Health-related quality of life in children with sickle cell anemia: impact of blood transfusion therapy

The Burden of Sickle Cell Disease on Children and Their Caregivers: Caregiver Reports of Children's Health-Related Quality of Life and School Experiences, Caregiver Burden, and Their Association with Frequency of Vaso-Occlusive Crises

Background

Children with sickle cell disease (SCD) experience a multiplex of disease-related symptoms and complications, including vaso-occlusive crises (VOCs), episodes characterized by extreme pain.

Methods

A cross-sectional observational survey examined the health-related quality of life (HRQoL) and school experiences of children with SCD 2 months-11 years, burden experienced by their caregivers, and associations between these outcomes and VOC frequency. Caregivers (N=167) of children with SCD in the US completed the Infant-Toddler Quality of Life-Short Form 47 (ITQoL-SF47) for children 2 months-4 years, the Child Health Questionnaire-Parent Form 50 (CHQ-PF50) and PROMIS Pain Interference and Sleep Disturbance Parent Proxy short forms for children 5-11 years, and a study-specific survey of school experiences.

Results

Children with SCD 2 months-4 years had lower ITQoL-SF47 scores (ie, worse HRQoL, p<0.001) than a normative sample of children; across domains, differences ranged from 18.73-45.03 points and exceeded minimal important difference (MID) thresholds. Except for the behavior domain, children with SCD 5-11 years had lower scores on all CHQ-PF50 domains than the normative sample (p<0.001); differences ranged from 6.78-36.37 points and exceeded MID thresholds. Children with more frequent VOCs had lower HRQoL and worse school experiences than children with less frequent VOCs (p<0.05, except for behavior domains). The largest differences based on VOC frequency were observed for overall health and bodily pain/discomfort among children 2 months-4 years (differences=40.88 and 32.50 points, respectively), and bodily pain and role/social limitations due to physical health among children 5-11 years (differences=38.99 and 37.80, respectively). Caregivers of children with more frequent VOCs experienced greater burden than caregivers of children with less frequent VOCs, though specific areas of impact (eg, caregiver emotions, time) differed across child age groups.

Conclusion

VOC frequency is negatively associated with HRQoL, highlighting the burden experienced by children with SCD and their caregivers.

Global burden of transfusion in sickle cell disease

Sickle cell disease (SCD) is the most common hereditary hemoglobinopathy. The underlying pathophysiology of the red blood cell (RBC) leads to pan-systemic complications which manifest at an early age. While curative and disease-modifying treatments exist for SCD, a key intervention in the management and treatment of SCD is RBC transfusion, which can alleviate or prevent many complications. SCD patients often require chronic RBC transfusion therapy which can result in complications, such as iron overload, alloimmunization and infection. In low- and middle-income countries (LMICs), SCD patients lack appropriate access to healthcare such as newborn screening, health education, prophylaxis for infection, and treatments to reduce both mortality and SCD-related adverse effects. Poor access to RBCs for transfusion, coupled with donated blood not meeting safety standards set by the World Health Organization, presents a significant barrier for patients requiring chronic transfusions in LMICs. Unmet needs associated with blood collection, blood component processing and recipient matching all pose a serious problem in many LMICs, although this varies depending on geographic location, political organizations and economy. This review aims to provide an overview of the global burden of SCD, focusing on the availability of current treatments and the burden of chronic RBC transfusions in patients with SCD.

Sense of coherence or self-efficacy as predictors of health-related quality of life in sickle cell disease patients

Patients with sickle cell disease (SCD) suffer from impaired health-related quality of life (HRQoL). This study aimed to determine the level of HRQoL, sense of coherence (SOC), and self-efficacy (SE) in a sample of SCD patients, and to explore predictors of their physical and mental HRQoL. A cross-sectional descriptive study was conducted on 83 SCD patients of one university hospital. The data of the study was collected through Persian versions of the Short-Form Health Survey SF-36 (RAND 36-item), the Sense of Coherence Scale (SOC-13), and the Sickle Cell Self-Efficacy Scale (SCSES). The mean age of the patients was 26.34 ± 8.19 years old. Patients' mean scores for the Physical Component Summary (PCS), Mental Component Summary (MCS), SOC, and SCSES were 40.57 ± 17.18 (range: 0-100), 50.44 ± 17.95 (range: 0-100), 52.40 ± 15.35 (range: 13-91), 26.40 ± 6.96 (range: 9-45), respectively. Regression models showed that the level of the patients' SOC, was the main predictor of the MCS (β = 0.37, p < 0.001). However, the level of the patients' SE was the main predictor of the PCS (β = 0.30, p = 0.004). Also, "blood transfusion history" in patients was a common predictor for both the PCS (β =  - 0.28, p = 0.008) and the MCS (β =  - 0.29, p = 0.003). These results can assist nurses and clinicians to plan clinical interventions for SCD patients by focusing on increasing the level of the SOC and SE and improving SCD patients' HRQoL. Furthermore, measuring the level of the SOC and self-efficacy as screening tests are useful to find patients with a greater risk of impaired HRQoL.

Adhesion molecules and cerebral microvascular hemodynamic abnormalities in sickle cell disease

Cerebrovascular abnormalities are a common feature of sickle cell disease that may be associated with risk of vaso-occlusive pain crises, microinfarcts, and cognitive impairment. An activated endothelium and adhesion factors, VCAM-1 and P-selectin, are implicated in sickle cell vasculopathy, including abnormal hemodynamics and leukocyte adherence. This study examined the association between cerebral expression of these adhesion factors and cortical microvascular blood flow dynamics by using in-vivo two-photon microscopy. We also examined the impact of blood transfusion treatment on these markers of vasculopathy. Results showed that sickle cell mice had significantly higher maximum red blood cell (RBC) velocity (6.80 ± 0.25 mm/sec, p ≤ 0.01 vs. 5.35 ± 0.35 mm/sec) and more frequent blood flow reversals (18.04 ± 0.95 /min, p ≤ 0.01 vs. 13.59 ± 1.40 /min) in the cortical microvasculature compared to controls. In addition, sickle cell mice had a 2.6-fold (RFU/mm2) increase in expression of VCAM-1 and 17-fold (RFU/mm2) increase in expression of P-selectin compared to controls. This was accompanied by an increased frequency in leukocyte adherence (4.83 ± 0.57 /100 μm/min vs. 2.26 ± 0.37 /100 μm/min, p ≤ 0.001). We also found that microinfarcts identified in sickle cell mice were 50% larger than in controls. After blood transfusion, many of these parameters improved, as results demonstrated that sickle cell mice had a lower post-transfusion maximum RBC velocity (8.30 ± 0.98 mm/sec vs. 11.29 ± 0.95 mm/sec), lower frequency of blood flow reversals (12.80 ± 2.76 /min vs. 27.75 ± 2.09 /min), and fewer instances of leukocyte adherence compared to their pre-transfusion imaging time point (1.35 ± 0.32 /100 μm/min vs. 3.46 ± 0.58 /100 μm/min). Additionally, we found that blood transfusion was associated with lower expression of adhesion factors. Our results suggest that blood transfusion and adhesion factors, VCAM-1 and P-selectin, are potential therapeutic targets for addressing cerebrovascular pathology, such as vaso-occlusion, in sickle cell disease.

Sickle-Cell Disease and Stroke: Quality of Life of Patients in a Chronic Transfusion Regimen from the Caregivers' Perspective

Strokes affect up to 10% of children with sickle-cell disease (SCD). The most commonly used strategy to prevent a first-time stroke or its recurrence is to perform periodic red blood cell transfusions. This article aims to evaluate the quality of life (QoL) of children and adolescents with SCD undergoing a chronic transfusion regimen (CTR) for stroke prophylaxis, according to their caregivers' perception. A cross-sectional study was conducted using a sociodemographic interview with an application of a validated instrument (Pediatric Quality of Life Inventory) involving 16 caregivers of patients with SCD aged <18 years undergoing CTR in a reference center. The data were processed using STATA version 13.0. The caregivers were predominantly the mothers of the minors that were part of the study cohort (87.5%), an income of <2 minimum wages (81.2% of cases) and >8 years of schooling (56.2%). The patients had a mean age of 10.4 years, 68.8% were male, 75% were mixed-race and came from small towns and rural areas (68.8%). The overall mean QoL was 45.8 (95% confidence interval [CI] 42.5-49.2). Female patients and those aged <12 years had lower levels of overall QoL. The emotional dimension of the children was the least compromised as per the caregivers' perception. The mean QoL of children with SCD on a CTR is lower than the estimated global mean QoL reported in the literature. It is possible that the occurrence of a stroke enhances the caregivers' negative perceptions about the QoL of patients with SCD.

Stroke in sickle cell disease and the promise of recent disease modifying agents

Sickle cell disease (SCD) is an inherited hemoglobinopathy affecting approximately 100,000 individuals in the United States. Cerebrovascular disease is among the most common and debilitating complications of SCA, with 53% experiencing silent cerebral infarct by age 30 and 3.8% experiencing overt stroke by age 40 years. This review highlights the burden of cerebrovascular disease in SCD, including both stroke and silent cerebral infarct (SCI). We then discuss the pathophysiology of stroke and cerebral fat embolism in the absence of a patent foramen ovale. This review also reveals that options for primary and secondary stroke prevention in SCD are still limited to hydroxyurea and blood transfusion, and that the role of aspirin and anticoagulation in SCD stroke has not been adequately studied. Limited data suggest that the novel disease-modifying agents for SCD management may improve renal dysfunction, leg ulcers, and lower the abnormally high TCD flow velocity. Further research is urgently needed to investigate their role in stroke prevention in SCD, as these novel agents target the main stroke contributors in SCD - hemolysis and vaso-occlusion. This literature review also explores the role of healthcare disparities in slowing progress in SCD management and research in the United States, highlighting the need for more investment in patient and clinician education, SCD management, and research.

