Sustained increase in annual transcranial Doppler screening rates in children with sickle cell disease: A quality improvement project.

INTRODUCTION: Individuals with sickle cell disease (SCD) at increased risk for stroke should undergo annual stroke risk assessment using transcranial Doppler (TCD) screening between the ages of 2 and 16. Though this screening can significantly reduce morbidity associated with SCD, screening rates at Boston Children's Hospital (and nationwide) remain below the recommended 100% screening adherence rates. METHODS: Three plan-do-study-act (PDSA) cycles were designed and implemented. The Specific, Measurable, Achievable, Relevant, and Time-Bound (SMART) aim of our quality improvement (QI) initiative was to sustainably increase the proportion of eligible patients receiving a TCD within 15 months of their last TCD to greater than 95%. An interrupted time series (ITS) analysis was performed, comparing TCD adherence rates from PDSA Cycle 1 to those from PDSA Cycles 2 and 3. RESULTS: Mean TCD adherence increased across all three PDSA cycles, from a baseline of 67% in the first cycle (January 2015 to September 2020) to 92% in the third cycle (May 2021 to March 2023). In the ITS analysis of TCD adherence rates, there was a significant difference in the final TCD adherence rate achieved compared to the rate predicted, with a total estimated increase in adherence of 17.9% being attributable to the interventions from PDSA Cycles 2 and 3. DISCUSSION: Although other QI initiatives had demonstrated ability to increase adherence to TCD screening for patients with SCD, this is the first QI project to collect data over such a prolonged period of time to demonstrate a sustained increase in screening rates throughout the intervention (an 8-year period).

The Risk of Kidney Injury in Patients With Sickle Cell Disease Treated With Ketorolac for Acute Pain.

Ketorolac, a nonsteroidal anti-inflammatory drug, is used in combination with opioids to manage vaso-occlusive episodes (VOEs). The relationship between ketorolac use and kidney injury in pediatric patients with sickle cell disease (SCD) remains incompletely understood. We hypothesize that ketorolac is associated with acute kidney injury (AKI) in patients with SCD presenting with pain. All nonsurgical hospitalizations for VOEs treated with ketorolac between January 2014 and December 2022 were included. We used optimal matching methodology to identify control admissions (2:1 ratio) and used nonparametric tests to compare ketorolac administration between cases and controls. A total of 1319 encounters/253 patients were included in this study. AKI was noted in 1.1% of encounters and 5.5% of patients. Cases had significantly higher initial BUN than controls (9.0 vs. 6.0 mg/dL, P =0.012). In cases versus controls, there was significantly lower serum sodium (136.0 vs. 138.0 mmol/L, P =0.021). There was no association between ketorolac dose and development of AKI among children with SCD. Higher BUN and lower sodium in cases suggest that patients with AKI were more volume depleted on admission than controls. This highlights the need for strict assessment of fluid status upon admission for VOE.

Increasing COVID-19 Vaccination Rates for Children With Sickle Cell Disease.

BACKGROUND: The COVID-19 vaccine is important for children with sickle cell disease (SCD). This quality improvement project's objective was to increase the proportion of children with SCD receiving ≥2 COVID-19 vaccine doses to ≥70% by June 2022. METHODS: We used the Model for Improvement framework. We assessed COVID-19 vaccination rates biweekly. Three plan-do-study-act cycles focusing on patient education, provider awareness, and access were performed. Process measures included the outcome of outreach calls and educational video views. Missed clinic appointments was our balancing measure. Line graphs and statistical process control charts were used to track changes. Interrupted time series was used to model implementation rates while accounting for preexisting trends. RESULTS: A total of 243 patients were included. During the preintervention (September 2021-January 2022) and intervention periods (February 2022-June 2022), overall vaccination rates increased from 33% to 41% and 41% to 64%, respectively. Mean vaccination rate in eligible children in each 2-week period increased from 2.1% to 7.2%. The achieved vaccination rate was 11% greater than predicted for patients with SCD. For the general population the achieved vaccination rate was 23% lower than predicted. The proportion of missed visits did not change (9.0% vs. 9.6%). During outreach calls, 10 patients (13.5%) booked a vaccine. Forty percent of patients watched the promotional video. CONCLUSIONS: A significant number of patients with SCD are not vaccinated against COVID-19. Targeting misinformation and improving vaccine access aided in increasing vaccination. Additional interventions are needed as a large number of patients remain unvaccinated.

