Survival of children with sickle cell disease

Detection of Subclinical Cardiac Dysfunction in Patients With Sickle Cell Disease Using Speckle-Tracking Echocardiography

Sickle cell disease (SCD) is characterized by chronic anemia and recurrent ischemia-reperfusion episodes, which can lead to high-output heart failure. The impact of SCD on cardiac structure and function remains underinvestigated. We conducted a single-institution retrospective analysis of clinical and echocardiographic data from patients with hemoglobin SS SCD (SCD-SS) between January 2016 and June 2022. Patients with known heart failure, left ventricular (LV) ejection fraction <50%, moderate or severe valvular heart disease, congenital heart disease, established coronary artery disease, diabetes mellitus, hypertension, or coexistent lung disease were excluded. Compared with healthy controls (n = 28), patients with SCD-SS (n = 66) had a significantly higher left atrial (LA) volume index (35.7 vs 23.9 ml/m², p <0.001) and average E/e' (7.4 vs 6.5, p = 0.003) but having lower average e' (12.3 vs 13.6 cm/s, p = 0.047) and LA reservoir strain (32.9% vs 42.4%, p <0.001). Patients with SCD-SS had higher LV end-diastolic (132.5 vs 104.1 ml, p <0.001) and LV end-systolic volumes (51.0 vs 43.8 ml, p = 0.017) with reduced LV global longitudinal strain (17.6% vs 20.0%, p <0.001). In addition, patients with SCD-SS showed reduced right ventricular (RV) global longitudinal strain (19.7% vs 22.8%, p <0.001) in the setting of normal RV tricuspid annular plane systolic excursion. Maximal systolic tricuspid regurgitation velocity (231 vs 202 cm/s, p <0.001) and right atrial area (16.6 vs 12.8 cm², p <0.001) were statistically greater in SCD-SS. Hemoglobin and hematocrit negatively correlated with LA volume index, average E/e', LV end-diastolic volume, and LV end-systolic volume. In conclusion, patients with SCD-SS had notable differences in cardiac chamber size and impaired LV, RV, and LA strain compared with healthy controls. Further investigations are needed to assess the impact of these variables on SCD clinical course and prognosis.

Hydroxyurea mobile directly observed therapy versus standard monitoring in patients with sickle cell anemia: a phase 2 randomized trial

BACKGROUND

Sickle cell anemia (SCA) prevalence remains high in sub-Saharan Africa. Long-term treatment with hydroxyurea (HU) increases survival, however, poor adherence to treatment could limit effectiveness. Whilst HU treatment adherence is currently high, this might decrease over time.

METHODS

We conducted a single-center, randomized, open-label, parallel group phase 2 controlled clinical trial to determine whether mobile Directly Observed Therapy (m-DOT) increases HU treatment adherence (NCT02844673). Eligible participants were adults with homozygous SCA. People on a chronic blood transfusion program, with hemoglobin (Hb) A levels greater than 20% of the total Hb, total Hb less than 4 g/dL, pregnant or HIV positive were excluded. After a 3-month pre-treatment period participants were randomized to either m-DOT or standard monitoring arm. All participants received smart mobile phones and were treated with HU (15 mg/kg) daily for three months. In the m-DOT arm, drug intake was video recorded on cell phone by the participant and the video sent to the study team. The primary objective was to evaluate the effect of m-DOT on adherence to HU treatment by medication possession ratio (MPR).

RESULTS

Of the 86 participants randomized, 76 completed the trial (26.13 ± 6.97 years, 63.5 % female). Adherence was high (MPR > 95 %) in both groups, 29 (80.6 %) in m-DOT versus 37 (94.9 %) in the standard monitoring arm (P = 0.079). No HU treatment was withheld from participants due to safety concerns.

CONCLUSIONS

m-DOT did not increase adherence to HU treatment. We recommend that further testing in larger trials with a longer follow up period be undertaken.

Point-of-Care Newborn Screening for Sickle Cell Disease at Selected Health Facilities in the Gambia

Sickle cell disease (SCD) contributes significantly to childhood morbidity and mortality in sub-Saharan Africa. Early diagnosis through newborn screening (NBS) and subsequent comprehensive follow-up care will reduce the burden. Up till now, the prevalence of SCD among newborns remains unknown in The Gambia and there is no national NBS programme to address this significant public health issue. We assessed the real-time frequency of SCD in the country and determined differences in the pattern of SCD phenotypes among different ethnic groups. A preliminary prospective feasibility study was done in eight purposively selected hospitals in the seven Health Administrative Regions and Banjul. Consecutive newborn babies delivered or managed in these facilities were screened using HemoTypeSC, a sensitive and specific ELISA-based point-of-care test (POCT). Babies identified as SCD with HemoTypeSC were retested at age ≥6 months using alkaline cellulose acetate hemoglobin electrophoresis (ACAE). Head-to-head comparison between HemoType screening and gold standard HPLC could not be done. 1,168 newborn babies were screened from April 14 to August 12, 2023. Fifteen (1.3%) had homozygous HbS (HbSS), two (0.2%) heterozygous for HbS and HbC (HbSC), 204 (17.5%) had sickle cell trait (HbAS), four (0.3%) heterozygous for HbA and HbC (HbAC), and 943 (80.7%) had normal hemoglobin (HbAA). The 17 with SCD (HbSS and HbSC) comprised of 7 (2.2%) of 324 Fula; 6 (1.4%) of 426 Mandinka; 2 (1.6%) of 125 Jola and 2 (1.3%) of 150 Wolof. Fourteen (82.4%) of the 17 accepted the diagnosis and were enrolled into the SCD program. For these 14, HemoTypeSC had 100% sensitivity with ACAE when repeated at age ≥6 months. In addition to determining the real-time newborn prevalence of SCD and trait in The Gambia for the first time, this pilot study showed that SCD-POCT is feasible in Gambian health facilities.

National Quality Indicators in Pediatric Sickle Cell Anemia

OBJECTIVE

To assess nationally endorsed claims-based quality measures in pediatric sickle cell anemia (SCA).

METHODS

Using data from the Sickle Cell Data Collection programs in California and Georgia from 2010 to 2019, we evaluated 2 quality measures in individuals with hemoglobin S/S or S/β-zero thalassemia: (1) the proportion of patients aged 3 months to 5 years who were dispensed antibiotic prophylaxis for at least 300 days within each measurement year and (2) the proportion of patients aged 2 to 15 years who received at least 1 transcranial Doppler ultrasound (TCD) within each measurement year. We then evaluated differences by year and tested whether performance on quality measures differed according to demographic and clinical factors.

RESULTS

Only 22.2% of those in California and 15.5% in Georgia met or exceeded the quality measure for antibiotic prophylaxis, with increased odds associated with rural residence in Georgia (odds ratio 1.61; 95% confidence interval 1.21-2.14) compared with urban residence and a trend toward increased odds associated with a pediatric hematologist prescriber (odds ratio 1.28; 95% confidence interval 0.97, 1.69) compared with a general pediatrician. Approximately one-half of the sample received an annual assessment of stroke risk using TCD (47.4% in California and 52.7% in Georgia), with increased odds each additional year in both states and among younger children.

CONCLUSIONS

The rates of receipt of recommended antibiotic prophylaxis and annual TCD were low in this sample of children with SCA. These evidence-based quality measures can be tracked over time to help identify policies and practices that maximize survival in SCA.

