Sickle-cell disease

The effect of red blood cell disorders on male fertility and reproductive health

Male infertility is defined as a failure to conceive after 12 months of unprotected intercourse owing to suspected male reproductive factors. Non-malignant red blood cell disorders are systemic conditions that have been associated with male infertility with varying severity and strength of evidence. Hereditary haemoglobinopathies and bone marrow failure syndromes have been associated with hypothalamic-pituitary-gonadal axis dysfunction, hypogonadism, and abnormal sperm parameters. Bone marrow transplantation is a potential cure for these conditions, but exposes patients to potentially gonadotoxic chemotherapy and/or radiation that could further impair fertility. Iron imbalance might also reduce male fertility. Thus, disorders of hereditary iron overload can cause iron deposition in tissues that might result in hypogonadism and impaired spermatogenesis, whereas severe iron deficiency can propagate anaemias that decrease gonadotropin release and sperm counts. Reproductive urologists should be included in the comprehensive care of patients with red blood cell disorders, especially when gonadotoxic treatments are being considered, to ensure fertility concerns are appropriately evaluated and managed.

A Review of Gene Therapies for Hemoglobinopathies

Due to the significant morbidity and mortality of hemoglobinopathies, curative options have long been pursued. The overall goal of gene therapy is to modify a patient's own hematopoietic stem cells to overcome the deleterious effects of the underlying genetic defect by gene addition, gene editing, or gene silencing. Gene addition incorporates genes with superior function than the abnormal gene; gene editing takes advantage of molecular tools such as zinc finger proteins, Transcription Activator-Like Effector Nucleases and Clustered Regularly Interspaced Short Palindromic Repeats coupled with Cas9 proteins (CRISPR-Cas9) which allow for sequence-specific breaks in DNA that disrupt gene function; and gene silencing suppresses gene expression by interference with mRNA transcription/protein translation or epigenetic modification. The majority of gene therapy strategies for hemoglobinopathies have targeted erythroid-specific BCL11A, a major regulator of fetal hemoglobin repression at the gamma-globin locus, in the normal fetal-to-adult hemoglobin switch that occurs shortly after birth. Other goals have involved the incorporation of anti-sickling globins, such as βT87Q or βAS3. Landmark clinical trials of gene therapy in transfusion-dependent thalassemia and sickle cell disease have shown remarkable efficacy and acceptable safety and culminated in recent regulatory approvals of gene therapy for both diseases in Europe and the United States.

The role of preoperative transfusion in sickle cell disease, a systematic review and meta-analysis

This systematic review and meta-analysis aimed to provide guidance on preoperative blood transfusion strategies for patients with sickle cell disease (SCD). We included all randomized controlled and observational studies exploring the clinical outcomes of preoperative blood transfusion among patients with SCD compared to the conservative transfusion strategy until 14/09/2022. Sixteen studies involving 3486 participants were analysed. The findings revealed a significantly higher bleeding rate in patients who received preoperative transfusion than those who followed a conservative strategy (RR = 4.32, 95% CI 1.75-10.68, P = 0.002, I2 = 0%). However, the two strategies had no significant differences in other clinical outcomes, such as acute chest syndrome, painful crisis, fever, neurological complications, thrombosis, ICU admission, and mortality. It is important to note that all the included studies had a moderate risk of bias. Preoperative transfusion in SCD was associated with a higher bleeding risk but a similar risk in other outcomes compared to conservative strategies. Notably, the increased bleeding risk observed seldom had clinical significance. We recommend individualizing management strategies, considering the overall positive impact of transfusions in reducing complications. Further high-quality studies are needed to refine recommendations.

Hospitalization Events Among Adolescents and Adults With Sickle Cell Disease in a Tertiary Care Center in Central India

BACKGROUND

Sickle cell disease (SCD) is an inherited red blood cell disorder, wherein mutation causes the substitution of glutamic acid to valine at the sixth position of the β-globin chain. These include sickle cell anemia (homozygous sickle mutation), sickle-beta thalassemia, and hemoglobin SCD. The clinical manifestations of SCD are protean. Individuals with SCD suffer from both acute and chronic complications, which include recurring episodes of pain commonly called vaso-occlusive crisis (VOC) - acute chest syndrome (ACS); aseptic necrosis of the bone; micro-infarction of the spleen, brain, and kidney; infections; stroke; and organ damage affecting every part of the body. SCD necessitates frequent hospitalizations because of severe complications, which pose a significant burden on caregivers and economic strain on healthcare systems. The pattern of hospital admission with SCD varies in different parts of the world.

OBJECTIVE

This study aimed to determine the causes of hospitalization among adolescent and adult patients with SCD and to determine factors associated with their hospital stay.

METHODS

The study was a hospital-based prospective observational study comprising adolescent and adult patients diagnosed with SCD, aged 15-45 years, who were hospitalized in the Department of General Medicine at All India Institute of Medical Sciences in Raipur from August 2021 to August 2022.

RESULT

According to our study, the primary reason for hospitalization was a painful crisis, accounting for 63% of cases, followed by infection (17%), ACS (11%), and acute hemolytic crisis (9%). Notably, we did not observe any significant differences between genders and causes of admission (p > 0.05). Joint pain (p = 0.005), back pain (p = 0.001), and chest pain (p = 0.001) were more frequently reported by adults over the age of 19. In addition, our analysis of the duration of hospital stays and various factors revealed that patients admitted for infections had a significantly longer mean hospital stay duration (p = 0.040).

CONCLUSION

Acute painful crises were the primary cause of hospital admission among individuals with SCD; many patients also encountered infections and ACS. Furthermore, patients who experienced infections and VOC had a lengthier duration of hospital stay. Therefore, it is essential to provide them with comprehensive instructions on various preventive measures against infections and the factors that trigger painful crises.

Revolutionising healing: Gene Editing's breakthrough against sickle cell disease

Recent advancements in gene editing illuminate new potential therapeutic approaches for Sickle Cell Disease (SCD), a debilitating monogenic disorder caused by a point mutation in the β-globin gene. Despite the availability of several FDA-approved medications for symptomatic relief, allogeneic hematopoietic stem cell transplantation (HSCT) remains the sole curative option, underscoring a persistent need for novel treatments. This review delves into the growing field of gene editing, particularly the extensive research focused on curing haemoglobinopathies like SCD. We examine the use of techniques such as CRISPR-Cas9 and homology-directed repair, base editing, and prime editing to either correct the pathogenic variant into a non-pathogenic or wild-type one or augment fetal haemoglobin (HbF) production. The article elucidates ways to optimize these tools for efficacious gene editing with minimal off-target effects and offers insights into their effective delivery into cells. Furthermore, we explore clinical trials involving alternative SCD treatment strategies, such as LentiGlobin therapy and autologous HSCT, distilling the current findings. This review consolidates vital information for the clinical translation of gene editing for SCD, providing strategic insights for investigators eager to further the development of gene editing for SCD.

Investigation on the relationship between hemoglobin concentration and stroke risk: a bidirectional Mendelian randomization study

Background

The relationship between hemoglobin concentration and stroke has garnered significant interest in the research community. However, findings from published observational epidemiological studies on this relationship have been inconclusive. By using publicly available genome-wide association study (GWAS) aggregated statistics, a two-sample Mendelian randomization analysis is conducted to explore the causal relationship between hemoglobin concentration and stroke.

Methods

Summary statistics data from UK Biobank for hemoglobin concentration and from the FinnGen R9 and MEGASTROKE consortium for stroke are used. A series of quality control steps are taken to select eligible instrumental SNPs closely related to exposure. In order to make the conclusion more robust and reliable, several robust analysis methods are employed including inverse variance weighted, weighted median, MR-Egger regression, which are based on different assumptions of two-sample MR Analysis. Meanwhile, sensitivity analyses such as pleiotropy test and MR-Egg regression, are performed to mitigate horizontal pleiotropy and heterogeneity.

