cell Disease, Cystic Fibrosis, and Duchenne Muscular Dystrophy. We present the statistics used to generate the datasets and study the statistical properties of output data. The datasets, as well as the code used to generate them, are available as Open Data and Open Source Software.

CONCLUSION

The results of our work can serve as a starting point for researchers and developers working on methods and platforms that aim to improve the availability of rare disease data. Potential applications include using the datasets for testing purposes during the implementation of information systems or tailored privacy-enhancing technologies.

The enigma of sickle cell hepatopathy: Pathophysiology, clinical manifestations and therapy

Sickle cell disease (SCD) is one of the most common genetic disorders in the world predominantly affecting economically disadvantaged populations. There is a notable discrepancy between the growing adult SCD population and available diagnostic and therapeutic interventions for SCD. Sickle cell hepatopathy (SCH) is an all-inclusive term to describe the acute and chronic liver manifestations of SCD. The pathophysiology of SCH follows no defined pattern or sequence that poses challenges to clinicians and researchers alike. Evidence is lacking for this underreported disease at various levels from diagnostic to therapeutic options. This paper reviews the basic pathophysiology, clinical features, biochemical and radiological findings of various SCH manifestations and outlines the management of each condition. Old and new therapy options in SCD including hydroxyurea, red blood cell exchange transfusion, ursodeoxycholic acid, voxelotor, l-glutamine and crizanlizumab have been reviewed to investigate the role of these options in treating SCH. The role of liver transplant, haematopoietic stem cell transplant and gene therapy in SCH patients have been reviewed.

Association of elevated tricuspid regurgitation velocity with cerebrovascular and kidney disease in children with sickle cell disease

BACKGROUND

Tricuspid regurgitation velocity (TRV), measured by echocardiography, is a surrogate marker for pulmonary hypertension. Limited pediatric studies have considered the association between TRV and surrogate markers of end-organ disease.

METHODS

We conducted a cross-sectional study that evaluated the prevalence of elevated TRV ≥2.5 m/s and its associations with renal and cerebrovascular outcomes in children with sickle cell disease (SCD) 1-21 years of age in two large sickle cell cohorts, the University of Alabama at Birmingham (UAB) sickle cell cohort, and the Sickle Cell Clinical Research and Intervention Program (SCCRIP) cohort at St. Jude Children's Research Hospital. We hypothesized that patients with SCD and elevated TRV would have higher odds of having either persistent albuminuria or cerebrovascular disease.

RESULTS

We identified 166 children from the UAB cohort (mean age: 13.49 ± 4.47 years) and 325 children from the SCCRIP cohort (mean age: 13.41 ± 3.99 years) with echocardiograms. The prevalence of an elevated TRV was 21% in both UAB and SCCRIP cohorts. Elevated TRV was significantly associated with cerebrovascular disease (odds ratio [OR] 1.88, 95% confidence interval [CI]: 1.12-3.15; p = .017) and persistent albuminuria (OR 1.81, 95% CI: 1.07-3.06; p = .028) after adjusting for age, sex, treatment, and site.

CONCLUSION

This cross-sectional, multicenter study identifies associations between surrogate markers of pulmonary hypertension with kidney disease and cerebrovascular disease. A prospective study should be performed to evaluate the longitudinal outcomes for patients with multiple surrogate markers of end-organ disease.

Immunization adherence among children with sickle cell disease and sickle cell trait: Results of a population-based study

INTRODUCTION

Despite the importance of timely vaccine completion for protection from infectious disease, there is limited knowledge of the immunization adherence rates of children with sickle cell disease (SCD).

METHODS

This is a retrospective cohort study comparing the immunization rates of children with SCD to those with sickle cell trait between 2008 and 2019 in Georgia. Completion rates for each vaccine and the proportion of children with up-to-date status at 24 and 35 months were calculated and compared between the cohorts. Chi-square tests with odds ratios (OR) for differences and 95% confidence intervals (CIs) were reported on the overall up-to-date rates and rates for individual vaccines at 24 and 35 months for the two cohorts.

RESULTS

Children with SCD had higher up-to-date rates than children with sickle cell trait at 24 and 35 months. At 35 months, the overall up-to-date rates (OR = 1.17; 95% CI, 1.04-1.31; p = .004) and the four-dose pneumococcal conjugate vaccine series (OR = 1.36; 95% CI, 1.18-1.57; p < .001) were significantly different between the groups. Both cohorts had the highest completion rates for the hepatitis B series and the lowest rates for the varicella vaccine. Doses of diphtheria, tetanus, and acellular pertussis vaccine; varicella; and pneumococcal conjugate vaccines were most commonly missed by children in both cohorts.

CONCLUSIONS

Children with SCD have better immunization coverage than children with sickle cell trait, but there is an opportunity for improvement. Policymakers and healthcare professionals should focus on increasing access to care coordination services among children with SCD to ensure on-time and preventive healthcare services.

Respiratory management of acute chest syndrome in children with sickle cell disease

Acute chest syndrome (ACS) is a leading cause of respiratory distress and hospitalisation in children with sickle cell disease (SCD). The aetiology is multifactorial and includes fat embolism, venous thromboembolism, alveolar hypoventilation and respiratory infections, with the latter being particularly common in children. These triggers contribute to a vicious cycle of erythrocyte sickling, adhesion to the endothelium, haemolysis, vaso-occlusion and ventilation-perfusion mismatch in the lungs, resulting in the clinical manifestations of ACS. The clinical presentation includes fever, chest pain, dyspnoea, cough, wheeze and hypoxia, accompanied by a new pulmonary infiltrate on chest radiography. Respiratory symptoms may overlap with those of acute asthma, which may be difficult to distinguish. Patients with ACS may deteriorate rapidly; thus prevention, early recognition and aggressive, multidisciplinary team management is essential. In this narrative review, we highlight the current evidence regarding the epidemiology, pathophysiology, treatment and preventative strategies for ACS, focusing on the aspects of major interest for the paediatric pulmonologist and multidisciplinary team who manage children with SCD.

