Sustainability of newborn screening for sickle cell disease in resource-poor countries: A systematic review.

Sickle cell disease (SCD) is a worldwide genetic blood disorder. Roughly 400,000 babies are born with SCD each year worldwide. More than 75% of these births occur in sub-Saharan Africa. The establishment of sustainable newborn screening NBS programs is an excellent approach to improving the health of persons living with SCD. The need to set up such programs in Africa cannot be overemphasized. However, initial implementation does not guarantee sustainability. More than 500 children with sickle cell anaemia (SCA) die every day due to lack of access to early diagnosis and related treatment. We systematically highlighted suggestions proffered so far, for the sustainability of NBS in low income, high burden countries. We searched online databases, PubMed, and Google Scholar for literature on sustainability of newborn screening (NBS) published between 2012 and 2022. Articles were included if they reported as outcome; sustainability, government participation, scaling up and expansion of NBS, improved patient enrolment in the newborn screening programe. Articles not suggesting same were excluded. Data were extracted from published reports. Primary outcome was government participation and enhanced patient enrolment in the NBS programe. Thematic content analysis was applied using inductive and deductive codes. We came up with 9 major themes. This study is registered with PROSPERO with registration number as CRD42023381821. Literature search yielded 918 articles (including manual searching). After screening, nine (9) publications were suitable for data extraction and analysis. Two more articles were added by manual searching, making a total of eleven (11) articles. The most frequently addressed core elements of sustainability in these papers were complete integration of services into national health care systems for sustainability of NBS programs in Low-income high-burden countries, funding and engagement from government partners from the very beginning of program development should be prioritized. Screening should be tailored to the local context; using DBS on HemoTypeSC could be a game changer for scaling up and expanding the newborn screening program in Sub-Saharan Africa.

Spleen Uptake in Sickle Cell Anemia on Bone Scan.

A patient who had sickle cell disease and had spleen uptake on bone scans is described, and additional causes for that finding are discussed.

Mast cell extracellular trap formation underlies vascular and neural injury and hyperalgesia in sickle cell disease.

Sickle cell disease (SCD) is the most common inherited monogenetic disorder. Chronic and acute pain are hallmark features of SCD involving neural and vascular injury and inflammation. Mast cells reside in the vicinity of nerve fibers and vasculature, but how they influence these structures remains unknown. We therefore examined the mechanism of mast cell activation in a sickle microenvironment replete with cell-free heme and inflammation. Mast cells exposed to this environment showed an explosion of nuclear contents with the release of citrullinated histones, suggestive of mast cell extracellular trap (MCET) release. MCETs interacted directly with the vasculature and nerve fibers, a cause of vascular and neural injury in sickle cell mice. MCET formation was dependent upon peptidylarginine deiminase 4 (PAD4). Inhibition of PAD4 ameliorated vasoocclusion, chronic and acute hyperalgesia, and inflammation in sickle mice. PAD4 activation may also underlie neutrophil trap formation in SCD, thus providing a novel target to treat the sequelae of vascular and neural injury in SCD.

Health-Related Quality of Life of Omani Adult Patients with Sickle Cell Disease at the Sultan Qaboos University Hospital.

Objectives: This study aimed to determine the health-related quality of life (HRQoL) of adult Omani patients with sickle cell disease (SCD). The quality of life of these patients in Oman is unknown. Methods: This cross-sectional study was conducted at the Sultan Qaboos University Hospital, Muscat, Oman, from June to October 2022 and included patients with SCD. A validated Arabic version of the 36-Item Short-Form Health Survey (SF-36) was used to assess HRQoL in 8 domains. Results: A total of 235 patients with SCD were included in this study, the majority of whom were female (74.9%) and between 18 and 35 years of age (64.6%). The lowest HRQoL was reported for the domain of role limitations due to physical health (median score = 25.0, interquartile range [IQR] = 35.0), while the highest was seen for role limitations due to emotional problems (median score = 66.7, IQR = 100.0). Frequent SCD-related emergency department visits/hospital admissions and the adverse effect of SCD on patients' social lives had a significant negative impact on SF-36 scores for all 8 HRQoL domains (P ≤0.05). Additionally, SCD's impact on academic performance and a history of having been bullied due to SCD had a significant negative impact on SF-36 scores for 7 domains (P ≤0.05). Conclusion: Omani adult patients with SCD reported relatively poor HRQoL in several domains, with various factors found to be significantly associated with this. Healthcare providers and policy makers should consider offering additional clinical, educational and financial support to these patients to enhance their HRQoL.