Results

The two-sample Mendelian randomized study indicates a negative association between hemoglobin concentration and stroke, suggesting that hemoglobin concentration acts as a protective factor against stroke. From the FinnGen database, there is a negative association between hemoglobin concentration and stroke, with an odds ratio (OR) of 0.82 and a 95% confidence interval (CI) of 0.73-0.92, p = 0.0006. Similarly, the MEGASTROKE database findings reinforce this observation. The negative association between hemoglobin concentration and stroke (OR: 0.91, 95%CI: 0.83-1.00, p = 0.040), ischemic stroke (OR: 0.87, 95%CI: 0.79-0.96, p = 0.004), and cardiogenic stroke (OR: 0.82, 95% CI: 0.69-0.99, p = 0.039) further suggests that higher hemoglobin levels might confer a protective effect against these conditions.

Conclusion

Hemoglobin concentration serves as a protective factor against stroke, and managing abnormal hemoglobin levels can effectively reduce the incidence of stroke.

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.

Acute care utilization among individuals with sickle cell disease and related cardiopulmonary and renal complications

Cardiopulmonary and renal end organ (CPR) complications are associated with early mortality among individuals with sickle cell disease (SCD). However, there is limited knowledge regarding acute care utilization for individuals with SCD and CPR complications. Our objective was to determine the prevalence of CPR complications in a state specific SCD population and compare acute care utilization among individuals with and without CPR complications. We leveraged 2017-2020 data for individuals with SCD identified by the Sickle Cell Data Collection program in Wisconsin. The prevalence of CPR complications is determined for distinct age groups. Generalized linear models adjusted for age compared the rate of acute care visits/person/year among individuals who had cardiopulmonary only, renal only, both cardiopulmonary and renal, or no CPR complications. There were 1378 individuals with SCD, 52% females, mean (SD) age 28.3 (18.5) years; 48% had at least one CPR complication during the study period. The prevalence of CPR complications was higher in adults (69%) compared to pediatric (15%) and transition (51%) groups. Individuals with SCD and cardiopulmonary complications had higher acute visit rates than those without CPR complications (5.4 (IQR 5.0-5.8) vs 2.4 (IQR 2.1-2.5), p <0.001)). Acute care visit rates were similar between individuals with SCD who had renal only complications and no CPR complications (2.7 (IQR 2.5-3.0) vs 2.4 (2.1-2.5), p = 0.24). The high acute care visit rates, especially for those with cardiopulmonary complications, warrant further investigation to understand risk factors for CPR complications, the underlying reasons and identify effective disease management strategies.

TSH Receptor Reduces Hemoglobin S Polymerization and Increases Deformability and Adhesion of Sickle Erythrocytes

SCD is a hereditary disorder caused by genetic mutation in the beta-globin gene, resulting in abnormal hemoglobin, HbS that forms sickle-shaped erythrocytes under hypoxia. Patients with SCD have endocrine disorders and it was described that 7% of these patients have clinical hypothyroidism. Recent studies have shown that mature erythrocytes possess TSH receptors. Thus, we aimed to assess the effects of TSH on SCD erythrocytes. The experiments were conducted using different concentrations of TSH (1, 2, 3, and 5 mIU/L). In HbS polymerization assay, erythrocytes were exposed to TSH in hypoxia to induce polymerization, and measurements were taken for 30 minutes. The deformability assay was made using Sephacryl-S 500 columns to separate deformable from nondeformable cells. Static adhesion test utilized thrombospondin to assess erythrocyte adhesion in the presence of TSH. TSH at all contractions were able to reduce polymerization of HbS and increase deformability. The static adhesion of erythrocytes at the lowest concentrations of 1 and 2 mIU/L were increased, but at higher contractions of 3 and 5 mIU/L, static adhesion was not modulated. The results suggest that TSH has potential involvement in the pathophysiology of sickle cell disease by inhibiting HbS polymerization, positively modulating deformability and impacting static adhesion to thrombospondin.

Diagnosis and management of chronic thromboembolic pulmonary hypertension (CTEPH) in sickle cell disease: A review

Pulmonary hypertension in sickle cell disease (SCD) is a complex phenomenon resulting from multiple overlapping etiologies, including pulmonary vasoconstriction in the setting of chronic hemolytic anemia, diastolic dysfunction, and chronic thromboembolic disease. The presence of pulmonary hypertension of any cause in SCD confers a significant increase in mortality risk. Evidence to guide the management of patients with sickle cell disease and chronic thromboembolic pulmonary hypertension (CTEPH) is scant and largely the realm of case reports and small case series. Centered on a discussion of a complex young patient with hemoglobin hemoglobin SC who ultimately underwent treatment with pulmonary thromboendarterectomy, we review the available literature to guide management and discuss and overview of treatment of CTEPH in SCD, considering the unique considerations and challenges facing patients suffering from this multisystem disease.

The crucial role of NRF2 in erythropoiesis and anemia: Mechanisms and therapeutic opportunities

The nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor crucial in cellular defense against oxidative and electrophilic stresses. Recent research has highlighted the significance of NRF2 in normal erythropoiesis and anemia. NRF2 regulates genes involved in vital aspects of erythroid development, including hemoglobin catabolism, inflammation, and iron homeostasis in erythrocytes. Disrupted NRF2 activity has been implicated in various pathologies involving abnormal erythropoiesis. In this review, we summarize the progress made in understanding the mechanisms of NRF2 activation in erythropoiesis and explore the roles of NRF2 in various types of anemia. This review also discusses the potential of targeting NRF2 as a new therapeutic approach to treat anemia.

Models of care for sickle cell disease in low-income and lower-middle-income countries: a scoping review

Sickle cell disease has a growing global burden falling primarily on low-income countries (LICs) and lower-middle-income countries (LMICs) where comprehensive care is often insufficient, particularly in rural areas. Integrated care models might be beneficial for improving access to care in areas with human resource and infrastructure constraints. As part of the Centre for Integration Science's ongoing efforts to define, systematise, and implement integrated care delivery models for non-communicable diseases (NCDs), this Review explores models of care for sickle cell disease in LICs and LMICs. We identified 99 models from 136 studies, primarily done in tertiary, urban facilities in LMICs. Except for two models of integrated care for concurrent treatment of other conditions, sickle cell disease care was mostly provided in specialised clinics, which are low in number and accessibility. The scarcity of published evidence of models of care for sickle cell disease and integrated care in rural settings of LICs and LMICs shows a need to implement more integrated models to improve access, particularly in rural areas. PEN-Plus, a model of decentralised, integrated care for severe chronic non-communicable diseases, provides an approach to service integration that could fill gaps in access to comprehensive sickle cell disease care in LICs and LMICs.

The interaction between particles and vascular endothelium in blood flow

Particle-based drug delivery systems have shown promising application potential to treat human diseases; however, an incomplete understanding of their interactions with vascular endothelium in blood flow prevents their inclusion into mainstream clinical applications. The flow performance of nano/micro-sized particles in the blood are disturbed by many external/internal factors, including blood constituents, particle properties, and endothelium bioactivities, affecting the fate of particles in vivo and therapeutic effects for diseases. This review highlights how the blood constituents, hemodynamic environment and particle properties influence the interactions and particle activities in vivo. Moreover, we briefly summarized the structure and functions of endothelium and simulated devices for studying particle performance under blood flow conditions. Finally, based on particle-endothelium interactions, we propose future opportunities for novel therapeutic strategies and provide solutions to challenges in particle delivery systems for accelerating their clinical translation. This review helps provoke an increasing in-depth understanding of particle-endothelium interactions and inspires more strategies that may benefit the development of particle medicine.

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.

