Managing sickle cell disease

Oxygen gradient ektacytometry-derived biomarkers are associated with acute complications in sickle cell disease

ABSTRACT

We investigated the potential of the point of sickling (PoS; the pO2 tension at which red cells start to sickle), determined by oxygen gradient ektacytometry to serve as a biomarker associated with the incidence of acute sickle cell disease-related complications in 177 children and 50 adults. In the pediatric cohort, for every 10 mmHg increase in PoS reflecting a greater likelihood of sickling, the likelihood of an individual experiencing >1 type of acute complication increased; the adjusted odds ratio (aOR) was 1.65. For every 0.1 increase in minimum elongation index (EImin; reflecting improved red blood cell deformability at hypoxia), the aOR was 0.50. In the adult cohort, for every 10 mmHg increase in PoS, we found an aOR of 3.00, although this was not significant after correcting for multiple testing. There was a trend for an association between higher PoS and greater likelihood of vaso-occlusive episodes (VOEs; children aOR, 1.35; adults aOR, 2.22). In children, only EImin was associated with VOEs (aOR, 0.68). When data of both cohorts were pooled, significant associations with PoS and/or EImin were found for all acute complications, independently and when >1 type of acute complication was assessed. These findings indicate that oxygen gradient ektacytometry generates novel biomarkers and provides a rationale for further development of these biomarkers in the assessment of clinical severity, evaluation of novel therapies, and as surrogate clinical trial end points. These biomarkers may be useful in assessing efficacy of novel therapies like pyruvate kinase activators, voxelotor, and L-glutamine.

Renal outcomes in pediatric patients with sickle cell disease: a single center experience in Saudi Arabia

Background

Sickle cell nephropathy (SCN) is a significant complication of sickle cell disease (SCD) with an asymptomatic onset in childhood and potential progression to chronic kidney disease (CKD). The clinical findings of SCN include hyposthenuria, hematuria, proteinuria, hyperfiltration, and CKD. Data on renal manifestation among patients with SCD in Saudi Arabia is lacking. Therefore, this study aimed to evaluate renal outcomes in patients with SCD who visited a hematology clinic at the National Guard Hospital, Jeddah.

Methods

We conducted a retrospective chart review of renal complications in patients with SCD who are within 0-14 years of age and on regular follow-ups at the pediatric hematology clinic in King Abdulaziz Medical City-Jeddah, Saudi Arabia.

Results

Among the 140 patients with SCD, 99 met the inclusion criteria. The median age at diagnosis was 18 (1-108) months. Two SCD phenotypes were observed, with 82 (83%) patients having sickle cell anemia (HbSS) and 17 (17%) having HbS/B+ thalassemia. Of the total patients, 92 (93%) were administered hydroxyurea (HU), with a median starting age of 48 (9-168) months. The most common renal complication observed during routine urinalysis was hematuria (38%), followed by proteinuria (11%). After stratifying the sample into four age groups (0-3 years old, 4-7 years old, 8-11 years old, and 12-14 years old), the mean glomerular filtration rate (GFR) values were 96.16, 101.36, 112.69, and 120.11 ml/min/1.73 m2 respectively. Renal imaging revealed abnormal findings in 27 (29%) patients. The most common abnormality observed on US was increased echogenicity (43%).

Conclusion

SCN is a significant complication of SCD. In this study, we assessed the renal outcomes in pediatric patients with SCD. After analyzing the clinical findings of SCN, we concluded that the presence of renal complications in pediatric patients presented a progressive pattern.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

Bill & Melinda Gates Foundation.

Radiological manifestation of avascular necrosis (AVN) in sickle cell disease (SCD): a review of diagnostic imaging

Symptomatic avascular necrosis (AVN) imposes a higher risk for acute care consumption in adults living with SCD. Symptomatic AVN, have higher rates of visits to the emergency department, higher rates of admissions, and longer lengths of stay in hospitals. Properly timed diagnosis and early interventions can reduce morbidity and enhance the quality of life in these patients. Vaso-occlusion secondary to sickling leads to osteonecrosis of the joint/bone (AVN, dactylitis) and invites infection (osteomyelitis and septic arthritis). Understanding and awareness of the imaging features related to this major morbidity complication are essential for early diagnosis and prompt management. In about half of the patients with SCD, AVN can lead to chronic pain, particularly in the head of the femur and humerus. Humeral and femoral head AVN tend to be linked with each other.  Vertebral bone compression and collapse secondary to AVN have also been reported.  The diagnosis of AVN must be accurate, as the condition is complex requiring specific treatment according to the grade of bone and joint involvement. There are several classifications or staging systems used for grading bone and joint involvement. Knowledge of the image patterns and grade of affection in different joints and bones and the degree of progression of AVN lesions can markedly improve management decisions on AVN-specific surgical versus non-surgical interventions and improve patient outcomes. The aim of this report is to summarize the different imaging techniques and their role in the proper/early diagnosis and follow up of patients with AVN with detailed examples of the common sites involved.

Early Strokes Are Associated with More Global Cognitive Deficits in Adults with Sickle Cell Disease

This study sought to link neurocognitive profiles in sickle cell disease (SCD) patients with clinical characteristics. We conducted a prospective cohort study of adults with SCD who underwent comprehensive neuropsychological assessment at the UMGGR clinic at Henri Mondor Hospital, Créteil (France). A cluster analysis was performed based on neuropsychological testing scores. The association between clusters and clinical profiles was assessed. Between 2017 and 2021, 79 patients with a mean age of 36 [range 19-65] years were included. On principal component analysis, a 5-factor model presented the best fit (Bartlett's sphericity test [χ2 (171) = 1345; p < 0.001]), explaining 72% of the variance. The factors represent distinct cognitive domains and anatomical regions. On hierarchical classification, three clusters emerged. Cluster 1 (n = 24) presented deficits in all five factors compared to Cluster 3 (n = 33). Cluster 2 (n = 22) had deficits in all factors, but to a lesser extent than Cluster 1. MoCA scores mirrored the severity of these cognitive deficits. Age, genotype and stroke prevalence did not differ significantly between clusters. However, the time of first stroke occurrence differed significantly between Cluster 1 and 2-3: 78% of strokes occurred during childhood, whereas 80% and 83% occurred during adulthood in Clusters 2 and 3, respectively. Educational attainment was also reduced in Cluster 1. SCD patients with childhood stroke seem to be at increased risk of a global cognitive deficit profile. In addition to existing methods of primary and secondary stroke prevention, early neurorehabilitation should be prioritized in order to reduce the long-term cognitive morbidity of SCD.

Complementary and alternative medicine for children with sickle cell disease: A systematic review

BACKGROUND

Complementary and alternative medicine (CAM) is a popular alternative to opioid and other analgesics in sickle cell disease (SCD). We review the effectiveness, prevalence, and factors associated with CAM use in the pediatric SCD population.

METHODS

The review protocol was created based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A literature search was conducted in MEDLINE, Embase, Cochrane Library, PubMed, and Web of Science.

RESULTS

Twenty-four studies were examined. The prevalence of CAM use in pediatric patients with SCD ranged from 36 to 84.5%. Common inpatient CAM interventions were yoga, virtual reality, and acupuncture, which decreased pain scale scores. Outpatient CAMs were consisted of cognitive behavioral therapy, massage therapy, and guided-imagery, which increased pain tolerability and decreased pain scale scores.

CONCLUSIONS

CAM modalities can decrease pain scale scores. However, the impact of specific CAM modalities on emergency department visits, hospitalizations, and school absences were inconclusive.

