Whole-blood transcriptome analysis reveals distinct gene expression signatures in paediatric patients with sickle cell anaemia before and after exercise.

Sickle cell anaemia (SCA) patients display elevated levels of circulating pro-inflammatory cytokines and endothelial activation markers compared to healthy peers. The impact of exercise on the pro-inflammatory state in SCA remains unclear. This study aimed to characterize the whole-blood transcriptome profile in response to an acute bout of exercise in paediatric SCA patients. Twenty-three SCA participants (13 ± 3 years, 52% girls) and 17 healthy controls (14 ± 3 years, 29% girls) performed eight 2-min bouts of cycle ergometry interspersed with 1-min rest intervals. Whole-blood transcriptome profile (RNA-seq) was performed before and after exercise. At baseline, gene pathways associated with gas transport in erythrocytes were up-regulated in SCA patients compared to controls. Following exercise, gene pathways associated with innate immunity were altered in both groups. Interaction analyses revealed 160 annotated genes (101 up- and 59 down-regulated) that differentially altered by exercise in SCA patients. Moreover, genes that exhibited a blunted response to exercise in SCA patients were enriched in the IL-17 signalling pathway, suggesting an impaired innate immune response to exercise. This data will contribute to the development of evidence-based exercise prescription guidelines for this patient population.

Exagamglogene Autotemcel for Transfusion-Dependent ß-Thalassemia.

BACKGROUND: Exagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis through ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing of the erythroid-specific enhancer region of BCL11A in autologous CD34+ hematopoietic stem and progenitor cells (HSPCs). METHODS: We conducted an open-label, single-group, phase 3 study of exa-cel in patients 12 to 35 years of age with transfusion-dependent ß-thalassemia and a ß0/ß0, ß0/ß0-like, or non-ß0/ß0-like genotype. CD34+ HSPCs were edited by means of CRISPR-Cas9 with a guide mRNA. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was transfusion independence, defined as a weighted average hemoglobin level of 9 g per deciliter or higher without red-cell transfusion for at least 12 consecutive months. Total and fetal hemoglobin concentrations and safety were also assessed. RESULTS: A total of 52 patients with transfusion-dependent ß-thalassemia received exa-cel and were included in this prespecified interim analysis; the median follow-up was 20.4 months (range, 2.1 to 48.1). Neutrophils and platelets engrafted in each patient. Among the 35 patients with sufficient follow-up data for evaluation, transfusion independence occurred in 32 (91%; 95% confidence interval, 77 to 98; P<0.001 against the null hypothesis of a 50% response). During transfusion independence, the mean total hemoglobin level was 13.1 g per deciliter and the mean fetal hemoglobin level was 11.9 g per deciliter, and fetal hemoglobin had a pancellular distribution (≥94% of red cells). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No deaths or cancers occurred. CONCLUSIONS: Treatment with exa-cel, preceded by myeloablation, resulted in transfusion independence in 91% of patients with transfusion-dependent ß-thalassemia. (Supported by Vertex Pharmaceuticals and CRISPR Therapeutics; CLIMB THAL-111 ClinicalTrials.gov number, NCT03655678.).

Exagamglogene Autotemcel for Severe Sickle Cell Disease.

BACKGROUND: Exagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis by means of ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing of autologous CD34+ hematopoietic stem and progenitor cells (HSPCs) at the erythroid-specific enhancer region of BCL11A. METHODS: We conducted a phase 3, single-group, open-label study of exa-cel in patients 12 to 35 years of age with sickle cell disease who had had at least two severe vaso-occlusive crises in each of the 2 years before screening. CD34+ HSPCs were edited with the use of CRISPR-Cas9. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was freedom from severe vaso-occlusive crises for at least 12 consecutive months. A key secondary end point was freedom from inpatient hospitalization for severe vaso-occlusive crises for at least 12 consecutive months. The safety of exa-cel was also assessed. RESULTS: A total of 44 patients received exa-cel, and the median follow-up was 19.3 months (range, 0.8 to 48.1). Neutrophils and platelets engrafted in each patient. Of the 30 patients who had sufficient follow-up to be evaluated, 29 (97%; 95% confidence interval [CI], 83 to 100) were free from vaso-occlusive crises for at least 12 consecutive months, and all 30 (100%; 95% CI, 88 to 100) were free from hospitalizations for vaso-occlusive crises for at least 12 consecutive months (P<0.001 for both comparisons against the null hypothesis of a 50% response). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No cancers occurred. CONCLUSIONS: Treatment with exa-cel eliminated vaso-occlusive crises in 97% of patients with sickle cell disease for a period of 12 months or more. (CLIMB SCD-121; ClinicalTrials.gov number, NCT03745287.).