Hydroxyurea at escalated dose versus fixed low-dose hydroxyurea in adults with sickle cell disease

Hydroxyurea reduces the frequency of vaso-occlusive complications, increases hemoglobin, and decreases mortality in sickle cell disease (SCD). Although current guidelines recommend escalation to maximum tolerated dose (MTD), the use of fixed low-dose hydroxyurea is common in low-resource countries. We conducted a systematic review and meta-analysis to evaluate the efficacy of escalated doses versus fixed low-dose of hydroxyurea in adults with SCD. Nine studies were included in the quantitative synthesis, four evaluating fixed low-dose and five evaluating escalated doses of hydroxyurea. Average daily doses of hydroxyurea in the fixed low-dose and escalated dose studies were ~10 and 22 mg/kg, respectively. There was no difference in the estimate of vaso-occlusive crisis rate between escalated and fixed low-dose studies (p = .73). The mean difference in hemoglobin from baseline to follow-up was greater for fixed low-dose than escalated dose studies (1.07 g/dL vs. 0.54 g/dL, p = .01). No difference was seen in the mean estimate of fetal hemoglobin. Despite limited eligible studies and substantial heterogeneity of effect between the studies for several outcomes, there appears to be clinical equipoise regarding the most appropriate hydroxyurea dosing regimen in adults with SCD. Controlled studies of hydroxyurea at MTD versus fixed low-dose in adults with SCD are required.

Madrid Newborn Sickle Cell Disease Cohort: clinical outcomes, stroke prevention and survival

In May 2003, Madrid established the universal newborn screening (NBS) for sickle cell disease (SCD). However, there are no studies resembling the evolution of a SCD neonate cohort followed according to national guidelines in Spain. The aim of this study is to describe the morbimortality and the stroke prevention programme in patients diagnosed by SCD NBS in Madrid. This is a multicentre, observational, prospective cohort study between 2003 and 2018; 187 patients diagnosed with SCD were included (151 HbSS, 6 HbSβ0, 27 HbSC, 3 HbSβ +), and median follow-up was 5.2 years (0.03-14.9). There were 5 deaths: 2 related to SCD in patients with severe genotype (HbSS/HbSβ0). Overall survival reached 95% and SCD-related survival 96.8%. The most frequent events were fever without focus, vaso-occlusive crises and acute chest syndromes. Eight strokes occurred in 5 patients which led to a 90.7% stroke-free survival in severe genotype patients (first stroke rate, 0.54 per 100 patient-years). Transcranial Doppler (TCD) was performed in 95% of eligible patients; 75% of children with pathological TCD remained stroke-free. Regarding HbSS/HbSβ0 patients, 50.1% received hydroxyurea and 9.5% haematopoietic stem cell transplantation. This study reflects the evolution of Madrid SCD cohort and provides morbimortality data similar to other developed countries.

Overview of the Association Between the Pathophysiology, Types, and Management of Sickle Cell Disease and Stroke

Sickle cell disease (SCD) is a genetic blood disorder that affects hemoglobin and increases stroke risk, particularly in childhood. This review examines the pathophysiological association between SCD and stroke, the classification of stroke types, risk factors, diagnosis, management, prevention, and prognosis. A comprehensive literature search was conducted via PubMed, Scopus, and Cochrane databases. Relevant studies on SCD and stroke pathophysiology, classification, epidemiology, diagnosis, treatment, and prevention were identified. Sickle cell disease causes red blood cells to become rigid and sickle-shaped, obstructing blood vessels. Recurrent sickling alters cerebral blood flow and damages vessel walls, often leading to ischemic or hemorrhagic strokes (HS). These occur most frequently in childhood, with ischemic strokes (IS) being more common. Key risk factors include a prior transient ischemic attack (TIA), low hemoglobin, and a high leukocyte count. Neuroimaging is essential for diagnosis and determining stroke type. Primary prevention centers on blood transfusions and hydroxyurea for those at high risk. Acute treatment involves promptly restoring blood flow and managing complications. However, significant knowledge gaps remain regarding stroke mechanisms, optimizing screening protocols, and improving long-term outcomes. This review synthesizes current evidence on SCD and stroke to highlight opportunities for further research and standardizing care protocols across institutions. Ultimately, a holistic perspective is critical for mitigating the high risk of debilitating strokes in this vulnerable patient population.

Dental arch form in a sample of Iraqi adults with sickle cell anemia using 3D scanning technique: A cross-sectional study

OBJECTIVE

Sickle cell anemia (SCA) is a hematological condition that involves the synthesis of sickle-shaped, hemoglobin with a short lifespan. This study employed three-dimensional (3D) scanning to pinpoint the most common arch form in a sample of Iraqi adults with SCA.

MATERIALS AND METHODS

A cross-sectional study included maxillary and mandibular casts of 50 patients (25 male and 25 female) with SCA and 50 participants in a control group (25 male and 25 female). The facio-axial (FA) point was digitized on each tooth's labial or buccal surface using SolidWorks® 2020 software. The dimensions of the arch were calculated using two proportional measures and four linear measurements. The dental arch form was determined using 3M templates, and the arches were categorized as square, ovoid, or tapered to establish the most-common arch form. Chi-square was used to compare arch form distribution, and an independent t-test was used to calculate the difference between the control group and the SCA group.

RESULTS

The tapered arch was the predominant form in SCA males and females for the maxilla and the mandible. The molar vertical distance (upper and lower) was significantly higher in males in the SCA group than in males in the control group. There was no significant difference between females in the SCA group and females in the control group.

CONCLUSION

Most patients with SCA had tapered arches. Sagittal jaw dimensions in males with SCA were more affected by marrow hyperplasia. There was little if any to no effect on females with SCA.

Emerging Therapies and Advances in Sickle Cell Disease with a Focus on Renal Manifestations

The underlying mechanisms of disease in sickle cell disease (SCD) contribute to a multifaceted nephropathy, commonly manifested as albuminuria. In severe SCD genotypes ( e.g. , Hemoglobin SS [HbSS]), albuminuria and CKD are major predictors of mortality in this population. Therefore, the monitoring and management of renal function is an intrinsic part of comprehensive care in SCD. Management of nephropathy in SCD can be accomplished with SCD-directed therapies and/or CKD-directed therapies. In the past 5 years, novel disease-modifying and palliative therapies have been approved in SCD to target aspects of the disease, such as anemia, inflammation, and vasculopathy. Along with conventional hydroxyurea and chronic transfusion, l -glutamine, crizanlizumab, and voxelotor have all been shown to mitigate some adverse effect of SCD, and their effect on nephropathy is being investigated. CKD-directed therapies such as renin-angiotensin-aldosterone system blockers have long been used in SCD nephropathy; however, more complete long-term studies on benefits are needed. Given the effect of renal disease on survival, further assessment of the mechanisms and efficacy of these SCD-directed or CKD-directed therapeutic agents is essential.

Sickle Cell Hemoglobin Genotypes Affect Malaria Parasite Growth and Correlate with Exosomal miR-451a and let-7i-5p Levels

Malaria affects a significant portion of the global population, with 247 million cases in 2021, primarily in Africa. However, certain hemoglobinopathies, such as sickle cell trait (SCT), have been linked to lower mortality rates in malaria patients. Hemoglobin (Hb) mutations, including HbS and HbC, can cause sickle cell disease (SCD) when both alleles are inherited (HbSS and HbSC). In SCT, one allele is inherited and paired with a normal allele (HbAS, HbAC). The high prevalence of these alleles in Africa may be attributed to their protective effect against malaria. Biomarkers are crucial for SCD and malaria diagnosis and prognosis. Studies indicate that miRNAs, specifically miR-451a and let-7i-5p, are differentially expressed in HbSS and HbAS compared to controls. Our research examined the levels of exosomal miR-451a and let-7i-5p in red blood cells (RBCs) and infected red blood cells (iRBCs) from multiple sickle Hb genotypes and their impact on parasite growth. We assessed exosomal miR-451a and let-7i-5p levels in vitro in RBC and iRBC supernatants. Exosomal miRNAs exhibited distinct expression patterns in iRBCs from individuals with different sickle Hb genotypes. Additionally, we discovered a correlation between let-7i-5p levels and trophozoite count. Exosomal miR-451a and let-7i-5p could modulate SCD and malaria severity and serve as potential biomarkers for malaria vaccines and therapies.

COVID-19 infection and pain in adolescents with sickle cell disease: A case series

Adolescents with sickle cell disease (SCD) have been shown to have pain-related sequelae following COVID-19 infection. In this case series, we discuss five adolescents with SCD and SARS-CoV-2 infection who subsequently developed complex pain circumstances manifested as: (1) increased frequency of acute care visits or admissions for pain; (2) new onset chronic pain; (3) new onset neuropathic pain; (4) escalation in the complexity of pharmacologic therapies; (5) increased use of nonpharmacologic interventions. While more research is needed to fully understand the implications of COVID-19 infection on pain in adolescents with SCD, these cases suggest the presence of a complex relationship.