Double Trouble: COVID-19 Infection Exacerbates Sickle Cell Crisis Outcomes in Hospitalized Patients-Insights from National Inpatient Sample 2020

Background: This study investigated the impact of COVID-19 on patients with sickle cell crisis (SCC) using National Inpatient Sample (NIS) data for the year 2020. Methods: A retrospective cohort analysis was conducted utilizing International Classification of Diseases (ICD-10) codes to identify adults who were admitted with a principal diagnosis of sickle cell crisis. The primary outcomes examined were inpatient mortality, while the secondary outcomes assessed included morbidity, hospital length of stay, and resource utilization. Analyses were conducted with STATA. Multivariate logistic and linear regression analyses were used to adjust for confounding variables. Results: Of 66,415 adult patients with a primary SCC diagnosis, 875 were identified with a secondary diagnosis of COVID-19 infection. Unadjusted mortality rate was higher for SCC patients with COVID-19 (2.28%) compared to those without (0.33%), with an adjusted odds ratio (aOR) of 8.49 (p = 0.001). They also showed increased odds of developing acute respiratory failure (aOR = 2.37, p = 0.003) and acute kidney injury requiring dialysis (aOR = 8.66, p = 0.034). Additionally, these patients had longer hospital stays by an adjusted mean of 3.30 days (p < 0.001) and incurred higher hospitalization charges by an adjusted mean of USD 35,578 (p = 0.005). Conclusions: The SCC patients with COVID-19 presented higher mortality rates, increased morbidity indicators, longer hospital stays, and substantial economic burdens.

End Organ Affection in Sickle Cell Disease

Sickle cell disease is an orphan disease affecting ethnic minorities and characterized by profound systemic manifestations. Although around 100,000 individuals with SCD are living in the US, the exact number of individuals is unknown, and it is considered an orphan disease. This single-gene disorder leads to red blood cell sickling and the deoxygenation of hemoglobin, resulting in hemolysis. SCD is associated with acute complications such as vaso-occlusive crisis, infections, and chronic target organ complications such as pulmonary disease and renal failure. While genetic therapy holds promise to alter the fundamental disease process, the major challenge in the field remains the target end organ damage and ways to mitigate or reverse it. Here, we provide an overview of the clinical manifestations and pathogenesis with a focus on end-organ damage and current therapeutic options, including recent FDA-approved stem cell and gene editing therapies.

Prevalence of Pulmonary Hypertension among Sudanese Patients with Sickle Cell Disease

Background

Sickle Cell Disease (SCD) is a hereditary condition characterized by aberrant red blood cell morphology, leading to persistent hemolytic anemia. The consequential impact of SCD on the pulmonary vasculature can result in pulmonary hypertension (PHT), a severe complication that detrimentally affects the well-being and survival of individuals with SCD. The prevalence and risk determinants of PHT in SCD patients exhibit variations across diverse geographical regions and populations. This study aims to ascertain the prevalence of PHT among Sudanese SCD patients and identify associated factors.

Methods

A cohort of thirty-one adult sickle cell disease (SCD) patients, as confirmed by hemoglobin electrophoresis, were recruited for participation in this cross-sectional study. Comprehensive data encompassing demographic, clinical, and laboratory parameters were collected. Doppler echocardiography was employed to quantify pulmonary arterial systolic pressure (PASP) and evaluate right ventricular size and function.

Results

Within our cohort, the prevalence of PHT was 29%. Active cigarette smoking demonstrated a significant association with PHT (P=0.042), while hydroxyurea therapy exhibited no noticeable impact on PHT (P=0.612).

Conclusion

Our investigation revealed a PHT prevalence of less than one-third in our SCD patient population, aligning with prior studies. Notably, independent of other factors, cigarette smoking emerged as a distinct risk factor for PHT in SCD patients. This highlights the potential utility of smoking cessation as an intervention to delay the onset of this condition. However, further research is imperative to elucidate the mechanisms through which smoking contributes to PHT development in individuals with SCD.

Distribution of Silent Cerebral Infarcts in Adults With Sickle Cell Disease

BACKGROUND AND OBJECTIVES

Previously we demonstrated that 90% of infarcts in children with sickle cell anemia occur in the border zone regions of cerebral blood flow (CBF). We tested the hypothesis that adults with sickle cell disease (SCD) have silent cerebral infarcts (SCIs) in the border zone regions, with a secondary hypothesis that older age and traditional stroke risk factors would be associated with infarct occurrence in regions outside the border zones.

METHODS

Adults with SCD 18-50 years of age were enrolled in a cross-sectional study at 2 centers and completed a 3T brain MRI. Participants with a history of overt stroke were excluded. Infarct masks were manually delineated on T2-fluid-attenuated inversion-recovery MRI and registered to the Montreal Neurological Institute 152 brain atlas to generate an infarct heatmap. Border zone regions between anterior, middle, and posterior cerebral arteries (ACA, MCA, and PCA) were quantified using the Digital 3D Brain MRI Arterial Territories Atlas, and logistic regression was applied to identify relationships between infarct distribution, demographics, and stroke risk factors.