A Reference Equation for Peak Oxygen Uptake for Pediatric Patients Who Undergo Treadmill Cardiopulmonary Exercise Testing.

Pediatric patients are often referred to cardiopulmonary exercise testing (CPET) laboratories for assessment of exercise-related symptoms. For clinicians to understand results in the context of performance relative to peers, adequate fitness-based prediction equations must be available. However, reference equations for prediction of peak oxygen uptake (VO2peak) in pediatrics are largely developed from field-based testing, and equations derived from CPET are primarily developed using adult data. Our objective was to develop a pediatric reference equation for VO2peak. Clinical CPET data from a validation cohort of 1,383 pediatric patients aged 6 to 18 years who achieved a peak respiratory exchange ratio ≥1.00 were analyzed to identify clinical and exercise testing factors that contributed to the prediction of VO2peak from tests performed using the Bruce protocol. The resultant prediction equation was applied to a cross-validation cohort of 1,367 pediatric patients. Exercise duration, gender, weight, and age contributed to the prediction of VO2peak, generating the following prediction equation: (R2 = 0.645, p <0.001, standard error of the estimate = 6.19 ml/kg/min): VO2peak (ml/kg/min) =16.411+ 3.423 (exercise duration [minutes]) - 5.145 (gender [0 = male, 1 = female]) - 0.121 (weight [kg]) + 0.179 (age [years]). This equation was stable across the age range included in the present study, with differences ≤0.5 ml/kg/min between mean measured and predicted VO2peak in all age groups. In conclusion, this study represents what we believe is the largest pediatric CPET-derived VO2peak prediction effort to date, and this VO2peak prediction equation provides clinicians who perform and interpret exercise tests in pediatric patients with a resource with which to better quantify fitness when CPET is not available.

Reference Values for Cardiorespiratory Fitness in Patients Aged 6 to 18 Years.

OBJECTIVE: To develop reference values for cardiorespiratory fitness, as quantified by peak oxygen uptake (VO2peak) and treadmill time, in patients aged 6 through 18 years referred for cardiopulmonary exercise testing (CPET). STUDY DESIGN: We reviewed a clinical pediatric CPET database for fitness data in children aged 6-18 years with no underlying heart disease. CPET was obtained via the Bruce protocol utilizing objectively confirmed maximal effort via respiratory exchange ratio. Fitness data (VO2peak and treadmill test duration) were analyzed to determine age- and sex-specific reference values for this pediatric cohort. RESULTS: Data from 2025 pediatric CPETs (53.2% female) were included in the analyses. VO2peak increased with age in males, but not females. Treadmill test duration increased with age in both males and females. Fitness was generally higher in males when compared with females in the same age groups. CONCLUSIONS: Our study provides extensive reference values for both VO2peak and total treadmill test time via the Bruce protocol for a pediatric population without known cardiac disease. Furthermore, the inclusion of objectively confirmed maximal exercise effort increases confidence in these findings compared with prior studies in this area. Clinicians performing CPET in pediatric populations can utilize these reference values to characterize test results according to representative peer data.

Return visit rates after an emergency department discharge for children with sickle cell pain episodes.