Penicillin V prophylaxis uptake among children living with sickle cell disease in a specialist sickle cell clinic in Ghana: A cross-sectional study

Background and Aims

Penicillin V prophylaxis protects children living with sickle cell disease (SCD) from bacteria infections especially Streptococcus pneumonia. However, the uptake of penicillin V prophylaxis is difficult to assess and often poor among SCD patients. Therefore, this study sought to investigate oral penicillin V prophylaxis adherence among SCD children using urine assay and self-reported methods and the associated factors.

Methods

The study employed an analytical cross-sectional design in the assessment of penicillin V prophylaxis adherence using both urine assay and self-reported methods. Multiple logistic regression analysis was used to determine the factors associated with penicillin V prophylaxis adherence. A p value < 0.05 was considered statistically significant.

Results

Among the 421 SCD patients recruited, penicillin V prophylaxis adherence was observed to be 30.0% and 68.0% for the objective and subjective methods of assessment, respectively. For the objective method of assessment, being cared for by grandparents increased the odds of penicillin V adherence (adjusted odds ratio [aOR] = 3.68, confidence interval [CI] = 1.03-13.15). However, SCD patients within the ages of 10-14 years (aOR = 0.36, CI = 0.17-0.80), >14 years (aOR = 0.17, CI = 0.05-0.61), SCD patient cared for by married caregivers/parents (aOR = 0.32, CI = 0.14-0.72), SCD patient cared for by divorced caregivers/parents (aOR = 0.23, CI = 0.07-0.75), SCD patients taking homemade (herbal) preparations for the treatment of SCD (aOR = 0.42, CI = 0.21-0.83), and inappropriate intake of penicillin V prophylaxis (aOR = 0.27, CI = 0.11-0.67) reduced the odds of penicillin V adherence. For the subjective method of assessment, taking homemade preparation (herbal) for the treatment of SCD (aOR = 0.52, CI = 0.30-0.89) and inappropriate intake of penicillin V (aOR = 0.32, CI = 0.17-0.60) reduced the odds of penicillin V adherence.

Conclusion

This study reports a relatively low adherence rate of penicillin V prophylaxis among children living with SCD. Educating and counseling both SCD patients and/or caregivers on the need to be adherent to penicillin V prophylaxis could prevent complications that may arise from nonadherence.

The effect of intensity of conditioning regimen on the outcome of HSCT in children with sickle cell disease

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) provides a cure for patients with sickle cell disease (SCD). This study describes the effect of conditioning regimen intensity on HSCT outcomes among children younger than 14 years with SCD.

METHODS

Transplants from HLA-matched related donors (MRD) and unrelated donors (MUD) using either myeloablative conditioning (MAC) regimens or reduced intensity conditioning (RIC) regimens were considered. Event-free survival (EFS) was the primary endpoint. Secondary endpoints included overall survival (OS) and occurrence of GVHD.

RESULTS

48 SCD patients underwent HSCT, 45 (93.8%) patients had MRD, 1 (2.1%) had 9/10 related donor, and 2 (4.1%) had MUD. The median age at transplant was 8.6 years (range, 3.1-13.8). Conditioning regimens were myeloablative (MAC) in 41 (85.4%) patients and of reduced intensity in 7 (14.6%) patients. EFS at 2 years was 100% among MAC group compared to 29% in the RIC group (p < .001). The median follow-up was 43.4 months (range 26.8-134). All events in the RIC group were secondary graft failure. However, OS was 100% in both groups at 2 years. Acute GVHD II-IV was diagnosed in 2 (4.1%) patients. Chronic GVHD occurred in 2 (4.1%) patients. GVHD did not occur in patients who underwent MUD HSCT.

CONCLUSIONS

MAC in children with SCD is well tolerated and associated with an excellent outcome for HLA-matched HSCT in SCD. There was a high rate of secondary graft failure with the use of RIC. Future studies are needed to optimize RIC regimens in HSCT of children with SCD.

Clinical outcome of pre-operative blood transfusion for sickle cell disease patients in post-operative complications

BACKGROUND

Preoperative blood transfusion for patients with sickle cell disease is a debatable topic and it can be lifesaving. Sickle cell disease patients are at high risk for vaso-occlusive crisis due to the large concentration of sickle hemoglobin (HgbS) in their blood. Despite the current extensive research into this disease, there is still no consensus over whether blood transfusion is a preferable preoperative modality among patients undergoing elective surgical procedures.

METHOD

A retrospective observational study, which enrolled 204 patients with Sickle cell disease who underwent surgery at King Fahad Hospital of the University (KFHU) over the last five years. The primary objective was to determine whether there is evidence that preoperative blood transfusion for SCD patients undergoing surgical procedures will reduce postoperative complications related to SCD.

RESULTS

A total of 204 patients were included, of which 30% had preoperative blood transfusion. Majority of patient 44% had undergone cholecystectomy. On multivariate logistic regression analysis, patients who did not undergo blood transfusion had significantly higher risk to develop post-operative SCD complications (OR=3.07, P value= 0.002). In addition, they had significantly prolonged hospitalization (OR= 2.22, P value= 0.08). In contrast, patients who received blood transfusion had lower risk for developing post-operative SCD related complications (OR=1.87, P value= 0.29), and decrease in the duration of hospitalization by (OR=0.49, P value= 0.045).

CONCLUSION

Our study showed that patients who had not undergo preoperative blood transfusion had higher risk to develop postoperative complications and prolonged hospital stay compared to those who underwent blood transfusion.

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.

MicroRNAs miR-451a and Let-7i-5p Profiles in Circulating Exosomes Vary among Individuals with Different Sickle Hemoglobin Genotypes and Malaria

Sickle cell disease (SCD) occurs when two alleles of mutated hemoglobin (HbS or HbC) are inherited (HbSS and HbSC) rather than one (HbAS or HbAC), which indicates a person carries the sickle cell trait. The high prevalence of these two alleles in Africa have been associated with reduced malaria susceptibility. Recent in vitro research has been shown that microRNAs (miRNAs) miR-451a and let-7i-5p are differentially expressed in HbSS erythrocytes compared to healthy controls (HbAA) and are overexpressed in Plasmodium-infected malaria erythrocytes. However, these miRNAs have not been fully examined in the plasma of people with different sickle hemoglobin genotypes. Plasma circulating miRNAs are commonly encapsulated in extracellular vesicles, such as exosomes, and are thought to play a role in disease development. Circulating exosomal miR-451a and let-7i-5p were quantified from individuals with various hemoglobin genotypes (HbAA, HbAS, HbAC, HbSS, HbSC, and HbCC) with (+) and without (-) malaria. The results showed a higher level of exosomal let-7i-5p and miR-451a in HbSS-. Exosomal let-7i-5p and miR-451a levels were lower in HbSS+ compared to other genotypes. Based on the area under the curve (AUC) of the Receiver Operating Characteristics (ROCs), both exosomal miRNAs may be useful disease biomarkers for SCD with malaria. Finally, miR-451a and let-7i-5p modulate genes involved in inflammation, making them potential biomarkers of pathogenesis for both diseases.