Health-related quality of life of patients with sickle cell disease aged 8-17 years at Kamuzu Central Hospital, Malawi

BACKGROUND

Sickle cell disease (SCD) is characterized by both acute and chronic complications that affect the daily lives of patients and lower their quality of life.

OBJECTIVE

To describe the health-related quality of life (HRQoL) and the associated factors in children aged 8-17 years with SCD attending the pediatric hematology clinic at Kamuzu Central Hospital (KCH) in Lilongwe, Malawi.

METHODS

A mixed-methods cross-sectional study was conducted at KCH. Patient data were collected with the aid of a standardized case report form. HRQoL was assessed using PedsQL™ Sickle Cell Disease Module by the child's report. Associations between HRQoL scores and independent variables were evaluated by a linear regression model. In-depth interviews were then carried out and the qualitative data were analyzed using content thematic analysis.

RESULTS

A hundred and sixty-three children with SCD were enrolled and 52.1% were females. Their median age was 11.2 ± 2.7 years. The mean global HRQoL score of the children was 62 ± 17.3. The highest scores were in the treatment domain (72.5 ± 15.1) while the lowest scores were in the emotions domain (55.2 ± 28.7). The mean pain score was 58.8 ± 16.3. The factors associated with low HRQoL scores were pain (β-coefficient -6.97 CI (-3.07,-15.58); p value .034) and low hemoglobin levels (β-coefficient 2.29 CI (.65-3.91); p value .006).

CONCLUSION

The HRQoL of this population is low. Pain and low hemoglobin were significantly associated with low HRQoL scores. Adequate treatment to control pain and increase the steady-state hemoglobin may improve the HRQoL of children with SCD. Interventions to address low emotional scores are recommended.

Barriers and Facilitators to Chronic Red Cell Transfusion Therapy in Pediatric Sickle Cell Anemia

Background: Chronic red cell transfusion (CRCT) therapy is one of a few effective disease-modifying therapies for children with sickle cell anemia (SCA). CRCT is recommended for primary and secondary stroke prevention for at-risk children with SCA and is sometimes used for other disease-related complications. However, CRCT can be resource- and time-intensive for patients/families, providers, and organizations. This study was conducted to provide a comprehensive, multilevel examination of barriers and facilitators to transfusion therapy in children with SCA from health care provider and caregiver perspectives. Methods: A qualitative descriptive approach was used to conduct key informant interviews in a sample of 26 caregivers and 25 providers across the United States. Interviews were analyzed using directed content analysis with the Multilevel Ecological Model of Health as an initial coding framework and the constant comparison method. Results: Ten barrier themes and 10 facilitator themes emerged across all ecological levels. Themes most commonly occurred on the patient and organizational levels. Key barriers themes included Logistical Challenges, Obtaining and Maintaining Venous Access, Alloantibodies/Alloimmunization and Reactions, and Iron Overload and Adherence to Chelation Therapy. Key facilitator themes included Nursing and Non-nursing Staff Support, Positive Child/Family Experiences, Logistical Help and Social Resources, Blood Bank and Access to Blood, and Transfusion-Specific Resources. Discussion: The comprehensive understanding of multilevel barriers and facilitators to transfusion therapy, including the role of nursing, in children with SCA can inform strategies to improve CRCT for patients/families and providers and can also be applied by organizations seeking to implement transfusion services for SCA.

Stroke in sickle cell disease in association with bilateral absence of the internal carotid arteries. Case report

Background

Congenital absence of the internal carotid artery (ICA) is a highly infrequent congenital incidence and occurs in less than 0.01% of the population; bilateral absence is exceedingly rare, diagnosed below 10% of the unilateral absence of the ICA. Sickle cell disease (SCD) is a serious disorder and carries a high risk of stroke.

Case presentation

We present a five-year-old child with SCD who experienced an ischemic stroke episode with epileptic seizures. Neuroimaging revealed the agenesis of both ICAs. The frequency, embryology, and collateral pathway of the vascular anomaly as the clinical presentation, of this rare hematologic disease, are discussed.

Conclusions

Sickle cell disease (SCD) carries a high risk of stroke. Congenital absence of ICA occurs in less than 0.01% of the population; bilateral absence is diagnosed below 10% of the unilateral absence of the ICA.

The Correlation Between Surgical Procedures and Quality of Life Among Sickle Cell Disease Patients: A Perspective Saudi Study

INTRODUCTION

Sickle cell disease (SCD) is among the common prevalent diseases in Saudi Arabia. It is associated with several complications that sometimes necessitate surgical procedures. Those patients can also have a lower quality of life (QoL) due to several reasons. Our aim in this study is to highlight the association between sociodemographic data, clinical data, and SCD-related surgeries in patients with their QoL.

METHODS

A cross-sectional study was performed using a validated Arabic version of the World Health Organization QoL-BREF (WHOQOL-BREF) questionnaire distributed in electronic form. Male and female Arabic speakers (18+ years old) of Saudi origin were included in this study; those who did not meet these criteria were excluded.

RESULTS

We distributed 309 questionnaires to the targeted subjects; however, only 204 met our inclusion criteria. Our findings revealed 135 female respondents and 69 male respondents. Interestingly, splenectomy was not significantly associated with a difference in all aspects of QoL in SCD patients. However, the data showed significantly lower respective mean scores for physical health (p=0.002 & p=0.022) and overall QoL (p=0.024 & p=0.042) for those who underwent cholecystectomy and hip arthroplasty. In contrast, shoulder arthroplasty appeared to be associated with significantly lower mean scores for physical health (T=-2.597; p=0.010) and the environmental aspect of QoL (T=-2.016; p=0.045).

CONCLUSION

Cholecystectomy, hip arthroplasty, and shoulder arthroplasty were significantly associated with lower QoL in SCD patients.

Health-related quality of life in hemoglobinopathies: A systematic review from a global perspective

BACKGROUND

Sickle cell disease (SCD) and thalassemia are inherited blood disorders, which can lead to life-threatening events and chronic organ damage. Recent advances in treatments have increased life expectancy, and hemoglobinopathies have become chronic illnesses with social and emotional impairments. Thus, health-related quality of life (HRQOL) assessment has a fundamental role in disease management and treatment, and generic and disease-specific questionnaires are reliable and validated measures to estimate disease burden. The heterogeneous distribution of treatment opportunities worldwide influences physical, social, and emotional disease perception.

OBJECTIVES

To review publications concerning HRQOL for SCD and thalassemia in different areas of the world in order to gather a global perspective of questionnaires used and outcomes evaluated.

METHODS

A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Medline databases were searched on 29 September 2021. Inclusion criteria were as follows: (1) studies of HRQOL assessment in SCD and thalassemia patients by using the PROMIS, the SF-36, the SCSES, the PedsQL-SCD, the PedsQOL generic core scale, the ASCQ-Me, and the TranQoL; and (2) every article type, including non-English studies. We excluded studies that were not limited to SCD or thalassemia and studies that were not specific to hemoglobinopathies, and not consistent with the topic of HRQOL assessment. We did not include the gray literature. A total of 102 out of 124 articles from PubMed, Cochrane Library, and Google Scholar were eligible for inclusion (66 SCD articles and 36 thalassemia articles). The quality of studies was assessed through Critical Appraisal tools for use in JBI Systematic Reviews. Data extraction was conducted using a standardized data collection form (authors, year and country of publication, study design, age and number of patients, HRQOL questionnaires, questionnaire language, and clinical outcomes).

RESULTS

The evaluation of HRQOL was conducted on all continents, but differences in the worldwide frequency of HRQOL assessment were observed. HRQOL of SCD patients was less investigated in Europe. HRQOL of thalassemia patients was less investigated in South-East Asia and Africa. Generic HRQOL questionnaires (PROMIS, SF-36, and PedsQL) were frequently adopted, while disease-specific ones (ASCQ-Me, SCSES for SCD, and TranQoL for thalassemia) were less used. Translation into local languages has been often performed.

CONCLUSION

Health-related quality of life is a complex outcome that has been increasingly incorporated in clinical research and clinical practice worldwide, although with regional differences. Disease-specific outcomes (pain for SCD and transfusion burden for thalassemia) and healthcare system characteristics, particularly in low-income countries, have an impact on HRQOL and should be considered in healthcare plans.

Economic evaluation of regular transfusions for cerebral infarct recurrence in the Silent Cerebral Infarct Transfusion Trial

Children with preexisting silent cerebral infarcts on regular transfusion therapy had 50% lower hospitalization costs than standard care.

The incremental cost-effectiveness ratio for transfusion therapy to prevent infarct recurrence was $22 025 for every infarct prevented.

In 2020, the American Society of Hematology published evidence-based guidelines for cerebrovascular disease in individuals with sickle cell anemia (SCA). Although the guidelines were based on National Institutes of Health–sponsored randomized controlled trials, no cost-effectiveness analysis was completed for children with SCA and silent cerebral infarcts. We conducted a cost-effectiveness analysis comparing regular blood transfusion vs standard care using SIT (Silent Cerebral Infarct Transfusion) Trial participants. This analysis included a modified societal perspective with direct costs (hospitalization, emergency department visit, transfusion, outpatient care, and iron chelation) and indirect costs (special education). Direct medical costs were estimated from hospitalizations from SIT hospitals and unlinked aggregated hospital and outpatient costs from SIT sites by using the Pediatric Health Information System. Indirect costs were estimated from published literature. Effectiveness was prevention of infarct recurrence. An incremental cost-effectiveness ratio using a 3-year time horizon (mean SIT Trial participant follow-up) compared transfusion vs standard care. A total of 196 participants received transfusions (n = 90) or standard care (n = 106), with a mean age of 10.0 years. Annual hospitalization costs were reduced by 54% for transfusions vs standard care ($4929 vs $10 802), but transfusion group outpatient costs added $22 454 to $137 022 per year. Special education cost savings were $2634 over 3 years for every infarct prevented. Transfusion therapy had an incremental cost-effectiveness ratio of $22 025 per infarct prevented. Children with preexisting silent cerebral infarcts receiving blood transfusions had lower hospitalization costs but higher outpatient costs, primarily associated with the oral iron chelator deferasirox. Regular blood transfusion therapy is cost-effective for infarct recurrence in children with SCA. This trial is registered at www.clinicaltrials.gov as #NCT00072761.