Budget Impact of Disease-Modifying Treatments and a CRISPR Gene-Edited Therapy for Sickle Cell Disease.

BACKGROUND AND OBJECTIVE: Treatment of sickle cell disease (SCD) has traditionally focused on symptomatic and preventative care. Recent advances in novel therapeutic developments, likely to be orphan-designated, are anticipated to carry a substantial price tag. This study assesses the potential budget impact of adopting disease-modifying treatments, crizanlizumab and voxelotor, and pioneering CRISPR gene-edited therapy, CTX001, in the Belgian healthcare system. METHODS: The perspective of the Belgian healthcare payer (RIZIV-INAMI including patient copayments), a 5-year horizon with a 2-10% uptake of disease-modifying interventions, and a 2% uptake of CTX001 were considered. Data, encompassing target population, current (chronic and acute management, curative hematopoietic stem cell transplantation) and new (crizanlizumab, voxelotor, and CTX001) interventions, clinical effectiveness, adverse events, healthcare resource utilization, and associated costs, were gathered through a comprehensive literature review (first phase) and two Delphi panels involving hematologists (second phase). The cost difference between a "world with and without crizanlizumab, voxelotor, and CTX001" was calculated to obtain the budget impact. Three scenario analyses were conducted: a 5-13% and 4% uptake analysis, a 10-18% and 8% uptake analysis, respectively for disease-modifying treatments (crizanlizumab and voxelotor) and CTX001, and a 0% crizanlizumab uptake and managed entry agreements analysis . A ± 20% univariate sensitivity analysis was performed to test the robustness of the analysis. RESULTS: The total five-year cumulative budget impact was estimated at €30,024,968, with 91% attributed to drug acquisition costs. The largest budget impact share was for CTX001 (€25,575,150), while crizanlizumab (€2,301,095) and voxelotor (€2,148,723) was relatively small. In scenarios one and three, a two-fold increase of the cumulative budget impact to €60,731,772 and a four-fold increase to €120,846,256 from the base case was observed. In scenario three, this budget impact decreased by 63% to €11,212,766. Patient population size, number of treated patients, and drug costs influenced the analysis the most, while discontinuation, acute crisis, and adverse event rates had comparatively minimal impact. CONCLUSIONS: Belgian decision-makers may consider alternative financing models, such as outcome-based risk-sharing agreements or annuities, to ensure sustainable coverage of these treatments. This study adheres to recommended practices for assessing budget impact of orphan drugs, distinguishing it from earlier studies with potentially weaker methodologies.

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.

[Sickle cell disease - common and dangerous complications]. / ABC om Sicklecellsjukdom ­ vanliga och farliga komplikationer.

Sickle cell disease is a genetic disorder affecting hundreds of thousands of people worldwide. This article will focus on the most common and dangerous acute complications to sickle cell disease. Vaso-occlusive crisis is the most common manifestation of sickle cell disease. Rapid pain relief and treating the underlying cause are cornerstones of the treatment. Acute chest syndrome is the most common cause for intensive care unit admission and death among adult patients with sickle cell disease. The condition is treated as vaso-occlusive crises, but patients often need blood transfusions and respiratory support. Patients with sickle cell disease have an increased risk of stroke. Treatment follows the usual guidelines for stroke with the addition of blood- or exchange transfusions. Splenic sequestration is a rare but acute and life-threatening complication, most commonly seen in children. The condition can quickly lead to hypovolemic shock and the treatment aims to maintain adequate circulation and to treat the underlying cause.

Cell and gene therapy accessibility.