RESULTS

Of 113 participants with SCD (median age 26.1 years, interquartile range [IQR] 21.6-31.4 years, 51% male), 56 (49.6%) had SCIs. Participants had a median of 5.5 infarcts (IQR 3.2-13.8). Analysis of infarct distribution showed that 350 of 644 infarcts (54.3%) were in 4 border zones of CBF and 294 (45.6%) were in non-border zone territories. More than 90% of infarcts were in 3 regions: the non-border zone ACA and MCA territories and the ACA-MCA border zone. Logistic regression showed that older participants have an increased chance of infarcts in the MCA territory (odds ratio [OR] 1.08; 95% CI 1.03-1.13; p = 0.001) and a decreased chance of infarcts in the ACA-MCA border zone (OR 0.94; 95% CI 0.90-0.97; p < 0.001). The presence of at least 1 stroke risk factor did not predict SCI location in any model.

DISCUSSION

When compared with children with SCD, in adults with SCD, older age is associated with expanded zones of tissue infarction that stretch beyond the traditional border zones of CBF, with more than 45% of infarcts in non-border zone regions.

Left ventricular global longitudinal strain and acute myocardial injury in patients with sickle cell disease admitted to the intensive care unit for vaso-occlusive crisis

In patients with sickle cell disease (SCD), SCD-related cardiomyopathy may be partly due to repeated ischaemic events related to sickling during vaso-occlusive crises, but few clinical studies support this hypothesis. We evaluated the incidence of acute myocardial ischaemia during vaso-occlusive crises as assessed by the left ventricular global longitudinal strain (LVGLS) and high-sensitive cardiac troponin T (hs-cTnT). We included adult patients with SCD admitted to the intensive care unit (ICU) for vaso-occlusive crisis. We collected hs-cTnT and measured LVGLS with echocardiography at admission (day 1), day 2, day 3 and ICU discharge. Among 55 patients included, considering only the first hospitalization of patients admitted several times, 3 (5%) had elevated hs-cTnT at ≥1 time point of the ICU stay. It was ≤2 times the upper limit of normal in two of these patients. LVGLS was altered at ≥1 time point of the ICU stay in 13 (24%) patients. Both hs-cTnT and LVGLS were abnormal at ≥1 time point of the hospital stay in 2 (4%) patients. Acute myocardial injury as assessed by troponin elevation and LVGLS impairment was a rare event during vaso-occlusive crises.

Mortality in adults with sickle cell disease: Results from the sickle cell disease implementation consortium (SCDIC) registry

The cause of death in people affected by sickle cell disease (SCD) is often challenging to define as prior studies have used retrospective or administrative data for analysis. We used a prospective longitudinal registry to assess mortality and clinical co-morbidities among subjects enrolled in the Sickle Cell Disease Implementation Consortium (SCDIC) registry. At enrollment, we collected the following data: patient-reported demographics, SCD phenotype, baseline laboratory values, comorbidities, and current medications. Subjects were followed for a median of 4.7 years before the present analysis. The relationship of clinical co-morbidities (at time of enrollment) to mortality was determined using survival analysis, adjusting for SCD phenotype and gender. There was a total of 2439 people with SCD enrolled in the SCDIC registry. One hundred and twenty-eight participants (5%) died during the observation period (2017-2022). Six people died from trauma and were excluded from further analysis. Proximate cause of death was unwitnessed in 17% of the deaths, but commonest causes of death include cardiac (18%), acute chest or respiratory failure (11%), sudden unexplained death (8%). Enrollment characteristics of the individuals who died (n = 122) were compared to those of survivors (n = 2317). Several co-morbidities at enrollment increased the odds of death on univariate analysis. All co-morbidities were included in a multivariable model. After backward elimination, iron overload, pulmonary hypertension, and depression, remained statistically significant predictors of the risk of death. SCD reduces life expectancy. Improved comprehensive and supportive care to prevent end-organ damage and address comorbidities is needed for this population.

Impact of hospitalized vaso-occlusive crises in the previous calendar year on mortality and complications in adults with sickle cell disease: a French population-based study

Background

Historically, sickle cell disease (SCD) patients experiencing frequent hospitalized vaso-occlusive crises (HVOC) have been associated with increased mortality, yet recent data reflecting the widespread use of hydroxyurea and advancements in disease management remain limited. Our study aims to assess the association between HVOC and mortality or severe complications in patients with SCD in this new treatment landscape.

Methods

This was a retrospective observational cohort study using the French national health data system. Between 01-01-2012 and 12-31-2018, all SCD patients ≥16 years old (ICD-10 codes D57.0-2) were included and followed until 12-31-2018. HVOC was defined as a hospitalization of ≥1 night with primary diagnosis of SCD with crisis, following an emergency room visit. The association between HVOC and severe complications was assessed with a Cox proportional hazards model.

Findings

In total, 8018 patients (56.6% females; 4538/8018) were included. The 2018 SCD standardized one-year period prevalence was 17.9 cases/100,000 person-years [17.4; 18.3]. The mean rate was 0.84 (1.88) HVOC/person-year. In 2018, 70% (5323/7605), 22% (1671/7605), and 8% (611/7605) of patients experienced 0, 1-2, or 3+ HVOCs, respectively. The median survival time between HVOCs was 415 days [386; 439]. Overall, 312 patients died (3.9%) with a mean age of 49.8 (19.4). Compared to patients without HVOC, the hazard ratios of death in patients with 1-2 or 3+ HVOCs the year prior to death were 1.67 [1.21; 2.30] and 3.70 [2.30; 5.93], respectively. Incidence of acute chest syndrome, pulmonary embolism, osteonecrosis, and sepsis increased with the HVOCs category, but not stroke. In 2018, 29.5% (180/611) of patients with 3+ HVOCs did not take hydroxyurea.