Ketamine use for management of vaso-occlusive pain in pediatric sickle cell disease.

BACKGROUND: Typical sickle cell disease (SCD) vaso-occlusive pain episode (VOE) management includes opioids, which are often inadequate and can be associated with significant side effects. Ketamine, a dissociative anesthetic, is a potentially effective adjunct to VOE management. OBJECTIVES: This study aimed to characterize ketamine use for VOE management in pediatric SCD. METHOD: This retrospective case series summarizes a single-center experience regarding the use of ketamine for inpatient management of pediatric VOE in 156 admissions from 2014 to 2020. RESULTS: Continuous low-dose ketamine infusion was most commonly prescribed to adolescents and young adults as an adjunct to opioids (median starting dose 2.0 µg/kg/min; median maximum dose 3.0 µg/kg/min). Ketamine was started a median of 13.7 hours after admission. Median ketamine infusion duration was 3 days. In most encounters, ketamine infusion was discontinued prior to opioid patient-controlled analgesia (PCA) discontinuation. The majority of encounters (79.3%) had a reduction in either PCA dose, continuous opioid infusion, or both while receiving ketamine. Low-dose ketamine infusion was associated with side effects noted in 21.8% (n = 34) of encounters. The most common side effects included dizziness (5.6%), hallucinations (5.1%), dissociation (2.6%), and sedation (1.9%). There were no reports of ketamine withdrawal. Most patients who received ketamine went on to receive it again during a subsequent admission. CONCLUSION: Further study is needed to determine the optimal timing of ketamine initiation and dosing. The variability of ketamine administration highlights the need for standardized protocols for ketamine use in VOE management.

Patient Controlled Analgesia for Vaso-Occlusive Episodes in Children: A Retrospective Study.

OBJECTIVE: To describe Patient-Controlled Analgesia (PCA) administration in pediatric patients admitted with sickle cell vaso-occlusive episode (VOE). METHODS: This single-center retrospective study included all inpatient hematology admissions for VOE between 2014 and 2020. PCA-ratio was calculated as the ratio of bolus over continuous IV opioids dose, and time to PCA adjustment as time between first PCA order and a subsequent order that increased dosing or changed opioid medication. RESULTS: A total of 866 encounters (172 unique patients) with PCA for VOE were included. The mean age was 15.4 years old (SD = 5.0). On average, after admission (hospital arrival), the first opioid dose was given at 1 hour, PCA started at 3.5 hours, and mean length of stay was 4.3 days (SD = 2.5). The mean initial PCA-ratio was 1.7 (SD = 0.6). There were no significant associations between age, gender, initial pain score, or admission hemoglobin and PCA-ratio (linear regression model P = 0.443). In 24.7% of encounters, the PCA was adjusted within 6 hours. After adjusting by age and gender, lower admission pain scores (OR = 1.15, P = 0.004), lower PCA-ratio (OR = 2.1, P = 0.003), longer time to PCA start (OR = 1.2, P = 0.001), and no adjuvant ketamine (OR = 2.4, P < 0.001) were associated with PCA unadjusted within 6 hours. CONCLUSION: At our institution, patients with VOE received opioids and PCA within the first hours of admission. PCAs were started at a ratio of 1.5-1.8, considered normal continuous. While no specific PCA-ratio was clearly superior for pain control, lower ratios (high continuous infusion) were associated with not requiring PCA adjustments at 6 hours. Prospective studies are needed.

Consensus definition of essential, optimal, and suggested components of a pediatric sickle cell disease center.