Management of Salter-Harris Type 1 Fracture Complicated with Osteomyelitis in a Sickle Cell Disease Patient: A Case Report and Review of Literature

Salter-Harris fractures may occur due to a single injury or repetitive stress fractures on the extremities. Type I to III fractures are managed medically, while types IV and V, which are rare, are treated surgically. In the pediatric population, Salter-Harris I fractures of the distal tibia are commonly seen, and management of such fractures are well established in the literature. Despite the availability of a wide range of treatment for such fractures, osteonecrosis or avascular necrosis of the proximal femur can subsequently develop. Avascular necrosis is cell death secondary to metabolic disturbances, trauma, adverse effects of certain medications, or sickle cell disease. Avascular necrosis commonly affects the talus, humerus, or tibia in addition to the femoral head. Radiographic images are essential for prompt diagnosis and to minimize negative health outcomes in these patients. However, Salter-Harris I fracture in sickle cell patients can be very challenging due to these patients' vulnerability to bone infections and sickle cell crisis. In this case report, our patient with a history of sickle cell disease and with a diagnosis of Salter-Harris I fracture was treated with surgical intervention as type V, which is discussed in this article, and responded well to treatment. Thus, this case suggests a new approach to managing Salter-Harris I fractures complicated with osteomyelitis in sickle cell patients.

Safety and efficacy of voxelotor in pediatric patients with sickle cell disease aged 4 to 11 years

BACKGROUND

Sickle cell disease (SCD) is a devastating, multisystemic disorder that affects millions of people worldwide. The earliest clinical manifestations of SCD can affect infants as young as 6 months of age, and pediatric patients are at risk for acute and life-threatening complications. Early intervention with treatments that target the underlying pathophysiological mechanism of SCD, sickle hemoglobin (HbS) polymerization, are expected to slow disease progression and circumvent disease-associated morbidity and mortality.

PROCEDURE

The HOPE-KIDS 1 trial (NCT02850406) is an ongoing four-part, phase 2a, open-label, single- and multiple-dose study to evaluate the pharmacokinetics, efficacy, and safety of voxelotor-a first-in-class HbS polymerization inhibitor-in patients aged 6 months to 17 years with SCD. Initial findings from a cohort of 45 patients aged 4 to 11 years who received voxelotor treatment for up to 48 weeks are reported.

RESULTS

Hemoglobin (Hb) response, defined as a >1.0 g/dl increase from baseline, was achieved at week 24 by 47% (n = 16/34) of patients with Hb measurements at baseline and week 24. At week 24, 35% (n = 12/34) and 21% (n = 7/34) of patients had a >1.5 g/dl increase and a >2.0 g/dl increase from baseline in Hb concentration, respectively. Concurrent improvements in hemolytic markers were observed. Voxelotor was well tolerated in this young cohort, with no newly emerging safety signals.

CONCLUSIONS

Based on its mechanism as an HbS polymerization inhibitor, voxelotor improves Hb levels and markers of hemolysis and has the potential to mitigate SCD-related complications; these results support its use in patients aged ≥4 years.

Molecular Mechanisms of Hepatic Dysfunction in Sickle Cell Disease: Lessons From The Townes Mouse Model

Sickle cell disease (SCD) is an autosomal-recessive-genetic disorder that affects ~100,000 Americans and millions of people worldwide. Erythrocyte sickling, vaso-occlusion, sterile inflammation and hemolysis are the major pathophysiological pathways leading to liver injury in SCD. Although hepatic dysfunction affects up to 10-40% of SCD patients, therapeutic approaches to prevent liver injury in SCD are not known, and the molecular mechanisms promoting progressive liver injury in SCD remain poorly understood. Animal models have been beneficial in bridging the gap between preclinical and translational research in SCD. Recent advances in methodology have allowed the development of several humanized mouse models to address various aspects of SCD related liver diseases. This review provides an overview of current knowledge of the molecular mechanisms and potential therapeutic options of SCD associated liver dysfunction using the Townes mouse model.

High risk and low prevalence diseases: Acute chest syndrome in sickle cell disease

INTRODUCTION

Acute chest syndrome (ACS) in sickle cell disease (SCD) is a serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of ACS in SCD, including diagnosis and management in the emergency department (ED) based on current evidence.

DISCUSSION

ACS is defined by respiratory symptoms and/or fever and a new radiodensity on chest imaging in a patient with SCD. There are a variety of inciting causes, including infectious and non-infectious etiologies. Although ACS is more common in those with homozygous SCD, clinicians should consider ACS in all SCD patients, as ACS is a leading cause of death in SCD. Patients typically present with or develop respiratory symptoms including fever, cough, chest pain, and shortness of breath, which can progress to respiratory failure requiring mechanical ventilation in 20% of adult patients. However, the initial presentation can vary. While the first line imaging modality is classically chest radiograph, lung ultrasound has demonstrated promise. Further imaging to include computed tomography may be necessary. Management focuses on analgesia, oxygen supplementation, incentive spirometry, bronchodilators, rehydration, antibiotics, consideration for transfusion, and specialist consultation. Empiric antibiotics that cover atypical pathogens are necessary along with measures to increase oxygen-carrying capacity in those with hypoxemia such as simple transfusion or exchange transfusion.

CONCLUSIONS

An understanding of ACS can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Transfer of Care for People with Severe Forms of Thalassemia: Learning from Past Experiences to Create a Transition Plan

PURPOSE

To demonstrate the need for developing standardized healthcare transition plans for persons with severe forms of thalassemia as life expectancy continues to improve.

DESIGN AND METHODS

This study utilized an original questionnaire to explore the factors that determined whether individuals residing in North America transferred their thalassemia care from a pediatric to an adult specialist, and what components they believed should be included in a healthcare transition plan.

RESULTS

Approximately one-third of respondents remained under the care of a pediatric hematologist, most commonly citing the thalassemia knowledge of the specialist as their reason for not transferring their care. Additionally, this group also reported more thalassemia-related services available at their healthcare facility, better access to flexible hours for blood transfusions and increased satisfaction with their care. Adults with thalassemia recommend enhanced communication between patient and provider and building opportunities for patients to assume the role of self advocate as key components for a healthcare transition plan.

CONCLUSIONS

There is an inconsistency in the transfer-of-care experience of adults with severe forms of thalassemia living in North America. Development of a healthcare transition program would benefit from the input of those who have gone through this process.

PRACTICE IMPLICATIONS

A well informed healthcare transition program can enhance the quality of life of those with thalassemia. The training and educational background of nurses and genetic counselors make them uniquely qualified to guide patients on how to advocate for themselves and to ensure continuity of care during a healthcare transition.

Patient-reported neurocognitive symptoms influence instrumental activities of daily living in sickle cell disease

Individuals with sickle cell disease (SCD) experience neurocognitive decline, low medication adherence, increased unemployment, and difficulty with instrumental activities of daily living (IADL). The relationship between self-perceived cognitive difficulties and IADLs, including employment, school enrollment, independence, engagement in leisure activities, and medication adherence is unknown. We hypothesized that self-reported difficulties across neurocognitive areas would predict lower IADL skills. Adolescent and adult participants of the multi-site Sickle Cell Disease Implementation Consortium (SCDIC) (n = 2436) completed patient-reported outcome (PRO) measures of attention, executive functioning, processing speed, learning, and comprehension. Cognitive symptoms were analyzed as predictors in multivariable modeling. Outcome variables included 1) an IADL composite that consisted of employment, participation in school, reliance on others, and leisure pursuits, and 2) hydroxyurea adherence. Participants reported cognitive difficulty across areas of attention (55%), executive functioning (51%), processing speed (57%), and reading comprehension (65%). Executive dysfunction (p < 0.001) and sometimes or often experiencing learning difficulties (p < 0.001 and p = 0.04) and poor comprehension (p = 0.000 and p = 0.001), controlled for age (p < 0.001), pain (p < 0.001), and hydroxyurea use (p = 0.001), were associated with poor IADL skills. Executive functioning difficulties (p = 0.021), controlled for age (p = 0.013 for ages 25-34), genotype (p = 0.001), and hemoglobin (p = 0.004), predicted hydroxyurea non-adherence. Analysis of PRO measures indicated that cognitive dysfunction is prevalent in adolescents and adults with SCD. Cognitive dysfunction translated into clinically meaningful outcomes. PRO of cognitive symptoms can be used as an important adjunct clinical tool to monitor symptoms that impact functional skills, including engagement in societal activities and medication adherence.