Interpretation

Patients must be closely monitored during their hospitalizations to intensify treatment and check treatment compliance. Innovative therapies are also required.

Funding

The study was funded by Novartis.

Birth Prevalence of Sickle Cell Disease and County-Level Social Vulnerability - Sickle Cell Data Collection Program, 11 States, 2016-2020

Sickle cell disease (SCD) remains a public health priority in the United States because of its association with complex health needs, reduced life expectancy, lifelong disabilities, and high cost of care. A cross-sectional analysis was conducted to calculate the crude and race-specific birth prevalence for SCD using state newborn screening program records during 2016-2020 from 11 Sickle Cell Data Collection program states. The percentage distribution of birth mother residence within Social Vulnerability Index quartiles was derived. Among 3,305 newborns with confirmed SCD (including 57% with homozygous hemoglobin S or sickle β-null thalassemia across 11 states, 90% of whom were Black or African American [Black], and 4% of whom were Hispanic or Latino), the crude SCD birth prevalence was 4.83 per 10,000 (one in every 2,070) live births and 28.54 per 10,000 (one in every 350) non-Hispanic Black newborns. Approximately two thirds (67%) of mothers of newborns with SCD lived in counties with high or very high levels of social vulnerability; most mothers lived in counties with high or very high levels of vulnerability for racial and ethnic minority status (89%) and housing type and transportation (64%) themes. These findings can guide public health, health care systems, and community program planning and implementation that address social determinants of health for infants with SCD. Implementation of tailored interventions, including increasing access to transportation, improving housing, and advancing equity in high vulnerability areas, could facilitate care and improve health outcomes for children with SCD.

Defining curative endpoints for sickle cell disease in the era of gene therapy and gene editing

A growing number of gene therapy- and gene editing-based treatments for patients with sickle cell disease (SCD) are entering clinical trials. These treatments, designed to target the underlying cause of SCD, have the potential to provide functional cures, which until now were possible only through allogeneic hematopoietic stem cell transplant. However, as these novel approaches advance from early- to late-stage clinical trials, it is essential to identify physiologically and clinically relevant endpoints that can demonstrate the achievement of a functional cure for SCD. Here, we present an overview of the pathophysiology of SCD and current treatment options, review ongoing SCD clinical trials using gene therapy or gene editing approaches, and identify the most relevant endpoints for demonstrating the attainment of a functional cure for SCD.

Computing Sickle Erythrocyte Health Index on quantitative phase imaging and machine learning

Sickle cell disease (SCD) is a genetic disorder characterized by abnormal hemoglobin and deformation of red blood cells (RBCs), leading to complications and reduced life expectancy. This study developed an in vitro assessment, the Sickle Erythrocyte Health Index, using quantitative phase imaging (QPI) and machine learning to model the health of RBCs in people with SCD. The health index combines assessment of cell deformation, sickle-shaped classification, and membrane flexibility to evaluate erythrocyte health. Using QPI and image processing, the percentage of sickle-shaped cells and membrane flexibility were quantified. Statistically significant differences were observed between individuals with and without SCD, indicating the impact of underlying pathophysiology on erythrocyte health. Additionally, sodium metabisulfite led to an increase in sickle-shaped cells and a decrease in flexibility in the sickle cell blood samples. Based on these findings, two approaches were used to calculate the Sickle Erythrocyte Health Index: one using hand-crafted features and one using learned features from deep learning models. Both indices showed significant differences between non-SCD and SCD groups and sensitivity to changes induced by sodium metabisulfite. The Sickle Erythrocyte Health Index has important clinical implications for SCD management and could be used by providers when making treatment decisions. Further research is warranted to evaluate the clinical utility and applicability of the Sickle Erythrocyte Health Index in diverse patient populations.

Transfusion of packed red blood cells in adults with sickle cell anemia treated at an emergency hospital

OBJECTIVE

The aim of this study was to analyze the prescription of packed red blood cells performed by emergency physicians for adults with sickle cell anemia.

METHODS

Transfusions performed in adults with sickle cell anemia treated at an emergency service in São Bernardo do Campo, São Paulo Brazil, between January 2018 and January 2022 were evaluated. For data comparison, the chi-square2 test was used. The significance level adopted was 5%.

RESULTS

A total of 114 transfusions were performed. The mean age was 41.8±16.4 years, and pretransfusion hemoglobin was 6.1±1.23 g/dL. Regarding the indication, the adequacy of transfusions performed in symptomatic individuals was significantly higher compared to asymptomatic individuals (100% vs. 3.9%, p<0.001). Symptomatic individuals received excessive volumes of packed red blood cells less frequently than asymptomatic individuals (17.5% vs. 56.9%, p<0.001). The filtered subtype, indicated for sickle cell anemia, was prescribed in only a quarter of the patients. However, non-indicated subtypes were frequently prescribed.

CONCLUSION

This study found low adequacy in the indication and calculation of the transfusion volume of packed red blood cells in asymptomatic individuals. Few patients received filtered red blood cells, resulting in increased risks of transfusion reactions. On the contrary, non-indicated subtypes were prescribed in a quarter of transfusions, which resulted in higher costs and delay in receiving packed red blood cells.

Homozygous Sickle Cell Disease after Age of 40: Follow-Up of a Cohort of 209 Patients in Senegal, West Africa

Objectives

The aim of this study was to describe the morbidity and mortality of homozygous sickle cell disease after the age of 40.

Methods

This was a cohort study of 209 patients followed from 1994 to 2022. All hemoglobin electrophoresis-confirmed SS sickle cell patients over 40 years were included. A descriptive study of epidemiological, diagnostic, therapeutic, and evolutionary data was used to assess morbidity and mortality.