BACKGROUND: High return visit rates after hospitalization for people with sickle cell disease (SCD) have been previously established. Due to a lack of multicenter emergency department (ED) return visit rate data, the return visit rate following ED discharge for pediatric SCD pain treatment is currently unknown. PROCEDURE: A seven-site retrospective cohort study of discharged ED visits for pain by children with SCD was conducted using the Pediatric Emergency Care Applied Research Network Registry. Visits between January 2017 and November 2021 were identified using previously validated criteria. The primary outcome was the 14-day return visit rate, with 3- and 7-day rates also calculated. Modified Poisson regression was used to analyze associations for age, sex, initial hospitalization rate, and a visit during the COVID-19 pandemic with return visit rates. RESULTS: Of 2548 eligible ED visits, approximately 52% were patients less than 12 years old, 50% were female, and over 95% were non-Hispanic Black. The overall 14-day return visit rate was 29.1% (95% confidence interval [CI]: 27.4%-30.9%; site range 22.7%-31.7%); the 7- and 3-day return visit rates were 23.0% (95% CI: 21.3%-24.6%) and 16.7% (95% CI: 15.3%-18.2%), respectively. Younger children had slightly lower 14-day return visit rates (27.3% vs. 31.1%); there were no associations for site hospitalization rate, sex, and a visit occurring during the pandemic with 14-day returns. CONCLUSION: Nearly 30% of ED discharged visits after SCD pain treatment had a return visit within 14 days. Increased efforts are needed to identify causes for high ED return visit rates and ensure optimal ED and post-ED care.

Development of a Pediatric Cardiology Cardiopulmonary Exercise Testing Database.

Cardiopulmonary exercise testing (CPET) provides clinicians with information vital to the management of pediatric cardiology patients. CPET can also be used to measure cardiorespiratory fitness (CRF) in these patients. CRF is a robust marker of overall health in children. However, a complete understanding of CRF in pediatric cardiology patients is limited by lack of large, standardized CPET databases. Our purpose was to develop a standardized CPET database, describe available data at our institution, and discuss challenges and opportunities associated with this project. CPETs performed from 1993 to present in an urban pediatric hospital were collected and compiled into a research database. Historical data included demographic and clinical variables and CPET outcomes, and additional variables were calculated and coded to facilitate analyses in these cohorts. Patient diagnoses were coded to facilitate sub-analyses of specific cohorts. Quality assurance protocols were established to ensure future database contributions and promote inter-institutional collaborations. This database includes 10,319 CPETs (56.1% male), predominantly using the Bruce Protocol. Patients ranging from ages 6 to 18 years comprise 86.8% of available CPETs. Diagnosis classification scheme includes patients with structurally normal hearts (n = 3,454), congenital heart disease (n = 3,614), electrophysiological abnormalities (n = 2,082), heart transplant or cardiomyopathy (n = 833), and other diagnoses (n = 336). Historically, clinicians were provided with suboptimal interpretive resources for CPET, often generalizing inferences from these resources to non-representative clinical populations. This database supports representative CRF comparisons and establishes a framework for future CRF-based registries in pediatric patients referred for CPET, ultimately improving clinical decision-making regarding fitness in these populations.

Emergency department visits and hospitalizations among patients with sickle cell disease in illinois, 2016-2020.

Sickle cell disease (SCD) state level surveillance data are limited. We performed a retrospective review of emergency department (ED) visits and hospitalizations from individuals with SCD in Illinois (2016-2020) using the Illinois Health and Hospital Association's Comparative Health Care and Hospital Data Reporting Services. There were 48,094 outpatient ED visits and 31,686 hospitalizations. Most visits (67%) occurred in Cook County, were covered by public insurance (77%) and were from individuals with medium high (40.3%) or high (36.1%) poverty levels. SCD healthcare utilization remains high and surveillance data may inform SCD program development and resource allocation at the state level.AbbreviationsCDCCenters for Disease Control and PreventionEDEmergency DepartmentFDAFood & Drug AdministrationICDInternational Classification of DiseasesILIllinoisSCDSickle cell disease.

South Asians Active Together (SAATH): Protocol for a multilevel physical activity intervention trial for South Asian American mother and daughter dyads.