Roles of Pharmacists in the Management of Sickle Cell Disease in Adults: A Narrative Review

Background: Sickle cell disease (SCD) is an autosomal, recessive, genetic condition of the sickle cell genes. It affects about 100 000 people in the United States where an estimated 1 out of every 365 black children and 1 out of every 13 black children will be born with SCD and sickle cell trait, respectively. Severe and unpredictable pain crisis are the leading cause of emergency department visit for adult patients with SCD and account for 90% of inpatient hospitalizations and 85% of all acute medical care, as well as high usage of medical resources. The care of patients with SCD is complex and requires a multidisciplinary approach. With a few pharmacotherapeutic options to reduce SCD complications and pain episodes, the role of pharmacists in the medication management is unclear. This article aims to outline the potential role of pharmacists in SCD management. Data sources: The authors searched Medline, PubMed, EMBASE, and Scopus from January 1, 1990 to August 31, 2022, for primary literature that assessed the role of pharmacists in managing patients with SCD. Results: The authors identified relevant studies and summarized the role of pharmacists in SCD management. Conclusions: Access to comprehensive health care is essential to ensure that patients with SCD have decreased hospitalizations and good health-related quality of life. Pharmacists are an integral part of the multidisciplinary health-care team and can help patients with SCD navigate the complexities of health care. Pharmacists are medication experts who are positioned to ensure comprehensive care in the acute and chronic SCD management.

[Sickle cell disease in French Guiana: assessing 30 years of neonatal screening (1992-2021)]

Background

Sickle cell disease is one of the most common genetic diseases in France. In French Guiana, neonatal screening was introduced in 1992, at the same time as other screening programs for childhood diseases. The aim of this study is to describe the organization of newborn screening for sickle cell disease in French Guiana.

Materials and methods

We used several data sources: data collected from hospital records since 2005, activity reports from the national neonatal screening program and data from screening campaigns organized by the Drepaguyane association between 2010 and 2021 on 1,300 subjects. Blood samples from newborns are collected by capillary or venous sampling and absorbed on blotting paper (Guthrie) at the same time as those for other neonatal screenings. The dried papers are sent to the inter-regional laboratory in Lille, for further processing. In Saint-Laurent-du-Maroni, in order to reduce the proportion of people lost to follow-up, a double screening is carried out and the results are returned before discharge from the maternity hospital. All data were entered into an anonymous Excel file. The data were analyzed using STATA software.

Results

Among the 175,593 screened neonates between 1992 and 2021, screening detected 823 infants with sickle cell disease and 17,950 heterozygotes. Sickle cell genotypes include 493 SS (60%), 302 SC (37%) and 28 S-Beta-thalassemia (3%). The incidence of sickle cell disease was 1/213, 95% CI [1/236-1/204], and that of heterozygotes 1/10, IC 95% [1/12-1/8]. The majority of these children (52%) were from the Maroni region. The delay between screening and test results was 7 days. Only pathological results (homozygous, heterozygous) were communicated to parents and/or the attending physician by post. These data confirm the upward trend in the number of children screened for sickle cell disease in French Guiana. Data from screening campaigns organized by the Drepaguyane association have enabled to describe the distribution of the various abnormal hemoglobin fractions, and to confirm that HbS is more frequent in Western French Guiana. In Cayenne, in 2021, the active file comprised 699 patients, including 266 children under 18 years old.

Discussion and conclusion

This study provides valuable data on 30 years of neonatal screening for sickle cell disease in French Guiana, and on the evolution of sickle cell disease patients. It confirms that French Guiana is the French territory with the highest incidence of sickle cell disease. This incidence continues to rise over time. The study reveals the improvement in the organization of sickle cell disease management in French Guiana between 1992, when screening was introduced, and the present day. It highlights the role of patient associations in the fight against this disease, by organizing awareness and screening campaigns. These data will be used to guide public health policies in the pursuit of improved care and primary prevention.

Clearance of VWF by hepatic macrophages is critical for the protective effect of ADAMTS13 in sickle cell anemia mice

ABSTRACT

Although it is caused by a single-nucleotide mutation in the β-globin gene, sickle cell anemia (SCA) is a systemic disease with complex, incompletely elucidated pathologies. The mononuclear phagocyte system plays critical roles in SCA pathophysiology. However, how heterogeneous populations of hepatic macrophages contribute to SCA remains unclear. Using a combination of single-cell RNA sequencing and spatial transcriptomics via multiplexed error-robust fluorescence in situ hybridization, we identified distinct macrophage populations with diversified origins and biological functions in SCA mouse liver. We previously found that administering the von Willebrand factor (VWF)-cleaving protease ADAMTS13 alleviated vaso-occlusive episode in mice with SCA. Here, we discovered that the ADAMTS13-cleaved VWF was cleared from the circulation by a Clec4f+Marcohigh macrophage subset in a desialylation-dependent manner in the liver. In addition, sickle erythrocytes were phagocytized predominantly by Clec4f+Marcohigh macrophages. Depletion of macrophages not only abolished the protective effect of ADAMTS13 but exacerbated vaso-occlusive episode in mice with SCA. Furthermore, promoting macrophage-mediated VWF clearance reduced vaso-occlusion in SCA mice. Our study demonstrates that hepatic macrophages are important in the pathogenesis of SCA, and efficient clearance of VWF by hepatic macrophages is critical for the protective effect of ADAMTS13 in SCA mice.

Substance use disorder of equimolar oxygen-nitrous oxide mixture in French sickle-cell patients: results of the PHEDRE study

BACKGROUND

In many countries, nitrous oxide is used in a gas mixture (EMONO) for short-term analgesia. Cases of addiction, with significant misuse, have been reported in hospitalized patients. Patients suffering from sickle cell disease (SCD) could represent a high-risk population for substance use disorder (SUD) due to their significant pain crisis and repeated use of EMONO. The objective of the PHEDRE study was to assess the prevalence of SUD for EMONO in French SCD patients.

RESULTS

A total of 993 patients were included. Among 339 EMONO consumers, only 38 (11%) had a SUD, with very few criteria, corresponding mainly to a mild SUD due to a use higher than expected (in quantity or duration) and relational tensions with the care teams. Almost all patients (99.7%) were looking for an analgesic effect, but 68% of patients were also looking for other effects. The independent risks factors associated with at least one SUD criterion were: the feeling of effects different from the expected therapeutic effects of EMONO, at least one hospitalization for vaso occlusive crisis in the past 12 months and the presence of a SUD for at least one other analgesic drug.

CONCLUSIONS

The use of EMONO was not problematic for the majority of patients. Manifestations of SUD that led to tensions with healthcare teams should alert and lead to an evaluation, to distinguish a true addiction from a pseudoaddiction which may be linked to an insufficient analgesic treatment related to an underestimation of pain in SCD patients.

TRIAL REGISTRATION

Clinical Trials, NCT02580565. Registered 16 October 2015, https://clinicaltrials.gov/.

Sickle cell disease and increased adverse maternal and perinatal outcomes in different genotypes

BACKGROUND

Sickle cell disease (SCD) comprises a heterogeneous group of inherited hemolytic disorders that increases the risk of maternal and perinatal complications due to chronic systemic inflammatory response, endothelial damage and vaso-occlusion. The contribution of genotypes to the severity of outcomes during pregnancy is not completely established.

METHODS

A retrospective study of medical charts was performed to compare maternal and perinatal outcomes in Hb SS, Hb SC disease and sickle-beta thalassemia (Hb Sβ) pregnancies followed at a high-risk antenatal care unit over a 6-year period. A descriptive analysis of morphological findings was performed of the placenta when pathology reports were available.

RESULTS

Sixty-two SCD pregnant women [25 Hb SS (40 %), 29 Hb SC (47 %) and 8 Hb Sβ (13 %)] were included. Overall, SCD was associated with maternal complications (77 %), preterm birth (30 %), cesarean section (80 %) and a need of blood transfusion. In general there were no statistically significant differences between genotypes. The only significant difference was the hemoglobin level at first antenatal care visit which was lower for the homozygous genotype (7.7 g/dL) compared to Hb SC and Hb Sβ (9.7 g/dL and 8.4 g/dL, respectively; p-value = 0.01). Ten of 15 evaluated placentas showed abnormal morphological findings CONCLUSION: SCD, regardless of the underlying genotype, is associated with increased adverse maternal and perinatal outcomes and placental abnormalities associated with maternal vascular malperfusion.