Results

Sex ratio (M/F) was 0.6. Median age was 47 (41-75). According to morbidity, 95.1% had less than 3 vaso-occlusive crises/year. Acute anemia was the most frequent complication (52.63%). Chronic complications were noted in 32.5%. At diagnosis, mean hemoglobin was 8.1 g/dl ± 1.9, HbS was 86.5 ± 10, and HbF was 9.4 ± 7.6. Number of patients transfused was 66%. We noted that 8.1% of patients died, 29.2% were lost to follow-up, and 62.7% were still being followed up. The risk factors identified for death were geographical origin, comorbidity, high HbS, low HbF, and thrombocytosis.

Conclusion

This study shows that homozygous SCD is increasingly becoming an adult disease and that it can be carried into old age in Africa. Advanced age over 40 is marked by an upsurge in chronic complications, making it essential to set up a screening program and to organize multidisciplinary follow-up.

Characteristics of Emergency Department Visits Made by Individuals With Sickle Cell Disease in the U.S., 1999-2020

Introduction

Individuals living with sickle cell disease experience high levels of morbidity that result in frequent utilization of the emergency department. The objective of this study was to provide updated national estimates of emergency department utilization associated with sickle cell disease in the U.S.

Methods

Data from the National Hospital Ambulatory Medical Care Survey for the years 1999-2020 were analyzed. Complex survey analysis was utilized to produce national estimates overall and by patient age groups.

Results

On average, approximately 222,612 emergency department visits occurred annually among individuals with sickle cell disease, a nearly 13% increase from prior estimates. The annual volume of emergency department visits steadily increased over time, and pain remains the most common patient-cited reason for visiting the emergency department. Patient-reported pain levels for individuals with sickle cell disease were high, with 64% of visits associated with severe pain and 21% associated with moderate pain. Public insurance sources continue to cover most visits, with Medicaid paying for 60% of visits and Medicare paying for 12% of visits. The average time spent in the emergency department increased from previous estimates by about an hour, rising to approximately 6 hours. The average wait time to see a provider was 53 minutes.

Conclusions

Utilization of the emergency department by individuals living with sickle cell disease remains high, especially for pain. With more than half of patients with sickle cell disease reporting severe pain levels, emergency department staff should be prepared to assess and treat sickle cell disease-related pain following evidence-based guidelines and recommendations. The findings of this study can help improve care in this population.

Impact of community health workers on quality of life in adolescents and young adults with sickle cell disease: The SHIP-HU study

Health-related quality of life (HRQoL) is an important outcome for patients with sickle cell disease (SCD). It is often poor compared with other chronic medical conditions or measured as a multidomain disease-specific construct. We previously reported outcomes in the Start Healing in Patients with Hydroxyurea (SHIP-HU) randomized controlled trial in adolescents and adults with SCD at six clinical sites. Besides the primary outcomes, we also measured HRQoL as a secondary outcome. Patients in the intervention arm were each assigned community health workers (CHWs) who provided case management services. CHW services were independent of medical management, and medical managers were blinded to the study arm. Patients in the control arm received only standard of care. We hypothesized that having a CHW would improve HRQoL in patients enrolled in SHIP-HU. We did not find significant differences between domains of HRQoL in the two study arms. Possible explanations include selection bias of enrolled versus unenrolled patients, selection bias of sites, medical providers and medical management, enforced blinding, and a lack of cooperation between medical managers and CHWs. The importance of CHWs and HRQoL is nonetheless recognized based on the literature. Future interventions on HRQoL in SCD should consider alternative study designs and multimodal interventions.

Characterizing epigenetic aging in an adult sickle cell disease cohort

ABSTRACT

Sickle cell disease (SCD) affects ∼100 000 predominantly African American individuals in the United States, causing significant cellular damage, increased disease complications, and premature death. However, the contribution of epigenetic factors to SCD pathophysiology remains relatively unexplored. DNA methylation (DNAm), a primary epigenetic mechanism for regulating gene expression in response to the environment, is an important driver of normal cellular aging. Several DNAm epigenetic clocks have been developed to serve as a proxy for cellular aging. We calculated the epigenetic ages of 89 adults with SCD (mean age, 30.64 years; 60.64% female) using 5 published epigenetic clocks: Horvath, Hannum, PhenoAge, GrimAge, and DunedinPACE. We hypothesized that in chronic disease, such as SCD, individuals would demonstrate epigenetic age acceleration, but the results differed depending on the clock used. Recently developed clocks more consistently demonstrated acceleration (GrimAge, DunedinPACE). Additional demographic and clinical phenotypes were analyzed to explore their association with epigenetic age estimates. Chronological age was significantly correlated with epigenetic age in all clocks (Horvath, r = 0.88; Hannum, r = 0.89; PhenoAge, r = 0.85; GrimAge, r = 0.88; DunedinPACE, r = 0.34). The SCD genotype was associated with 2 clocks (PhenoAge, P = .02; DunedinPACE, P < .001). Genetic ancestry, biological sex, β-globin haplotypes, BCL11A rs11886868, and SCD severity were not associated. These findings, among the first to interrogate epigenetic aging in adults with SCD, demonstrate epigenetic age acceleration with recently developed epigenetic clocks but not older-generation clocks. Further development of epigenetic clocks may improve their predictive ability and utility for chronic diseases such as SCD.

Comparison of in-hospital mortality in children and adolescents with sickle cell disease in a resource-limited setting before and during the COVID-19 pandemic

BACKGROUND

COVID-19 in children and adolescents with sickle cell disease (SCD) has variable presentations (from mild to severe disease), and the main symptoms are vaso-occlusive crises (VOC) and acute chest syndrome (ACS). We hypothesized that the desertion of hospitals due to the pandemic would lead to late arrival at the emergency room and an increased mortality. In this study, we sought to measure and compare the mortality of children with sickle cell disease before and during the COVID-19 pandemic.