Pain-Related Injustice Appraisals in Youth with Sickle Cell Disease: A Preliminary Investigation

OBJECTIVES

Sickle cell disease (SCD) is a genetic disorder that affects approximately 100,000 Americans, the majority of whom are African American. SCD-related pain often has deleterious effects on functioning and quality of life. The inherited nature of SCD, SCD-related stigma, and serious physical and functional impact of SCD-related pain create a situation ripe for individuals to appraise their SCD-related pain as unfair or unjust. The aim of this preliminary investigation is to explore the extent to which pediatric patients with SCD appraise their pain as unjust and how these appraisals relate to functioning.

METHODS

Participants were youth with SCD (N = 30, mean age = 11.3, 57% boys) who attended a hematology clinic visit. Patients were invited to complete paper-based questionnaires assessing pain-related injustice appraisals, pain catastrophizing, pain and hurt, functional disability, depression, anxiety, and peer relationships.

RESULTS

Results of hierarchical regressions indicate that pain-related injustice significantly predicted functional disability, depression, and anxiety after controlling for patient pain and catastrophizing.

CONCLUSIONS

These findings suggest that pain-related injustice appraisals are an important contributor to the pain experience of youth with SCD. Early identification and remediation of pain-related injustice appraisals could have long-term functional benefits for youth with SCD.

Chronic osteo-articular changes in patients with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is an autosomal recessive genetic disease in which a mutation occurs in the β-globin chain gene, resulting in abnormal hemoglobin levels. In an environment with reduced oxygen concentration, red blood cells change their conformation, resulting in chronic hemolysis and consequent anemia and vaso-occlusive crises with injuries to several organs, with a significant impairment of the osteoarticular system. This study aimed to verify the chronic osteoarticular alterations and their association with clinical and laboratory characteristics of patients with SCD with a more severe phenotype (SS and Sβ⁰), on a steady-state fasis.

METHODS

Fifty-five patients were referred to a medical consultation with a specialized assessment of the locomotor system, followed by laboratory tests and radiographic examinations.

RESULTS

In total, 74.5% patients had hemoglobinopathy SS; 67.3% were female; and 78.2% were non-whites. The mean patient age was 30.5 years. Most patients (61.8%) reported up to three crises per year, with a predominance of high-intensity pain (65.5%). Radiographic alterations were present in 80% patients. A total of 140 lesions were identified, most which were located in the spine, femur, and shoulders. Most lesions were osteonecrosis and osteoarthritis and were statistically associated with the non-use of hydroxyurea.

CONCLUSIONS

There was a high prevalence of chronic osteoarticular alterations, which was statistically associated only with the non-regular use of hydroxyurea.

Current modalities of sickle cell disease management

Sickle cell disease (SCD) affects nearly 100,000 people in the United States of America and the sickle gene is present in approximately 8% of black Americans. Among Africans, the prevalence of sickle cell trait (heterozygosity) is as high as 30%. While SCD occurs among varying racial and ethnic groups, it is more commonly prevalent in individuals of African or African-American descent. This inherited blood disorder causes varying symptoms and complications among affected children and adults and early diagnosis and treatment are essential to help reduce mortality rates. Because there is no cure for SCD, management is vital to survival. Hence, there are different approaches in use to aid those living with SCD; thus, this paper provides insight into the current methods that are implemented in the management and maintenance of this disease.

Effectiveness of a home-based therapeutic exercise program on lower back pain and functionality in Sickle Cell Disease (SCD) patients

Objective

To investigate the effectiveness of a home-based therapeutic exercise program on lower back pain and functionality of SCD patients.

Setting

A Hematology and Transfusion Medicine Center, University of Campinas (HEMOCENTRO-UNICAMP).

Methods

This was a prospective study, with a three-month follow-up of SCD patients with lower back pain. The lumbar spine functionality was evaluated by questionnaires, trunk flexion and extension analyses by fiber-optic-electrogoniometry and measurements of muscle strength of trunk flexor and extensors. The Intervention Group (IG) comprised 18 volunteers, median age 44y (28–58) and the control group (CG) comprised 15 volunteers, median age 42y (19–58), who did not perform exercises. The protocol consisted of daily home-based exercises with two evaluations: at the beginning and end of a three-month program. In order to compare the groups at baseline, the Fisher´s exact test and Mann–Whitney test were used for categorical and numeric variables, respectively. The Wilcoxon test was used for related samples comparing numeric measures of each group over time with a 5% (p < 0.05) significance level.

Results

After the intervention, patients demonstrated a significant improvement, according to the Visual-Analog-Scale (VAS; p = 0.01), Rolland Morris Disability questionnaire (RMDQ; p < 0.01) and trunk flexion and extension muscle strength (p < 0.01). No significant differences were found for the Start-Back-Screening-Tool-Brazil (SBST) and in measures of trunk flexion and extension range-of-motion (RoM).

Conclusion

Results suggest that daily home-based exercises for a three-month period ameliorate pain and improve disability related to lower back pain and muscle strength.

The increased neopterin content in turkish pediatric patients with sickle cell anemia

In the present study, the possible activation of cellular immunity in SCD patients was investigated. As immune activation parameters, neopterin concentrations and kynurenine/tryptophan ratio for tryptophan degradation in 35 pediatric patients with sickle cell disease (31 HbSS and 4 HbSß) were determined. Our results have shown that neopterin levels (both urinary and serum) are increased in pediatric patients with sickle cell disease. The increase in neopterin concentration was accompanied by significantly increased biopterin, kynurenine concentration and kynurenine/tryptophan ratio. The mechanism of immune activation and the effects of inflammatory mediators in sickle cell disease are poorly understood, especially in terms of cell-mediated immunity. Further in-vivo and in-vitro studies are required to illuminate the association between neopterin levels and neutrophil activation in sickle cell disease.

Sickle cell disease: Clinical presentation and management of a global health challenge

Sickle cell disease is an autosomal recessive, multisystem disorder, characterised by chronic haemolytic anaemia, painful episodes of vaso-occlusion, progressive organ failure and a reduced life expectancy. Sickle cell disease is the most common monogenetic disease, with millions affected worldwide. In well-resourced countries, comprehensive care programs have increased life expectancy of sickle cell disease patients, with almost all infants surviving into adulthood. Therapeutic options for sickle cell disease patients are however, still scarce. Predictors of sickle cell disease severity and a better understanding of pathophysiology and (epi)genetic modifiers are warranted and could lead to more precise management and treatment. This review provides an extensive summary of the pathophysiology and management of sickle cell disease and encompasses the characteristics, complications and current and future treatment options of the disease.

Neurologic complications in children under five years with sickle cell disease

INTRODUCTION

Sickle Cell Disease (SCD) is one of the most common genetic diseases in the world affecting every organ. The major challenge in the medical care of children with SCD is preventing end-organ dysfunction, particularly the brain. Major neurologic complications in children less than five years with SCD include, but are not limited to, Silent cerebral infarct, cerebral sinus thrombosis, epilepsy, reversible encephalopathy syndrome, and ischemic and hemorrhagic stroke. Recurrent headaches and migraine are not rare in children under five years with SCD. This review will focus on the neurologic complications and the description of the modifiable risk factors in children less than 5 years of age with emphasis on differences between high and low resource settings.

AREAS COVERED

Neurologic complications of children under 5 years of age and the modifiable risk factors. The PUBMED database was searched using medical subject headings (MeSH) and keywords for articles regarding neurologic complications in children under 5 years of age.

CONCLUSION

Neurologic complications in children under five years of age with SCD may be more frequent than currently reported, among which Silent cerebral infarct and cognitive impairment are the most common.