Patients with devastating illnesses demonstrate incredible courage in battling their disease. Innovative cell and gene therapies (CGTs), built on decades of research, are changing the lives of those who suffer from conditions ranging from cancer to sickle cell disease to neurologic diseases. Although hailed for their promise and recognized for benefits that will exceed the costs, the high prices of CGTs ($300 thousand to $4 million per dose) leave these therapies out of reach for many. This accessibility problem will only be solved if academia, industry, investors, funders, regulators, and advocacy groups work together to put CGT breakthroughs in the hands of all who stand to benefit.

Evaluation of a point-of-care rapid diagnostic test kit (SICKLECHECK) for screening of sickle cell diseases.

Sickle cell diseases (SCD) are the most common genetic disorders with significant morbidity and mortality worldwide, including in India. The high prevalence of this disorder in many geographical regions calls for the use of a point-of-care rapid diagnostic test (RDT) for early screening and management of the diagnosed cases to reduce the allied clinical severity. In view of this, the present study was undertaken for the validation of a point-of-care RDT kit (SICKLECHECKTM) for the screening of SCD. This validation and diagnostic accuracy study was conducted among the cases advised for screening of SCD. For validation, all the recruited cases were investigated for both the SICKLECHECKTM RDT kit and HPLC (Variant-II) considering HPLC as a gold standard. A total of 400 cases were screened for both tests. For the presence and absence of sickle cell hemoglobin in the samples, SICKLECHECKTM RDT kit results showed a sensitivity and specificity of 99.39% and 98.73% respectively with references to HPLC findings. For the detection of the 'AS' pattern, the SICKLECHECKTM RDT kit has shown a sensitivity and specificity of 99.07% and 98.81% respectively. For the detection of the 'SS' pattern, the SICKLECHECKTM RDT kit has shown a sensitivity and specificity of 97.92% and 100.0% respectively. Cases with ß thalassemia trait, hemoglobin E trait, hemoglobin Lepore trait and trait for hereditary-persistence-of-fetal-hemoglobin (high HbF %) diagnosed in HPLC were resulted with 'AA' pattern in SICKLECHECKTM RDT kit. The high sensitivity and specificity of the SICKLECHECKTM RDT kit insist on its use as a point-of-care screening tool for SCD especially where there is a lack of laboratory facilities as well as in hospital-based set-up requiring immediate diagnosis and management of SCD. However, for further confirmation, the samples should be analyzed with other gold standard techniques like HPLC.

Genome editing in K562 cells suggests a functional role for the XmnI Gg polymorphism: a widely used genetic marker in ß-thalassemia and sickle cell disease patients.

The XmnI Gg -158 C/T polymorphism has been widely associated with fetal hemoglobin (HbF) levels, the severity of disease, and the response to the drug hydroxyurea (HU) in both ß-thalassemia (ß-thal) and sickle cell disease (SCD) patients. However, the functional significance of this single nucleotide polymorphism (SNP) remains unclear. To gain insight, green fluorescence protein (GFP) cassettes harboring the XmnI C or T alleles in their left homology arms (i.e. Gg promoters) were knocked into the Gg gene(s) of K562 cells via CRISPR/Cas9. Subsequently, the GFP fluorescence levels were compared in the ensuing cell populations and isolated clones. In both instances, median fluorescence intensities (MFI) of the knockin cells having the inserted XmnI T allele were higher than those having the XmnI C allele. Our results suggest that the XmnI T allele can increase Gg expression in K562 cells. The possible functional significance of the XmnI Gg -158 C/T polymorphism provides a rationale for the aforementioned associations. Furthermore, the XmnI polymorphism as a functional SNP substantiates its importance as a prognostic marker.

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.

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.

CRISPR-directed gene-editing induces genetic rearrangement within the human globin gene locus.