South Asian (SA), including Asian Indian and Pakistani Americans, have a high burden of cardiometabolic risk factors and low levels of physical activity (PA). Increasing PA in the U.S. population is a national priority; however, SA American women and girls experience unique barriers to PA that are not addressed by current promotion efforts. To address this gap, our community-based participatory research partnership developed the South Asians Active Together (SAATH) intervention. This study is a two-arm randomized clinical trial to evaluate the effects, mediators, and implementation of the 18-week SAATH intervention. A total of 160 mother-daughter dyads will be randomized in a 1:1 ratio to the SAATH intervention and control groups. The intervention was designed for mother-daughter dyads and targets individual, interpersonal, and family levels through (1) group exercise classes, (2) mother-daughter discussions, and (3) peer group discussions. The intervention targets the environment level through community partner meetings aimed at creating environment changes to enhance PA opportunities for SA women and girls. The control group will receive PA education materials. We hypothesize that dyads who receive the intervention will have significantly greater increases in moderate- and vigorous-intensity PA (MVPA) from baseline to 4 months, compared to the control group. MVPA will be measured at 12 months in intervention participants to examine if changes are sustained. A process evaluation will use the reach, effectiveness, adoption, implementation, and maintenance (RE-AIM) framework. This study will fill knowledge gaps about the effectiveness and implementation of culturally adapted, community-based PA interventions for SA women and girls.

Motivators and Barriers to Physical Activity among Youth with Sickle Cell Disease: Brief Review.

PURPOSE: Health disparities for minority groups include a low rate of physical activity and underserved urban minority youth with chronic disease are among the least active population segments, as exemplified by sickle cell disease (SCD). "Exercise prescriptions" for youth with chronic diseases need to be evidence based and align with psychologic motivators and barriers. This scoping review sought evidence for psychosocial motivators or barriers to physical activity (PA) in youth with SCD and other chronic disease that could be relevant to SCD. METHODS: Five databases were searched for studies on urban minority youth published between 2009 and 2022. RESULTS: Keyword searching yielded no papers on SCD and PA motivation and barriers. Adding health-related quality of life (HRQL) in SCD found eleven relevant papers. Widening the search to chronic disease in minority youth resulted in a total of 49 papers. Three thematic categories and seven sub-themes emerged. PA barriers added by chronic disease include fear of triggering disease complications, negative relationships due to disease limitations on performance in sports, and lack of suitable environment for PA that accommodates the chronic disease. PA motivators are similar for youth without chronic disease: self-efficacy, autonomy, positive relationships with peers and parents and coach/teacher. CONCLUSION: Direct descriptions of PA motivations and barriers to PA in SCD are limited to fatigue and fear of sickle vaso-occlusive pain. The PA barriers and motivators found for urban youth with chronic disease overlap with themes in healthy adolescents from underserved minorities. Community-based interventions could strengthen PA motivators (self-efficacy, autonomy, positive relationships with peers and parents and coach/teacher) but need disease accommodations to overcome the barriers (fear of triggering disease complications, environmental limitations, and negative relationships). Evidence-based exercise prescriptions might incorporate educational modules to overcome disease stigma and misconceptions. Prospective studies of PA motivators and barriers could improve HRQL in SCD.

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

BACKGROUND: Sickle cell disease (SCD) is a devastating, multisystemic disorder that affects millions of people worldwide. The earliest clinical manifestations of SCD can affect infants as young as 6 months of age, and pediatric patients are at risk for acute and life-threatening complications. Early intervention with treatments that target the underlying pathophysiological mechanism of SCD, sickle hemoglobin (HbS) polymerization, are expected to slow disease progression and circumvent disease-associated morbidity and mortality. PROCEDURE: The HOPE-KIDS 1 trial (NCT02850406) is an ongoing four-part, phase 2a, open-label, single- and multiple-dose study to evaluate the pharmacokinetics, efficacy, and safety of voxelotor-a first-in-class HbS polymerization inhibitor-in patients aged 6 months to 17 years with SCD. Initial findings from a cohort of 45 patients aged 4 to 11 years who received voxelotor treatment for up to 48 weeks are reported. RESULTS: Hemoglobin (Hb) response, defined as a >1.0 g/dl increase from baseline, was achieved at week 24 by 47% (n = 16/34) of patients with Hb measurements at baseline and week 24. At week 24, 35% (n = 12/34) and 21% (n = 7/34) of patients had a >1.5 g/dl increase and a >2.0 g/dl increase from baseline in Hb concentration, respectively. Concurrent improvements in hemolytic markers were observed. Voxelotor was well tolerated in this young cohort, with no newly emerging safety signals. CONCLUSIONS: Based on its mechanism as an HbS polymerization inhibitor, voxelotor improves Hb levels and markers of hemolysis and has the potential to mitigate SCD-related complications; these results support its use in patients aged ≥4 years.

