Should Sickle Cell Disease be Among the Risk Factors for Use of Thromboprophylaxis in Adolescents and Young Adults ?

Abstract Introduction: As published by Naik both in single-institution and multi-institution data, adults with sickle cell disease have a baseline hypercoagulable state in addition to traditional risk factors. In pediatrics, venous thromboembolism (VTE) is often overlooked because of the low incidence in children. In addition, there is no unified consensus that supports the use of prophylaxis or screening of the pediatric population at risk. Although the incidence of VTE in the general pediatric population is low, there may be those children, including those with sickle cell disease (SCD), who would benefit from VTE prophylaxis. Objectives: Estimate the contribution of sickle cell disease to rates of VTE in adolescents and young adults, compare rates of prophylaxis in the pediatric units versus the adult units, and determine risk factors associated with VTE occurrence in a hospital serving a large population with sickle cell disease. Methods: This study was a retrospective chart review of patients aged 14-25 admitted to the Pediatric Intensive Care Unit (PICU), to the Pediatric Sickle Cell Service, and to the Medical Intensive Care Unit (MICU) between the dates of April 1, 2014 and April 30, 2015. Anyone older than age 18 admitted to the PICU or Pediatric Sickle Cell Service was considered part of pediatrics. Charts were searched manually for incidence of VTE during hospitalization, risk factors for developing VTE, history of prior VTE, use of therapeutic anticoagulation, and prophylaxis use and type. Data was analyzed using a multivariate regression analysis. Results: In the 13-month period, 251 AYA admissions (108 to the PICU and 143 to the Sickle cell Unit) and 67 MICU admissions were reviewed. 66/67 (99%) MICU patients received either chemical or mechanical prophylaxis against VTE compared to 9/251 (3.5%) children. Event rates of VTE were 3/67 (4.5%) in MICU and 2/251 (0.8%) in the Pediatric units - 1 in the Sickle Cell unit and 1 in the PICU. In the pediatric units, none of the patients receiving prophylaxis had an acute VTE and both patients with VTE were not on prophylaxis. Both adolescents had central lines in place at the time of VTE occurrence. Of the MICU events, one patient had SCD and was taking systemic anticoagulation for previous VTE but had a central line in place. The other MICU patients both had infections, one with Crohns Disease and the other with a central line placed (table 2). The multivariate regression analysis demonstrated that prior history of a VTE and prolonged LOS were positively correlated with increased risk for VTE, both with a confidence interval of 95% and a corrected critical value of 0.003 using the Bonferroni correction (table 1). Conclusion: Of the 5 VTE events in the 318 AYA hospitalizations reviewed, two (40%) were in patients with SCD (ages 17 and 24). As expected, overall VTE incidence in AYA is low in our institution, and appear to be associated with heightened inflammation and central line placement. VTE events in the pediatric unit were in patients not receiving any prophylaxis, which is not surprising when VTE prophylaxis orders were rare on the pediatric units (3.5%). In both our pediatric unit cases, prophylaxis may have prevented the VTE. A consensus protocol to identify high risk children is being implemented and refined with ongoing data collection. The data from our hospital AYA population enriched in SCD reinforces previous data from adult sickle cell populations that the magnitude of VTE risk attributable to SCD can be high. SCD probably should be among the screening criteria when deciding VTE prophylaxis in hospitalized adolescents. Disclosures Hsu: Purdue Pharma: Research Funding; Gerson Lehman Group: Consultancy; Hilton Publishing: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Astra Zeneca: Consultancy, Research Funding; Eli Lilly: Research Funding; Sancilio: Research Funding; Centers for Medicare and Medicaid Innovation: Research Funding; EMMI Solutions: Consultancy; Mast Therapeutics: Research Funding.

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Alkaline Phosphatase Is Associated with Red Cell Alloimmunization in the Pulmonary Hypertension and Hypoxic Response (PUSH) Sickle Cell Disease Cohort

Blood ◽

10.1182/blood-2020-143036 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 20-20

Author(s):

Victoria Brooks ◽

Oluwalonimi Adebowale ◽

Victor R. Gordeuk ◽

Sergei Nekhai ◽

James G. Taylor

Keyword(s):

Risk Factors ◽

Alkaline Phosphatase ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Research Funding ◽