Sickle cell disease (SCD) requires coordinated, specialized medical care for optimal outcomes. There are no United States (US) guidelines that define a pediatric comprehensive SCD program. We report a modified Delphi consensus-seeking process to determine essential, optimal, and suggested elements of a comprehensive pediatric SCD center. Nineteen pediatric SCD specialists participated from the US. Consensus was predefined as 2/3 agreement on each element's categorization. Twenty-six elements were considered essential (required for guideline-based SCD care), 10 were optimal (recommended but not required), and five were suggested. This work lays the foundation for a formal recognition process of pediatric comprehensive SCD centers.

Ticagrelor vs placebo for the reduction of vaso-occlusive crises in pediatric sickle cell disease: the HESTIA3 study.

The phase 3 HESTIA3 study assessed the efficacy and safety of the reversible P2Y12 inhibitor ticagrelor vs placebo in preventing vaso-occlusive crises in pediatric patients with sickle cell disease (SCD). Patients aged 2 to 17 years were randomly assigned 1:1 to receive weight-based doses of ticagrelor or matching placebo. The primary end point was the rate of vaso-occlusive crises, a composite of painful crises and/or acute chest syndrome (ACS). Key secondary end points included number and duration of painful crises, number of ACS events, and number of vaso-occlusive crises requiring hospitalization or emergency department visits. Exploratory end points included the effect of ticagrelor on platelet activation. In total, 193 patients (ticagrelor, n = 101; placebo, n = 92) underwent randomization at 53 sites across 16 countries. The study was terminated 4 months before planned completion for lack of efficacy. Median ticagrelor exposure duration was 296.5 days. The primary end point was not met: estimated yearly incidence of vaso-occlusive crises was 2.74 in the ticagrelor group and 2.60 in the placebo group (rate ratio, 1.06; 95% confidence interval, 0.75-1.50; P = .7597). There was no evidence of efficacy for ticagrelor vs placebo across secondary end points. Median platelet inhibition with ticagrelor at 6 months was 34.9% predose and 55.7% at 2 hours' postdose. Nine patients (9%) in the ticagrelor group and eight patients (9%) in the placebo group had at least one bleeding event. In conclusion, no reduction of vaso-occlusive crises was seen with ticagrelor vs placebo in these pediatric patients with SCD. This trial was registered at www.clinicaltrials.gov as #NCT03615924.

High-Throughput Assay to Screen Small Molecules for Their Ability to Prevent Sickling of Red Blood Cells.

Sickle cell disease (SCD) is an inherited disorder of hemoglobin (Hb); approximately 300,000 babies are born worldwide with SCD each year. In SCD, fibers of polymerized sickle Hb (HbS) form in red blood cells (RBCs), which cause RBCs to develop their characteristic "sickled" shape, resulting in hemolytic anemia and numerous vascular complications including vaso-occlusive crises. The development of novel antisickling compounds will provide new therapeutic options for patients with SCD. We developed a high-throughput "sickling assay" that is based on an automated high-content imaging system to quantify the effects of hypoxia on the shape and size of RBCs from HbSS SCD patients (SS RBCs). We used this assay to screen thousands of compounds for their ability to inhibit sickling. In the assay, voxelotor (an FDA-approved medication used to treat SCD) prevented sickling with a z'-factor > 0.4, suggesting that the assay is capable of identifying compounds that inhibit sickling. We screened the Broad Repurposing Library of 5393 compounds for their ability to prevent sickling in 4% oxygen/96% nitrogen. We identified two compounds, SNS-314 mesylate and voxelotor itself, that successfully prevented sickling. SNS-314 mesylate prevented sickling in the absence of oxygen, while voxelotor did not, suggesting that SNS-314 mesylate acts by a mechanism that is different from that of voxelotor. The sickling assay described in this study will permit the identification of additional, novel antisickling compounds, which will potentially expand the therapeutic options for SCD.

Standardizing Opioid Prescribing in a Pediatric Hospital: A Quality Improvement Effort.