Evaluation of Sickle Cell Module for Quality of Life in Egyptian Children and Adolescents Patients: Impact of Psychiatric and Disease Specific Variables

Sickle cell disease (SCD) impacts the physical, emotional, and psychological aspects of life. We aimed to study the quality of life (QoL) in Egyptian children and adolescents with SCD using the sickle cell module in relations to social, psychological and disease variables. A cross sectional study included 40 patients with SCD between 5 and 18 years. Details of diagnosis, SCD related complications, socioeconomic status were revised. Psychological assessment was done using children depression inventory, revised Children's Manifest anxiety scale and Health related QoL for both patients and parents using a validated Arabic age specific version of sickle cell module. Significant better scores for communication problems in mothers with college degree was found compared with other academic levels with no significant difference in QoL in relation to father education and significant higher communication problems with high rate of hospitalization (P = .021). Pain score was higher in 8-13 years compared with 13-18 years age groups. Significant worse scores for worrying was found in females, P = 0.033; Depression was found in 90% of studied patients. The main determinants of QoL in patients with SCD were maternal education and frequency of hospitalization. Depression is of alarming frequency for intervention.

Biopsychosocial Predictors of Quality of Life in Paediatric Patients With Sickle Cell Disease

Sickle cell disease (SCD) refers to a group of inherited blood disorders with considerable morbidity that causes severe pain, reduces life expectancy, and requires significant self-management. Acute painful episodes are the hallmark of SCD, but persistent daily pain is also highly prevalent in this population. Characterising the impact and experience of SCD-related morbidity (i.e., sleep disruption, frequent emergency department visits, cognitive dysfunction) on health-related quality of life (HRQOL) requires multiple assessment methods to best capture the underlying mechanisms. To gain a greater understanding of the effect of common symptom categories on HRQOL and to determine potential pain coping targets, the present study investigated whether demographic, socioeconomic, sleepiness, pain burden, frequency of emergency department (ED) visits, and cognition predicted HRQOL in a paediatric sample of patients with SCD. Our study was a secondary analysis of baseline assessment data of children with SCD aged 8-15 years (n = 30) in the Prevention of Morbidity in Sickle Cell Anaemia Phase 2b (POMSb2) randomised controlled clinical trial of auto-adjusting continuous positive airways pressure. Patients completed cognitive testing (IQ, Processing Speed Index, Delis-Kaplan Executive Function Scale (DKEFS) Tower, Conner's Continuous Performance Test), sleepiness (Epworth Sleepiness Scale), and HRQOL (PedsQL Sickle Cell Module) at baseline. Patients reported pain burden (Sickle Cell Pain Burden Inventory-Youth) each month over 8 visits. Caregivers provided demographic information and reported their child's executive function (Behavioural Rating Inventory of Executive Function) at baseline. Data from our analysis demonstrated that demographic factors (i.e., age, gender, level of neighbourhood deprivation) and treatment variables (i.e., hydroxyurea use) did not independently predict HRQOL, and laboratory values (i.e., haemoglobin, haematocrit, mean oxygen saturation) were not significantly correlated with HRQOL (ps > 0.05). However, sleepiness, pain burden, ED visits, and executive dysfunction independently predicted HRQOL (R ² = 0.66) with large effects (η² = 0.16 to 0.32). These findings identify specific, measurable symptom categories that may serve as targets to improve HRQOL that are responsive to change. This knowledge will be useful for multimodal interventions for paediatric patients with SCD that include sleep management, pain coping strategies, and executive function training.

A systematic review of quality of life in sickle cell disease and thalassemia after stem cell transplant or gene therapy

Patients with sickle cell disease (SCD) and thalassemia experience several complications across their lifespan that lead to impairment in different health-related quality of life (HRQOL) domains. There is increasing interest in curative therapies for patients with SCD and thalassemia, including hematopoietic stem cell transplant (HSCT) and gene therapy; however, the effect of these therapies on various HRQOL domains remains unclear. Our objective was to systematically evaluate the most recent evidence for the effect of HSCT and gene therapy on HRQOL in patients with SCD and thalassemia. A systematic search of medical literature databases was conducted. A total of 16 studies (thalassemia, n = 9; SCD, n = 6; both, n = 1) involving 517 participants met inclusion criteria (thalassemia, n = 416; SCD, n = 101). HSCT was associated with a small to large positive effects in most HRQOL domains (Cohen's d; mean = 0.47; median = 0.37; range, 0.27-2.05). In thalassemia, HSCT was frequently associated with large positive effects in physical and emotional HRQOL domains (median d = 0.79 and d = 0.57, respectively). In SCD, HSCT was associated with large positive effects in all HRQOL domains. Emerging data suggest improvement in HRQOL outcomes across different domains following gene therapy in thalassemia and SCD. The quality of evidence was moderate in 13 studies (81%). HSCT has a positive impact on several HRQOL domains in patients with SCD and thalassemia; however, more longitudinal studies are warranted to assess the sustainability of these effects. Reporting HRQOL outcomes from ongoing gene therapy or gene-editing trials in SCD and thalassemia is key to better understand the benefits of such therapies.

Antigen density dictates RBC clearance, but not antigen modulation, following incompatible RBC transfusion in mice

Incompatible red blood cell (RBC) transfusion can result in life-threatening transfusion complications that can be challenging to manage in patients with transfusion-dependent anemia. However, not all incompatible RBC transfusions result in significant RBC removal. One factor that may regulate the outcome of incompatible RBC transfusion is the density of the incompatible antigen. Despite the potential influence of target antigen levels during incompatible RBC transfusion, a model system capable of defining the role of antigen density in this process has not been developed. In this study, we describe a novel model system of incompatible transfusion using donor mice that express different levels of the KEL antigen and recipients with varying anti-KEL antibody concentrations. Transfusion of KEL+ RBCs that express high or moderate KEL antigen levels results in rapid antibody-mediated RBC clearance. In contrast, relatively little RBC clearance was observed following the transfusion of KEL RBCs that express low KEL antigen levels. Intriguingly, unlike RBC clearance, loss of the KEL antigen from the transfused RBCs occurred at a similar rate regardless of the KEL antigen density following an incompatible transfusion. In addition to antigen density, anti-KEL antibody levels also regulated RBC removal and KEL antigen loss, suggesting that antigen density and antibody levels dictate incompatible RBC transfusion outcomes. These results demonstrate that antibody-induced antigen loss and RBC clearance can occur at distinct antigen density thresholds, providing important insight into factors that may dictate the outcome of an incompatible RBC transfusion.

Patient-reported Outcome Measures in Pediatric Non-Malignant Hematology: A Systematic Review

Patient-reported outcome measures (PROMs) are questionnaires completed by patients or caregivers without influence by health care professionals. As such, PROMs show subjective health experiences, enhance the clinical information available to providers, and inform clinical action. The objective of this systematic review is to identify and list which validated PROMs have been used to monitor health-related quality of life in pediatric patients with nonmalignant hematology (hemophilia, immune thrombocytopenia, sickle cell disease, and thalassemia). Databases (MEDLINE, Embase, HaPI, CINAHL, and PsycTESTS) were searched to identify publications that validated or used PROMs as an outcome measure in the 4 disease groups. Overall, 209 articles met the inclusion criteria, identifying 113 PROMs. Of the 113 identified PROMs, 95 are generic and can be used in multiple disease groups. The Pediatric Quality of Life Generic Core Scales was the most frequently used generic PROM (68 studies). The 18 remaining PROMs were disease specific. The results of this review, together with the COSMIN tool for selecting outcome measures, will allow clinicians to evaluate the PROMs that are best suited to their patient population. In addition, the focus groups are currently being conducted with patients, parents, and clinicians to determine the optimal use of PROMs in the clinical environment.

Social aspects of chronic transfusions: addressing social determinants of health, health literacy, and quality of life

Chronic monthly transfusions are a lifesaving preventative therapy for many patients with sickle cell disease; however, the burden of this therapy for patients and families is high. In the United States, there is overlap in the population affected by sickle cell disease and those with the greatest burden of social needs. Hematology providers caring for patients with SCD have an opportunity to screen for and mitigate social determinants of health, especially in those receiving chronic transfusion therapy given the frequent interactions with the healthcare system and increased demand on already potentially limited resources. Given the complexity of the treatment and medication regimens, providers caring for patients receiving chronic transfusions should implement universal strategies to minimize the impact of low health literacy, as this therapy imposes a significant demand on the health literacy skills of a family. Despite the social and literacy burden of this intervention, it is reassuring that quality of life is preserved as patients with SCD on chronic transfusion therapy often report higher health related quality of life than their peers receiving other disease modifying therapies.

Blood transfusion for preventing primary and secondary stroke in people with sickle cell disease

BACKGROUND

Sickle cell disease is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. Sickle cell disease can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Stroke affects around 10% of children with sickle cell anaemia (HbSS). Chronic blood transfusions may reduce the risk of vaso-occlusion and stroke by diluting the proportion of sickled cells in the circulation. This is an update of a Cochrane Review first published in 2002, and last updated in 2017.