Clinical Utility of the Addition of Molecular Genetic Testing to Newborn Screening for Sickle Cell Anemia

Sickle cell disease (SCD) is a group of related yet genetically complex hemoglobinopathies. Universal newborn screening (NBS) for SCD is performed in the United States and many other nations. Classical, protein-based laboratory methods are often adequate for the diagnosis of SCD but have specific limitations in the context of NBS. A particular challenge is the differentiation of sickle cell anemia (SCA) from the benign condition, compound heterozygosity for HbS and gene-deletion hereditary persistence of fetal hemoglobin (HbS/HPFH). We describe a sequential cohort of 44 newborns identified over 4.5 years who had molecular genetic testing incorporated into NBS for presumed SCA (an “FS” pattern). The final diagnosis was something other than SCA in six newborns (12%). Three (7%) had HbS/HPFH. All had a final, correct diagnosis at the time of their first scheduled clinic visit in our center (median 8 weeks of age). None received initial counseling for an incorrect diagnosis. In summary, genetic testing as a component of NBS for SCD is necessary to provide correct genetic counseling and education for all newborns' families at their first visit to a sickle cell center. Genetic testing also permits the use of early, pre-symptomatic hydroxyurea therapy by preventing infants with HbS/HPFH from receiving unnecessary therapy. We argue that genetic testing should be incorporated into contemporary NBS for SCD.

Hospital Use and Mortality in Transition-Aged Patients With Sickle Cell Disease

OBJECTIVES

Childhood mortality in sickle cell disease (SCD) has decreased, but the transition period is associated with poor outcomes and higher mortality rates. We analyzed recent US hospitalizations and mortality trends in the transition-aged population and evaluated for differences between patients with and without SCD.

METHODS

Nationwide Inpatient Sample database was used to analyze hospitalizations among individuals aged 16 to 24 years from 2003 to 2017. Diagnoses were coded by using International Classification of Diseases, Ninth Revision, Clinical Modification and International Classification of Diseases, 10th Revision, Clinical Modification. We performed bivariate analyses to assess associations between sociodemographic characteristics and SCD hospitalizations, joinpoint regression analysis to describe mortality rate trends in SCD hospitalizations, and adjusted survey logistic regression to assess associations between patient characteristics and in-hospital mortality among transition-aged SCD and non-SCD-related hospitalizations.

RESULTS

There were 37 344 532 hospital encounters of patients aged 16 to 24 years during 2003-2017; both SCD and non-SCD hospitalizations increased with age. Female patients accounted for 78% of non-SCD and 54.9% of SCD hospitalizations. Although there was a +3.2% average annual percent change in SCD hospitalizations, total SCD in-hospital mortality rates did not have a statistically significant increase in average annual percent change over the study period. Patients with SCD aged 19 to 21 and 22 to 24 were more likely to suffer in-hospital mortality than those aged 16 to 18 (odds ratio = 2.09 and 2.71, respectively); the increased odds in mortality by age were not seen in our non-SCD population.

CONCLUSIONS

Transition-aged hospitalizations increase with age, but SCD hospitalizations have disparate age-related mortality rates. Hospital-based comprehensive care models are vital to address the persistent burden of early adulthood mortality in SCD.

Content validation of observer-reported sickle cell pain diaries (SCPD-CS and SCPD-CN): results from interviews with caregivers

BACKGROUND

Patients with sickle cell disease (SCD) experience daily pain and acute episodes known as sickle cell pain crises (SCPCs). The Sickle Cell Pain Diary-Caregiver Report (SCPD-C) is an observer-reported diary for use by caregivers of children ages < 12 years with SCD. This study reports on the content validity of the SCPD-C.

METHODS

The SCPD-C was developed based on a literature review, measurement expert input, and a patient advisory board including clinicians. Three rounds of interviews (including both concept elicitation and cognitive debriefing methodologies) were conducted with caregivers of children with SCD aged < 12 to evaluate the content validity of the SCPD-C.

RESULTS

Across three rounds of interviews, caregivers confirmed concepts in the SCPD-C and described observed impacts that were important and were added. Overall, caregivers evaluated the SCPD-C as easy to understand, with some minor adaptations for clarity. Additionally, the diary was split into two versions based on the child's age and school enrollment status (SCPD-CS for school-aged and SCPD-CN for non-school age children).

CONCLUSIONS

Caregivers provided valuable input that led to important additions and changes to the measures. The SCPD-CS and SCPD-CN are appropriate and fit-for-purpose observer-reported outcome measures of SCPC-related pain frequency and severity, and impacts on health-related quality of life.

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.

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.

Epidemiology of Stroke in Sickle Cell Disease

Sickle cell disease is the most common cause of stroke in childhood, both ischaemic and haemorrhagic, and it also affects adults with the condition. Without any screening or preventative treatment, the incidence appears to fall within the range 0.5 to 0.9 per 100 patient years of observation. Newborn screening with Penicillin prophylaxis and vaccination leading to reduced bacterial infection may have reduced the incidence, alongside increasing hydroxyurea prescription. Transcranial Doppler screening and prophylactic chronic transfusion for at least an initial year has reduced the incidence of stroke by up to 10-fold in children with time averaged mean of the maximum velocity >200 cm/s. Hydroxyurea also appears to reduce the incidence of first stroke to a similar extent in the same group but the optimal dose remains controversial. The prevention of haemorrhagic stroke at all ages and ischaemic stroke in adults has not yet received the same degree of attention. Although there are fewer studies, silent cerebral infarction on magnetic resonance imaging (MRI), and other neurological conditions, including headache, epilepsy and cognitive dysfunction, are also more prevalent in sickle cell disease compared with age matched controls. Clinical, neuropsychological and quantitative MRI screening may prove useful for understanding epidemiology and aetiology.

Analysis of clinical presentation, hematological factors, self-reported bed net usage, and malaria burden in sickle cell disease patients

BACKGROUND

Sickle cell anemia (SCA) is a severe monogenic disorder, caused by single nucleotide mutations in the hemoglobin (Hb) gene, that is prevalent in malaria endemic regions of the world. Sickle cell trait (SCT) individuals carry only one of the mutated alleles and were shown to be protected against malaria. However, defining the relative contribution of hematological, clinical, and environmental factors to the overall burden of malaria in individuals with hemoglobinopathies such as SCA has been challenging.

METHODS

We hypothesized that hematological differences, clinical presentations, and self-reported bed net usage among Plasmodium-infected and uninfected individuals may govern overall malaria burden in individuals with sickle cell disease (SCD). We conducted a cross-sectional study in Ghana from 2014 to 2019 and described clinical presentations, hematological characteristics, and bed net use based on a comprehensive questionnaire. Hematological characteristics were compared using a parametric or nonparametric ANOVA, pending if data passed D'Agostino & Pearson normality test. When comparing only two Hb genotypes hematological characteristics a Mann-Whitney U-test were used. Logistic regressions and Chi-squared tests were used to compare questionnaire responses between Hb genotypes. All statistical significance was set at p < 0.05.

FINDINGS

Multiple hematological parameters were significantly (p < 0.05) altered depending on sickle cell genotype and/or malaria status. When compared to other Hb genotypes, SCA individuals with or without malaria had significantly (p < 0.05) higher WBC and platelets counts and lower Hb levels. While the sickle cell genotype may affect malaria severity, SCT and SCA participants were found to significantly (p < 0.007) use bet nets more than HbAA participants.

INTERPRETATIONS

Our findings can be utilized to enhance national guidelines for reducing the incidence of malaria especially among individuals with SCD, SCT protection and health disparities among hemoglobinopathies.

FUNDING

This study was supported by the National Institute for Health.

Anti-sickling activities of two isolated compounds from the root of Combretum racemosum P. beauv. (Combretaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Evaluation of plants such as Combretum racemosum with claimed traditional use in the management of sickle cell anaemia in Nigeria and other parts of West Africa could serve as a useful research strategy in the search for potential anti-sickling drugs and templates.

AIM OF THE STUDY

This study aimed at evaluating the antisickling potential of C. racemosum by activity-guided purification and isolation of its active constituents.

MATERIALS AND METHODS

Crude methanol extract of the root of C. racemosum and the fractions obtained by partitioning with chloroform, ethyl acetate, and aqueous were investigated for anti-sickling activity against sodium metabisulphite induced sickling of sickle cell haemoglobin (HbSS). Repeated chromatographic separations were conducted on the most active chloroform fraction to purify and isolate bioactive compounds for further tests for anti-sickling activity. The characterization of the isolated compounds was done by mass spectrometry (FD⁺MS) and nuclear magnetic resonance (¹HNMR) spectroscopy.