BACKGROUND: Opioids are indicated for moderate-to-severe pain caused by trauma, ischemia, surgery, cancer and sickle cell disease, and vaso-occlusive episodes (SCD-VOC). There is only limited evidence regarding the appropriate number of doses to prescribe for specific indications. Therefore, we developed and implemented an opioid prescribing algorithm with dosing guidelines for specific procedures and conditions. We aimed to reach and sustain 90% compliance within 1 year of implementation. METHODS: We conducted this quality improvement effort at a pediatric academic quaternary care institution. In 2018, a multidisciplinary team identified the need for a standard approach to opioid prescribing. The algorithm guides prescribers to evaluate the medical history, physical examination, red flags, pain type, and to initiate opioid-sparing interventions before prescribing opioids. Opioid prescriptions written between January 2015 and September 2020 were included. Examples from 2 hospital departments will be highlighted. Control charts for compliance with guidelines and variability in the doses prescribed are presented for selected procedures and conditions. RESULTS: Over 5 years, 83 037 opioid prescriptions in 53 804 unique patients were entered electronically. The encounters with ≥1 opioid prescription decreased from 48% to 25% between 2015 and 2019. Compliance with the specific guidelines increased to ∼85% for periacetabular osteotomies and SCD-VOC and close to 100% for anterior-cruciate ligament surgery. In all 3 procedures and conditions, variability in the number of doses prescribed decreased significantly. CONCLUSION: We developed an algorithm, guidelines, and a process for improvement. The number of opioid prescriptions and variability in opioid prescribing decreased. Future evaluation of specific initiatives within departments is needed.

Prevalence and Predictors of Iron Deficiency in Adolescent and Young Adult Outpatients: Implications for Screening.

Current screening guidelines may not be adequate to identify iron deficiency (ID) and iron deficiency anemia (IDA) in adolescent and young adults. Adolescent and young adult outpatients from 4 hospital-based clinics (N = 493) reported on diet, health, and bleeding, and had phlebotomy for iron and hematologic tests. We examined sex-specific factors associated with ID and IDA and ability of universal and risk factor-based screening using hemoglobin and hemoglobin plus ferritin to detect ID and IDA. Among females (n = 350), 34.6% had ID and 6.3% had IDA. Nearly 1 in 3 females with ID had no risk factors. Among males, 12.6% had ID; none had IDA. More than 1 in 3 males with ID did not have risk factors. Current screening approaches would have missed ID in 47% to 82% of females and 95% to 100% of males. ID was prevalent in both male and female adolescents and young adult outpatients. New approaches to screening for ID are needed to accurately evaluate iron status in this population.

Belzutifan, a Potent HIF2α Inhibitor, in the Pacak-Zhuang Syndrome.

The integration of genomic testing into clinical care enables the use of individualized approaches to the management of rare diseases. We describe the use of belzutifan, a potent and selective small-molecule inhibitor of the protein hypoxia-inducible factor 2α (HIF2α), in a patient with polycythemia and multiple paragangliomas (the Pacak-Zhuang syndrome). The syndrome was caused in this patient by somatic mosaicism for an activating mutation in EPAS1. Treatment with belzutifan led to a rapid and sustained tumor response along with resolution of hypertension, headaches, and long-standing polycythemia. This case shows the application of a targeted therapy for the treatment of a patient with a rare tumor-predisposition syndrome. (Funded by the Morin Family Fund for Pediatric Cancer and Alex's Lemonade Stand Foundation.).

SLC25A38 congenital sideroblastic anemia: Phenotypes and genotypes of 31 individuals from 24 families, including 11 novel mutations, and a review of the literature.

The congenital sideroblastic anemias (CSAs) are a heterogeneous group of inherited disorders of erythropoiesis characterized by pathologic deposits of iron in the mitochondria of developing erythroblasts. Mutations in the mitochondrial glycine carrier SLC25A38 cause the most common recessive form of CSA. Nonetheless, the disease is still rare, there being fewer than 70 reported families. Here we describe the clinical phenotype and genotypes of 31 individuals from 24 families, including 11 novel mutations. We also review the spectrum of reported mutations and genotypes associated with the disease, describe the unique localization of missense mutations in transmembrane domains and account for the presence of several alleles in different populations.