OBJECTIVES

To assess risks and benefits of chronic blood transfusion regimens in people with sickle cell disease for primary and secondary stroke prevention (excluding silent cerebral infarcts).

SEARCH METHODS

We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 8 October 2019. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register: 19 September 2019.

SELECTION CRITERIA

Randomised controlled trials comparing red blood cell transfusions as prophylaxis for stroke in people with sickle cell disease to alternative or standard treatment. There were no restrictions by outcomes examined, language or publication status.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and the risk of bias and extracted data.

MAIN RESULTS

We included five trials (660 participants) published between 1998 and 2016. Four of these trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of sickle cell disease. Three trials compared regular red cell transfusions to standard care in primary prevention of stroke: two in children with no previous long-term transfusions; and one in children and adolescents on long-term transfusion. Two trials compared the drug hydroxyurea (hydroxycarbamide) and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children); and one in secondary prevention (children and adolescents). The quality of the evidence was very low to moderate across different outcomes according to GRADE methodology. This was due to the trials being at a high risk of bias due to lack of blinding, indirectness and imprecise outcome estimates. Red cell transfusions versus standard care Children with no previous long-term transfusions Long-term transfusions probably reduce the incidence of clinical stroke in children with a higher risk of stroke (abnormal transcranial doppler velocities or previous history of silent cerebral infarct), risk ratio 0.12 (95% confidence interval 0.03 to 0.49) (two trials, 326 participants), moderate quality evidence. Long-term transfusions may: reduce the incidence of other sickle cell disease-related complications (acute chest syndrome, risk ratio 0.24 (95% confidence interval 0.12 to 0.48)) (two trials, 326 participants); increase quality of life (difference estimate -0.54, 95% confidence interval -0.92 to -0.17) (one trial, 166 participants); but make little or no difference to IQ scores (least square mean: 1.7, standard error 95% confidence interval -1.1 to 4.4) (one trial, 166 participants), low quality evidence. We are very uncertain whether long-term transfusions: reduce the risk of transient ischaemic attacks, Peto odds ratio 0.13 (95% confidence interval 0.01 to 2.11) (two trials, 323 participants); have any effect on all-cause mortality, no deaths reported (two trials, 326 participants); or increase the risk of alloimmunisation, risk ratio 3.16 (95% confidence interval 0.18 to 57.17) (one trial, 121 participants), very low quality evidence. Children and adolescents with previous long-term transfusions (one trial, 79 participants) We are very uncertain whether continuing long-term transfusions reduces the incidence of: stroke, risk ratio 0.22 (95% confidence interval 0.01 to 4.35); or all-cause mortality, Peto odds ratio 8.00 (95% confidence interval 0.16 to 404.12), very low quality evidence. Several review outcomes were only reported in one trial arm (sickle cell disease-related complications, alloimmunisation, transient ischaemic attacks). The trial did not report neurological impairment, or quality of life. Hydroxyurea and phlebotomy versus red cell transfusions and chelation Neither trial reported on neurological impairment, alloimmunisation, or quality of life. Primary prevention, children (one trial, 121 participants) Switching to hydroxyurea and phlebotomy may have little or no effect on liver iron concentrations, mean difference -1.80 mg Fe/g dry-weight liver (95% confidence interval -5.16 to 1.56), low quality evidence. We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: risk of stroke (no strokes); all-cause mortality (no deaths); transient ischaemic attacks, risk ratio 1.02 (95% confidence interval 0.21 to 4.84); or other sickle cell disease-related complications (acute chest syndrome, risk ratio 2.03 (95% confidence interval 0.39 to 10.69)), very low quality evidence. Secondary prevention, children and adolescents (one trial, 133 participants) Switching to hydroxyurea and phlebotomy may: increase the risk of sickle cell disease-related serious adverse events, risk ratio 3.10 (95% confidence interval 1.42 to 6.75); but have little or no effect on median liver iron concentrations (hydroxyurea, 17.3 mg Fe/g dry-weight liver (interquartile range 10.0 to 30.6)); transfusion 17.3 mg Fe/g dry-weight liver (interquartile range 8.8 to 30.7), low quality evidence. We are very uncertain whether switching to hydroxyurea and phlebotomy: increases the risk of stroke, risk ratio 14.78 (95% confidence interval 0.86 to 253.66); or has any effect on all-cause mortality, Peto odds ratio 0.98 (95% confidence interval 0.06 to 15.92); or transient ischaemic attacks, risk ratio 0.66 (95% confidence interval 0.25 to 1.74), very low quality evidence.

AUTHORS' CONCLUSIONS

There is no evidence for managing adults, or children who do not have HbSS sickle cell disease. In children who are at higher risk of stroke and have not had previous long-term transfusions, there is moderate quality evidence that long-term red cell transfusions reduce the risk of stroke, and low quality evidence they also reduce the risk of other sickle cell disease-related complications. In primary and secondary prevention of stroke there is low quality evidence that switching to hydroxyurea with phlebotomy has little or no effect on the liver iron concentration. In secondary prevention of stroke there is low-quality evidence that switching to hydroxyurea with phlebotomy increases the risk of sickle cell disease-related events. All other evidence in this review is of very low quality.

Patient and family experience with chronic transfusion therapy for sickle cell disease: A qualitative study

Background

There is a limited understanding of the patient and family experience of Chronic Transfusion Therapy (CTT) for prevention of complications of Sickle Cell Disease (SCD). We sought to understand patient and family experience with CTT using qualitative methods.

Methods

Fifteen parents of children < 18 years old and nine children 12–18 years old with SCD who were receiving CTT for > 1 year were interviewed using a semi-structured interview format, and interviews were analyzed using open coding methods.

Results

Four themes created a narrative of the patient and family experience of CTT: 1) Burden of CTT, 2) Coping with CTT, 3) Perceived benefits and risks of CTT, and 4) Decision making regarding CTT. Participants reported substantial burden of CTT, including the impact of CTT on daily life and family, distress about venous access, burden of chelation therapy, and anxiety about CTT complications. Participants described how they coped with CTT. Participants reported increased energy, decreased pain, fewer hospitalizations, and stroke prevention with CTT, but also recognized complications of CTT, though awareness was limited in adolescents. Parents described sharing in the informed decision-making process with their healthcare provider about CTT, but adolescent patient participants reported that they were not involved in this process.

Conclusions

CTT is associated with significant patient and family burden. Support from family, healthcare providers and school may help individuals cope with some of this burden. These findings provide the basis for future studies to identify strategies to mitigate the burden of CTT and improve the patient experience with this therapy. Future studies should also systematically assess patient knowledge about the key components of CTT and chelation using quantitative assessments.

Interventions for preventing silent cerebral infarcts in people with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. SCD can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Silent cerebral infarcts are the commonest neurological complication in children and probably adults with SCD. Silent cerebral infarcts also affect academic performance, increase cognitive deficits and may lower intelligence quotient.

OBJECTIVES

To assess the effectiveness of interventions to reduce or prevent silent cerebral infarcts in people with SCD.

SEARCH METHODS

We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 14 November 2019. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register: 07 October 2019.

SELECTION CRITERIA

Randomised controlled trials comparing interventions to prevent silent cerebral infarcts in people with SCD. There were no restrictions by outcomes examined, language or publication status.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

We included five trials (660 children or adolescents) published between 1998 and 2016. Four of the five trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of SCD. One trial focused on preventing silent cerebral infarcts or stroke; three trials were for primary stroke prevention and one trial dealt with secondary stroke prevention. Three trials compared the use of regular long-term red blood cell transfusions to standard care. Two of these trials included children with no previous long-term transfusions: one in children with normal transcranial doppler (TCD) velocities; and one in children with abnormal TCD velocities. The third trial included children and adolescents on long-term transfusion. Two trials compared the drug hydroxyurea and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children), and one in secondary prevention (children and adolescents). The quality of the evidence was moderate to very low across different outcomes according to GRADE methodology. This was due to trials being at high risk of bias because they were unblinded; indirectness (available evidence was only for children with HbSS); and imprecise outcome estimates. Long-term red blood cell transfusions versus standard care Children with no previous long-term transfusions and higher risk of stroke (abnormal TCD velocities or previous history of silent cerebral infarcts) Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, risk ratio (RR) 0.11 (95% confidence interval (CI) 0.02 to 0.86) (one trial, 124 participants, low-quality evidence); but make little or no difference to the incidence of silent cerebral infarcts in children with previous silent cerebral infarcts on magnetic resonance imaging and normal or conditional TCDs, RR 0.70 (95% CI 0.23 to 2.13) (one trial, 196 participants, low-quality evidence). No deaths were reported in either trial. Long-term red blood cell transfusions may reduce the incidence of: acute chest syndrome, RR 0.24 (95% CI 0.12 to 0.49) (two trials, 326 participants, low-quality evidence); and painful crisis, RR 0.63 (95% CI 0.42 to 0.95) (two trials, 326 participants, low-quality evidence); and probably reduces the incidence of clinical stroke, RR 0.12 (95% CI 0.03 to 0.49) (two trials, 326 participants, moderate-quality evidence). Long-term red blood cell transfusions may improve quality of life in children with previous silent cerebral infarcts (difference estimate -0.54; 95% confidence interval -0.92 to -0.17; one trial; 166 participants), but may have no effect on cognitive function (least squares means: 1.7, 95% CI -1.1 to 4.4) (one trial, 166 participants, low-quality evidence). Transfusions continued versus transfusions halted: children and adolescents with normalised TCD velocities (79 participants; one trial) Continuing red blood cell transfusions may reduce the incidence of silent cerebral infarcts, RR 0.29 (95% CI 0.09 to 0.97 (low-quality evidence). We are very uncertain whether continuing red blood cell transfusions has any effect on all-cause mortality, Peto odds ratio (OR) 8.00 (95% CI 0.16 to 404.12); or clinical stroke, RR 0.22 (95% CI 0.01 to 4.35) (very low-quality evidence). The trial did not report: comparative numbers for SCD-related adverse events; quality of life; or cognitive function. Hydroxyurea and phlebotomy versus transfusions and chelation Primary prevention, children (121 participants; one trial) We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts (no infarcts); all-cause mortality (no deaths); risk of stroke (no strokes); or SCD-related complications, RR 1.52 (95% CI 0.58 to 4.02) (very low-quality evidence). Secondary prevention, children and adolescents with a history of stroke (133 participants; one trial) We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts, Peto OR 7.28 (95% CI 0.14 to 366.91); all-cause mortality, Peto OR 1.02 (95%CI 0.06 to 16.41); or clinical stroke, RR 14.78 (95% CI 0.86 to 253.66) (very low-quality evidence). Switching to hydroxyurea and phlebotomy may increase the risk of SCD-related complications, RR 3.10 (95% CI 1.42 to 6.75) (low-quality evidence). Neither trial reported on quality of life or cognitive function.