Impact of hydroxyurea dose and adherence on hematologic outcomes for children with sickle cell anemia.

BACKGROUND: Hydroxyurea is the primary treatment for sickle cell anemia (SCA), yet real-world implementation in high-income settings is suboptimal. Variation in prescribed hydroxyurea dose and patient adherence in these settings can both affect actual exposure to hydroxyurea. Quantifying the contributions of hydroxyurea dose and medication adherence to the relationship between hydroxyurea exposure and hematologic parameters could inform strategies to optimize exposure and improve outcomes. PROCEDURE: We evaluated the relationship between hydroxyurea exposure, defined by average prescribed dose and adherence, and hematologic parameters using data from children with SCA who were enrolled in two prospective hydroxyurea adherence studies. Hydroxyurea adherence was assessed by video directly observed therapy or electronic pill bottle and medication administration record. Average prescribed dose was abstracted from prescriptions in patients' electronic medical record. Participants with a hydroxyurea exposure >20 mg/kg/day and ≤20 mg/kg/day were included in the higher and lower exposure groups, respectively. RESULTS: Forty-five participants were included in the analysis (56% male; median age 12 years [range 2-19]; 98% Black). Higher exposed participants (n = 23) were prescribed a higher dose (27.2 vs. 24.4 mg/kg/day, p = .002) and had better adherence (0.92 vs. 0.71, p ≤ .001) compared to lower exposed participants (n = 22). Higher exposure was associated with higher fetal hemoglobin (p = .04) and mean corpuscular volume (p = .02). CONCLUSIONS: Higher hydroxyurea exposure is associated with improved hematologic parameters in the high-income setting and is affected by both prescribed dose and adherence. Future studies are needed to optimize both adherence and hydroxyurea prescribing and confirm that increasing exposure improves clinical outcomes in this setting.

Pediatric Cardiopulmonary Exercise Testing: Interoperability Through Domain Analysis Modeling and a National Survey.

PURPOSE: The electronic health record, data science advances, and dynamic environmental and infectious threats to child health highlight the need for harmonized and interoperable approaches to pediatric cardiopulmonary exercise testing (CPET). Accordingly, we developed a terminology harmonization in exercise medicine and exercise science domain analysis model (THEMES DAM) to structure CPET data elements. METHODS: THEMES DAM identified 114 data elements, including participant information, calibration, equipment, protocols, laboratory personnel, encouragement strategies, and analysis procedures. We used the THEMES DAM, vetted by the international data standards organization HL7, to construct a current-state survey of pediatric CPET centers in the United States. Forty-eight of 101 centers responded to a questionnaire covering seven major topic areas (38 items). RESULTS: Centers predominantly performed between 100 and 500 tests annually. Cardiac disease represented 55% of referrals. Almost all centers calibrated gas concentrations and flow daily, but 42% never calibrated their treadmill or cycle ergometers. All centers measured V̇O2peakbut calculated differently. Centers used a variety of protocols (e.g., for treadmill: 61%, Bruce; 43%, modified Bruce; 59%, other); 44% calculated CPET slopes from submaximal portions of CPET (e.g., V̇O2-HR). All centers verbally encouraged participants, but only 40% used a standardized approach. The interpretation of CPET was done by physicians (60%), exercise physiologists (25%), exercise technicians (10%), nurses (1%), or others (4%). Ninety-one percent would agree to collaborate in multicenter research, 89% to establish dynamic reference values, and 83% to better interpret CPET. CONCLUSIONS: The survey data and the implementation of THEMES DAM could accelerate interoperability across multiple centers. This would facilitate a nimble approach to create pediatric reference values responsive to the constantly changing health environment and stimulate novel approaches to CPET research and clinical application.