Simvastatin-Mediated Nrf2 Activation Induces Fetal Hemoglobin and Antioxidant Enzyme Expression to Ameliorate the Phenotype of Sickle Cell Disease

Sickle cell disease (SCD) is a pathophysiological condition of chronic hemolysis, oxidative stress, and elevated inflammation. The transcription factor Nrf2 is a master regulator of oxidative stress. Here, we report that the FDA-approved oral agent simvastatin, an inhibitor of hydroxymethyl-glutaryl coenzyme A reductase, significantly activates the expression of Nrf2 and antioxidant enzymes. Simvastatin also induces fetal hemoglobin expression in SCD patient primary erythroid progenitors and a transgenic mouse model. Simvastatin alleviates SCD symptoms by decreasing hemoglobin S sickling, oxidative stress, and inflammatory stress in erythroblasts. Particularly, simvastatin increases cellular levels of cystine, the precursor for the biosynthesis of the antioxidant reduced glutathione, and decreases the iron content in SCD mouse spleen and liver tissues. Mechanistic studies suggest that simvastatin suppresses the expression of the critical histone methyltransferase enhancer of zeste homolog 2 to reduce both global and gene-specific histone H3 lysine 27 trimethylation. These chromatin structural changes promote the assembly of transcription complexes to fetal γ-globin and antioxidant gene regulatory regions in an antioxidant response element-dependent manner. In summary, our findings suggest that simvastatin activates fetal hemoglobin and antioxidant protein expression, modulates iron and cystine/reduced glutathione levels to improve the phenotype of SCD, and represents a therapeutic strategy for further development.

Nitric oxide: A potential etiological agent for vaso-occlusive crises in sickle cell disease

Nitric oxide (NO), a vasodilator contributes to the vaso-occlusive crisis associated with the sickle cell disease (SCD). Vascular nitric oxide helps in vasodilation, controlled platelet aggregation, and preventing adhesion of sickled red blood cells to the endothelium. It decreases the expression of pro-inflammatory genes responsible for atherogenesis associated with SCD. Haemolysis and activated endothelium in SCD patients reduce the bioavailability of NO which promotes the severity of sickle cell disease mainly causes vaso-occlusive crises. Additionally, NO depletion can also contribute to the formation of thrombus, which can cause serious complications such as stroke, pulmonary embolism etc. Understanding the multifaceted role of NO provides valuable insights into its therapeutic potential for managing SCD and preventing associated complications. Various clinical trials and studies suggested the importance of artificially induced nitric oxide and its supplements in the reduction of severity. Further research on the mechanisms of NO depletion in SCD is needed to develop more effective treatment strategies and improve the management of this debilitating disease.

Acute kidney injury is more common in hospitalised children with sickle cell anaemia in Africa

AIM

To document the prevalence, severity, hospital outcome and factors associated with acute kidney injury (AKI) in hospitalised children with sickle cell anaemia (SCA).

METHODS

In this prospective observational study involving children aged 0.5-17 years with SCA requiring hospitalisation, we used serum creatinine level at 0 and 48 h of hospitalisation to determine the presence of AKI.

RESULTS

The study involved 155 children with SCA aged 0.5-17 years with a median (interquartile range) age of 7.8 (4.3-11.0) years. Acute kidney injury occurred in 27 (17.4%) children with 33.3% reaching stage 3. Hepatomegaly (81.5% vs. 55.4%; p = 0.015), splenomegaly (33.3% vs. 10.9%; p = 0.003), dipstick proteinuria (22.2% vs. 5.4%; p = 0.004), and hematuria (29.6% vs. 3.1%; p = <0.001) were more common in those with AKI. In contrast, children with AKI had lower haematocrit (16.9% vs. 22.2%; p = <0.001) and serum bicarbonate (16.7 vs. 19.1 mmoL/L; p = 0.010) compared with those without AKI. Those with AKI had longer hospital stay (median [interquartile range]: 7 [4-12] days vs. 4 [3-6] days; p = 0.008).

CONCLUSION

AKI is common among hospitalised children with AKI and is associated with longer hospital stay.

ATYPICAL FOVEAL AND PARAFOVEAL ABNORMALITIES IN SICKLE CELL DISEASE

PURPOSE

The primary aim was to describe the patterns of paramacular involvement, not yet reported but that optical coherence tomography angiography can now detect in patients with sickle cell disease. The secondary aim was to search arguments concerning the physiopathogeny of paramacular involvement.

METHODS

This institutional cohort retrospective study was conducted in a Referral Center for Ophthalmological Rare Diseases. Follow-up included an ophthalmologic examination with optical coherent tomography and optical coherent tomography angiography.

RESULTS

One hundred and thirty-two patients with SCD were included. Typical sickle cell maculopathy was observed in temporal area in 84 eyes (40.0%) of SS patients and eight eyes (14.8%) of SC patients ( P < 0.001). Enlargement of the foveal avascular zone was observed in 10 eyes of eight SS patients. Two atypical parafoveal abnormalities were found in SS patients only. The first one consisted of macular thinning with normal vascularization in 15 eyes of 11 patients. The second atypical maculopathy was large areas of loss of vascularization without retinal thinning 10 eyes of six patients. Multivariate analysis did not show a statistically significant relation between the peripheral sickle retinopathy stage and the different type of sickle cell maculopathy ( P = 0.21).

CONCLUSION

Those atypical sickle cell maculopathy may correspond to early forms preceding a typical sickle cell disease maculopathy (SCDM). This would point toward several physiopathogenic mechanisms. The first one included the existence of ischemia that can be related to anemia. Presence of retinal thinning without vascular involvement point out to a neurogenic mechanism.

Readability and Quality of Online Information on Sickle Cell Retinopathy for Patients

PURPOSE

This study aims to evaluate the readability and quality of Internet-based health information on sickle cell retinopathy.

DESIGN

Retrospective cross-sectional website analysis.

METHODS

To simulate a patient's online search, the terms "sickle cell retinopathy" and "sickle cell disease in the eye" were entered into the top 3 search engines (Google, Bing and Yahoo). The first 20 results of each search were retrieved and screened for analysis. The DISCERN questionnaire, the Journal of the American Medical Association (JAMA) standards, and the Health on the Net (HON) criteria were used to evaluate the quality of the information. The Flesch-Kincaid Grade Level (FKGL), the Flesch Reading Ease (FRES), and the Automated Readability Index (ARI) were used to assess the readability of each website.

RESULTS

Of 16 online sources, 12 (75%) scored moderately on the DISCERN tool. The mean DISCERN score was 40.91 (SD, 10.39; maximum possible, 80). None of the sites met all of the JAMA benchmarks, and only 3 (18.75%) of the websites had HONcode certification. All of the websites had scores above the target American Medical Association grade level of 6 on both the FKGL and ARI. The mean FRES was 57.76 (±4.61), below the recommended FRES of 80 to 90.

CONCLUSION

There is limited online information available on sickle cell retinopathy. Most included websites were fairly difficult to read and of substandard quality. The quality and readability of Internet-based, patient-focused information on sickle cell retinopathy needs to be improved.