Red blood cell exchange in patients with sickle cell disease-indications and management: a review and consensus report by the therapeutic apheresis subsection of the AABB

BACKGROUND

A prior practice survey revealed variations in the management of patients with sickle cell disease (SCD) and stressed the need for comprehensive guidelines. Here we discuss: 1) common indications for red blood cell exchange (RCE), 2) options for access, 3) how to prepare the red blood cells (RBCs) to be used for RCE, 4) target hemoglobin (Hb) and/or hematocrit (Hct) and HbS level, 5) RBC depletion/RCE, and 6) some complications that may ensue.

STUDY DESIGN AND METHODS

Fifteen physicians actively practicing apheresis from 14 institutions representing different areas within the United States discussed how they manage RCE for patients with SCD.

RESULTS

Simple transfusion is recommended to treat symptomatic anemia with Hb level of less than 9 g/dL. RCE is indicated to prevent or treat complications arising from the presence of HbS. The most important goals are reduction of HbS while also preventing hyperviscosity. The usual goals are a target HbS level of not more than 30% and Hct level of less than 30%.

CONCLUSION

Although a consensus as to protocol details may not be possible, there are areas of agreement in the management of these patients, for example, that it is optimal to avoid hyperviscosity and iron overload, that a target Hb S level in the range of 30% is generally desirable, and that RCE as an acute treatment for pain crisis in the absence of other acute or chronic conditions is ordinarily discouraged.

Legal Evidence of Subjective States: A Brain-Based Model of Chronic Pain Increases Accuracy and Fairness in Law

Advances in structural and functional neuroimaging offer new ways to conceptualize chronic pain disorders and to prevent, diagnose, and treat chronic pain. Advances in pain science, though, do not entail changes in the concepts of chronic pain in law and culture. Authoritative legal and cultural conceptions of chronic pain continue to promote abstruse theories, characterizing these disorders as arising out of everything from a person's unmet need for love to resistance to "patriarchy." These constructs have consequences, impeding treatment and affecting whether individuals with chronic pain can obtain legal redress. Legal systems themselves are disadvantaged, as adjudicators struggle to make sense of regulations and presumptions at odds with the medical evidence that they must evaluate. Law's pain schema is so misdescriptive that, paradoxically, it can reward fraudulent claims and disadvantage legitimate ones. This review discusses advances in neuroimaging and related sciences that are contributing to an emerging neurological model of chronic pain. It then describes doctrines and cases in the United States and United Kingdom, demonstrating how law's pre-neurological model of pain complicates the legal process for all participants. It concludes with suggestions for doctrinal revisions, which may have broader effects on law's long-standing dualistic conception of body versus mind.

Improving routine outpatient monitoring for patients with sickle-cell disease on hydroxyurea

Hydroxyurea is the gold standard treatment for prevention of vaso-occlusive crises in patients with sickle-cell anaemia. It has a narrow therapeutic index and dangerous side effects including cytopenias. There is high variation in dose–response across the population. Therefore, a robust outpatient monitoring programme is crucial to ensure efficacy and safety of treatment. However, there has historically been difficulty engaging the target population in regular laboratory test monitoring programmes. This project aimed to ensure that all patients on hydroxyurea had routine blood tests at least once every 2 months which were reviewed and acted upon within the 3-year project life cycle. A specialist haematology nurse prescriber clinic service was introduced, first informally, and then formally to take blood tests, alter medication dosing, prescribe it and then write a clinic letter. The mean number of tests per patient per year rose from 0.21 at baseline to 9.05 after 2 years of the formal nurse prescriber clinic. This led to an associated increase in dose changes from 0.23 to 1.45 per patient per year. This improved the number of patients on the optimum dose of hydroxyurea. Furthermore, due to increased confidence in the outpatient monitoring, the total number of people being prescribed hydroxyurea increased from 26 to 42. Restriction of prescriptions to only those enrolled in the service has prevented unmonitored patients being at risk of the potential toxicities associated with doses that are too high. The introduction of a formal nurse-led clinic has improved the safety, efficacy and compliance and increased the number of patients on the gold standard preventative treatment for vaso-occlusive crises in sickle-cell anaemia.

Sensitivity of alternative measures of functioning and wellbeing for adults with sickle cell disease: comparison of PROMIS® to ASCQ-Me℠

BACKGROUND

Sickle Cell Disease (SCD) causes profound suffering and decrements in daily functioning. Demand is growing for valid and reliable measures to systematically document these effects, particularly in adults. The Adult Sickle Cell Quality of Life Measurement System, ASCQ-Me℠, was developed for this purpose. ASCQ-Me℠ is one of four measurement systems housed within the Person-Centered Assessment Resource (PCAR), funded by the National Institutes of Health, to support clinical research. To help users select the best of these measures for adults with SCD, we evaluated and compared two PCAR systems: one designed to be "universally applicable" (the Patient-Reported Outcome Measurement Information System, PROMIS®) and one designed specifically for SCD (ASCQ-Me℠).

METHODS

Respondents to PROMIS and ASCQ-Me questions were 490 adults with SCD from seven geographically-disbursed clinics within the US. Data were collected for six ASCQ-Me measures (Emotional Impact, Sleep Impact, Social Impact, Stiffness Impact, Pain Impact, SCD Pain Episode Frequency and Severity) and ten PROMIS measures (Pain Impact, Pain Behavior, Physical Functioning, Anxiety, Depression, Fatigue, Satisfaction with Discretionary Social Activities, Satisfaction with Social Roles, Sleep Disturbance, and Sleep-Related Impairment). Statistical analyses, including analysis of variance and multiple linear regression, were conducted to determine the sensitivity of measures to SCD severity. SCD severity was assessed via a checklist of associated treatments and conditions.

RESULTS

For those with the most severe SCD, PROMIS scores showed worse health compared to the general population for nine of ten health domains: the magnitude of the difference ranged 0.5 to 1.1 standard deviation units. The PROMIS domains most severely affected were Physical Functioning and Pain (Impact and Behavior). Significant differences by tertile of the SCD-MHC were shown for most PROMIS short forms and all ASCQ-Me short and fixed forms. In most models, ASCQ-Me measures explained statistically significant unique variance in SCD-MHC scores complementary to that explained by corresponding PROMIS measures.

CONCLUSIONS

Study results supported the validity of both PROMIS and ASCQ-Me measures for use in adults with SCD. Compared to comparable PROMIS scores, most ASCQ-Me scores were better predictors of SCD disease severity, as measured by a medical history checklist. The clinical implications of these results require further investigation.

A Paper-Based Test for Screening Newborns for Sickle Cell Disease

The high cost, complexity and reliance on electricity, specialized equipment and supplies associated with conventional diagnostic methods limit the scope and sustainability of newborn screening for sickle cell disease (SCD) in sub-Saharan Africa and other resource-limited areas worldwide. Here we describe the development of a simple, low-cost, rapid, equipment- and electricity-free paper-based test capable of detecting sickle hemoglobin (HbS) in newborn blood samples with a limit of detection of 2% HbS. We validated this newborn paper-based test in a cohort of 159 newborns at an obstetric hospital in Cabinda, Angola. Newborn screening results using the paper-based test were compared to conventional isoelectric focusing (IEF). The test detected the presence of HbS with 81.8% sensitivity and 83.3% specificity, and identified SCD newborns with 100.0% sensitivity and 70.7% specificity. The use of the paper-based test in a two-stage newborn screening process could have excluded about 70% of all newborns from expensive confirmatory testing by IEF, without missing any of the SCD newborns in the studied cohort. This study demonstrates the potential utility of the newborn paper-based test for reducing the overall cost of screening newborns for SCD and thus increasing the practicality of universal newborn SCD screening programs in resource-limited settings.

Imaging of musculoskeletal manifestations in sickle cell disease patients

Sickle cell disease (SCD) is a hereditary red cell disorder with clinical manifestations secondary to sickling or crescent-shaped distortion of the red blood cells. Major clinical manifestations of SCD include haemolytic anaemia and vaso-occlusive phenomena resulting in ischaemic tissue injury and organ damage. Chronic sequelae of the anaemia and vaso-occlusive processes involving the musculoskeletal system include complications related to extramedullary haematopoiesis, osteonecrosis, myonecrosis and osteomyelitis. Sickle cell bone disease is one of the commonest clinical presentations. Awareness and knowledge of the imaging features related to these complications are essential for early diagnosis and prompt management. In this article, the pathophysiology and key imaging findings related to these complications are reviewed.