MATERIAL AND METHODS

We conducted a retrospective cohort study at the sickle cell disease management center of Laquintinie Hospital in Douala (Cameroon). The study period was divided into two, i.e., from March 2019 to February 2020 (Pre-COVID-19) and from March 2020 to February 2021 (COVID-19). All administrative and ethical considerations were fully respected. Data were analyzed using SPSS 20.0.

RESULTS

Overall, 823 patients were admitted during the study period. Males represented 52.4% of the overall population, giving a sex ratio of 1.1:1. We admitted 479 patients during the pre-COVID-19 period versus 344 patients during the COVID-19 period, which is a 28.2% drop in admissions during the COVID-19 period. The mortality rate was 3.5% during the pre-COVID-19 period and 3.2% during the COVID-19 period (p>0.05). The most common causes of death were ACS (39.3%, n = 11), severe anemia (25.0%, n = 7), and VOC (17.9%, n = 5). ACS (adjusted odds ratio [aOR]=3.628, 95% confidence interval [CI], [1.645-7.005], p<0.001) was significantly associated with mortality.

CONCLUSION

During the COVID-19 pandemic, although the consultation frequency decreased, the mortality rate of sickle cell disease patients remained unchanged.

Preferences for potential benefits and risks for gene therapy in the treatment of sickle cell disease

Objective of this study is to quantify benefit-risk tradeoffs pertaining to potential gene therapies among adults and parents/caregivers of children with sickle cell disease (SCD). A discrete-choice experiment survey was developed in which respondents selected their preferred treatment alternatives in a series of experimentally controlled pairs of hypothetical gene therapies and a "no gene therapy" option. Gene therapy alternatives were defined based on the chance of eliminating SCD symptoms, expected increases in life expectancy they could offer, treatment-related risk of death, and potential increases in lifetime cancer risk. Respondents made selections based on their current disease severity and in the context of expectations of worsened disease. Three clinical sites and 1 patient organization recruited 174 adult patients and 109 parents of children with SCD to complete the survey. Adult and parent respondents were generally willing to choose gene therapies, but the adults required higher expected levels of efficacy (ie, higher chance of eliminating symptoms) than parents to choose gene therapies that conferred mortality risks of ≥10%. When adults and parents of children with less severe symptoms were asked to consider scenarios of higher levels of disease severity, the increased risk tolerance, and the lowest acceptable level of efficacy for gene therapies with mortality risks dropped by >50%. Baseline SCD symptoms are a major driver of gene therapy acceptability. Adults and parents of patients with milder symptoms may prefer other treatment options; however, an expectation of symptoms deterioration triggers strong reassessment of the acceptable benefit-risk balance of this novel technology.

Illness Intrusiveness in Adults with Sickle Cell Disease: The Role of Fatigue

Chronic illness experiences often interfere with daily functioning (a concept known as illness intrusiveness) and health-related quality of life (HRQoL). However, less is known about the role of specific symptoms in predicting illness intrusiveness in sickle cell disease (SCD). This exploratory study examined associations between common SCD-related symptoms (i.e., pain, fatigue, depression, and anxiety), illness intrusiveness, and HRQoL among adults with SCD (n = 60). Illness intrusiveness significantly correlated with fatigue severity (r = .39, p = .002), depression severity (r = .45, p < .001), anxiety severity (r = .41, p = .001), physical HRQoL (r = - .53, p < .001), and mental HRQoL (r = - .44, p < .001). Multiple regression revealed a significant overall model, (R2 = .28, F(4, 55) = 5.21, p = .001), with fatigue, but not pain, depression, or anxiety, significantly predicting illness intrusiveness (β = .29, p = .036). Results suggest that fatigue may be a primary factor contributing to illness intrusiveness-a determinant of HRQoL-in individuals with SCD. Given the limited sample size, larger confirmatory studies are warranted.

Understanding multi-level barriers to medication adherence among adults living with sickle cell disease

There is limited research that identifies and examines multi-level barriers to medication adherence among adults with Sickle Cell Disease (SCD); Identify multi-level barriers to medication adherence among adults with SCD; and Examine the relationship between multi-level barriers and medication adherence levels. A cross-sectional study included 130 adults (ages ≥ 18 years old) living with SCD who receive treatment/care from one of the 10 adult SCD clinics within the Networking California for sickle cell care initiative. Study measures included the medication adherence report scale (Professor Rob Horne), Beliefs about Medicine Questionnaire (Professor Rob Horne), and patient reported outcomes measurement information system. Participants reported barriers to medication adherence across 3 levels: Community-level barriers (e.g., COVID-19 pandemic); Institutional-level barriers (e.g., bad experiences with the health care system); and Individual-level barriers (e.g., beliefs and depression severity). Depression severity and patient concerns about SCD medication were inversely correlated with medication adherence (rs = -0.302, P < .001; rs = -0.341, P < .001 respectively). Patient beliefs about the necessity of SCD medication were insignificantly correlated with medication adherence (rs = 0.065, P = .464). Medication adherence was higher among patients who had fewer adherence barriers than multiple adherence barriers (Median medication adherence: fewer barriers = 22 vs multiple barrier = 20.50, P = .085), suggesting clinical significance although statistically insignificant. Identifying multi-level adherence barriers and examining their relationship with medication adherence will help develop targeted public health strategies to promote improved medication adherence and wellness among adults with SCD.