Monogenic Disorders of ROS Production and the Primary Anti-Oxidative Defense

Oxidative stress, characterized by an imbalance between the production of reactive oxygen species (ROS) and the cellular anti-oxidant defense mechanisms, plays a critical role in the pathogenesis of various human diseases. Redox metabolism, comprising a network of enzymes and genes, serves as a crucial regulator of ROS levels and maintains cellular homeostasis. This review provides an overview of the most important human genes encoding for proteins involved in ROS generation, ROS detoxification, and production of reduced nicotinamide adenine dinucleotide phosphate (NADPH), and the genetic disorders that lead to dysregulation of these vital processes. Insights gained from studies on inherited monogenic metabolic diseases provide valuable basic understanding of redox metabolism and signaling, and they also help to unravel the underlying pathomechanisms that contribute to prevalent chronic disorders like cardiovascular disease, neurodegeneration, and cancer.

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.

A Need for Daycare Unit for Sickle Cell Disease Patients in Oman

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What is the effectiveness of surgical and non-surgical therapies in the treatment of ischemic priapism in patients with sickle cell disease? A systematic review by the EAU Sexual and Reproductive Health Guidelines Panel

Sickle cell disease (SCD) is an inherited hemoglobin disorder characterized by the occlusion of small blood vessels by sickle-shaped red blood cells. SCD is associated with a number of complications, including ischemic priapism. While SCD accounts for at least one-third of all priapism cases, no definitive treatment strategy has been established to specifically treat patients with SC priapism. The aim of this systematic review was to assess the efficacy and safety of contemporary treatment modalities for acute and stuttering ischemic priapism associated with SCD. The primary outcome measures were defined as resolution of acute priapism (detumescence) and complete response of stuttering priapism, while the primary harm outcome was as sexual dysfunction. The protocol for the review has been registered (PROSPERO Nr: CRD42020182001), and a systematic search of Medline, Embase, and Cochrane controlled trials databases was performed. Three trials with 41 observational studies met the criteria for inclusion in this review. None of the trials assessed detumescence, as a primary outcome. All of the trials reported a complete response of stuttering priapism; however, the certainty of the evidence was low. It is clear that assessing the effectiveness of specific interventions for priapism in SCD, well-designed, adequately-powered, multicenter trials are strongly required.

Ambulatory blood pressure monitoring in pediatric patients with sickle cell anemia

INTRODUCTION

Sickle cell anemia (SCA) is a hemoglobinopathy presenting severe endothelial damage associated with increased prevalence of hypertension (HTN). Few studies have used ambulatory blood pressure monitoring (ABPM) in pediatric patients with SCA. The aim of this study was to characterize the ABPM profile in children with SCA.

METHODS

A retrospective cross-sectional study was conducted on all subjects <18 years of age with SCA who presented at a medical reference center in the city of Cartagena, Colombia. Anthropometric, clinical laboratory, treatment, and ABPM parameters, including ambulatory arterial stiffness index (AASI) were registered.

RESULTS

The study included 79 patients, of these, 23 (29%) children had normal BP, 49 (62%) had abnormal BP and 7 (9%) had HTN. Mean age was 10.5 ± 3.6 years and 44 (56%) cases were male. Forty-eight (60%) patients had pre-HTN. Masked HTN was present in 6 (8%) patients. One (1%) had ambulatory HTN, and another one (1%) had white coat HTN. The HTA group exhibited significantly higher systolic BP and diastolic BP compared to the other groups in 24-hour BP readings, daytime BP, and night-time BP ABPM parameters ( P  < 0.05), except for daytime DBP ( P  = 0.08). Mean AASI was 0.4 ± 0.2. The HTN group had the highest AASI value compared to the other groups ( P = 0.006).

CONCLUSION

Significant alterations in ABPM parameters are frequently observed in pediatric patients with SCA. The incorporation of ABPM, along with the assessment of AASI, is recommended for a comprehensive evaluation of cardiovascular and renal risk in SCA patients.

Society for Maternal-Fetal Medicine Consult Series #68: Sickle cell disease in pregnancy

Pregnant individuals with sickle cell disease have an increased risk of maternal and perinatal morbidity and mortality. However, prepregnancy counseling and multidisciplinary care can lead to favorable maternal and neonatal outcomes. In this consult series, we summarize what is known about sickle cell disease and provide guidance for sickle cell disease management during pregnancy. The following are Society for Maternal-Fetal Medicine recommendations.

Rates of Opioid Misuse Amongst Patients Receiving Pain Management for Sickle Cell Disease in An Urban Setting

Background and Objective: Sickle Cell Disease (SCD) is known to cause acute severe pain episodes known as vaso-occlusive crisis (VOC) mainly treated with opioid analgesics. Since the opioid epidemic there is an interest in determining the opioid misuse potential in these patients. Therefore, the primary objective of this study is to determine the rates of opioid misuse among patients with SCD by assessing the rate of unexpected drug screening results in a sickle cell disease clinic. Methods: This was a retrospective chart review study conducted at the outpatient sickle cell disease clinic. The primary independent variables were the prescribed opioid medications while the primary dependent variable was the collected opioid metabolite. Descriptive statistics, linear regression and multivariate logistic regression analysis were conducted using SPSS version 24. Results: A total of 100 participants were recruited from July 1, 2018, to June 30, 2020 with 71 included in the analysis. The total mean of morphine milligram equivalents (MME) for all participants was 71.1±104.9 with 71% of participants having a daily calculated MME of <90MME. The odds of misusing an opioid were 6.72 times higher (P<.02) if a participant used marijuana compared to a participant who didn't. In addition, the odds of misusing an opioid were 2.47 times higher (P<.04) if the patient was prescribed an opioid daily dose greater than 90 MME as opposed to a daily dose less than 90 MME. Conclusion: Participants who consumed greater than 90 MME's per day and utilized marijuana were more likely to misuse opioids.

Inflammation and autoimmunity are interrelated in patients with sickle cell disease at a steady-state condition: implications for vaso-occlusive crisis, pain, and sensory sensitivity

This study aimed to comprehensively analyze inflammatory and autoimmune characteristics of patients with sickle cell disease (SCD) at a steady-state condition (StSt) compared to healthy controls (HCs) to explore the pathogenesis of StSt and its impact on patients' well-being. The study cohort consisted of 40 StSt participants and 23 HCs enrolled between July 2021 and April 2023. StSt participants showed elevated white blood cell (WBC) counts and altered hematological measurements when compared to HCs. A multiplex immunoassay was used to profile 80 inflammatory cytokines/chemokines/growth factors in plasma samples from these SCD participants and HCs. Significantly higher plasma levels of 35 analytes were observed in SCD participants, with HGF, IL-18, IP-10, and MCP-2 being among the most significantly affected analytes. Additionally, autoantibody profiles were also altered, with elevated levels of anti-SSA/Ro60, anti-Ribosomal P, anti-Myeloperoxidase (MPO), and anti-PM/Scl-100 observed in SCD participants. Flow cytometric analysis revealed higher rates of red blood cell (RBC)/reticulocyte-leukocyte aggregation in SCD participants, predominantly involving monocytes. Notably, correlation analysis identified associations between inflammatory mediator levels, autoantibodies, RBC/reticulocyte-leukocyte aggregation, clinical lab test results, and pain crisis/sensitivity, shedding light on the intricate interactions between these factors. The findings underscore the potential significance of specific biomarkers and therapeutic targets that may hold promise for future investigations and clinical interventions tailored to the unique challenges posed by SCD. In addition, the correlations between vaso-occlusive crisis (VOC)/pain/sensory sensitivity and inflammation/immune dysregulation offer valuable insights into the pathogenesis of SCD and may lead to more targeted and effective therapeutic strategies.

Clinical Trial Registration

ClinicalTrials.gov, Identifier: NCT05045820.

Caught between pity, explicit bias, and discrimination: a qualitative study on the impact of stigma on the quality of life of persons living with sickle cell disease in three African countries

PURPOSE

Sickle cell disease (SCD) is an inherited blood disorder characterized by unpredictable episodes of acute pain and numerous health complications. Individuals with SCD often face stigma from the public, including perceptions that they are lazy or weak tending to exaggerate their pain crisis, which can profoundly impact their quality of life (QoL).