Sickle Cell Disease: A Brief Update

Sickle cell disease (SCD) is an inherited monogenic disease characterized by misshapen red blood cells that causes vaso-occlusive disease, vasculopathy, and systemic inflammation. Approximately 300,000 infants are born per year with SCD globally. Acute, chronic, and acute-on-chronic complications contribute to end-organ damage and adversely affect quantity and quality of life. Hematopoietic stem cell transplantation is the only cure available today, but is not feasible for the vast majority of people suffering from SCD. Fortunately, new therapies are in late clinical trials and more are in the pipeline, offering hope for this unfortunate disease, which has increasing global burden.

Use of Cellular and Plasma Apheresis in the Critically Ill Patient: Part II: Clinical Indications and Applications

Apheresis is the process of separating the blood and removing or manipulating a cellular or plasma component for therapeutic benefit. Such procedures may be indicated in the critical care setting as primary or adjunctive therapy for certain hematologic, neurologic, renal, and autoimmune/rheumatologic disorders. In part I of this series, the technical aspects of apheresis were described and the physiologic rationale and clinical considerations were discussed. This review highlights the pathophysiologic basis, specific clinical indications, and treatment parameters for disorders that more commonly require management in the intensive care unit. The choice of plasma or cellular apheresis in these cases is guided by wellaccepted, evidence-based clinical treatment guidelines. For some disorders, such as liver failure, severe sepsis, and multiple-organ dysfunction syndrome, apheresis treatment approaches remain experimental. Ongoing studies are investigating the potential utility of conventional plasma exchange, ex vivo plasma manipulation, and newer technologies for these and other disorders in severely ill patients.

Ethnomedicinal survey of medicinal plants used in the management of sickle cell disorder in Southern Nigeria

ETHNOPHARMACOLOGICAL RELEVANCE

The present study entails the medicinal plant species used to manage sickle cell disorder in Southern States of Nigeria.

MATERIALS AND METHODS

The ethnomedicinal information was gathered through multistage approach from three geopolitical zones of Southern Nigeria, which were purposively selected. Semi-structured questionnaires were administered on 500 respondents in 125 locations. The ethnomedicinal data collected were analyzed using quantitative value indices such as fidelity level (percentage) and use value. The information got was cross checked using literature search and other related materials.

RESULT

Five hundred respondents comprising 53.12% females and 46.88% males were observed. It was noted that 26.70% were illiterate while 73.30% had formal education. Seventy-nine percent is traditional healers, 27% herb traders and the other 4% are those who have awareness of sickle cell disease . One hundred and seventy five plant species belonging to 70 families, of which Fabaceae made up 26.76% and Euphorbiaceae 16.90% forming the highest occurrence. It was observed that leaves were the most common plant part used (69.10%) followed by root (15%) and stem bark (14%) in the preparation for sickle cell management. Majority (48.57%) of these plants were harvested from wild with 38.86% being trees. Citrus aurantifolia and Newbouldia laevis had highest use values of 0.69 and 0.64 respectively. Plants with the least use value (0.001) include Abrus canescens, Acacia xanthophloea, Aerva lanata and Axonopus compressus. The result of fidelity level values of the plant species for the management of Sickle Cell Disorder (SCD) revealed that Citrus aurantifolia had the highest value of 70.2% while Angraecum distichum and Axonopus compressus had the lowest Fidelity Level value of 0.18%.

CONCLUSION

The study revealed that people in the studied areas were well grounded in the medicinal plants used to manage sickle cell disease. This study reported for the first time 102 plant species having anti-sickling potentials with Fabaceae and Euphorbiaceae as the most dominant plant families. Many of the claimed plants were harvested from the wild showing threat thus providing needs for conservation of plants. The documented plants had high use value and fidelity level that provided quantitative and qualitative ethnomedicinal evaluation within and across the plant families. These give room for further scientific investigations in pharmacological profiles.

Adults with sickle cell disease may perform cognitive tests as well as controls when processing speed is taken into account: a preliminary case-control study

AIMS

This study aimed to: (1) evaluate cognitive function among adults with sickle cell disease using a computer-administered neuropsychological test; and (2) replicate previously identified differences in processing speed between patients with sickle cell disease and controls.

BACKGROUND

Previous evidence suggests that, compared with controls, adult patients with sickle cell disease have poorer cognitive functioning across most domains but the most significant deficits appear to be in the area of processing speed.

DESIGN

Cross-sectional case-control study conducted from June 2008-June 2010.

METHODS

Cognitive functioning was measured using computerized, self-administered, neuropsychological tests among 31 patients with sickle cell disease and 17 controls matched for age, gender and race. The assessment averaged 30 minutes and scores were recorded for seven computerized tests: verbal and visual memory, finger tapping, symbol digit coding, Stroop test, shifting attention and continuous performance.

RESULTS

Patients with sickle cell disease scored 10·76 points lower on the CNS Vital Signs processing speed domain than controls. Although non-significant, patients scored 5·73 points lower on the full index than controls but after adjusting for processing speed, mean scores for patients were 3 points greater compared with controls. Differences in executive functioning and attention were not significant and memory did not differ between groups.

CONCLUSION

Using a brief, computer-administered 30-minute neuropsychological test, we were able to replicate previous findings showing a greater than 10-point deficit in processing speed among patients with sickle cell disease. When differences in processing speed are taken into account, patients perform equally well or better than controls on cognitive tasks.

Spectrum of Sickle Cell Diseases in Patients Diagnosed at a Tertiary Care Centre in Karnataka with Special Emphasis on their Clinicohaematological Profile

INTRODUCTION

Sickle cell disease is a monogenic disorder with considerable clinical diversity and Sickle haemoglobin is responsible for wide spectrum of disorders which vary with respect to severity of anaemia, frequency of crises and duration of survival. As they are confused with many other clinically aggressive disorders, precision in diagnosis is essential both to proper clinical management and subsequent genetic counselling. Hence, this study was taken up in order to diagnose these conditions and administer suitable counselling measures to minimise the incidence of sickle cell disease in the future.

AIM

The aim of this study was to identify the spectrum of all Sickle cell diseases diagnosed at a tertiary care centre in Bangalore, Karnataka, India who presented over a period of five years from 2009 to 2013 and also to screen the parents and siblings of the patients for their carrier status.

MATERIALS AND METHODS

We reviewed 26 cases of Sickle Cell Disease (SCD) and also 38 parents & 10 siblings of these children for their carrier status. Haemoglobin electrophoreses was performed by using alkaline gel method, followed by High Performance Liquid Chromatography when needed.

RESULTS

A total of 26 children diagnosed with SCD were enrolled in the study. Most common entity was Sickle Cell Anaemia (SCA), followed by sickle thalassaemia and Sickle Cell Trait (SCT). Commonest clinical presentation was fever and pallor. Amongst the parents and siblings, sickle cell trait was the most common entity followed by thalassaemia trait. One interesting case of HbSE disease was encountered, which is a rare entity in India.

CONCLUSION

This study brings out the total spectrum of SCDs in a tertiary care centre in Karnataka, with more emphasis on screening of the parents and siblings for their carrier status.

Risk Factors for Visual Impairment in Patients with Sickle Cell Disease in London

Purpose

Dramatically improved health care in recent years has increased the life expectancy of patients with sickle cell disease (SCD) as well as the prognosis for its ocular complications. We sought to identify risk factors for visual impairment in patients with SCD in London 4 decades after Goldberg's seminal studies.

Methods

Patients 16 years and older with SCD (genotypes HbSS, HbSC, HbSβ-thalassemia) attending hematology and ophthalmology services were offered ocular examination. Retinopathy was graded according to the Goldberg classification. Visual impairment was defined as corrected distance visual acuity of 20/40 or poorer.