A Newborn Screening Program for Sickle Cell Disease in Murcia (Spain)

Sickle cell disease (SCD) is an inherited autosomal recessive hemoglobin disorder caused by the presence of hemoglobin S, a mutant abnormal hemoglobin caused by a nucleotide change in codon 6 of the β-globin chain gene. SCD involves a chronic inflammatory state, exacerbated during vaso-occlusive crises, which leads to end-organ damage that occurs throughout the lifespan. SCD is associated with premature mortality in the first years of life. The process of sickling provokes asplenia in the first years of life with an increased risk of infection by encapsulated germs. These complications can be life-threatening and require early diagnosis and management. The most important interventions recommend an early diagnosis of SCD to ensure that affected newborns receive immediate care to reduce mortality and morbidity. The newborn screening program in the region of Murcia for SCD began in March 2016. We aimed to determine the incidence of sickle cell anemia and other structural hemoglobinopathies in the neonatal population of the region of Murcia, an area of high migratory stress, and to systematically assess the benefit of newborn screening for SCD, leading to earlier treatment, as well as to offer genetic counseling to all carriers. The prevalence of SCD in our region is similar to others in Spain, except for Catalonia and Madrid. The newborns with confirmed diagnoses of SCD received early attention, and all the carriers received genetic counseling.

Invasive Bacterial Infections in Children With Sickle Cell Disease: 2014-2019

BACKGROUND

Children with sickle cell disease (SCD) are at a high risk of invasive bacterial infections (IBI). Universal penicillin prophylaxis and vaccination, especially against Streptococcus pneumoniae, have deeply changed its epidemiology. Analysis of IBI in children with SCD in a post-13-valent pneumococcal vaccine era is limited.

METHODS

Twenty-eight pediatric hospitals from 5 European countries retrospectively collected IBI episodes in SCD children aged 1 month to 18 years between 2014 and 2019. IBI was defined as a positive bacterial culture or polymerase chain reaction from a normally sterile fluid: blood, cerebrospinal, joint, or pleural fluid and deep surgical specimen.

RESULTS

We recorded 169 IBI episodes. Salmonella spp. was the main isolated bacteria (n = 44, 26%), followed by Streptococcus pneumonia (Sp; n = 31, 18%) and Staphylococcus aureus (n = 20, 12%). Salmonella prevailed in osteoarticular infections and in primary bacteremia (45% and 23% of episodes, respectively) and Sp in meningitis and acute chest syndrome (88% and 50%, respectively). All Sp IBI occurred in children ≤10 years old, including 35% in children 5 to 10 years old. Twenty-seven (17%) children had complications of infection and 3 died: 2 because of Sp, and 1 because of Salmonella. The main risk factors for a severe IBI were a previous IBI and pneumococcal infection (17 Sp/51 cases).

CONCLUSIONS

In a post-13-valent pneumococcal vaccine era, Salmonella was the leading cause of bacteremia in IBI in children with SCD in Europe. Sp came second, was isolated in children ≤10 years old, and was more likely to cause severe and fatal cases.

Recent national trends in outcomes and economic disparities among adult sickle cell disease-related admissions

Sickle cell disease (SCD) is an inherited disorder caused secondary to a mutation in the hemoglobin beta subunit. There is sparse information regarding the trends in outcomes of SCD admissions in the past decade where rapid advances have been made in treatment. In this study, we wanted to analyze the trends and outcomes of SCD admissions in the United States from 2011 to 2019 and the influence of socio-economic status. Data were obtained from the National Inpatient Sample (NIS) database using the International Classification of Disease (ICD-9) and ICD-10 codes. Trends for primary in-hospital outcomes including mortality, length of stay (LOS), and total hospitalization charges (THC) were assessed. The impact of economic status on these outcomes was also studied. There was an annual percent change (APC) in the number of admissions for SCD of + 2.5% from 2010 to 2015 (95% CI: 1.3-3.8%, p = 0.003). However, there was no significant change in the number of admissions between 2015 and 2019 (95% CI - 1.8-0.7%, p = 0.323). The overall mortality across the years has decreased by about 4% yearly at the population level (p = 0.008, 95% CI 2-8%). However, the inpatient mortality for the high-income group had decreased significantly from 2010 to 2019, whereas there was no difference in the mortality rate for the low-income group across the decade. Despite the advances in the understanding of SCD and its treatment, its benefits have not reached all the people affected. Meaningful progress in healthcare is not achievable unless these economic disparities are addressed. Economic policies to address these inequities are the need of the hour.

The Occurrence of Depression Among Adults With Sickle Cell Disease in Saudi Arabia

Introduction Sickle cell disease (SCD) is recognized as a widely prevalent genetic disorder that impacts individuals globally and is inherited within families. The primary cause of SCD is a singular genetic mutation that affects the globin chain of the hemoglobin protein. Depression and its symptoms are frequently observed in individuals with SCD. This observation has led to a higher probability of adverse health outcomes. Therefore, the primary objective of this study was to analyze depression among Saudi Arabian adults with sickle cell disease. Method The online survey questionnaire was administered in both Arabic and English to collect essential information regarding SCD distress among the urban adult population in Saudi Arabia, using a cross-sectional study design. Data analysis was conducted using IBM SPSS software version 25 (IBM Corp., Armonk, NY, USA) and Microsoft Excel (Microsoft Corporation, Redmond, WA, USA). The study was designed with a statistical power of 80% at a cut-off value of 0.05 and 0.2. Diverse statistical approaches have been utilized to examine the connection between independent variables, including methods such as Chi-square analysis and Pearson's statistical assessment. Result A total of 685 respondents were included in the survey for this study, with the majority of the participants from the eastern region (31%) and between the age groups of 25 and 30 years (34%) showing a lot of enthusiasm There was a clear dominance of the Saudi population (71%) who spoke Arabic (83%). Female (65%) participants showed more interest in this survey. The collected data were organized comprehensively in tables to facilitate a better understanding of the study's findings. P-values less than 0.05 were considered significant for the obtained results. Conclusion The study has shown that there were a variety of depression entanglements as a result of SCD, but they were handled well with the necessary measures by medical care professionals with much-needed psychological counseling and well-equipped medical facilities.