METHODS

In a qualitative phenomenological study conducted in Cameroon, Ghana, and Tanzania, we explored stakeholders' perceptions of SCD-related stigma using three analytical frameworks: Bronfenbrenner's Ecological Systems Theory; The Health Stigma and Discriminatory Framework; and A Public Health Framework for Reducing Stigma.

RESULTS

The study reveals that SCD-related stigma is marked by prejudice, negative labelling and social discrimination, with derogatory terms such as sickler, ogbanje (one who comes and goes), sika besa (money will finish), ene mewu (I can die today, I can die tomorrow), vampire (one who consumes human blood), and Efiewura (landlord-of the hospital), commonly used to refer to individuals living with SCD. Drivers of stigma include frequent crises and hospitalizations, distinct physical features of individuals living with SCD, cultural misconceptions about SCD and its association with early mortality. Proposed strategies for mitigating stigma include public health education campaigns about SCD, integrating SCD into school curricula, healthcare worker training and community engagement.

CONCLUSION

The results highlight the importance of challenging stigmatizing narratives on SCD and recognizing that stigmatization represents a social injustice that significantly diminishes the QoL of individuals living with SCD.

Awareness of sickle cell disease among nursing undergraduates in Farasan: Its interference with malaria

Aim

The present study was conducted to generate data on awareness and incidence of sickle cell disease (SCD) and also to adduce the widespread myths peddled about SCD.

Materials and Methods

Students studying in the Department of Nursing were recruited. A pretested, self-administered sickle cell assessment questionnaire was distributed electronically through WhatsApp group to collect necessary data. Participants were screened for malaria by thin blood smear analyses, and their hemoglobin (Hb) contents (g/dL) were determined by Sahli's haemoglobinometer. Statistical analyses were done using Origin (version 8.1, USA). A reliability study was performed for the validity of questionnaire data.

Results

Study participants had significantly high awareness regarding SCDs (89.9%, P < 0.001). Most participants (96.3%) were aware about government policy regarding premarital screening for genetic disorders and replied that the government has strict health policies backed by equally robust laboratory diagnostics. Moreover, none of the participants had SCDs, although their parents had a consanguineous marriage. Thin blood smear analyses of participants did not reveal any cases of Plasmodium falciparum. However, significant percentages (33.1%) were found to be anemic, probably due to their dietary habits and lifestyles, as has been reflected by questionnaire analyses. Furthermore, a very less number of students had knowledge about genetic variations that might occur in malaria-endemic regions after long exposure to offer protection from malaria. Knowledge about management practices was also lacking among study participants (29%).

Conclusion

This research points to the necessity that the nursing study plan should focus on providing specific training on management skills and preventive measures for SCDs, which is of paramount importance.

Genetic variants and effect modifiers of QT interval prolongation in patients with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a common inherited blood disorder among African Americans (AA), with premature mortality which has been associated with prolongation of the heart rate-corrected QT interval (QTc), a known risk factor for sudden cardiac death. Although numerous genetic variants have been identified as contributors to QT interval prolongation in the general population, their impact on SCD patients remains unclear. This study used an unweighted polygenic risk score (PRS) to validate the previously identified associations between SNPs and QTc interval in SCD patients, and to explore possible interactions with other factors that prolong QTc interval in AA individuals with SCD.

METHODS

In SCD patients, candidate genetic variants associated with the QTc interval were genotyped. To identify any risk SNPs that may be correlated with QTc interval prolongation, linear regression was employed, and an unweighted PRS was subsequently constructed. The effect of PRS on the QTc interval was evaluated using linear regression, while stratification analysis was used to assess the influence of serum alanine transaminase (ALT), a biomarker for liver disease, on the PRS effect. We also evaluated the PRS with the two subcomponents of QTc, the QRS and JTc intervals.

RESULTS

Out of 26 candidate SNPs, five risk SNPs were identified for QTc duration under the recessive model. For every unit increase in PRS, the QTc interval prolonged by 4.0 ms (95% CI: [2.0, 6.1]; p-value: <0.001) in the additive model and 9.4 ms in the recessive model (95% CI: [4.6, 14.1]; p-value: <0.001). Serum ALT showed a modification effect on PRS-QTc prolongation under the recessive model. In the normal ALT group, each PRS unit increased QTc interval by 11.7 ms (95% CI: [6.3, 17.1]; p-value: 2.60E-5), whereas this effect was not observed in the elevated ALT group (0.9 ms; 95% CI: [-7.0, 8.8]; p-value: 0.823).

CONCLUSION

Several candidate genetic variants are associated with QTc interval prolongation in SCD patients, and serum ALT acts as a modifying factor. The association of a CPS1 gene variant in both QTc and JTc duration adds to NOS1AP as evidence of involvement of the urea cycle and nitric oxide metabolism in cardiac repolarization in SCD. Larger replication studies are needed to confirm these findings and elucidate the underlying mechanisms.

Neurological abnormalities among pediatric patients with sickle cell disease in Saudi Arabia: a single-center retrospective study

Introduction

Sickle cell disease (SCD) is a common inherited blood disorder characterized by the production of abnormal sickle-shaped red blood cells. SCD can lead to various complications including neurological issues. Early detection and treatment are crucial for preventing these complications. This study aimed to describe the neurological manifestations, radiological findings, and neurological diagnosis related to SCD in Saudi children with the aim of contributing to the formulation of population-based guidelines for screening and treating SCD-related neurological complications.

Methods

This descriptive retrospective study included pediatric patients aged < 14 years diagnosed with SCD who were regularly followed up at the hematology clinic in KAMC, Jeddah, Saudi Arabia, from January 2008 to January 2022. Demographic and clinical data were collected from the clinical charts of 101 participants.

Results

This study included 101 patients with SCD with a mean age of 23 months at diagnosis. Among these, 59% had SCD and high fetal hemoglobin (HbF) levels. Neurological sequelae, including seizures, stroke, and other abnormalities, were observed in 26.7% of patients. There were no significant differences in the onset of neurological issues between the patients with SCD-high HbF and those with other SCD phenotypes.

Discussion

This study highlights the increased risk of brain injury and neurocognitive deficits in children with SCD. The occurrence of neurological sequelae in many patients emphasizes the need for early detection and intervention. Some patients experience neurological complications despite having high HbF levels, suggesting that further interventions are needed. This study has some limitations, including its small sample size and retrospective nature.

Conclusion

Early detection and intervention are crucial for neurological complications in patients with SCD. This study emphasizes the need for further research and effective treatment strategies considering the presence of neurological complications despite the presence of high HbF levels. Large-scale studies and population-specific guidelines are warranted for better understanding and management of SCD-related neurological complications in the Saudi population.

Adherence to Hydroxyurea and Patients' Perceptions of Sickle Cell Disease and Hydroxyurea: A Cross-Sectional Study

Background and Objectives: Hydroxyurea is a crucial treatment for sickle cell disease (SCD), but some patients' adherence to it remains suboptimal. Understanding patients' perspectives on SCD and HU is essential for improving adherence. This study aimed to assess hydroxyurea adherence and patients' perceptions of SCD and hydroxyurea among SCD patients in the Jazan region of Saudi Arabia. Materials and Methods: This cross-sectional study collected data from 217 SCD patients using self-administered questionnaires from August 2022 to January 2023. The survey covered patient demographics, SCD consequences, and other clinical data. We used the Brief Illness Perception Questionnaire (B-IPQ) to measure patients' disease perception and the 8-item Morisky Medication Adherence Scale (MMAS-8) to evaluate patients' adherence to HU. Data were analysed using descriptive, t-test, and chi-square tests, and the p-value was set at <0.05 for significance. Results: More than half of the patients were male, with a mean age of 28.09 ± 8.40 years. About 57.6% of the patients were currently using HU. About 81.6% of HU users reported low adherence. The adherence was lower among individuals with infections/recurrent infections and in patients who received repeated blood transfusions. ICU admission, blood transfusion, and certain SCD complications were associated with HU use. Male patients had a higher perception of SCD consequences, concern, and understanding. ICU-admitted and recurrent hospitalized patients had a higher perception of the SCD-related consequences, symptoms, concerns, and emotional responses. Conclusions: HU seems a well-established and efficacious disease-modifying agent, but its underutilization for SCD patients remains challenging. To overcome the adherence challenges, healthcare providers must educate SCD patients about the role of hydroxyurea in lowering disease severity and addressing side effects to obtain maximum benefits. Healthcare providers may consider tailored educational interventions to improve adherence, particularly for patients with infections, recurrent hospitalizations, or repeated blood transfusions. Further research is needed to identify strategies for improving hydroxyurea adherence and patient education among SCD patients.