AUTHORS' CONCLUSIONS

We identified no trials for preventing silent cerebral infarcts in adults, or in children who do not have HbSS SCD. Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, but may have little or no effect on children with normal TCD velocities. In children who are at higher risk of stroke and have not had previous long-term transfusions, long-term red blood cell transfusions probably reduce the risk of stroke, and other SCD-related complications (acute chest syndrome and painful crises). In children and adolescents at high risk of stroke whose TCD velocities have normalised, continuing red blood cell transfusions may reduce the risk of silent cerebral infarcts. No treatment duration threshold has been established for stopping transfusions. Switching to hydroxyurea with phlebotomy may increase the risk of silent cerebral infarcts and SCD-related serious adverse events in secondary stroke prevention. All other evidence in this review is of very low-quality.

Blood transfusions for treating acute chest syndrome in people with sickle cell disease

BACKGROUND

Sickle cell disease is an inherited autosomal recessive blood condition and is one of the most prevalent genetic blood diseases worldwide. Acute chest syndrome is a frequent complication of sickle cell disease, as well as a major cause of morbidity and the greatest single cause of mortality in children with sickle cell disease. Standard treatment may include intravenous hydration, oxygen as treatment for hypoxia, antibiotics to treat the infectious cause and blood transfusions may be given. This is an update of a Cochrane Review first published in 2010 and updated in 2016.

OBJECTIVES

To assess the effectiveness of blood transfusions, simple and exchange, for treating acute chest syndrome by comparing improvement in symptoms and clinical outcomes against standard care.

SEARCH METHODS

We searched The Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. Date of the most recent search: 30 May 2019.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials comparing either simple or exchange transfusion versus standard care (no transfusion) in people with sickle cell disease suffering from acute chest syndrome.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials and assessed the risk of bias, no data could be extracted.

MAIN RESULTS

One trial was eligible for inclusion in the review. While in the multicentre trial 237 people were enrolled (169 SCC, 42 SC, 15 Sβ⁰-thalassaemia, 11Sβ+-thalassaemia); the majority were recruited to an observational arm and only ten participants met the inclusion criteria for randomisation. Of these, four were randomised to the transfusion arm and received a single transfusion of 7 to 13 mL/kg packed red blood cells, and six were randomised to standard care. None of the four participants who received packed red blood cells developed acute chest syndrome, while 33% (two participants) developed acute chest syndrome in standard care arm. No data for any pre-defined outcomes were available.

AUTHORS' CONCLUSIONS

We found only one very small randomised controlled trial; this is not enough to make any reliable conclusion to support the use of blood transfusion. Whilst there appears to be some indication that chronic blood transfusion may play a roll in reducing the incidence of acute chest syndrome in people with sickle cell disease and albeit offering transfusions may be a widely accepted clinical practice, there is currently no reliable evidence to support or refute the perceived benefits of these as treatment options; very limited information about any of the potential harms associated with these interventions or indeed guidance that can be used to aid clinical decision making. Clinicians should therefore base any treatment decisions on a combination of; their clinical experience, individual circumstances and the unique characteristics and preferences of adequately informed people with sickle cell disease who are suffering with acute chest syndrome. This review highlights the need of further high quality research to provide reliable evidence for the effectiveness of these interventions for the relief of the symptoms of acute chest syndrome in people with sickle cell disease.

Quality of life in pre-adolescent children with sickle cell disease in Brazil

Sickle cell disease (SCD) affects more than 13 million people and can have a significant impact on the quality of life (QoL) of those persons. We performed a cross-sectional study to evaluate the QoL in SCD children 8-12 years old enrolled from November 2014 to March 2016 in a large multicenter cohort study in Brazil. The PedsQL™ SCD Module was used to evaluate QoL in 412 children from six Brazilian health centers. The mean age of participants was 10.5 years and 193(46.7%) were women. The mean global score was 60.7, with a Cronbach´s alpha of 0.92. There were significant differences in socioeconomic demographics and treatments among participants at the six centers, but age, income, SCD genotype, and use of hydroxyurea did not significantly affect the QoL scores. After adjustment for all of these variables in a linear regression model, a significant difference was observed by site in global QoL score and the dimensions 'worry II'(β0 = 20.7, p < .00), 'treatment´(β0 = 66.8, p < .00) and communication II'(β0 = 45.8, p < .00). These dimensions are affected by the capacity of health professionals to provide clinical and psychological support to patients. Our results suggest that QoL of this patient population varied according the health center even adjusted by sociodemographics characteristics. Additional training of health professionals in psychological and clinical support could directly reduce patient apprehension about the disease its clinical complications.

Why, Who, When, and How? Rationale for Considering Allogeneic Stem Cell Transplantation in Children with Sickle Cell Disease

Considering the progress made in the management of sickle cell disease during the past 30 years, along with the excellent results obtained with hematopoietic stem cell transplantation (SCT), it is important to reexamine why, who, when and how to recommend allogeneic SCT in children with sickle cell disease. While sickle cell disease has a low risk of death in children and a high risk for morbidity during aging, SCT carries an early risk of death, graft-vs-host disease and infertility. Nevertheless, SCT offers at least 95% chance of cure with low risk of chronic graft-vs-host disease when a matched-sibling donor is available and the risks of infertility can be reduced by ovarian, sperm or testis cryopreservation. Thus, all available therapies such as hydroxyurea, transfusions and SCT should be presented to the parents, providers, and affected children and discussed with them from infancy. Furthermore, the use of these therapies should be adjusted to the severity of the disease and to local availabilities in order to choose the treatment offering the best benefit/risk ratio.

Current challenges in the management of patients with sickle cell disease - A report of the Italian experience

Sickle cell disease (SCD) is an inherited red blood cell disorder caused by a structural abnormality of hemoglobin called sickle hemoglobin (HbS). Clinical manifestations of SCD are mainly characterized by chronic hemolysis and acute vaso-occlusive crisis, which are responsible for severe acute and chronic organ damage. SCD is widespread in sub-Saharan Africa, in the Middle East, Indian subcontinent, and some Mediterranean regions. With voluntary population migrations, people harboring the HbS gene have spread globally. In 2006, the World Health Organization recognized hemoglobinopathies, including SCD, as a global public health problem and urged national health systems worldwide to design and establish programs for the prevention and management of SCD. Herein we describe the historical experience of the network of hemoglobinopathy centers and their approach to SCD in Italy, a country where hemoglobinopathies have a high prevalence and where SCD, associated with different genotypes including ß-thalassemia, is present in the native population.

Health-related quality of life of adolescents with sickle cell disease in sub-Saharan Africa: a cross-sectional study

Background

Sickle cell disease (SCD) is a chronic hematologic disease associated with increased morbidity and mortality. Hemoglobinopathies are the most prevalent genetic disease globally, and SCD is estimated to affect 0.7% of Ugandan. The disease may adversely impact on the quality of life of sickle cell patients. This study aimed to evaluate the health related quality of life (HRoL) of adolescents with SCD.

Methods

This was a mixed-methods study of adolescents with sickle cell disease and their caretakers living in Kampala city, Uganda. All children aged 8-17 years with homozygous sickle cell disease attending the sickle cell clinic at Mulago Hospital during the study period were included in this study. Participants completed the PedsQL™ generic core scales parent-proxy and child self-report questionnaire during a routine clinic visit. HRQoL was the primary outcome measured. Socio-demographics and disease related data were obtained through personal interview with caretakers and reviewing patients' medical records. Mean scores were used for HRQoL and linear regression for associated factors.

Results

Of the 140 adolescents with SCD included in the study, 40% were male. A total of 95 adolescents (68%) were between the age of 8-12 years with a mean age of 14.25 years. The physical function was assessed slightly higher by adolescents with a mean score of57.5 ± 20.3 compare to caretakers with 52.8 ± 22.1(p < 0.001). As assessed by caretakers, physical HRQoL scores were negatively associated with pain about-10.02 CI [- 19.22, - 0.81](p = 0.033), whereas it was positively associated with Pneumococcal vaccine with the score of 28.43 CI [16.78,40.09](p < 0.001) as assessed by adolescents and 31.37CI [22.22,40.51](p < 0.001) by caretakers. Pneumococcal vaccination impacted positively the psychosocial functioning with a score of 8.67CI [1.51,15.84] (p = 0.018) as assessed by children and 15.94 CI [5.50,26.38](p = 0.003) as assessed by the caretakers.

Conclusions

This study highlighted that pain was negatively associated with both physical and psychosocial functioning; whereas getting Pneumococcal vaccine was positively associated with both physical and psychosocial functioning as reported by children and caretakers.