RESULTS

The chloroform fraction (FA) (% sickled erythrocyte ranged from 3.0 to 34.1) exhibited better anti-sickling activity than aqueous (% sickled erythrocyte ranged from 38.9 to 51.5) as well as the crude methanol (% sickled erythrocyte ranged from 19.1 to 30.4). Hence, the phytochemical investigation was focused on the chloroform fraction, which led to the identification of two ellagic acid derivatives (3,3',4'-tri-O-methyl ellagic acid (A) and 3,3'-di-O- methyl ellagic acid (B). The two isolated compounds possessed good, comparable anti-sickling activities with compound A exhibiting a slightly better in vitro activity.

CONCLUSION

This paper reports for the first time anti-sickling principles from C. racemosum and therefore, provided some justification for the ethnomedicinal use of the plant in the management of sickle cell disease.

Hydroxyurea in children with sickle cell disease in a resource-poor setting: Monitoring and effects of therapy. A practical perspective

BACKGROUND

Although effectiveness of hydroxyurea (HU) in sickle cell disease is well established, unanswered questions persist about its use in African children. We determined real-life issues of acceptability, availability, and monitoring of HU use in Nigeria.

METHODS

A retrospective longitudinal review of laboratory data of patients on HU was done from case files, followed by a cross-sectional survey that captured families' perception of medication and clinic adherence, laboratory tests, benefits, side effects, and acceptability.

RESULTS

One hundred sixteen patients (1.2-17 years) received HU (mean ± SD = 18.5 ± 4.3 mg/kg/day) in 33 months. Eighty-nine had laboratory analysis. Dose escalation was the initial goal, but only 80% of patients had some form of it. Parents reported improvement in general well-being and reduction in bone pain episodes, hospital admissions, and blood transfusion. While most parents (89.5%) reported satisfaction with HU, 61% reported dissatisfaction with daily drug use, and the frequency and cost of monitoring. Sixteen percent voluntarily stopped therapy. Adherence to daily HU was 88.8%, doctor's appointments 24.5%, hematology tests 18.9%, and organ function tests 37.4%. There were no significant toxicities. Significant increases in hemoglobin, hemoglobin F and mean corpuscular volume, and reduction in absolute neutrophil count occurred despite inconsistent dose escalation.

CONCLUSION

HU (10-15 mg/kg/day starting dose) is safe and seems effective and acceptable to parents. Parental commitment to therapy, pre-HU education (that continues during therapy), provision of affordable HU, and subsidized laboratory tests are important considerations for initiating therapy. Special HU clinics may facilitate dose escalation and reduce frequency of monitoring. Studies are needed on feasibility of maximum tolerable dose HU protocols in sub-Saharan Africa without compromising safety.

Moving Toward a New Standard of Care for Acute Pediatric Stroke

Acute pediatric stroke is growing in incidence with the longer survivorship of children with medical complexities, yet detection and treatment of this disease continues to be met with limitations. It is essential for the frontline provider to appropriately identify various presentations of acute pediatric stroke for timely management to occur. Although studies in thrombolytic and endovascular recanalization therapies are limited, the safety and efficacy of these treatments continues to be explored. As pediatric tertiary care centers improve their stroke management, it is increasingly important to implement hospital protocols with a multifaceted approach. This article summarizes the issues and presentations behind identifying acute pediatric stroke, the research behind these emerging therapies in children, and the process of successfully applying pediatric stroke protocols. [Pediatr Ann. 2021;50(6):e242-e244.].

Opioid Use in Adults With Sickle Cell Disease Hospitalized During Vaso-Occlusive Crisis: A Systematic Review

Background

While pain is the hallmark of sickle cell disease (SCD), healthcare personnel are often ill-equipped to adequately treat patients who present in vaso-occlusive crisis (VOC). Although symptom severity varies from individual to individual, SCD is characterized by intervallic pain as a result of oxygen deprivation in tissues and organs. Regardless of pain severity, SCD patients are often viewed as drug seekers by healthcare personnel who have concerns regarding patients’ dependence on opioids which may lead to addiction. The objective was to assess the types and amount of opioids used to treat VOC in comparison to Centers for Disease Control opioid prescription guidelines.

Methods

Literature search was conducted using CINAHL, PubMed, the Cochrane Library, Web of Science and hand search. Data were analyzed from 1999 to 2018. Randomized trials, observational, and case studies involved hospitalized adults with SCD who were prescribed opioids to treat VOC. Quality assessment was conducted using Downs and Black checklist. Meta-analysis was not conducted.

Results

Five studies were conducted in the USA, Arabia and the Netherlands, and the USA and Canada were included. Participants were treated with either morphine or morphine milligram equivalent (MME). No study used the same method of opioid administration.

Conclusions

Patients with SCD who are hospitalized secondary to VOC mostly received opioids for pain well within the Centers for Disease Control and Prevention prescription guidelines. No uniform method exists. Additional research is warranted.

Allele-Specific Recombinase Polymerase Amplification to Detect Sickle Cell Disease in Low-Resource Settings

Sickle cell disease (SCD) is a group of common, life-threatening disorders caused by a point mutation in the β globin gene. Early diagnosis through newborn and early childhood screening, parental education, and preventive treatments are known to reduce mortality. However, the cost and complexity of conventional diagnostic methods limit the feasibility of early diagnosis for SCD in resource-limited areas worldwide. Although several point-of-care tests are commercially available, most are antibody-based tests, which cannot be used in patients who have recently received a blood transfusion. Here, we describe the development of a rapid, low-cost nucleic acid test that uses real-time fluorescence to detect the point mutation encoding hemoglobin S (HbS) in one round of isothermal recombinase polymerase amplification (RPA). When tested with a set of clinical samples from SCD patients and healthy volunteers, our assay demonstrated 100% sensitivity for both the β^A globin and β^S globin alleles and 94.7 and 97.1% specificities for the β^A globin allele and β^S globin allele, respectively (n = 91). Finally, we demonstrate proof-of-concept sample-to-answer genotyping of genomic DNA from capillary blood using an alkaline lysis procedure and direct input of diluted lysate into RPA. The workflow is performed in <30 min at a cost of <$5 USD on a commercially available benchtop fluorimeter and an open-source miniature fluorimeter. This study demonstrates the potential utility of a rapid, sample-to-answer nucleic acid test for SCD that may be implemented near the point of care and could be adapted to other disease-causing point mutations in genomic DNA.

Implementation science research for the scale-up of evidence-based interventions for sickle cell disease in africa: a commentary

BACKGROUND

The burden of sickle cell disease (SCD) is greatest among African nations. Effective scalability of evidence-based interventions (e.g., newborn screening, health education, prophylaxis for infection, optimal nutrition and hydration, hydroxyurea therapy, blood transfusions, and transcranial Doppler (TCD) screening) is urgently needed particularly in these settings for disease management. However, Africa is constrained by limited resources and the lack of capacity to conduct implementation science research for proper understanding of context, and assessment of barriers and facilitators to the uptake and scalability of evidence-based interventions (EBI) for SCD management.

MAIN BODY

We outline implementation science approaches to embed EBI for SCD within the African context and highlight key implementation research programs for SCD management. Building implementation research capacity will meet the major need of developing effective life-long and accessible locally-tailored interventions for patients with SCD in Africa.

CONCLUSION

This commentary communicates the importance of the application of implementation science methodology to scale-up evidence-based interventions for the management of SCD in order to reduce pain, prevent other morbidities and premature death experienced by people with SCD in Africa, and improve their overall quality of life.