In vitro delayed response to dihydroartemisinin of malaria parasites infecting sickle cell erythocytes

BACKGROUND

Decreased efficacy of artemisinin-based combination therapy (ACT) for Plasmodium falciparum malaria has been previously reported in patients with sickle cell disease (SCD). The main purpose of this study was to investigate the in vitro susceptibility of isolates to dihydro-artemisinin (DHA) to provide a hypothesis to explain this treatment failure.

METHODS

Isolates were collected from patients attending health centres in Abidjan with uncomplicated P. falciparum malaria. The haemoglobin type has been identified and in vitro drug sensitivity tests were conducted with the ring stage assay and maturation inhibition assay.

RESULTS

134 isolates were obtained. Parasitaemia and haemoglobin levels at inclusion were lower in patients with haemoglobin HbSS and HbSC than in patients with normal HbAA. After ex vivo RSA and drug inhibition assays, the lowest rate of parasitic growth was found with isolates from HbAS red cells. Conversely, a significantly higher survival rate of parasites ranging from 15 to 34% were observed in isolates from HbSS. Isolates with in vitro reduced DHA sensitivity correlate with lower RBC count and haematocrit and higher parasitaemia at inclusion compared to those with isolates with normal DHA sensitivity. However, this decrease of in vitro sensitivity to DHA was not associated with Kelch 13-Propeller gene polymorphism.

CONCLUSION

This study highlights an in vitro decreased sensitivity to DHA, for isolates collected from HbSS patients, not related to the Pfkelch13 gene mutations. These results are in line with recent studies pointing out the role of the redox context in the efficacy of the drug. Indeed, SCD red cells harbour a highly different ionic and redox context in comparison with normal red cells. This study offers new insights into the understanding of artemisinin selective pressure on the malaria parasite in the context of haemoglobinopathies in Africa.

Evaluating sheep hemoglobins with MD simulations as an animal model for sickle cell disease

Sickle cell disease (SCD) affects millions worldwide, yet there are few therapeutic options. To develop effective treatments, preclinical models that recapitulate human physiology and SCD pathophysiology are needed. SCD arises from a single Glu-to-Val substitution at position 6 in the β subunit of hemoglobin (Hb), promoting Hb polymerization and subsequent disease. Sheep share important physiological and developmental characteristics with humans, including the same developmental pattern of fetal to adult Hb switching. Herein, we investigated whether introducing the SCD mutation into the sheep β-globin locus would recapitulate SCD's complex pathophysiology by generating high quality SWISS-MODEL sheep Hb structures and performing MD simulations of normal/sickle human (huHbA/huHbS) and sheep (shHbB/shHbS) Hb, establishing how accurately shHbS mimics huHbS behavior. shHbS, like huHbS, remained stable with low RMSD, while huHbA and shHbB had higher and fluctuating RMSD. shHbB and shHbS also behaved identically to huHbA and huHbS with respect to β2-Glu6 and β1-Asp73 (β1-Asn72 in sheep) solvent interactions. These data demonstrate that introducing the single SCD-causing Glu-to-Val substitution into sheep β-globin causes alterations consistent with the Hb polymerization that drives RBC sickling, supporting the development of a SCD sheep model to pave the way for alternative cures for this debilitating, globally impactful disease.

Consensus of the Brazilian Association of Hematology, Hemotherapy and Cellular Therapy (ABHH) and the Brazilian Ministry of Health - General management of blood and blood products on the tests necessary for the release of exceptional medicines for sickle cell disease

To date, hydroxyurea is the only effective and safe drug that significantly reduces morbidity and mortality of individuals with Sickle cell disease. Twenty years of real-life experience has demonstrated that hydroxyurea reduces pain attacks, vaso-occlusive events, including acute chest syndrome, the number and duration of hospitalizations and the need for transfusion. The therapeutic success of hydroxyurea is directly linked to access to the drug, the dose used and adherence to treatment which, in part, is correlated to the availability of hydroxyurea. This consensus aims to reduce the number of mandatory exams needed to access the drug, prioritizing the requesting physician's report, without affecting patient safety.

LentiGlobin Administration to Sickle Cell Disease Patients: Effect on Serum Markers and Vaso-Occlusive Crisis

LentiGlobin, an innovative gene therapy, introduces a modified beta-globin gene that yields an anti-sickling hemoglobin variant. It boosts total hemoglobin levels, mitigates hemolysis, curtails inflammation, and addresses iron overload by reducing transfusion requirements. These changes, in turn, provide insights into disease mechanisms and treatment outcomes. Alterations in serum markers, such as hemoglobin levels and inflammatory biomarkers, can illuminate the therapeutic effectiveness of LentiGlobin and its impact on mitigating complications such as vaso-occlusive crises. Therefore, the purpose of this narrative review is to discuss the effects of LentiGlobin administration on diverse serum biomarkers and its correlation with vaso-occlusive crises in individuals with sickle cell disease (SCD).

Terminology for Retinal Findings in Sickle Cell Disease Research: A Scoping Review

OBJECTIVE

To review the current sickle cell disease (SCD) literature to assess how "retinopathy" has been defined and to identify ocular outcomes that have been measured and described.

DESIGN

A systematic scoping review of SCD literature was completed regarding ocular manifestations of SCD and vision outcomes across all medical specialties.

SUBJECTS

Participants with SCD and control patients were included in our data extraction.

METHODS

We reviewed English-language literature from 2000 to 2021 for eligible studies by searching PubMed, Google Scholar, Embase, and the Cochrane library using terms to encompass SCD and ocular findings.

MAIN OUTCOME MEASURES

Data collection included study information, patient characteristics, vision-related findings (inclusion criteria and/or study outcomes), and retinopathy characteristics (definition, when, how and by whom diagnosed).

RESULTS

We identified 4006 unique citations and 111 were included in the analysis. Ophthalmologists were senior authors of about half (59/111; 53.2%) of the articles; most articles were published between 2016 and 2021 (71/111; 70.0%). The studies had been conducted primarily in North America (54/111; 48.6%) or Europe (23/111; 20.7%); designs were cross-sectional (51/111; 45.9%), prospective cohort (28/111; 25.2%), retrospective cohort (27/111; 24.3%), and case-control (4/111; 3.6%). Among studies reporting any retinopathy, it was commonly defined as a combination of nonproliferative sickle cell retinopathy and proliferative sickle cell retinopathy (PSR; 52/87; 59.8%), infrequently as PSR only (6/87; 6.9%), or not defined at all (23/87; 26.4%). The Goldberg classification was used to grade retinopathy in almost half of the studies (41/87; 47.1%). Investigators reporting diagnostic methods used clinical fundus examination (56/111; 50.4%), OCT (24/111; 21.6%), fluorescein angiography (20/111; 18.0%), ultrawidefield fundus photographs (15/111; 13.5%), and OCT angiography (10/111; 9.0%), or did not report methods (28/111; 25.2%).