A systematic review of ketamine for the management of vaso-occlusive pain in sickle cell disease.

Vaso-occlusive episodes (VOEs) are a common complication of sickle cell disease (SCD) and a significant cause of morbidity. Managing VOE pain can be difficult and complex. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been used to manage VOE pain. This systematic literature review synthesizes research published from 2010 to 2020 on the use of ketamine infusion to decrease VOE pain. The review demonstrates that ketamine, a safe and effective treatment for VOE pain, could be considered more widely. However, the significant variability among published clinical studies with regard to dosing, timing of initiation, duration of infusion, and timing of discontinuation highlights the need for standardized ketamine infusion protocols for the management of VOE pain. We conclude with a brief discussion of key components of a potential standardized protocol supported by the literature reviewed as well as areas for future investigation.

Post-Transcriptional Genetic Silencing of BCL11A to Treat Sickle Cell Disease.

BACKGROUND: Sickle cell disease is characterized by hemolytic anemia, pain, and progressive organ damage. A high level of erythrocyte fetal hemoglobin (HbF) comprising α- and γ-globins may ameliorate these manifestations by mitigating sickle hemoglobin polymerization and erythrocyte sickling. BCL11A is a repressor of γ-globin expression and HbF production in adult erythrocytes. Its down-regulation is a promising therapeutic strategy for induction of HbF. METHODS: We enrolled patients with sickle cell disease in a single-center, open-label pilot study. The investigational therapy involved infusion of autologous CD34+ cells transduced with the BCH-BB694 lentiviral vector, which encodes a short hairpin RNA (shRNA) targeting BCL11A mRNA embedded in a microRNA (shmiR), allowing erythroid lineage-specific knockdown. Patients were assessed for primary end points of engraftment and safety and for hematologic and clinical responses to treatment. RESULTS: As of October 2020, six patients had been followed for at least 6 months after receiving BCH-BB694 gene therapy; median follow-up was 18 months (range, 7 to 29). All patients had engraftment, and adverse events were consistent with effects of the preparative chemotherapy. All the patients who could be fully evaluated achieved robust and stable HbF induction (percentage HbF/(F+S) at most recent follow-up, 20.4 to 41.3%), with HbF broadly distributed in red cells (F-cells 58.9 to 93.6% of untransfused red cells) and HbF per F-cell of 9.0 to 18.6 pg per cell. Clinical manifestations of sickle cell disease were reduced or absent during the follow-up period. CONCLUSIONS: This study validates BCL11A inhibition as an effective target for HbF induction and provides preliminary evidence that shmiR-based gene knockdown offers a favorable risk-benefit profile in sickle cell disease. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT03282656).

Hydroxyurea Optimization through Precision Study (HOPS): study protocol for a randomized, multicenter trial in children with sickle cell anemia.