Results

In total, 182 eyes of 182 patients (mean ± SD age, 37.2 ± 12.8 years; female, 65.9%) were included. Women were significantly older than men (mean ± SD age, 38.8 ± 13.1 vs 34.2 ± 11.8 years; p = 0.0174). There was no difference in mean age of each genotype group (p>0.15). Risk factors for sight-threatening proliferative sickle retinopathy (PSR) were age over 35 years (odds ratio [OR] 2.01; 95% confidence interval [CI] 1.05-3.89; p = 0.0359) and HbSC genotype (OR 4.06; 95% CI 2.07-7.98; p<0.0001). Although visual impairment was related to the presence of sight-threatening PSR (OR 7.23; 95% CI 1.50-35.0; p = 0.0138), it was not related to hemoglobin genotype (p>0.50).

Conclusions

We present the largest study of ocular findings in SCD in the United Kingdom. Sight-threatening PSR is a risk factor for visual impairment, but hemoglobin genotype status is not.

Sickle Cell Disease: A Review of Nonpharmacological Approaches for Pain

CONTEXT

Sickle cell disease (SCD) is a life-threatening condition that affects more than seven million people worldwide. The most common complication experienced by persons living with SCD is pain. Evidence supports the use of nonpharmacologic therapies in managing psychological and social complications of pain in persons with SCD, but there is little consensus if these approaches can also be applied for the treatment of pain in SCD.

OBJECTIVES

To describe and synthesize the use of nonpharmacological therapies for reducing pain of any type and origin in persons with SCD.

METHODS

A literature search was conducted using PsycINFO, PsycARTICLES, PubMed, CINAHL, and Embase. Databases were searched using the following terms: sickle cell, pain, and nonpharmacological therapies. Interventions were graded for methodological quality and categorized as 1) peer-support group therapies, 2) educational/psychological therapies, and 3) skill-based therapies.

RESULTS

Twenty-eight nonpharmacological interventions for persons with SCD were examined. Of these studies, a wide variety of nonpharmacological interventions were tested. Twelve studies yielded significant improvements in pain, three studies reported no positive effect or differences between experimental and control conditions on pain or a pain-related outcome, and one study reported a negative or detrimental intervention effect.

CONCLUSION

Approximately half of the studies reviewed demonstrated success in alleviating pain, suggesting that patients are able to use nonpharmacological interventions to reduce pain with some degree of success. Questions still remain regarding the efficacy and generalizability of these interventions for persons with SCD.

Validation of a Low-Cost Paper-Based Screening Test for Sickle Cell Anemia

Background

The high childhood mortality and life-long complications associated with sickle cell anemia (SCA) in developing countries could be significantly reduced with effective prophylaxis and education if SCA is diagnosed early in life. However, conventional laboratory methods used for diagnosing SCA remain prohibitively expensive and impractical in this setting. This study describes the clinical validation of a low-cost paper-based test for SCA that can accurately identify sickle trait carriers (HbAS) and individuals with SCA (HbSS) among adults and children over 1 year of age.

Methods and Findings

In a population of healthy volunteers and SCA patients in the United States (n = 55) the test identified individuals whose blood contained any HbS (HbAS and HbSS) with 100% sensitivity and 100% specificity for both visual evaluation and automated analysis, and detected SCA (HbSS) with 93% sensitivity and 94% specificity for visual evaluation and 100% sensitivity and 97% specificity for automated analysis. In a population of post-partum women (with a previously unknown SCA status) at a primary obstetric hospital in Cabinda, Angola (n = 226) the test identified sickle cell trait carriers with 94% sensitivity and 97% specificity using visual evaluation (none of the women had SCA). Notably, our test permits instrument- and electricity-free visual diagnostics, requires minimal training to be performed, can be completed within 30 minutes, and costs about $0.07 in test-specific consumable materials.

Conclusions

Our results validate the paper-based SCA test as a useful low-cost tool for screening adults and children for sickle trait and disease and demonstrate its practicality in resource-limited clinical settings.

Applicability of the SMART Model of Transition Readiness for Sickle-Cell Disease

OBJECTIVES

This study aimed to examine the applicability of the Social-ecological Model of Adolescent and Young Adult Readiness to Transition (SMART) model for adolescents and young adults (AYA) with sickle-cell disease (SCD).

METHODS

14 AYA with SCD (14-24 years old) and 10 clinical experts (6-20 years of experience) completed semi-structured interviews. AYA completed brief questionnaires. Interviews were coded for themes, which were reviewed to determine their fit within the SMART model.

RESULTS

Overall, most themes were consistent with the model (e.g., sociodemographics/culture, neurocognition/IQ, etc.). Factors related to race/culture, pain management, health-care navigation skills, societal stigma, and lack of awareness about SCD were salient for AYA with SCD.

CONCLUSIONS

Findings suggest the SMART model may be appropriate in SCD with the consideration of disease-related stigma. This study is a step toward developing a disease-specific model of transition readiness for SCD. Future directions include the development of a measure of transition readiness for this population.

Frequency distribution of sickle cell anemia, sickle cell trait and sickle/beta-thalassemia among anemic patients in Saudi Arabia

Background:

Notwithstanding, the growing incidence of sickle cell hemoglobinopathies (SCH) such as sickle cell anemia (SCA) or sickle cell disease, sickle/beta-thalassemia; the exact prevalence remains obscure in Saudi Arabia. Hence, this study is an attempt to determine the frequency of SCA and sickle cell trait (SCT) among all anemic patients with SCH treated at the King Abdul-Aziz Medical City (KAMC), Riyadh, Saudi Arabia. Furthermore, the hemoglobin (Hb) S and other Hb patterns (Hb AS and Hb F) were also estimated in SCA and SCT patients.

Materials and Methods:

Results of Hb capillary electrophoresis performed on all patients with SCH from January 2011 to December 2013 were evaluated retrospectively.

Results:

Of a total of 3332 patient data analyzed, 307 were anemic patients (58% males and 42% females) with SCH. The sickling test showed all the patients to be positive. Hb electrophoresis revealed the incidence of 96.7%, 3.3%, and 0% of the patients suffered from SCA, SCT and sickle/beta-thalassemia, respectively. Patients with SCA had a higher level of Hb F and showed no crisis when compared with other SCA patients who had lower or no Hb F levels.

Conclusion:

SCA is relatively frequent among males (56.4%) than females out of all patients with SCH. The SCA incidence was more common (48.5%) among children, frequency of SCT among adult age group was 1.6%, while sickle/beta-thalassemia was 0%.

Musculoskeletal Manifestations of Sickle Cell Disease: A Review

Sickle cell disease (SCD) is an inherited disorder of abnormal haemoglobin commonly encountered in the West African sub-region. It has varied osteoarticular and non-osseous complications that mimic some surgical conditions. The most common orthopaedic complications include avascular necrosis, osteomyelitis, septic arthritis, etc. A cautious and painstaking evaluation is required in handling these patients. Acute care and anaesthetic precautions are vital in ensuring an uneventful postoperative period.

Measuring Transition Readiness: A Correlational Study of Perceptions of Parent and Adolescents and Young Adults with Sickle Cell Disease

Adolescents and young adults (AYAs) often transfer from pediatric to adult care without adequate preparation, resulting in increased morbidity and mortality. The purpose of this descriptive research study of parent/AYA dyads was to measure perceptions of transition readiness. Factors that were found to be associated with perceptions of increased readiness to transition included AYA age, the amount of responsibility AYAs assume for their healthcare and the degree of parent involvement. More attention should be focused on these aspects of care to improve transition from pediatric to adult care for AYAs with sickle cell disease.

Adult sickle cell quality-of-life measurement information system (ASCQ-Me): conceptual model based on review of the literature and formative research

OBJECTIVES

Research-derived evidence about the impact of sickle cell disease (SCD) on the lives of affected adults is lacking. We conducted formative research to provide the basis for a comprehensive description of how SCD affects the lives of adults, with the goal of developing a SCD-specific quality-of-life measurement system.