Health-related Quality of Life in Children With Sickle Cell Disease Undergoing Chronic Red Cell Transfusion Therapy

Chronic red cell transfusion (CRCT) therapy is one of few disease-modifying treatments for sickle cell disease (SCD). This study evaluated health-related quality of life (HRQL) in children receiving CRCT relative to 2 comparison groups: children with similar, severe SCD and children with milder disease risk defined by SCD genotype. For this study, 67 children with SCD between the ages of 8 and 18 completed the self-report Pediatric Quality of Life Sickle Cell Disease module (PedsQL SCD) as part of a pilot clinical program during routine hematologic visits. A medical chart review was also performed. Linear regression suggested that children in the CRCT group had significantly higher self-reported HRQL ratings for domains related to pain, F2,64=4.07 (P=0.022) and pain-related functioning, F2,64=4.32 (P=0.017), compared with children with similar and milder disease risk. Exploratory analyses implied that children in the CRCT group also had fewer worries about SCD-related complications, F3,63=9.68 (P<0.001). These patient-perceived benefits of CRCT may have important implications for treatment decisions and for providing ancillary support for children with SCD and their families.

Challenges in preventing and treating hemolytic complications associated with red blood cell transfusion

Red blood cell (RBC) transfusion support represents a critical component of sickle cell disease (SCD) management. However, as with any therapeutic intervention, RBC transfusion is not without risk. Repeat exposure to allogeneic RBCs can result in the development of RBC alloantibodies that can make it difficult to find compatible RBCs for future transfusions and can directly increase the risk of developing acute or delayed hemolytic transfusion reactions, which can be further complicated by hyperhemolysis. Several prophylactic and treatment strategies have been employed in an effort to reduce or prevent hemolytic transfusion reactions. However, conflicting data exist regarding the efficacy of many of these approaches. We will explore the challenges associated with predicting, preventing and treating different types of hemolytic transfusion reactions in patients with SCD in addition to describing future strategies that may aid in the management of the complex transfusion requirements of SCD patients.

Sickle Cell Anemia: A review on the most severe form of Sickle Cell Disease

Sickle cell disease (SCD) is a group of hereditary disorders caused by a single point mutation in the β-globin gene. This mutation results in the formation of a mutated hemoglobin S (HbS) and the consequent sickle phenotype of erythrocytes. SCD is common in regions of malaria endemicity. However, changes in population dynamics enabled the movement of the mutated gene to other areas such as North America and Europe. Sickle cell anemia (SCA) is the most severe form of SCD and affects millions of people around the globe. The clinical manifestations of SCA arise primarily from the polymerization of deoxygenated hemoglobin S (deoxyHbS) leading to vascular occlusion and hemolytic anemia. Clinical complications of the disease are derived from deoxyHbS polymerization, but there are several therapeutic strategies to reduce the severity of the symptoms. Gene therapy has arisen as a new therapeutic approach aimed to cure rather than to treat the symptomatology of SCA by targeting the altered β-globin gene for gene correction.

Effect and clinical value of coagulation test on adverse reactions of blood transfusion in patients with major bleeding in ectopic pregnancy

Influence and clinical value of coagulation test on adverse reactions of blood transfusion in patients with major bleeding of ectopic pregnancy were analyzed. Six hundred and twenty-seven cases of ectopic pregnancy admitted to Zibo First Hospital from July 2014 to March 2017 were retrospectively analyzed. The 369 patients who had adverse reactions after blood transfusion were selected as the experimental group. Another 258 patients without adverse reaction after blood transfusion were selected as the control group. Blood samples were collected 8 h before and after blood transfusion in both groups, and blood test was performed including blood count (RBC), white blood cell count (WBC), platelet count (PLT), HB, hematocrit (HCT), as well as indicators of coagulation, including thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB). There was no significant difference between the two groups in blood routine and blood coagulation test (P>0.05). After transfusion, the RBC, WBC, PLT, HB and HCT in the experimental group were significantly lower than those in the control group (P<0.05). TT, PT and APTT were higher than those in the control group (P<0.05), while FIB was significantly lower than that in the control group (P<0.001). The coagulation in the experimental group after blood transfusion was significantly worse than that in the control group. Coagulation test can be used as a marker of adverse reactions after transfusion in patients with massive bleeding in pregnancy, providing reference and guidance for clinical diagnosis and treatment.

Red blood cell transfusion therapy for sickle cell patients with frequent painful events

BACKGROUND

Recurrent pain events or chronic pain are among the most common complications of sickle cell disease. Despite attempts to maximize adherence to and dosing of hydroxyurea, some patients continue to suffer from pain. Our institution developed a program to initiate chronic red blood cell transfusions for one year in patients clinically deemed to have high healthcare utilization from sickle cell pain, despite being prescribed hydroxyurea.

PROCEDURE

An institutional review board approved retrospective study to evaluate the health outcomes associated with a one-year red blood cell transfusion protocol in sickle cell patients experiencing recurrent pain events as compared with the health outcomes for these patients in the one year prior to receiving transfusion therapy. We performed a matched-pair analysis using a Wilcoxon signed rank to determine the impact of transfusion therapy on clinic visits, emergency department visits, hospital admissions, hospitalization days, and opioid prescriptions filled.

RESULTS

One year of transfusion therapy significantly reduced the number of total emergency department visits for pain (6 vs 2.5 pain visits/year, P = 0.005), mean hospitalizations for pain (3.4 vs 0.9 pain admissions/year), and mean hospital days per year for pain crisis (23.5 vs 4.5, P = 0.0001), as compared with the one year prior to transfusion therapy. We identified no significant difference in opioid prescriptions filled during the year of transfusion therapy.

CONCLUSION

Patients with frequent pain episodes may benefit from one year of transfusion therapy.

Hemoglobin F as a predictor of health-related quality of life in children with sickle cell anemia

PURPOSE

As treatment options for children with sickle cell anemia (SCA) continue to expand survival, evaluation of factors associated with health-related quality of life (HRQoL) is becoming an important aspect for further improving clinical management. Although the general features of SCA are similar, factors influencing HRQoL within a country may differ from those of other countries, therefore this study aimed to explore factors affecting HRQoL in children with SCA living in the Sultanate of Oman.

METHODS

This was a cross-sectional study in which the PedsQL™ Sickle Cell Disease Module was used to evaluate the overall HRQoL in children with SCA. The socio-demographic data, clinical, and treatment outcomes were collected. Univariate and multivariate linear regression analyses were used to identify predictors of HRQoL.

RESULTS

A total of 123 children with SCA, aged from 2 to 16 years were enrolled. The mean total HRQoL score was 52 ± 15% (9-94), where Worry II scale recorded the highest score. The multiple regression analysis revealed that the only predictors of total HRQoL score were hemoglobin F (B = 0.64, 95% confidence interval [CI] 0.149-1.118, P = 0.009) and to a lesser degree white blood cell count (B = - 0.99, 95% CI - 1.761 to - 0.198, P = 0.01), independently of other study parameters such as age, gender, spleen status, and hydroxyurea therapy.

CONCLUSIONS

Collectively, these findings indicated that hemoglobin F out-weighted white blood cell count in predicting HRQoL in Omani children with SCA. Recognition of these factors could help health professionals to develop effective strategies to improve the overall HRQoL in these young patients.

HABIT, a Randomized Feasibility Trial to Increase Hydroxyurea Adherence, Suggests Improved Health-Related Quality of Life in Youths with Sickle Cell Disease

OBJECTIVES

To examine the effect of a community health worker (CHW) intervention, augmented by tailored text messages, on adherence to hydroxyurea therapy in youths with sickle cell disease, as well as on generic and disease-specific health-related quality of life (HrQL) and youth-parent self-management responsibility concordance.

STUDY DESIGN

We conducted a 2-site randomized controlled feasibility study (Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment [HABIT]) with 2:1 intervention allocation. Youths and parents participated as dyads. Intervention dyads received CHW visits and text message reminders. Data were analyzed using descriptive statistics, the Wilcoxon signed-rank test, and growth models adjusting for group assignment, time, and multiple comparisons. Changes in outcomes from 0 to 6 months were compared with their respective minimal clinically important differences.

RESULTS

A total of 28 dyads (mean age of youths, 14.3 ± 2.6 years; 50% Hispanic) participated (18 in the intervention group, 10 in the control group), with 10.7% attrition. Accounting for group assignment, time, and multiple comparisons, at 6 months intervention youths reported improved generic HrQL total score (9.8 points; 95% CI, 0.4-19.2) and Emotions subscale score (15.0 points; 95% CI, 1.6-28.4); improved disease-specific subscale scores for Worry I (30.0 points; 95% CI, 8.5-51.5), Emotions (37.0 points, 95% CI, 9.4-64.5), and Communication I (17.8 points; 95% CI, 0.5-35.1); and 3-month dyad self-management responsibility concordance (3.5 points; 95% CI, -0.2 to 7.1). There were no differences in parent proxy-reported HrQL measures at 6 months.

CONCLUSIONS

These findings add to research examining effects of behavioral interventions on HrQL outcomes in youths with sickle cell disease.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02029742.