BACKGROUND: Sickle cell disease (SCD) is a severe and devastating hematological disorder that affects over 100,000 persons in the USA and millions worldwide. Hydroxyurea is the primary disease-modifying therapy for the SCD, with proven benefits to reduce both short-term and long-term complications. Despite the well-described inter-patient variability in pharmacokinetics (PK), pharmacodynamics, and optimal dose, hydroxyurea is traditionally initiated at a weight-based dose with a subsequent conservative dose escalation strategy to avoid myelosuppression. Because the dose escalation process is time consuming and requires frequent laboratory checks, many providers default to a fixed dose, resulting in inadequate hydroxyurea exposure and suboptimal benefits for many patients. Results from a single-center trial of individualized, PK-guided dosing of hydroxyurea for children with SCD suggest that individualized dosing achieves the optimal dose more rapidly and provides superior clinical and laboratory benefits than traditional dosing strategies. However, it is not clear whether these results were due to individualized dosing, the young age that hydroxyurea treatment was initiated in the study, or both. The Hydroxyurea Optimization through Precision Study (HOPS) aims to validate the feasibility and benefits of this PK-guided dosing approach in a multi-center trial. METHODS: HOPS is a randomized, multicenter trial comparing standard vs. PK-guided dosing for children with SCD as they initiate hydroxyurea therapy. Participants (ages 6 months through 21 years), recruited from 11 pediatric sickle cell centers across the USA, are randomized to receive hydroxyurea either using a starting dose of 20 mg/kg/day (Standard Arm) or a PK-guided dose (Alternative Arm). PK data will be collected using a novel sparse microsampling approach requiring only 10 µL of blood collected at 3 time-points over 3 h. A protocol-guided strategy more aggressive protocols is then used to guide dose escalations and reductions in both arms following initiation of hydroxyurea. The primary endpoint is the mean %HbF after 6 months of hydroxyurea. DISCUSSION: HOPS will answer important questions about the clinical feasibility, benefits, and safety of PK-guided dosing of hydroxyurea for children with SCD with potential to change the treatment paradigm from a standard weight-based approach to one that safely and effectively optimize the laboratory and clinical response. TRIAL REGISTRATION: ClinicalTrials.gov NCT03789591 . Registered on 28 December 2018.

Biochemical and therapeutic effects of Omega-3 fatty acids in sickle cell disease.

Sickle cell disease (SCD) is a hematologic disorder with complex pathophysiology that includes chronic hemolysis, vaso-occlusion and inflammation. Increased leukocyte-erythrocyte-endothelial interactions, due to upregulated expression of adhesion molecules and activated endothelium, are thought to play a primary role in initiation and progression of SCD vaso-occlusive crisis and end-organ damage. Several new pathophysiology-based therapeutic options for SCD are being developed, chiefly targeting the inflammatory pathways. Omega-3 fatty acids are polyunsaturated fatty acids that are known to have effects on diverse physiological processes. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the principal biologically active omega-3 fatty acids. The therapeutic effects of DHA and EPA on chronic inflammatory disorders and cardiovascular diseases are well recognized. The therapeutic effects of omega-3 fatty acids are attributed to their anti-inflammatory and anti-thrombotic eicosanoids, and the novel class of EPA and DHA derived lipid mediators: resolvins, protectins and maresins. Blood cell membranes of patients with SCD have abnormal fatty acids composition characterized by high ratio of pro-inflammatory arachidonic acid (AA) to anti-inflammatory DHA and EPA (high omega-6/omega-3 ratio). In addition, experimental and clinical studies provide evidence that treatment with DHA does confer improvement in rheological properties of sickle RBC, inflammation and hemolysis. The clinical studies have shown improvements in VOC rate, markers of inflammation, adhesion, and hemolysis. In toto, the results of studies on the therapeutic effects of omega-3 fatty acids in SCD provide good body of evidence that omega-3 fatty acids could be a safe and effective treatment for SCD.

Mutations in the iron-sulfur cluster biogenesis protein HSCB cause congenital sideroblastic anemia.

The congenital sideroblastic anemias (CSAs) can be caused by primary defects in mitochondrial iron-sulfur (Fe-S) cluster biogenesis. HSCB (heat shock cognate B), which encodes a mitochondrial cochaperone, also known as HSC20 (heat shock cognate protein 20), is the partner of mitochondrial heat shock protein A9 (HSPA9). Together with glutaredoxin 5 (GLRX5), HSCB and HSPA9 facilitate the transfer of nascent 2-iron, 2-sulfur clusters to recipient mitochondrial proteins. Mutations in both HSPA9 and GLRX5 have previously been associated with CSA. Therefore, we hypothesized that mutations in HSCB could also cause CSA. We screened patients with genetically undefined CSA and identified a frameshift mutation and a rare promoter variant in HSCB in a female patient with non-syndromic CSA. We found that HSCB expression was decreased in patient-derived fibroblasts and K562 erythroleukemia cells engineered to have the patient-specific promoter variant. Furthermore, gene knockdown and deletion experiments performed in K562 cells, zebrafish, and mice demonstrate that loss of HSCB results in impaired Fe-S cluster biogenesis, a defect in RBC hemoglobinization, and the development of siderocytes and more broadly perturbs hematopoiesis in vivo. These results further affirm the involvement of Fe-S cluster biogenesis in erythropoiesis and hematopoiesis and define HSCB as a CSA gene.