Neuroimaging in Sickle Cell Disease: A Review

Sickle cell disease is the most common hereditary hemoglobinopathy, which results in abnormally shaped and rigid red blood cells. These sickle-shaped red blood cells cause vaso-occlusion and ischemic phenomena that can affect any organ in the body. As a common cause of disability, the neurological manifestations of sickle cell disease are particularly important. Neuroimaging has a crucial role in the diagnosis, management, and prevention of the complications of sickle cell disease. These complications can affect the brain parenchyma, vasculature, and skull and can be ascribed directly or indirectly to a vasculopathy of small and large vessels. Vaso-occlusion can cause ischemic stroke. Ischemic damage in the absence of an acute neurological deficit, and therefore only apparent on neuroimaging, is termed silent cerebral ischemia. Weakening of the arterial walls can cause aneurysms. In its most severe form, a vasculopathy of the terminal internal carotid arteries can progress to moyamoya syndrome, characterized by steno-occlusive disease and the formation of friable collateral arteries. Rupture of aneurysms or friable collateral arteries is a potential cause of intracranial hemorrhage. The skull and vertebrae may be affected by extra-medullary hematopoiesis, due to severe anemia, or iron deposition, due to chronic red blood cell transfusion. Impaired blood supply to bone is associated with osteomyelitis and osteonecrosis. Fat embolization syndrome is a rare complication of osteonecrosis, which may cause devastating neurological impairment. Awareness and early recognition of the diverse manifestations of sickle cell disease on neuroimaging is crucial to ensure optimal treatment in a complex patient cohort.

Trends in Sickle Cell Disease-Related Mortality in the United States, 1979 to 2017

STUDY OBJECTIVE

We provide an updated assessment of trends in sickle cell disease (SCD)-related mortality, a significant source of mortality in the United States among black persons, using 1979 to 2017 US mortality data.

METHODS

SCD-related deaths were identified with International Classification of Diseases codes. Because SCD-related death is rare in other races, the analysis focused on black decedents. Age-specific and average annual SCD-related death rates were calculated. Causes of death codes were categorized into 20 groups relevant to SCD outcomes. SCD-related deaths were compared with non-SCD-related deaths after matching on race, sex, age group, and year of death.

RESULTS

There were 25,665 SCD-related deaths reported among blacks in the United States from 1979 through 2017. During that period, the annual SCD-related death rate declined in children and increased in adults, and the median age at death increased from 28 to 43 years. Acute causes of death, such as infection and cerebrovascular complications, were more common in younger age groups. Chronic complications were more common in adults. SCD-related deaths were more likely to be related to acute cardiac, pulmonary, and cerebrovascular complications; acute infections; and chronic cardiac and pulmonary complications and renal disorders; and less likely to be related to drug overdose and chronic infections than non-SCD-related deaths.

CONCLUSION

These data indicate SCD-related deaths are now more likely to be related to chronic complications of the disease than to acute complications. More research regarding prevention and treatment of chronic complications of SCD is necessary because persons with SCD are living longer.

Longitudinal Description of Gonadal Function in Sickle-cell Patients Treated With Hematopoietic Stem Cell Transplant Using Alkylator-based Conditioning Regimens

OBJECTIVES

This study describes the hormone profiles for gonadal late effects after alkylator-based hematopoietic stem cell transplant (HSCT) regimens used for sickle-cell disease (SCD).

METHODS

This is a retrospective chart review of subjects followed in the post-HSCT clinic for sickle-cell disease. Patient demographics, pubertal development, characteristics of pre-HSCT disease severity, treatment before HSCT, conditioning regimens, presence of graft versus host disease and follicle-stimulating hormone, anti-Müllerian hormone (AMH), luteinizing hormone and testosterone were abstracted from the medical record.

RESULTS

Forty subjects (24 female individuals) with SCD were 9 (±4.3) years old at HSCT and 7.9 years (±5.6) from HSCT. At the time of transplant, 8% of female individuals and no male individuals were pubertal and 58% of female individuals and 38% of male individuals had been treated with hydroxyurea. Post-HSCT, all of the female individuals had diminished ovarian reserve on the basis of low AMH values and 10 of the pubertal female individuals (71%) had premature ovarian insufficiency defined as follicle-stimulating hormone >40 mIU/mL ×2. There was no ovarian recovery and AMH remained very low or undetectable up to 13 years post-HSCT. In male individuals, luteinizing hormone and testosterone levels were normal for age.

CONCLUSIONS

Post-HSCT for SCD, all female individuals had diminished ovarian reserve and most female individuals had POI, whereas male individuals had normal testosterone hormone production.

Update of the Spanish registry of haemoglobinopathies in children and adults

BACKGROUND AND OBJECTIVE

Patients with thalassaemia major (TM) and sickle cell disease (SCD) in Spain have been counted since the creation of the Spanish registry of haemoglobinopathies (REHem). The objective of this paper is to update the published data after the increase in cases due to the inclusion of adults and introduction of new-born screening in almost the whole country.

MATERIAL AND METHODS

An observational, descriptive, multicentre and ambispective study that included patients with haemoglobinopathies registered in the REHem, started in January 2014 and followed up annually. The data presented correspond until December 31, 2017.

RESULTS

Nine hundred and fifty-nine patients were collected. There were 75 cases of thalassaemia (62 TM), 826 of ECF and 58 of other types of haemoglobinopathies. The main diagnostic reason in the TM cohort was anaemia symptoms (70.6%), with a mean age at diagnosis of .7 years; in the SCD cohort it was neonatal screening (33.1%), with a mean age at diagnosis of 2.7 years; 26 patients with TM (41.9%) and 30 with SCD (3.6%) underwent a transplant. There were 2 deaths (3.2%) with TM and 19 (2.3%) with SCD. Overall survival was 96.7% in the TM and 97.5% in the SCD cases at 15 years.

CONCLUSIONS

Since the previous publication and after the diffusion of new-born screening, the most frequent diagnostic method, to the majority of autonomous regions, and the inclusion of adult patients to the registry, the REHem has increased by more than 240 cases, reaching a total of 959 records.

Curative vs targeted therapy for SCD: does it make more sense to address the root cause than target downstream events?

Sickle cell disease (SCD) places a heavy burden on a global and increasing population predominantly resident in resource-poor and developing countries. Progress continues to be made in preventing childhood mortality, and increasing numbers of chronically ill adults with disease are requiring care for disease sequelae. Curative therapies for SCD are therefore attractive to physicians and investigators focused on SCD. Gene therapies are being developed, and several are now in various stages of early-phase human clinical trials. However, we must also pursue avenues through which we can do the most good for the most people alive today. Such efforts include improving our understanding of disease mechanisms and which disease sequelae most strongly affect survival and interfere with quality of life. The pathways leading to disease sequelae are multiple, complex, and highly interactive. Four drugs have now been approved by the US Food and Drug Administration for SCD; however, each has a distinct mechanism and a measurable but limited effect on the many clinical sequelae of SCD. We therefore need to learn how to approach multi-agent therapy for SCD. The order of addition of each agent to treat a specific patient will need to be guided by response to previous therapy, risk factors identified for specific disease outcomes, and clinical studies to determine more comprehensively how the 4 currently approved drugs might interact and produce (or not) additive effects. Moreover, this will have to be accomplished with defined end points in mind, according to which pose the greatest threats to quality of life as well as survival.

Tricuspid regurgitation velocity and other biomarkers of mortality in children, adolescents and young adults with sickle cell disease in the United States: The PUSH study

In the US, mortality in sickle cell disease (SCD) increases after age 18-20 years. Biomarkers of mortality risk can identify patients who need intensive follow-up and early or novel interventions. We prospectively enrolled 510 SCD patients aged 3-20 years into an observational study in 2006-2010 and followed 497 patients for a median of 88 months (range 1-105). We hypothesized that elevated pulmonary artery systolic pressure as reflected in tricuspid regurgitation velocity (TRV) would be associated with mortality. Estimated survival to 18 years was 99% and to 25 years, 94%. Causes of death were known in seven of 10 patients: stroke in four (hemorrhagic two, infarctive one, unspecified one), multiorgan failure one, parvovirus B19 infection one, sudden death one. Baseline TRV ≥2.7 m/second (>2 SD above the mean in age-matched and gender-matched non-SCD controls) was observed in 20.0% of patients who died vs 4.6% of those who survived (P = .012 by the log rank test for equality of survival). The baseline variable most strongly associated with an elevated TRV was a high hemolytic rate. Additional biomarkers associated with mortality were ferritin ≥2000 μg/L (observed in 60% of patients who died vs 7.8% of survivors, P < .001), forced expiratory volume in 1 minute to forced vital capacity ratio (FEV1/FVC) <0.80 (71.4% of patients who died vs 18.8% of survivors, P < .001), and neutrophil count ≥10x10⁹ /L (30.0% of patients who died vs 7.9% of survivors, P = .018). In SCD children, adolescents and young adults, steady-state elevations of TRV, ferritin and neutrophils and a low FEV1/FVC ratio may be biomarkers associated with increased risk of death.