METHODS

We conducted a comprehensive literature review of patient-reported outcomes, followed by a series of focus groups and structured individual interviews with adults with SCD (n=122) and their health care providers (n=15).

RESULTS

We reviewed 473 abstracts and included 86 articles in the final review. The literature revealed broad categories of the impact of SCD and its treatment on the lives of adults-pain; emotional distress; social-role functioning; overall quality-of-life; and quality of care. We classified 1213 incidents from the focus groups and interviews into a taxonomy (16 domains) that met the criterion for saturation and was demonstrated to be reliable for the classification of incidents. The final conceptual model was built upon the taxonomy.

DISCUSSION

Our conceptual model was similar to previous models with the effects of pain predominating, interwoven with emotional distress, quality of care, and stigmatization. We found a broad range of emotions reflected, including positive effects of SCD. Items for the quality-of-life measure were derived from the taxonomy and the conceptual model may be of use in generating hypotheses for clinical research and improving understanding for clinicians of the lived experience of adults with SCD.

Multicenter COMPACT study of COMplications in patients with sickle cell disease and utilization of iron chelation therapy

BACKGROUND

Over the past few decades, lifespans of sickle cell disease (SCD) patients have increased; hence, they encounter multiple complications. Early detection, appropriate comprehensive care, and treatment may prevent or delay onset of complications.

OBJECTIVE

We collected longitudinal data on sickle cell disease (SCD) complication rates and associated resource utilization relative to blood transfusion patterns and iron chelation therapy (ICT) use in patients aged ≥16 years to address a gap in the literature.

RESEARCH DESIGN AND METHODS

Medical records of 254 SCD patients ≥16 years were retrospectively reviewed at three US tertiary care centers.

MAIN OUTCOME MEASURES

We classified patients into cohorts based on cumulative units of blood transfused and ICT history: <15 units, no ICT (Cohort 1 [C1]), ≥15 units, no ICT (Cohort 2 [C2]), and ≥15 units with ICT (Cohort 3 [C3]). We report SCD complication rates per patient per year; cohort comparisons use rate ratios (RRs).

RESULTS

Cohorts had 69 (C1), 91 (C2), and 94 (C3) patients. Pain led to most hospitalizations (76%) and emergency department (ED) (82%) visits. Among transfused patients (C2+C3), those receiving ICT were less likely to experience SCD complications than those who did not (RR [95% CI] C2 vs. C3: 1.33 [1.25-1.42]). Similar trends (RR [95% CI]) were observed in ED visits and hospitalizations associated with SCD complications (C2 vs. C3, ED: 1.94 [1.70-2.21]; hospitalizations: 1.61 [1.45-1.78]), but not in outpatient visits.

CONCLUSIONS

Although the most commonly reported SCD complication among all patients was pain, patients who received ICT were less likely to experience pain and other complications than those who did not. These results highlight the need for increased patient and provider education on the importance of comprehensive disease management.

Differences in quality of life between pediatric sickle cell patients who used hydroxyurea and those who did not

PURPOSE

The purpose of this paper is to examine the differences in quality of life (QoL) between two groups of pediatric sickle cell patients: those who used hydroxyurea and those who chose not to use the medication to treat sickle cell disease.

DESIGN/METHODOLOGY/APPROACH

The study was a quantitative, non-randomized, cross-sectional, comparative study. In total, 100 children ages seven to 17 participated in the study. Parents of the patients completed a demographic questionnaire while the participants completed the Pediatric Quality of Life Inventory (Peds QoL) and Sickle Cell Disease Quality of Life Inventory (SCD QoL).

FINDINGS

The Ped QoL regression analysis revealed that hydroxyurea use and parental marital status accounted for a significant proportion of the variance in Ped QoL. The SCD QoL regression analysis also revealed that hydroxyurea and age accounted for a significant proportion of the variance in SCD QoL. Finally, the regression analysis revealed that SCD, parental marital status, parental income, sex, age, race and number of siblings did not account for a significant proportion of the variance in SCD crises per year.

ORIGINALITY/VALUE

This paper proved a need to study the differences in QoL between those pediatric patients who used hydroxyurea and those who did not use the medication.

Patient reports of health outcome for adults living with sickle cell disease: development and testing of the ASCQ-Me item banks

Background

Providers and patients have called for improved understanding of the health care requirements of adults with sickle cell disease (SCD) and have identified the need for a systematic, reliable and valid method to document the patient-reported outcomes (PRO) of adult SCD care. To address this need, the Adult Sickle Cell Quality of Life Measurement System (ASCQ-Me) was designed to complement the Patient Reported Outcome Measurement Information System (PROMIS®). Here we describe methods and results of the psychometric evaluation of ASCQ-Me item banks (IBs).

Methods

At seven geographically-disbursed clinics within the US, 556 patients responded to questions generated to assess cognitive, emotional, physical and social impacts of SCD. We evaluated the construct validity of the hypothesized domains using exploratory factor analysis (EFA), parallel analysis (PA), and bi-factor analysis (Item Response Theory Graded Response Model, IRT-GRM). We used IRT-GRM and the Wald method to identify bias in responses across gender and age. We used IRT and Cronbach’s alpha coefficient to evaluate the reliability of the IBs and then tested the ability of summary scores based on IRT calibrations to discriminate among tertiles of respondents defined by SCD severity.

Results

Of the original 140 questions tested, we eliminated 48 that either did not form clean factors or provided biased measurement across subgroups defined by age and gender. Via EFA and PA, we identified three subfactors within physical impact: sleep, pain and stiffness impacts. Analysis of the resulting six item sets (sleep, pain, stiffness, cognitive, emotional and social impacts of SCD) supported their essential unidimensionality. With the exception of the cognitive impact IB, these item sets also were highly reliable across a broad range of values and highly significantly related to SCD disease severity.

Conclusion

ASCQ-Me pain, sleep, stiffness, emotional and social SCD impact IBs demonstrated exceptional measurement properties using modern and classical psychometric methods of evaluation. Further development of the cognitive impact IB is required to improve its sensitivity to differences in SCD disease severity. Future research will evaluate the sensitivity of the ASCQ-Me IBs to change in SCD disease severity over time due to health interventions.

Insurance status as a sociodemographic risk factor for functional outcomes and health-related quality of life among youth with sickle cell disease

Youth with sickle cell disease (SCD) are at risk for functional limitations and poor health-related quality of life (QoL). This study examined sociodemographic factors that may interact with medical complications to reduce functional ability and QoL among youth with SCD. Fifty-three patient/caregiver pairs (children 8 to 18 years; M=12.3 y) with SCD completed the Functional Disability Inventory and Pediatric Quality of Life Inventory questionnaires. Medical database reviews were conducted to collect health care utilization, disease complications, and sociodemographic information; insurance type (public vs. private insurance) and family zip code to access Census tract data reflecting neighborhood distress. Insurance type, but not neighborhood sociodemographic risk indicators, was significantly associated with disease-related complications and QoL. There were significant differences in both health care utilization and QoL by insurance type. Complications were higher in the group with public insurance. Insurance type seems to be more strongly related to disease outcomes and QoL than neighborhood sociodemographic distress. Closer attention to the contribution of insurance type to health outcomes may provide important insight to potential barriers for disease management. These issues are critically important for health care efficiency and equity for poor and underserved children with chronic health conditions.

Pitfalls of using administrative data sets to describe clinical outcomes in sickle cell disease

BACKGROUND

Administrative data sets are increasingly being used to describe clinical care in sickle cell disease (SCD). We recently used such an administrative database to look at the frequency of acute chest syndrome (ACS) and the use of transfusion to treat this syndrome in California patients from 2005 to 2010. Our results revealed a surprisingly low rate of transfusion for this life-threatening situation.