CRISPR-Cas is a revolutionary technology but has already demonstrated significant feasibility for clinical and non-clinical applications. While the efficiency and precision of this remarkable genetic tool is unprecedented, unfortunately, a series of collateral genetic rearrangement have been reported in response to double-stranded DNA breakage. Once these molecular scissions occur, the cascade of DNA repair reactions can lead to genomic rearrangements especially if breakage takes place within a family of sequence related genes. Here, we demonstrate that CRISPR- directed gene editing near the sickle cell mutation site generates a curious genetic outcome; a footprint of the δ globin gene proximal to the CRISPR/Cas cut site(s). This rearrangement is not dependent on the presence of an exogenously added DNA template but is apparently dependent on a double strand break. Our results the highlight recombinational capacity of double strand breaks in human chromosomes where the aim is to edit a human gene.

SURGICAL OUTCOMES IN CONCURRENT SICKLE CELL AND DIABETIC RETINOPATHY.

PURPOSE: To report the clinical features and outcomes in eyes that underwent vitreoretinal surgery for complications of concurrent sickle cell retinopathy and diabetic retinopathy. METHODS: Retrospective, consecutive case series of all eyes that underwent vitreoretinal surgery for complications secondary to concurrent sickle cell retinopathy and diabetic retinopathy between January 01, 2014, and December 31, 2021. RESULTS: The study included 20 eyes of 14 patients. Indications for surgery included tractional retinal detachment in 12 eyes (60%), combined tractional retinal detachment/rhegmatogenous retinal detachment in 6 eyes (30%), and vitreous hemorrhage in 2 eyes (10%). Pars plana vitrectomy was performed in all eyes. One eye received a scleral buckle at the same time as pars plana vitrectomy. There was no change in mean best-corrected visual acuity at the last follow-up examination (1.5 [20/678]) when compared with mean preoperative best-corrected visual acuity (1.6 [20/762], P = 0.83). Preoperative best-corrected visual acuity correlated with postoperative best-corrected visual acuity at the last follow-up examination in eyes with retinal detachment (r = 0.49, P = 0.04). Single operation anatomic success was achieved in 11 of 17 eyes (65%) with retinal detachment. CONCLUSION: Functional and anatomic outcomes after surgery in eyes with concurrent sickle cell retinopathy and diabetic retinopathy are relatively poor.

SURGICAL OUTCOMES OF RETINAL DETACHMENT ASSOCIATED WITH PROLIFERATIVE SICKLE CELL RETINOPATHY.

PURPOSE: To evaluate the long-term anatomic and visual outcomes in eyes with sickle cell retinopathy-related retinal detachments (RDs). METHODS: Patients who underwent surgery for sickle cell retinopathy-related RDs at the Wilmer Eye Institute or Wills Eye Hospital between 2008 and 2020 and followed for at least 6 months postoperatively were retrospectively reviewed. The primary outcome was the rate of single-surgery anatomic success and final reattachment. RESULTS: This study included 30 eyes from 28 patients (16 women and 12 men) with tractional RD (n = 13), rhegmatogenous RD (n = 1), and combined tractional RD/rhegmatogenous RD (n = 16). Mean age was 42.1 ± 15.1 years. The mean follow-up duration was 47.8 ± 34.1 months. Twenty-five (83.3%) eyes underwent pars plana vitrectomy and five (16.7%) eyes underwent pars plana vitrectomy with scleral buckling. Single-surgery anatomic success was achieved in 21 (70.0%) eyes at 6 months. Final reattachment was achieved in 28 (93.3%) eyes (22 eyes [73.3%] without tamponade). Recurrence of RDs was significantly associated with male gender (P = 0.041), absence of previous laser (P = 0.032), iatrogenic breaks (P = 0.035), retinectomy (P = 0.034), and silicone oil tamponade (P = 0.024). Overall, the logarithm of the minimum angle of resolution visual acuity improved from 1.53 ± 0.57 (Snellen equivalent, 20/678) to 1.15 ± 1.01 (20/283) at the final visit (P = 0.03); however, eyes with recurrent RD did not achieve significant visual improvement. CONCLUSION: Pars plana vitrectomy to repair sickle cell retinopathy-related RDs was effective in achieving anatomic success and improving vision in most eyes. Single-surgery anatomic success is critical for optimizing visual outcomes.