Hemoglobin disorders: lentiviral gene therapy in the starting blocks to enter clinical practice

The β-hemoglobinopathies, transfusion-dependent β-thalassemia and sickle cell disease, are the most prevalent inherited disorders worldwide and affect millions of people. Many of these patients have a shortened life expectancy and suffer from severe morbidity despite supportive therapies, which impose an enormous financial burden to societies. The only available curative therapy is allogeneic hematopoietic stem cell transplantation, although most patients do not have an HLA-matched sibling donor, and those who do still risk life-threatening complications. Therefore, gene therapy by one-time ex vivo modification of hematopoietic stem cells followed by autologous engraftment is an attractive new therapeutic modality. The first proof-of-principle of conversion to transfusion independence by means of a lentiviral vector expressing a marked and anti-sickling β^T87Q-globin gene variant was reported a decade ago in a patient with transfusion-dependent β-thalassemia. In follow-up multicenter Phase II trials with an essentially identical vector (termed LentiGlobin BB305) and protocol, 12 of the 13 patients with a non-β⁰/β⁰ genotype, representing more than half of all transfusion-dependent β-thalassemia cases worldwide, stopped red blood cell transfusions with total hemoglobin levels in blood approaching normal values. Correction of biological markers of dyserythropoiesis was achieved in evaluated patients. In nine patients with β⁰/β⁰ transfusion-dependent β-thalassemia or equivalent severity (β^IVS1-110), median annualized transfusion volume decreased by 73% and red blood cell transfusions were stopped in three patients. Proof-of-principle of therapeutic efficacy in the first patient with sickle cell disease was also reported with LentiGlobin BB305. Encouraging results were presented in children with transfusion-dependent β-thalassemia in another trial with the GLOBE lentiviral vector and several other gene therapy trials are currently open for both transfusion-dependent β-thalassemia and sickle cell disease. Phase III trials are now under way and should help to determine benefit/risk/cost ratios to move gene therapy toward clinical practice.

Sickle cell disease

Sickle cell disease (SCD) is a group of inherited disorders caused by mutations in HBB, which encodes haemoglobin subunit β. The incidence is estimated to be between 300,000 and 400,000 neonates globally each year, the majority in sub-Saharan Africa. Haemoglobin molecules that include mutant sickle β-globin subunits can polymerize; erythrocytes that contain mostly haemoglobin polymers assume a sickled form and are prone to haemolysis. Other pathophysiological mechanisms that contribute to the SCD phenotype are vaso-occlusion and activation of the immune system. SCD is characterized by a remarkable phenotypic complexity. Common acute complications are acute pain events, acute chest syndrome and stroke; chronic complications (including chronic kidney disease) can damage all organs. Hydroxycarbamide, blood transfusions and haematopoietic stem cell transplantation can reduce the severity of the disease. Early diagnosis is crucial to improve survival, and universal newborn screening programmes have been implemented in some countries but are challenging in low-income, high-burden settings.

The case for HLA-identical sibling hematopoietic stem cell transplantation in children with symptomatic sickle cell anemia

This article has a companion Counterpoint by DeBaun and Clayton.

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.

Interventions for preventing silent cerebral infarcts in people with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. SCD can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Silent cerebral infarcts are the commonest neurological complication in children and probably adults with SCD. Silent cerebral infarcts also affect academic performance, increase cognitive deficits and may lower intelligence quotient.

OBJECTIVES

To assess the effectiveness of interventions to reduce or prevent silent cerebral infarcts in people with SCD.

SEARCH METHODS

We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 19 September 2016. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register: 06 October 2016.

SELECTION CRITERIA

Randomised controlled trials comparing interventions to prevent silent cerebral infarcts in people with SCD. There were no restrictions by outcomes examined, language or publication status.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures.

MAIN RESULTS

We included five trials (660 children or adolescents) published between 1998 and 2016. Four of the five trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of SCD. One trial focused on preventing silent cerebral infarcts or stroke; three trials were for primary stroke prevention and one trial dealt with secondary stroke prevention.Three trials compared the use of regular long-term red blood cell transfusions to standard care. Two of these trials included children with no previous long-term transfusions: one in children with normal transcranial doppler (TCD) velocities; and one in children with abnormal TCD velocities. The third trial included children and adolescents on long-term transfusion.Two trials compared the drug hydroxyurea and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children), and one in secondary prevention (children and adolescents).The quality of the evidence was moderate to very low across different outcomes according to GRADE methodology. This was due to trials being at high risk of bias because they were unblinded; indirectness (available evidence was only for children with HbSS); and imprecise outcome estimates. Long-term red blood cell transfusions versus standard care Children with no previous long-term transfusions and higher risk of stroke (abnormal TCD velocities or previous history of silent cerebral infarcts) Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, risk ratio (RR) 0.11 (95% confidence interval (CI) 0.02 to 0.86) (one trial, 124 participants, low-quality evidence); but make little or no difference to the incidence of silent cerebral infarcts in children with previous silent cerebral infarcts on magnetic resonance imaging and normal or conditional TCDs, RR 0.70 (95% CI 0.23 to 2.13) (one trial, 196 participants, low-quality evidence).No deaths were reported in either trial.Long-term red blood cell transfusions may reduce the incidence of: acute chest syndrome, RR 0.24 (95% CI 0.12 to 0.49) (two trials, 326 participants, low-quality evidence); and painful crisis, RR 0.63 (95% CI 0.42 to 0.95) (two trials, 326 participants, low-quality evidence); and probably reduces the incidence of clinical stroke, RR 0.12 (95% CI 0.03 to 0.49) (two trials, 326 participants, moderate-quality evidence).Long-term red blood cell transfusions may improve quality of life in children with previous silent cerebral infarcts (difference estimate -0.54; 95% confidence interval -0.92 to -0.17; one trial; 166 participants), but may have no effect on cognitive function (least squares means: 1.7, 95% CI -1.1 to 4.4) (one trial, 166 participants, low-quality evidence). Transfusions continued versus transfusions halted: children and adolescents with normalised TCD velocities (79 participants; one trial)Continuing red blood cell transfusions may reduce the incidence of silent cerebral infarcts, RR 0.29 (95% CI 0.09 to 0.97 (low-quality evidence).We are very uncertain whether continuing red blood cell transfusions has any effect on all-cause mortality, Peto odds ratio (OR) 8.00 (95% CI 0.16 to 404.12); or clinical stroke, RR 0.22 (95% CI 0.01 to 4.35) (very low-quality evidence).The trial did not report: comparative numbers for SCD-related adverse events; quality of life; or cognitive function. Hydroxyurea and phlebotomy versus transfusions and chelation Primary prevention, children (121 participants; one trial)We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts (no infarcts); all-cause mortality (no deaths); risk of stroke (no strokes); or SCD-related complications, RR 1.52 (95% CI 0.58 to 4.02) (very low-quality evidence). Secondary prevention, children and adolescents with a history of stroke (133 participants; one trial)We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: silent cerebral infarcts, Peto OR 7.28 (95% CI 0.14 to 366.91); all-cause mortality, Peto OR 1.02 (95%CI 0.06 to 16.41); or clinical stroke, RR 14.78 (95% CI 0.86 to 253.66) (very low-quality evidence).Switching to hydroxyurea and phlebotomy may increase the risk of SCD-related complications, RR 3.10 (95% CI 1.42 to 6.75) (low-quality evidence).Neither trial reported on quality of life or cognitive function.

AUTHORS' CONCLUSIONS

We identified no trials for preventing silent cerebral infarcts in adults, or in children who do not have HbSS SCD.Long-term red blood cell transfusions may reduce the incidence of silent cerebral infarcts in children with abnormal TCD velocities, but may have little or no effect on children with normal TCD velocities. In children who are at higher risk of stroke and have not had previous long-term transfusions, long-term red blood cell transfusions probably reduce the risk of stroke, and other SCD-related complications (acute chest syndrome and painful crises).In children and adolescents at high risk of stroke whose TCD velocities have normalised, continuing red blood cell transfusions may reduce the risk of silent cerebral infarcts. No treatment duration threshold has been established for stopping transfusions.Switching to hydroxyurea with phlebotomy may increase the risk of silent cerebral infarcts and SCD-related serious adverse events in secondary stroke prevention.All other evidence in this review is of very low-quality.

Blood transfusion for preventing primary and secondary stroke in people with sickle cell disease

BACKROUND

Sickle cell disease is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. Sickle cell disease can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Stroke affects around 10% of children with sickle cell anaemia (HbSS). Chronic blood transfusions may reduce the risk of vaso-occlusion and stroke by diluting the proportion of sickled cells in the circulation.This is an update of a Cochrane Review first published in 2002, and last updated in 2013.

OBJECTIVES

To assess risks and benefits of chronic blood transfusion regimens in people with sickle cell disease for primary and secondary stroke prevention (excluding silent cerebral infarcts).

SEARCH METHODS

We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 04 April 2016.We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register: 25 April 2016.

SELECTION CRITERIA

Randomised controlled trials comparing red blood cell transfusions as prophylaxis for stroke in people with sickle cell disease to alternative or standard treatment. There were no restrictions by outcomes examined, language or publication status.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and the risk of bias and extracted data.