Spirometry use in Patients with Sickle Cell Disease with and without asthma and acute chest syndrome: A Multicenter Study

A de-identified data repository of electronic medical record (EMR) data, i2b2 (Informatics for Integrating Biology and the Bedside), including 4 geographically diverse academic medical centers, was queried to determine the use of diagnostic spirometry testing in African American children and young adults 5-34 years old with sickle cell disease (SCD) with or without a documented history of asthma and/or acute chest syndrome (ACS). A total of 2,749 patients were identified with SCD, of these 577 had asthma and 409 had ACS. Cross-referencing the CPT code for diagnostic spirometry showed that for patients identified as having SCD, a history or ACS, and a diagnosis of asthma, only 31% across all 4 centers had spirometry. Having an asthma diagnosis was associated with ACS. Among SCD patients with asthma, the proportion with ACS for the four centers was 47%, 75%, 38%, and 36% respectively. The bivariate association between asthma and ACS for each Center was significant for each (p<.001). To summarize, only one third of patients with co-morbid SCD, ACS, and asthma received the spirometry procedure as recommended in evidence-based guidelines, suggesting limited testing for changes in pulmonary function. Future studies to determine barriers and facilitators to implementation of pulmonary testing in SCD are warranted.

Paediatric to adult transition care for patients with sickle cell disease: a global perspective

Sickle cell disease is a life-threatening inherited condition designated as a public health priority by WHO. Increased longevity of patients with sickle cell disease in high-income, middle-income, and low-income countries present unprecedented challenges for all settings; however, a globally standardised solution for patient transition from paediatric to adult sickle cell disease health care is unlikely to address the challenges. We established a task force of experts from a multicountry (the USA, Europe, Middle East, and Africa) consortium. We combined themes from the literature with viewpoints from members of the task force and invited experts to provide a global overview of transition care practice, highlighting barriers to effective transition care and provide baseline recommendations that can be adapted to local needs. We highlighted priorities to consider for any young person with sickle cell disease transitioning from paediatric to adult health care: skills transfer, increasing self-efficacy, coordination, knowledge transfer, linking to adult services, and evaluating readiness (the SICKLE recommendations). These recommendations aim to ensure appropriate benchmarking of transition programming, but multisite prospective studies are needed to address this growing public health need.

Status quo of allogeneic stem cell transplantation for patients with sickle cell disease using matched unrelated donors

This mini review is based on an oral presentation reflecting the current status quo of allogeneic hematopoietic stem cell transplantation (HSCT) for patients with sickle cell disease (SCD) using matched unrelated donors (MUDs) presented at the EBMT Sickle Disease Meeting held in Regensburg, Germany, in May 2019. Although the clinical trial landscape for MUD HSCT in patients with SCD is limited to date, some attempts to improve patient outcome in terms of overall survival and event-free survival have been made recently, including optimization of conditioning regimens and prevention of engraftment failure as well as graft-versus-host disease. The results achieved by these approaches are summarized in this review and are still unsatisfactory. Whether new haploidentical transplantation protocols will achieve superior results and are able to replace MUD HSCT for patients with SCD remains to be elucidated.

Fatores de risco para mortalidade em pacientes com doença falciforme: uma revisão integrativa

RESUMO Objetivo Sumarizar fatores de risco e indicadores de mortalidade em pacientes com doença falciforme. Método Revisão integrativa em periódicos indexados nas bases de dados CINAHL, PubMed/MEDLINE, Science Direct/SCOPUS, SciELO e Web of Science. A questão norteadora foi elaborada por meio da estratégia Population, variable, outcome (PVO). A busca ocorreu no portal de periódicos da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior entre outubro e novembro de 2018. Resultados Dos 19 artigos, 18 eram coorte e um ensaio clínico randomizado. A amostra foi constituída, em sua maioria, pelo sexo feminino e genótipo HbSS. Se repetiram mais a taxa de mortalidade cumulativa e a curva de mortalidade global. Sete estudos identificaram fatores de risco com associação estatisticamente significativa para morte. Os mais frequentes foram o baixo nível de hemoglobina, variáveis hepáticas (enzimas fosfatase alcalina e transaminase glutâmico oxalacética) e cardiovasculares (velocidade de regurgitação da válvula tricúspide ≥ 2,5m/s). Conclusão e implicações para a prática Indicadores de mortalidade constituem ferramentas de manejo de pacientes com doença falciforme e prevenção de riscos e complicações. Há necessidade de estudos sobre os fatores relacionados à mortalidade desses pacientes. A prevenção do óbito, certamente, promoverá uma melhoria na qualidade de vida e na sobrevida dessa população.

Life-Threatening Infectious Complications in Sickle Cell Disease: A Concise Narrative Review

Sickle cell disease (SCD) results in chronic hemolytic anemia, recurrent vascular occlusion, insidious vital organ deterioration, early mortality, and diminished quality of life. Life-threatening acute physiologic crises may occur on a background of progressive diminishing vital organ function. Sickle hemoglobin polymerizes in the deoxygenated state, resulting in erythrocyte membrane deformation, vascular occlusion, and hemolysis. Vascular occlusion and increased blood viscosity results in functional asplenia and immune deficiency in early childhood, resulting in life-long increased susceptibility to serious bacterial infections. Infection remains a main cause of overall mortality in patients with SCD in low- and middle-income countries due to increased exposure to pathogens, increased co-morbidities such as malnutrition, lower vaccination rates, and diminished access to definitive care, including antibiotics and blood. Thus, the greatest gains in preventing infection-associated mortality can be achieved by addressing these factors for SCD patients in austere environments. In contrast, in high-income countries, perinatal diagnosis of SCD, antimicrobial prophylaxis, vaccination, aggressive use of antibiotics for febrile episodes, and the availability of contemporary critical care resources have resulted in a significant reduction in deaths from infection; however, chronic organ injury is problematic. All clinicians, regardless of their discipline, who assume the care of SCD patients must understand the importance of infectious disease as a contributor to death and disability. In this concise narrative review, we summarize the data that describes the importance of infectious diseases as a contributor to death and disability in SCD and discuss pathophysiology, prevalent organisms, prevention, management of acute episodes of critical illness, and ongoing care.

Immunization Adherence in Children With Sickle Cell Disease: A Single-Institution Experience

OBJECTIVES

The Advisory Committee on Immunization Practices (ACIP) recommends additional immunizations for people with asplenia or functional asplenia, such as children with sickle cell disease. Adherence rate to the recommended immunization schedule for functional asplenia remains low for children with sickle cell disease. The purpose of this study was to assess the immunization adherence for this population at a single institution in Kentucky and to evaluate the use of the Kentucky Immunization Registry (KYIR) by providers.

METHODS

A single-center retrospective chart review was conducted for 107 children with sickle cell disease ages 2 through 18 years. Immunization histories were obtained from the hospital EMRs, the sickle cell clinic EMR, the KYIR, and by requesting records from primary care physicians. Each patient was documented as either missing or having complete records in the KYIR.

RESULTS

The complete adherence rate to the ACIP-recommended immunization schedule for children with functional asplenia was 6% (6 of 107). Nearly all children were compliant with the Haemophilus influenzae type B vaccination, whereas the adherence rate for the meningococcal and pneumococcal vaccines ranged from 25% to 77%. The lowest immunization rate was observed in children eligible for the meningococcal B vaccine (25%). Only 3 patients had a complete immunization history documented in the KYIR.

CONCLUSIONS

Adherence to the ACIP-recommended immunization schedule for functionally asplenic patients is poor among children with sickle cell disease included in this study. Quality improvement measures should focus on increasing immunization adherence and improving documentation of immunization records in the KYIR for this patient population.