An emerging role for endothelial barrier support therapy for congenital disorders of glycosylation.

Congenital disorders of glycosylation (CDGs) are clinically heterogeneous disorders defined by a decreased ability to modify biomolecules with oligosaccharides. Critical disruptions in protein recognition, interaction, binding, and anchoring lead to broad physiological effects. Patients present with endocrinopathy, immunodeficiency, hepatopathy, coagulopathy, and neurodevelopmental impairment. Patients may experience mortality/morbidity associated with shock physiology that is frequently culture negative and poorly responsive to standard care. Oedema, pleural and pericardial effusions, ascites, proteinuria, and protein-losing enteropathy are observed with an exaggerated inflammatory response. The negative serum protein steady state results from several mechanisms including reduced hepatic synthesis and secretion, increased consumption, and extravasation. Disruption of the glycocalyx, a layer of glycosylated proteins that lines the endothelium preventing thrombosis and extravasation, is a suspected cause of endothelial dysfunction in CDG patients. We performed a retrospective review of CDG patients admitted to our institution with acute illness over the past 2 years. Longitudinal clinical and laboratory data collected during the sick and well states were assessed for biomarkers of inflammation and efficacy of interventions. Six patients representing 4 CDG subtypes and 14 hospitalisations were identified. Acute D-dimer elevation, proteinuria, decreased serum total protein levels, coagulation proteins, and albumin were observed with acute illness. Infusion of fresh frozen plasma, and in some cases protein C concentrate, was associated with clinical and biomarker improvement. This was notable with intra-patient comparison of treated vs untreated courses. Use of endothelial barrier support therapy may reduce endothelial permeability by restoring both regulatory serum protein homeostasis and supporting the glycocalyx and is likely a critical component of care for this population.

Geographic Differences in Phenotype and Treatment of Children with Sickle Cell Anemia from the Multinational DOVE Study.

BACKGROUND: DOVE (Determining Effects of Platelet Inhibition on Vaso-Occlusive Events) was a Phase 3, randomized, double-blind, placebo-controlled study conducted in children with sickle cell anemia at 51 sites in 13 countries across four continents. PROCEDURE: Data from DOVE were assessed for regional differences in subject phenotype and treatment. Demographics, baseline clinical and laboratory data, hydroxyurea (HU) use, vaso-occlusive crisis (VOCs; composite endpoint of painful crisis or acute chest syndrome (ACS, Beijing, China)), serious adverse events (SAEs, Florence, Italy), hospitalization, and treatments were compared across the Americas, Europe, North Africa/Middle East, and Sub-Saharan Africa (SSA). RESULTS: Race, body mass index, and blood pressures differed by region. Pre-enrollment VOCs were highest in the Americas. For subjects not on HU, baseline hemoglobin was lowest in SSA; reticulocyte count was lowest in the Americas. Within SSA, Kenya subjects presented higher baseline hemolysis. Painful crisis was the most common SAE, followed by ACS in the Americas and infections in other regions. VOC rate and percentage of VOC hospitalizations were highest in Europe. Regardless of region, most VOCs were treated with analgesics; approximately half were treated with intravenous fluids. The proportion of VOC-related transfusions was greatest in Europe. Lengths of hospital stay were similar across regions. CONCLUSIONS: Overall differences in SAEs and hospitalization for VOCs may be due to cultural diversities, resource utilization, disease severity, or a combination of factors. These data are of importance for the planning of future trials in SCA in a multinational setting.