CONCLUSIONS

There are inconsistencies in documentation of methods and outcomes in studies of SCD ophthalmic findings. Particularly concerning is the lack of documentation of ophthalmic examination methods, qualifications of examiners, and clarity and specificity of sickle cell retinopathy definitions. With the increase in SCD treatment research and novel systemic therapies available, it is important to adopt clear and consistent descriptions and rigorous data collection and reporting of ophthalmic outcomes in SCD studies.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Potential for a large-scale newborn screening strategy for sickle cell disease in Mali: A comparative diagnostic performance study of two rapid diagnostic tests (SickleScan® and HemotypeSC®) on cord blood

Sickle cell disease (SCD) is a life-threatening disease requiring reliable early diagnosis. We assessed the acceptability and diagnostic performances of two rapid diagnostic tests (RDTs) to identify SCD (HbSS, HbSC, HbS/β-thalassaemia) or SCD carrier (HbS/HbC) in a pilot SCD newborn screening (NBS) strategy in Mali. All consenting delivering women were offered SCD NBS using cord blood sampling on two RDTs (SickleScan® and HemotypeSC®) compared to the high-performance liquid chromatography (HPLC) gold standard to detect SCD states. From April 2021 to August 2021, 4333 delivering women were eligible of whom 96.1% were offered NBS: 1.6% refused, 13.8% delivered before consenting and 84.6% consented; 3648 newborns were diagnosed by HPLC; 1.64% had SCD (0.63% HbSS, 0.85% HbSC, 0.16 HbS/β-plus-thalassaemia); 21.79% were SCD carrier. To detect accurately SCD, SickleScan® had a sensitivity of 81.67% (95% confidence interval [CI]: 71.88-91.46) and a negative predictive value (NPV) of 99.69% (95% CI: 99.51-99.87); HemotypeSC® had a sensitivity of 78.33% (95% CI: 67.91-88.76) and a NPV of 99.64% (95% CI: 99.44-99.83). To detect SCD carrier: SickleScan® sensitivity was 96.10% (95% CI: 94.75-97.45) and NPV, 98.90% (95% CI: 98.51-99.29); HemotypeSC® sensitivity was 95.22% (95% CI: 93.74-96.70) and NPV, 98.66% (95% CI: 98.24-99.03). Routine SCD NBS was acceptable. Compared with HPLC, both RDTs had reliable diagnostic performances to exclude SCD-free newborns and to identify SCD carriers to be further confirmed. This strategy could be implemented in large-scale NBS programmes.

Safety of Ultrasound Contrast Agents in Pediatric Patients With Sickle Cell Disease and Trait

Ultrasound contrast agent (UCA) use is increasing. Recent isolated reports observed a rise in pain-related adverse events with the intravenous administration of the UCA Definity in adults with sickle cell disease. To date, no studies have investigated the incidence of similar adverse events with UCA Lumason or Optison. We describe our experience regarding the safety of Lumason and Optison in children with sickle cell disease and trait who underwent contrast-enhanced ultrasound exams in our department with intravenous, intravesical, and other intracavitary routes. No pain-related or other adverse events were observed in this pediatric population with any route of UCA administration.

A social profile of deaths related to sickle cell disease in India: a case for an ethical policy response

India accounts for 14.5 percent of the global SCD newborns, roughly over 42,000 a year, second to sub-Saharan Africa. Despite the availability of cheap diagnostic and treatment options, SCD remains a largely neglected disease within healthcare policy and practice. Epidemiological modeling based on small, often dated, regional studies (largely from sub-Saharan Africa) estimate that between 50 and 90 percent of affected children will/die before the age of 5 years. This premise, coupled with targets of reducing under 5 mortality (SDG 4), privileges public health interventions for screening and prevention of new births, undermining investments in long-term health and social care. This paper presents a retrospective, descriptive analysis of the socio-demographic profile of 447 patients diagnosed with sickle cell or sickle-beta thalassemia, who died following admission at a tertiary care entre in India. We used anonymized hospital records of 3,778 sickle cell patients, admitted in pediatric and adult/medical wards between January 2016 and February 2021. A majority of hospital deaths occurred in the second and third decades of life, following a hospital admission for a week. The overall mortality during 2016-2019 was 14% with little gender difference over time. Contrary to our expectations, the number of hospital deaths did not increase during the first year of the COVID-19 pandemic, between 2020 and 2021. The conclusion highlights the importance of longitudinal, socio-demo-graphic data on deaths as providing important insights for identifying ethical policy interventions focused on improving SCD outcomes over time, reducing inequities in access to care, and preventing what might be considered "excess" deaths.

Pain Control for Sickle Cell Crisis, a Novel Approach? A Retrospective Study

Background and Objectives: Pain management poses a significant challenge for patients experiencing vaso-occlusive crisis (VOC) in sickle cell disease (SCD). While opioid therapy is highly effective, its efficacy can be impeded by undesirable side effects. Local regional anesthesia (LRA), involving the deposition of a perineural anesthetic, provides a nociceptive blockade, local vasodilation and reduces the inflammatory response. However, the effectiveness of this therapeutic approach for VOC in SCD patients has been rarely reported up to now. The objective of this study was to assess the effectiveness of a single-shot local regional anesthesia (LRA) in reducing pain and consequently enhancing the management of severe vaso-occlusive crisis (VOC) in adults with sickle cell disease (SCD) unresponsive to conventional analgesic therapy. Materials and Methods: We first collected consecutive episodes of VOC in critical care (ICU and emergency room) for six months in 2022 in a French University hospital with a large population of sickle cell patients in the West Indies population. We also performed a systematic review of the use of LRA in SCD. The primary outcome was defined using a numeric pain score (NPS) and/or percentage of change in opioid use. Results: We enrolled nine SCD adults (28 years old, 4 females) for ten episodes of VOC in whom LRA was used for pain management. Opioid reduction within the first 24 h post block was -75% (50 to 96%). Similarly, the NPS decreased from 9/10 pre-block to 0-1/10 post-block. Five studies, including one case series with three patients and four case reports, employed peripheral nerve blocks for regional anesthesia. In general, local regional anesthesia (LRA) exhibited a reduction in pain and symptoms, along with a decrease in opioid consumption post-procedure. Conclusions: LRA improves pain scores, reduces opioid consumption in SCD patients with refractory pain, and may mitigate opioid-related side effects while facilitating the transition to oral analgesics. Furthermore, LRA is a safe and effective procedure.

The challenge of clinical end points in sickle cell disease

As most patients with sickle cell disease (SCD) do not have access to curative therapies, the availability of drug therapies that can modify disease severity remains highly desirable. Despite an increased understanding of the pathophysiology of SCD, only 4 drugs are approved by the US Food and Drugs Administration. Most drug trials in SCD have involved the use of acute pain episodes as the primary clinical end point. These studies have typically been to prevent or shorten the duration of such episodes. To date, no drug has received regulatory approval for shortening the duration of acute vaso-occlusive complications, likely highlighting the complex pathophysiology of acute pain episodes. Trials to prevent acute pain episodes have largely evaluated those episodes requiring health care use as a surrogate end point. However, with differences in culture and health care practices among countries, health care use may not reliably predict clinically important effects on acute pain episodes. This article discusses issues related to the use of health care use as the primary end point for prevention trials of acute pain episodes and highlights the importance of evaluating patient-reported outcomes as well as other SCD-related complications as outcome measures.

Using disease-modifying therapies in sickle cell disease

As curative therapy using allogeneic hematopoietic stem cell transplantation as well as gene therapy and gene editing remains inaccessible to most patients with sickle cell disease, the availability of drug therapies that are safe, efficacious, and affordable is highly desirable. Increasing progress is being made in developing drug therapies based on our understanding of disease pathophysiology. Four drugs, hydroxyurea, L-glutamine, crizanlizumab, and voxelotor, are currently approved by the US Food and Drug Administration, with multiple others at various stages of testing. With the limited efficacy of individual agents, combinations of agents will likely be required for optimal outcomes.