Risk factors associated with venous and arterial neonatal thrombosis in the intensive care unit: a multicentre case-control study.

BACKGROUND: Critically ill infants are susceptible to thrombosis due to several risk factors. The aim of this study was to identify risk factors associated with venous and arterial thrombosis in neonates admitted to the neonatal intensive care unit (NICU) and to identify differences in risk factors for venous versus arterial thrombosis. METHODS: We conducted a case-control study at 31 level IV NICUs using the Children's Hospital Neonatal Database between Jan 1, 2010, and Dec 13, 2016, in the USA. Cases were identified on the basis of having an outcome of venous or arterial thrombosis. Controls were matched by gestational age, presence of a central access device (CAD), hospital, and admission year. Four controls per case (1:4) were randomly selected. Bivariable and multivariable regression analyses were performed to examine the associations between potential risk factors and venous or arterial thrombosis. CAD-related risk factors were analysed in the subset of neonates with a CAD. FINDINGS: We identified 118 952 new admissions to 31 NICUs. The overall thrombosis incidence was 15·5 per 1000 NICU admissions (95% CI 14·8-16·2). After exclusion of patients with a length of hospitalisation longer than 3 days or heart disease, the study included 1326 thrombosis cases (1022 with venous thrombosis and 362 with arterial thrombosis; 58 patients had both types of thrombosis and are included within both of these numbers) and 5304 randomly selected controls. Venous thrombosis was independently associated with bloodstream infection (odds ratio 2·07, 95% CI 1·72-2·49; p<0·0001), maternal diabetes (1·62, 1·30-2·03; p<0·0001), abdominal or gastrointestinal surgery (1·36, 1·17-1·58; p<0·0001), thrombocytopenia (2·44, 2·02-2·94; p<0·0001), prolonged mechanical ventilation (1·27, 1·10-1·46; p=0·0014), and age 7 days or older at admission (1·49, 1·28-1·74; p<0·0001). Arterial thrombosis was independently associated with maternal hypertension (1·42, 1·05-1·91; p=0·030), thrombocytopenia (2·20, 1·59-3·06; p<0·0001), prolonged mechanical ventilation (1·58, 1·24-2·01; p=0·0002), age 7 days or older at admission (1·35, 1·05-1·74; p=0·0018), and small for gestational age (1·56, 1·13-2·16; p=0·0003). In the CAD subset analysis, CAD duration of 21 days or longer (venous thrombosis: 1·52, 1·15-2·01, p=0·0034; arterial thrombosis: 1·98, 1·25-3·14, p=0·035) and CAD in both the upper and lower body (venous thrombosis: 2·43, 1·92-3·08, p<0·0001; arterial thrombosis: 1·58, 1·02-2·45, p=0·040) were associated with higher odds of thrombosis. INTERPRETATION: Identification of thrombosis-associated risk factors will be useful in developing a risk prediction model to prevent thrombosis and in improving outcomes. The study results add to the knowledge of the differences in risk factors for venous versus arterial thrombosis in neonates and to the understanding of the associations of CAD characteristics with neonatal thrombosis. FUNDING: Bristol-Myers Squibb-Pfizer Alliance.

Heart rate variability associated with acute exercise challenge in children with sickle cell anaemia.

We examined heart rate variability (HRV) during exercise testing in 20 children with sickle cell anaemia (SCA) and 12 controls. Subjects achieved lower median HRV at peak exercise [standard deviation of R-wave to R-wave intervals (SDNN), 2·3 vs 2·9 ms, P = 0·027; logarithmic transformation of high frequency power (lnHF), 0·9 vs 1·3 ln(ms2 ), P = 0·047] and had lower post-exercise HRV across minute-by-minute analysis of recovery. After adjustment for haemoglobin, fitness and SCA status, subjects had lower HRV at the end of recovery with differences increasing as baseline HRV increased. Further investigation of HRV and exercise safety in SCA is warranted.