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.

Effect of donor type and conditioning regimen intensity on allogeneic transplantation outcomes in patients with sickle cell disease: a retrospective multicentre, cohort study

BACKGROUND

Donors other than matched siblings and low-intensity conditioning regimens are increasingly used in haematopoietic stem cell transplantation. We aimed to compare the relative risk of donor type and conditioning regimen intensity on the transplantation outcomes of in patients with sickle cell disease.

METHODS

For this retrospective cohort study, we collected data from 90 US centres reported to the Center for International Blood and Marrow Transplant Research. Eligible patients were younger than 50 years, had genetically confirmed sickle cell disease (Hb SS) or sickle beta thalassemia (Hb Sβ), and underwent allogeneic haematopoietic cell transplantation between Jan 15, 2008, and Dec 28, 2017. We considered transplants from donor-recipient pairs matched at the allele-level (HLA-A, HLA-B, HLA-C, and HLA-DRB1), including HLA-matched sibling donors, haploidentical related donors, matched unrelated donors, or mismatched unrelated donors. The main outcome was event-free survival. The effect of donor type, conditioning regimen intensity (myeloablative, non-myeloablative, and reduced-intensity regimens), age (≤12 or 13-49 years), sex, performance score, comorbidity index, recipient cytomegalovirus serostatus, graft type (bone marrow, peripheral blood, or umbilical cord blood), and transplantation period (2008-12 and 2013-17) on outcomes was studied using Cox regression models.

FINDINGS

Of 996 patients with sickle cell disease and who underwent transplantation in 2008-17, 910 (91%) were included (558 [61%] patients had HLA-matched sibling donors, 137 [15%] haploidentical related donors, 111 [12%] matched unrelated donors, and 104 [11%] mismatched unrelated donors). The median follow-up was 36 months (IQR 18-60) after transplantation from HLA-matched siblings, 25 months (12-48) after transplantation from haploidentical related donors, 37 months (23-60) after transplantation from HLA-matched unrelated donors, and 47 months (24-72) after transplantation from mismatched unrelated donors. Event-free survival was worse in recipients aged 13 years or older than in those younger than 13 years (hazard ratio 1·74, 95% CI 1·24-2·45; p=0·0014) and in those who received a transplant from haploidentical related donors (5·30, 3·17-8·86; p<0·0001), matched unrelated donors (3·71, 2·39-5·75; p<0·0001), and mismatched unrelated donors (4·34, 2·58-7·32; p<0·0001) than in patients who received a transplant from matched siblings. There was no significant difference in event-free survival between recipients of transplants from non-sibling donors: haploidentical related donors (1·43, 0·81-2·50; p=0·21) or mismatched unrelated donors (1·17, 0·67-2·05; p=0·58) versus HLA-matched unrelated donors, or mismatched unrelated donors versus haploidentical related donors (1·22, 0·65-2·27; p=0·98). Event-free survival was also worse in patients conditioned with reduced-intensity regimens (1·97, 1·15-3·36; p=0·013) than in those conditioned with non-myeloablative regimens, but did not differ between those who received myeloablative compared with non-myeloablative regimens (1·57, 0·95-2·61; p=0·079). Interpretation Our data suggest that event-free survival is improved in patients with sickle cell disease who receive an allogenic transplantation at age 12 years or younger and those with an HLA-matched sibling donor. For patients without a matched sibling available for transplantation, our data do not favour one alternative donor type over another in this setting.

FUNDING

National Institutes of Health and US Health Services Research Administration, Department of Health and Human Services.

Acute Care Utilization at End of Life in Sickle Cell Disease: Highlighting the Need for a Palliative Approach

Background: People with sickle cell disease (SCD) have a life expectancy of <50 years, so understanding their end-of-life care is critical. Objective: We aimed to determine where individuals with SCD were dying and their patterns of care in the year preceding death to highlight end-of-life research priorities and possible opportunities for intervention. Design: Using the California SCD Data Collection Program database (containing administrative data, vital records, and Medicaid claims), we examined people with SCD who died between 2006 and 2015 (cases) at age <80 years and examined their hospital and emergency department (ED) utilization in their last year of life. Comparators included living controls with SCD matched 1:1 based on age, analysis year, insurance, and income. Results: We identified 486 people with SCD (cases) who died at a median age of 45 years (SD: 16 years). Most died in the hospital (63%) and ED (15%). In their last year of life, people with SCD were hospitalized for an average of 42 days (SD: 49 days) over five admissions. Inpatient admissions and ED visits were stable throughout the year until the month before death when acute care utilization sharply increased. In their last year of life, cases had more hospitalizations than controls, but similar ED utilization. Conclusions: People with SCD are dying acutely at a young age and most die in the hospital and the ED. Since clinicians caring for people with SCD currently cannot predict which acute events may be life-threatening, a comprehensive palliative approach to people with SCD must extend beyond chronic pain management and psychosocial support to include advance care planning.

Long-term event-free survival, chimerism and fertility outcomes in 234 patients with sickle-cell anemia younger than 30 years after myeloablative conditioning and matched-sibling transplantation in France

Allogeneic stem cell transplantation remains the only curative treatment for sickle cell anemia (SCA), but the place of myeloablative conditioning in the procedure remains to be defined. The aim of the present study was to analyze long-term outcomes, including chimerism, SCA-related events and biological data (hemoglobin, reticulocytes, HbS%), and fertility in a French series of 234 SCA patients under 30 years of age who, from 1988 to 2012, received a matched-sibling-donor stem cell transplantation following standardized myeloablative conditioning [busulfan, cyclophosphamide and rabbit antithymocyte globulin (ATG)]. Since the first report of the series (1988-2004), 151 new consecutive patients with SCA have been similarly transplanted. Considering death, non-engraftment or rejection (donor cells <5%) as events, the 5-year event-free survival was 97.9% (95% confidence interval: 95.5-100%), confirming, since the year 2000, an at least 95% chance of cure. In the overall cohort (n=234, median follow up 7.9 years), event-free survival was not associated with age, but chronic-graft-versus-host disease (cGvHD) was independently associated with recipient’s age >15 years (hazard ratio=4.37; P=0.002) and lower (5-15 vs. 20 mg/kg) ATG dose (hazard ratio=4.55; P=0.001). At one year, 44% of patients had mixed chimerism (5-95% donor cells), but those prepared with ATG had no graft rejection. No events related to SCA occurred in patients with mixed chimerism, even those with 15-20% donor cells, but hemolytic anemia stigmata were observed with donor cells <50%. Myeloablative transplantation with matched-sibling donor currently has a higher event-free survival (98%) in patients under 30 years of age than that reported for non-myeloablative conditioning (88%). Nevertheless, the risk of cGvHD in older patients and the need to preserve fertility might be indications for a non-myeloablative conditioning.

Parent and Guardian Knowledge of Hematopoietic Cell Transplantation as a Treatment Option for Sickle Cell Disease

Beginning early in childhood, patients with sickle cell disease (SCD) are at risk of life-threatening and debilitating health events. Despite the high morbidity and mortality of this disease, hematopoietic cell transplantation (HCT), a curative treatment for SCD, remains underutilized. In the literature there is a paucity of data concerning medical decision maker (MDM) awareness of HCT as a treatment option for SCD. The objective of this study was to estimate the proportion of parents/guardians of children with SCD who are aware of HCT as a treatment option, and to identify the demographic factors associated with knowledge of this therapy's curative potential. Between November 2015 and December 2016, 327 parents/guardians were surveyed across 4 clinical sites in 3 Midwestern US cities. Although 82% of parents/guardians had heard of HCT in the past and 78% were aware of the therapy's curative potential, nearly half indicated that they did not know whether HCT could specifically cure their child of the disease. Respondents who had discussed HCT with their child's physician had 5 times higher odds of being aware of HCT's curative potential than those who had not. These findings suggest that additional efforts to enhance MDM knowledge of HCT as well as shared decision making in the use of this therapy, is warranted.