10-Year Cumulative Incidence and Indications for Revision Total Knee Arthroplasty Among Patients Who Have Sickle Cell Disease

BACKGROUND

Literature regarding total knee arthroplasty (TKA) outcomes in sickle cell disease (SCD) is limited. Moreover, 10-year survivorship of SCD implants is unknown. This study aimed to observe 10-year cumulative incidence and indications for revision TKA in patients who did and did not have SCD.

METHODS

Patients who underwent primary TKA were identified using a large national database. The SCD patients were matched by age, sex, and a comorbidity index to a control cohort in a 1:4 ratio. The 10-year cumulative incidence rates were determined using Kaplan-Meier survival analyses. Multivariable analyses were conducted using Cox proportional hazard modeling. Chi-squared analyses were conducted to compare indications for revision between cohorts. In total, 1,010 SCD patients were identified, 100,000 patients included in the unmatched control, and 4,020 patients included in the matched control.

RESULTS

Compared to the unmatched control cohort, SCD patients exhibited higher 10-year all-cause revision (HR: 1.86; P < .001) with higher proportions of revisions for periprosthetic joint infection (PJI) (P < .001), aseptic loosening (P < .001), and hematoma (P < .001). Compared to the matched control, SCD patients had higher 10-year all-cause revision (Hazard Ratio (HR): 1.39; P = .034) with a higher proportion of revisions for PJI (P = .044), aseptic loosening (P = .003), and hematoma (P = .019).

CONCLUSION

Independent of other comorbidities, SCD patients are more likely to undergo revisions for PJI, aseptic loosening, and hematoma compared to patients who do not have SCD. Due to the high-risk of these complications, perioperative and postoperative surgical optimization should be enforced in SCD patients.

Determinants of ventricular arrhythmias in sickle cell anemia: toward better prevention of sudden cardiac death

Sudden death is 1 of the leading causes of death in adults with sickle cell anemia (SCA) but its etiology remains mostly unknown. Ventricular arrhythmia (VA) carries an increased risk of sudden death; however, its prevalence and determinants in SCA are poorly studied. This study aimed to identify the prevalence and predictors of VA in patients with SCA. From 2019 to 2022, 100 patients with SCA were referred to the physiology department to specifically analyze cardiac function and prospectively included in the DREPACOEUR registry. They underwent a 24-hour electrocardiogram monitoring (24h-Holter), transthoracic echocardiography, and laboratory tests on the same day. The primary end point was the occurrence of VA, defined as sustained or nonsustained ventricular tachycardia (VT), >500 premature ventricular contractions (PVCs) on 24h-Holter, or a recent history of VT ablation. The mean patient age was 46 ± 13 years, and 48% of the patients were male. Overall, VA was observed in 22 (22%) patients. Male sex (81% vs 34%; P = .02), impaired global longitudinal strain (GLS): -16% ± 1.9% vs -18.3% ± 2.7%; P = .02), and decreased platelet count (226 ± 96 giga per liter [G/L] vs 316 ± 130 G/L) were independently associated with VA. GLS correlated with PVC load every 24 hours (r = 0.39; P < .001) and a cutoff of -17.5% could predict VA with a sensitivity of 82% and a specificity of 63%. VAs are common in patients with SCA, especially in men. This pilot study uncovered GLS as a valuable parameter for improving rhythmic risk stratification.

Cervical precancer screening with HPV DNA testing and mobile colposcopy in women with sickle cell disease in Accra, Ghana

Background

Worldwide, about 20-25 million people are affected by sickle cell disease (SCD), with 60% of patients living in sub-Saharan Africa. Despite recent therapeutic advancements resulting in improved life expectancy among SCD patients, the prevalence of high-risk human papillomavirus (hr-HPV) and cervical lesions have not been studied in women with SCD. We determined the prevalence of hr-HPV and cervical lesions among women with SCD and recommended strategies for reducing cervical cancer incidence in this cohort.

Methods

Through the mPharma 10,000 Women Initiative, women with SCD attending routine visits at the Ghana Institute of Clinical Genetics SCD clinic were screened by trained nurses. Screening was performed via concurrent MA-6000 hr-HPV DNA testing and enhanced visual assessment (EVA) mobile colposcopy from mobileODT.

Results

Among 168 participants screened (mean age, 43.0 years), the overall prevalence rates of hr-HPV infection and cervical lesions were 28.6% (95% CI, 21.7-35.4) and 3.6% (95% CI, 0.8-6.4), respectively. The hr-HPV prevalence rates stratified by haemoglobin genotype were 29.4% (95% CI, 19.7-39.1) and 28.6% (95% CI, 18.5-38.7) for genotypes SS and SC, respectively. None of the five women with the SF genotype tested hr-HPV positive, and the only patient with Sbthal genotype tested hr-HPV positive. Two women were EVA 'positive' but hr-HPV negative, whereas four were EVA positive and hr-HPV positive. Exploratory analysis revealed no significant associations between hr-HPV positivity and age, education level, marital status or parity.

Conclusion

In the absence of a comprehensive national cervical screening programme aimed at including women with SCD as a special population, cervical cancer may increase in frequency among SCD patients. Thus, there is a need to build capacity and expand the scope of screening services for women with SCD.

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.