Cerebral and skeletal muscle tissue oxygenation during exercise challenge in children and young adults with sickle cell anaemia.

We used near-infrared spectroscopy to examine tissue oxygenation (StO2) during exercise in 17 children and young adults with sickle cell anaemia (SCA) and 13 controls. Patients had lower cerebral StO2 at all exercise stages and demonstrated significantly greater decreases in cerebral StO2 later during exercise. Quadriceps StO2 increased similarly in patients and controls during early exercise, but decreases from baseline were greater in patients during later exercise. At similar workloads, patients demonstrated lower cerebral StO2 (69·2 ± 6·6 vs. 79·5 ± 5·3%, P < 0·001) and trended towards lower quadriceps StO2 (67·7 ± 9·0 vs. 73·2 ± 7·9%, P = 0·09) . Further studies of tissue oxygenation during exercise in SCA are warranted.

Safety of maximal cardiopulmonary exercise testing in individuals with sickle cell disease: a systematic review.

OBJECTIVE: We evaluated the safety of maximal cardiopulmonary exercise testing (CPET) in individuals with sickle cell disease (SCD). Maximal CPET using gas exchange analysis is the gold standard for measuring cardiopulmonary fitness in the laboratory, yet its safety in the SCD population is unclear. DESIGN: Systematic review. DATA SOURCES: Systematic search of Medline (PubMed), EMBASE, Cochrane, ClinicalTrials.gov and professional society websites for all published studies and abstracts through December 2020. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Two reviewers independently extracted data of interest from studies that assessed safety outcomes of maximal CPET in children and adults with SCD. A modified version of the Newcastle-Ottawa Scale was used to assess for risk of bias in studies included. RESULTS: In total, 24 studies met inclusion/exclusion criteria. Adverse events were reported separately or as part of study results in 36 (3.8%) of 939 participants with SCD undergoing maximal CPET in studies included. Most adverse events were related to transient ischaemic changes on ECG monitoring or oxygen desaturation during testing, which did not result in arrhythmias or other complications. Only 4 (0.43%) of 939 participants experienced pain events due to maximal CPET. CONCLUSION: Maximal CPET appears to be a safe testing modality in children and adults with SCD and can be used to better understand the physiological basis of reduced exercise capacity and guide exercise prescription in this population. Some studies did not focus on reporting adverse events related to exercise testing or failed to mention safety monitoring, which contributed to risk of bias.

Digital behavioural interventions for people with sickle cell disease.

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To identify and assess the effects of digital behavioural interventions focused on behavioural change in people with SCD on: medication adherence or disease management (such as managing acute and chronic pain), or both, on health- and other-related outcomes;specific subgroups defined by age (i.e. children, adolescents and adults) and type of modality or delivery (e.g. cell phone, the Internet).

American Society of Hematology 2021 guidelines for sickle cell disease: stem cell transplantation.

BACKGROUND: Sickle cell disease (SCD) is a life-limiting inherited hemoglobinopathy that results in significant complications and affects quality of life. Hematopoietic stem cell transplantation (HSCT) is currently the only curative intervention for SCD; however, guidelines are needed to inform how to apply HSCT in clinical practice. OBJECTIVE: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and health professionals in their decisions about HSCT for SCD. METHODS: The multidisciplinary guideline panel formed by ASH included 2 patient representatives and was balanced to minimize potential bias from conflicts of interest. The Mayo Evidence-Based Practice Research Program supported the guideline development process, including performing systematic evidence reviews (through 2019). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment. RESULTS: The panel agreed on 8 recommendations to help patients and providers assess how individuals with SCD should consider the timing and type of HSCT. CONCLUSIONS: The evidence review yielded no randomized controlled clinical trials for HSCT in SCD; therefore, all recommendations are based on very low certainty in the evidence. Key recommendations include considering HSCT for those with neurologic injury or recurrent acute chest syndrome at an early age and to improve nonmyeloablative regimens. Future research should include the development of a robust SCD registry to serve as a comparator for HSCT studies.