PROCEDURE

To validate these results, we compared California OSPHD (Office of Statewide Health Planning and Development) administrative data with medical record review of patients diagnosed with ACS identified by two pediatric and one adult hospital databases during 2009-2010.

RESULTS

ACS or a related pulmonary process accounted for one-fifth of the inpatient hospital discharges associated with the diagnosis of SCD between 2005 and 2010. Only 47% of those discharges were associated with a transfusion. However, chart reviews found that hospital databases over-reported visits for ACS. OSHPD underreported transfusions compared to hospital data. The net effect was a markedly higher true rate of transfusion (40.7% vs. 70.2%).

CONCLUSIONS

These results point out the difficulties in using this administrative data base to describe clinical care for ACS given the variation in clinician recognition of this entity. OSPHD is widely used to inform health care policy in California and contributes to national databases. Our study suggests that using this administrative database to assess clinical care for SCD may lead to inaccurate assumptions about quality of care for SCD patients in California. Future studies on health services in SCD may require a different methodology.

Tramadol use in pediatric sickle cell disease patients with vaso-occlusive crisis

AIM: To evaluate whether the addition of scheduled oral tramadol to intravenous morphine and intravenous ketorolac reduces morphine requirements.

METHODS: This single-centered, Institutional Review Board-approved, retrospective study at Moses Cone Memorial Hospital included pediatric patients who were ≥ 2 years old with vaso-occlusive crisis (VOC) caused by sickle cell disease (SCD), were on morphine patient-controlled analgesia (PCA), and had scheduled oral tramadol added to their standard pain regimen. The study population was admitted between March 2008 and March 2011. The data was collected from electronic records and included age, weight, morphine use, tramadol use, hemoglobin, pain scores, number of days on PCA, length of hospital stay, respiratory rate, and polyethylene glycol use. Thirty patients were analyzed as independent admissions and seven patients as paired admissions.

RESULTS: Eighteen pediatric SCD patients with VOC received morphine PCA and intravenous ketorolac and twelve patients received morphine PCA and intravenous ketorolac and scheduled oral tramadol. Baseline characteristics were similar between both groups with the exception of the average weight, which was greater in the tramadol group than in the morphine group. The average morphine requirements in patients with and without the use of tramadol were similar, both for the independent admissions [0.58 mg/kg per day vs 0.65 mg/kg per day (P = 0.31)] and the paired admissions [0.71 mg/kg per day vs 0.77 mg/kg per day (P = 0.5)]. The daily polyethylene glycol requirement was less in the tramadol group for both the independent [0.5 g/kg per day vs 0.6 g/kg per day (P = 0.64)] and paired admissions analyses [and 0.41 g/kg per day vs 0.55 g/kg per day (P = 0.67)].

CONCLUSION: The addition of scheduled tramadol in patients receiving concomitant morphine and ketorolac demonstrates a trend toward decreased morphine and polyethylene glycol use.

Left ventricular systolic function in sickle cell anemia: a meta-analysis

BACKGROUND

We sought to evaluate whether patients with sickle cell anemia (SCA) have left ventricular (LV) systolic dysfunction.

METHODS AND RESULTS

We conducted a Medline, Embase, Ebscohost, and Google scholar literature search articles published before April 2010. All studies that compared any measure of LV function (eg, ejection fraction [EF], fractional shortening [FS], or cardiac index [CI]) between normal control subjects and SCA (hemoglobin SS) patients were included. Among 57 studies that qualified for review, 19 studies including 841 SCA patients and 554 control subjects met the inclusion criteria. There were no significant differences in either LVEF (Hedge g = 0.15; 95% confidence interval -0.84 to 1.14; P = .76) or FS (P = .28) between SCA patients and control subjects. CI was significantly higher (P < .001) and LV end-systolic stress-volume index (load independent) was significantly lower (P < .001) in SCA patients. All LV systolic measures inversely correlated with age (all P < .001). LV end-systolic and -diastolic dimensions were significantly higher in SCA patients and increased with age.

CONCLUSIONS

SCA patients have similar load-dependent but lower load-independent measures of LV systolic function than control subjects. SCA is associated with LV dilation. LV structural and functional abnormalities appear to be age dependent with progressive LV dilation and impairment over time.

Management of sickle cell disease from childhood through adulthood

Sickle cell disease (SCD) is a genetic disorder characterised by anaemia and "sickling" of red blood cells, leading to chronic haemolytic anaemia, vascular injury, and organ dysfunction. Although children and adults experience many similar symptoms and problems, complications increase with age, leading to early mortality. Hydroxyurea (hydroxycarbamide), the only US Food and Drug Administration-approved treatment, continues to be under-utilised and other treatments available to children are often inaccessible for adults. Haematopoietic stem-cell transplantation is a curative option, but is limited by a lack of donors and concerns for transplant-related toxicities. Although comprehensive programs exist in paediatrics, affected adults may not have access to preventative and comprehensive healthcare because of a lack of providers or care coordination. They are often forced to rely on urgent care, leading to increased healthcare utilisation costs and inappropriate treatment. This problem highlights the importance of primary care during the transition from paediatrics to adulthood.

Iron: effect of overload and deficiency

Iron is a redox active metal which is abundant in the Earth's crust. It has played a key role in the evolution of living systems and as such is an essential element in a wide range of biological phenomena, being critical for the function of an enormous array of enzymes, energy transduction mechanisms, and oxygen carriers. The redox nature of iron renders the metal toxic in excess and consequently all biological organisms carefully control iron levels. In this overview the mechanisms adopted by man to control body iron levels are described.Low body iron levels are related to anemia which can be treated by various forms of iron fortification and supplementation. Elevated iron levels can occur systemically or locally, each giving rise to specific symptoms. Systemic iron overload results from either the hyperabsorption of iron or regular blood transfusion and can be treated by the use of a selection of iron chelating molecules. The symptoms of many forms of neurodegeneration are associated with elevated levels of iron in certain regions of the brain and iron chelation therapy is beginning to find an application in the treatment of such diseases. Iron chelators have also been widely investigated for the treatment of cancer, tuberculosis, and malaria. In these latter studies, selective removal of iron from key enzymes or iron binding proteins is sought. Sufficient selectivity between the invading organism and the host has yet to be established for such chelators to find application in the clinic.Iron chelation for systemic iron overload and iron supplementation therapy for the treatment of various forms of anemia are now established procedures in clinical medicine. Chelation therapy may find an important role in the treatment of various neurodegenerative diseases in the near future.

Low-shear red blood cell oxygen transport effectiveness is adversely affected by transfusion and further worsened by deoxygenation in sickle cell disease patients on chronic transfusion therapy

BACKGROUND

Simple chronic transfusion therapy (CTT) is a mainstay for stroke prophylaxis in sickle cell anemia, but its effects on hemodynamics are poorly characterized. Transfusion improves oxygen-carrying capacity, reducing demands for high cardiac output. While transfusion decreases factors associated with vasoocclusion, including percent hemoglobin (Hb)S, reticulocyte count, and circulating cell-free Hb, it increases blood viscosity, which reduces microvascular flow. The hematocrit-to-viscosity ratio (HVR) is an index of red blood cell oxygen transport effectiveness that varies with shear stress and balances the benefits of improved oxygen capacity to viscosity-mediated impairment of microvascular flow. We hypothesized that transfusion would improve HVR at high shear despite increased blood viscosity, but would decrease HVR at low shear.

STUDY DESIGN AND METHODS

To test this hypothesis, we examined oxygenated and deoxygenated blood samples from 15 sickle cell patients on CTT immediately before transfusion and again 12 to 120 hours after transfusion.

RESULTS

Comparable changes in Hb, hematocrit (Hct), reticulocyte count, and HbS with transfusion were observed in all subjects. Viscosity, Hct, and high-shear HVR increased with transfusion while low-shear HVR decreased significantly.

CONCLUSION

Decreased low-shear HVR suggests impaired oxygen transport to low-flow regions and may explain why some complications of sickle cell anemia are ameliorated by CTT and others may be made worse.