MAIN RESULTS

We included five trials (660 participants) published between 1998 and 2016. Four of these trials were terminated early. The vast majority of participants had the haemoglobin (Hb)SS form of sickle cell disease.Three trials compared regular red cell transfusions to standard care in primary prevention of stroke: two in children with no previous long-term transfusions; and one in children and adolescents on long-term transfusion.Two trials compared the drug hydroxyurea (hydroxycarbamide) and phlebotomy to long-term transfusions and iron chelation therapy: one in primary prevention (children); and one in secondary prevention (children and adolescents).The quality of the evidence was very low to moderate across different outcomes according to GRADE methodology. This was due to the trials being at a high risk of bias due to lack of blinding, indirectness and imprecise outcome estimates. Red cell transfusions versus standard care Children with no previous long-term transfusionsLong-term transfusions probably reduce the incidence of clinical stroke in children with a higher risk of stroke (abnormal transcranial doppler velocities or previous history of silent cerebral infarct), risk ratio 0.12 (95% confidence interval 0.03 to 0.49) (two trials, 326 participants), moderate quality evidence.Long-term transfusions may: reduce the incidence of other sickle cell disease-related complications (acute chest syndrome, risk ratio 0.24 (95% confidence interval 0.12 to 0.48)) (two trials, 326 participants); increase quality of life (difference estimate -0.54, 95% confidence interval -0.92 to -0.17) (one trial, 166 participants); but make little or no difference to IQ scores (least square mean: 1.7, standard error 95% confidence interval -1.1 to 4.4) (one trial, 166 participants), low quality evidence.We are very uncertain whether long-term transfusions: reduce the risk of transient ischaemic attacks, Peto odds ratio 0.13 (95% confidence interval 0.01 to 2.11) (two trials, 323 participants); have any effect on all-cause mortality, no deaths reported (two trials, 326 participants); or increase the risk of alloimmunisation, risk ratio 3.16 (95% confidence interval 0.18 to 57.17) (one trial, 121 participants), very low quality evidence. Children and adolescents with previous long-term transfusions (one trial, 79 participants)We are very uncertain whether continuing long-term transfusions reduces the incidence of: stroke, risk ratio 0.22 (95% confidence interval 0.01 to 4.35); or all-cause mortality, Peto odds ratio 8.00 (95% confidence interval 0.16 to 404.12), very low quality evidence.Several review outcomes were only reported in one trial arm (sickle cell disease-related complications, alloimmunisation, transient ischaemic attacks).The trial did not report neurological impairment, or quality of life. Hydroxyurea and phlebotomy versus red cell transfusions and chelationNeither trial reported on neurological impairment, alloimmunisation, or quality of life. Primary prevention, children (one trial, 121 participants)Switching to hydroxyurea and phlebotomy may have little or no effect on liver iron concentrations, mean difference -1.80 mg Fe/g dry-weight liver (95% confidence interval -5.16 to 1.56), low quality evidence.We are very uncertain whether switching to hydroxyurea and phlebotomy has any effect on: risk of stroke (no strokes); all-cause mortality (no deaths); transient ischaemic attacks, risk ratio 1.02 (95% confidence interval 0.21 to 4.84); or other sickle cell disease-related complications (acute chest syndrome, risk ratio 2.03 (95% confidence interval 0.39 to 10.69)), very low quality evidence. Secondary prevention, children and adolescents (one trial, 133 participants)Switching to hydroxyurea and phlebotomy may: increase the risk of sickle cell disease-related serious adverse events, risk ratio 3.10 (95% confidence interval 1.42 to 6.75); but have little or no effect on median liver iron concentrations (hydroxyurea, 17.3 mg Fe/g dry-weight liver (interquartile range 10.0 to 30.6)); transfusion 17.3 mg Fe/g dry-weight liver (interquartile range 8.8 to 30.7), low quality evidence.We are very uncertain whether switching to hydroxyurea and phlebotomy: increases the risk of stroke, risk ratio 14.78 (95% confidence interval 0.86 to 253.66); or has any effect on all-cause mortality, Peto odds ratio 0.98 (95% confidence interval 0.06 to 15.92); or transient ischaemic attacks, risk ratio 0.66 (95% confidence interval 0.25 to 1.74), very low quality evidence.

AUTHORS' CONCLUSIONS

There is no evidence for managing adults, or children who do not have HbSS sickle cell disease.In children who are at higher risk of stroke and have not had previous long-term transfusions, there is moderate quality evidence that long-term red cell transfusions reduce the risk of stroke, and low quality evidence they also reduce the risk of other sickle cell disease-related complications.In primary and secondary prevention of stroke there is low quality evidence that switching to hydroxyurea with phlebotomy has little or no effect on the liver iron concentration.In secondary prevention of stroke there is low-quality evidence that switching to hydroxyurea with phlebotomy increases the risk of sickle cell disease-related events.All other evidence in this review is of very low quality.

A trial of unrelated donor marrow transplantation for children with severe sickle cell disease

Children with sickle cell disease experience organ damage, impaired quality of life, and premature mortality. Allogeneic bone marrow transplant from an HLA-matched sibling can halt disease progression but is limited by donor availability. A Blood and Marrow Transplant Clinical Trials Network (BMT CTN) phase 2 trial conducted from 2008 to 2014 enrolled 30 children aged 4 to 19 years; 29 were eligible for evaluation. The primary objective was 1-year event-free survival (EFS) after HLA allele-matched (at HLA-A, -B, -C, and -DRB1 loci) unrelated donor transplant. The conditioning regimen included alemtuzumab, fludarabine, and melphalan. Graft-versus-host disease (GVHD) prophylaxis included calcineurin inhibitor, short-course methotrexate, and methylprednisolone. Transplant indications included stroke (n = 12), transcranial Doppler velocity >200 cm/s (n = 2), ≥3 vaso-occlusive pain crises per year (n = 12), or ≥2 acute chest syndrome episodes (n = 4) in the 2 years preceding enrollment. Median follow-up was 26 months (range, 12-62 months); graft rejection was 10%. The 1- and 2-year EFS rates were 76% and 69%, respectively. The corresponding rates for overall survival were 86% and 79%. The day 100 incidence rate of grade II-IV acute GVHD was 28%, and the 1-year incidence rate of chronic GVHD was 62%; 38% classified as extensive. There were 7 GVHD-related deaths. A 34% incidence of posterior reversible encephalopathy syndrome was noted in the first 6 months. Although the 1-year EFS met the prespecified target of ≥75%, this regimen cannot be considered sufficiently safe for widespread adoption without modifications to achieve more effective GVHD prophylaxis. The BMT CTN #0601 trial was registered at www.clinicaltrials.gov as #NCT00745420.

Initial Evaluation of the Pediatric PROMIS® Health Domains in Children and Adolescents With Sickle Cell Disease

BACKGROUND

The Patient Reported Outcomes Measurement Information System (PROMIS®) has developed pediatric self-report scales measuring several unidimensional health attributes (domains) suitable for use in clinical research, but these measures have not yet been validated in sickle cell disease (SCD).

PROCEDURE

A convenience sample of SCD children, aged 8-17 years, from two sickle cell programs was recruited at routine clinic visits, including some for hydroxyurea monitoring or monthly transfusions. Children completed PROMIS pediatric items using an online data collection platform, the PROMIS Assessment Center Web site.

RESULTS

A total of 235 participants (mean age 12.5 ± 2.8 years, 49.8% female) participated in the study. Adolescents (ages 12-17 years) reported significantly higher pain interference and depressive symptoms, and worse lower extremity physical functioning domain scores compared to younger children (ages 8-11 years). Female participants reported significantly higher pain interference, fatigue, and depressive symptoms, and worse lower extremity physical functioning domain scores compared with their male counterparts. Participants with hip or joint problems that limited usual activities reported significantly higher pain, fatigue, and depressive symptoms scores, and worse upper/lower extremity physical functioning scores as did participants who had experienced sickle pain in the previous 7 days.

CONCLUSIONS

PROMIS pediatric measures are feasible in a research setting and identify expected differences in known group comparisons in a sample of SCD children. The large domain score differences between those with or without SCD-related complications suggest the potential usefulness of these measures in clinical research, but further validation studies are needed, particularly in clinical practice settings.

Central nervous system complications and management in sickle cell disease

With advances in brain imaging and completion of randomized clinical trials (RCTs) for primary and secondary stroke prevention, the natural history of central nervous system (CNS) complications in sickle cell disease (SCD) is evolving. In order of current prevalence, the primary CNS complications include silent cerebral infarcts (39% by 18 years), headache (both acute and chronic: 36% in children with sickle cell anemia [SCA]), ischemic stroke (as low as 1% in children with SCA with effective screening and prophylaxis, but ∼11% in children with SCA without screening), and hemorrhagic stroke in children and adults with SCA (3% and 10%, respectively). In high-income countries, RCTs (Stroke Prevention in Sickle Cell Anemia [STOP], STOP II) have demonstrated that regular blood transfusion therapy (typically monthly) achieves primary stroke prevention in children with SCA and high transcranial Doppler (TCD) velocities; after at least a year, hydroxycarbamide may be substituted (TCD With Transfusions Changing to Hydroxyurea [TWiTCH]). Also in high-income countries, RCTs have demonstrated that regular blood transfusion is the optimal current therapy for secondary prevention of infarcts for children with SCA and strokes (Stroke With Transfusions Changing to Hydroxyurea [SWiTCH]) or silent cerebral infarcts (Silent Infarct Transfusion [SIT] Trial). For adults with SCD, CNS complications continue to be a major cause of morbidity and mortality, with no evidence-based strategy for prevention.

Immunophenotypic parameters and RBC alloimmunization in children with sickle cell disease on chronic transfusion

Alloimmunization against red blood cell (RBC) antigens is a cause of morbidity and mortality in transfused patients with sickle cell disease (SCD). To investigate distinguishing characteristics of patients who develop RBC alloantibodies after transfusion (responders) versus those who do not (non-responders), a cross-sectional study of 90 children with SCD on chronic RBC transfusion therapy at a single institution was conducted in which 18 immune parameters (including T and B cell subsets) were tested via flow cytometry, and medical records were reviewed. RBC alloimmunization was present in 26/90 (29%) patients, with anti-E, K, and C among the most commonly detected alloantibodies despite prophylactic matching for these antigens at the study institution. In addition, RBC autoantibodies had been detected in 18/26 (69%) of alloimmunized versus 7/64 (11%) of non-alloimmunized patients (P < 0.0001). Alloimmunized patients were significantly older (median 13.0 years vs. 10.7 years, P = 0.010) and had more RBC unit exposures (median 148 U vs. 82 U, P = 0.020) than non-alloimmunized patients. Sex, age at initiation of chronic transfusion, splenectomy, stroke, and transfusion outside of the study institution were not significantly associated with RBC alloimmunization. Alloimmunized patients had a significantly increased percentage of CD4+ T memory cells compared to non-alloimmunized patients (57% vs. 49%, P = 0.0047), with no other significant differences in immune cell subsets or laboratory values detected between these groups. Additional research of RBC alloimmunization is needed to optimize transfusion therapy and to develop strategies to prevent alloimmunization.