Severe Disease ◽

Case Control ◽

Red Cell ◽

Cell Disease ◽

History Of

Background: Blood transfusion is a common therapy for sickle cell disease (SCD). Although, highly effective, a major limitation is development of alloantibodies to minor blood group antigens on donor red cells. Alloimmunization has a prevalence of 2-5% for transfusions in the general population, but it is significantly higher in SCD. Risk factors for alloimmunization have been poorly characterized, although number of lifetime transfusions is an important risk factor. Alloimmunization has been clinically observed in children with a prevalence of about 7%. With development of each antibody, blood donor matching becomes increasingly difficult and expensive with an increased risk for transfusion reactions and diminished availability of compatible red cell units for treatment of SCD. The ability to identify risk factors for developing alloantibodies would be beneficial for clinicians. To identify markers for alloimmunization in SCD, we have analyzed children and adults who developed this complication. Methods: We analyzed The Pulmonary Hypertension and Hypoxic Response in Sickle Cell Disease (PUSH) study, which enrolled n=468 pediatric and n=59 adult SCD subjects. In both children and adults, alloimmunization cases were defined as a history of at least 1 alloantibody. Controls in both cohorts were defined as subjects with no history of alloantibodies and receipt of more than 10 lifetime red cell transfusions. All others within the study who did not meet these criteria were assigned to a third comparison group. To identify differences between cases, controls and all others, we performed univariate analyses (using ANOVA or Kruskal Wallace where appropriate) for clinical parameters and laboratories. Case control comparisons were also performed for selected variables and plasma levels for 11 cytokines. Results were further analyzed using regression modeling. Results: The overall prevalence of alloimmunization was 7.3% among children (34/468 subjects; median age 12, range 3-20 years) compared to 28.8% in adults (17/59 subjects; median age 37, range 18-73 years). When only considering those with >10 lifetime transfusions, the prevalence was considerably higher at 29.3% and 54.8% in children and adults, respectively. At the same time, 8 pediatric (23.5%) and 5 adult (29.4%) alloimmunization cases had received fewer than 10 transfusions. In a 3-way pediatric cohort comparison (cases, controls and all others), risk factors associated with alloimmunization included SS genotype, older age and markers of more severe disease (higher ferritin, WBCs, platelets and total bilirubin). Comparison of cases to controls showed alkaline phosphatase (P=0.05) was significantly lower in cases, whereas AST (P=0.02) was significantly higher even with adjustment for age. Levels of plasma cytokines MCP-1 (P=0.01) and IFNgamma (P=0.08) were lower in cases from a subset of the pediatric cohort. In adults, only 4/59 (6.8%) subjects had never received a lifetime transfusion (all non-SS). In the adult 3-way comparisons, only SS genotype and higher ferritin were associated with alloimmunization. The adult case control analysis showed higher absolute monocyte count (P=0.02), absolute eosinophil count (P=0.04) and absolute basophil count (P=0.008) in association with alloimmunization cases. In addition, alkaline phosphatase was again significantly lower among cases (P=0.02) as seen in the pediatric cohort. There were no significant differences in cytokine levels among adults. Conclusions: When considering only transfused SCD patients, the prevalence of alloimmunization is higher than 30%. As seen in prior studies, higher lifetime red cell transfusions are an important risk factor especially among adults where most patients have received transfusions. Children who develop alloantibodies appear to have laboratory markers of more severe disease, but this is not observed in adults. A novel association observed across both pediatric and adult subjects is a significantly lower serum alkaline phosphatase in those with alloantibodies. The results of this study suggest a need for improved tracking of red cell transfusion therapy in the US for SCD patients due to a high prevalence of alloimmunization. Further study is also needed to elucidate the significance of the alkaline phosphatase association. Disclosures Gordeuk: CSL Behring: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; Novartis: Consultancy; Ironwood: Research Funding; Imara: Research Funding.

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Risk Factors for Adverse Maternal and Fetal Outcomes in Pregnant Patients with Sickle Cell Disease

Blood ◽

10.1182/blood-2021-151914 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3117-3117

Author(s):

Sherraine Della-Moretta ◽

William Marshall ◽

Rui Li ◽

Erin Cleary ◽

Philip Samuels ◽

...

Keyword(s):

Risk Factors ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Research Funding ◽

Maternal Age ◽

Acute Chest Syndrome ◽

Hypertensive Disorders Of Pregnancy ◽

Cell Disease ◽

History Of ◽

Maternal Bmi

Abstract Background Approximately 100,000 Americans are affected by sickle cell disease (SCD), an inherited hematologic disorder. In women with sickle cell disease, pregnancy is associated with increased maternal and fetal adverse outcomes (Elenga et al). However, there is a paucity of data on risk factors for adverse events in this population. This retrospective study seeks to add to the deficient repertoire of information regarding maternal and fetal outcomes in patients with sickle cell disease and their children. Methods We retrospectively evaluated pregnancy outcomes of women with SCD who had previously undergone echocardiography from the year 2000-2021. The associations between clinical variables and adverse hematologic (AHE), cardiac (ACE), obstetric (AOE) and fetal/neonatal (ANE) events were evaluated by the Generalized Linear Model (GLM). The adverse hematologic events were vaso-occlusive crisis (VOC) antepartum and postpartum, acute chest syndrome, venous thromboembolism antepartum and postpartum, and transfusion antepartum. Results We identified 43 women/59 pregnancies with a median maternal age 27 years old (interquartile range [IQR] 20), pre-pregnancy BMI 25 kg/m2 (IQR 16). Maternal sickle cell genotype was SS in 31 (72%) women/37 (63%) pregnancies, SC in 8 (18%) women/18 (31%) pregnancies, and other genotype in 4 (9%) women/4 (7%) pregnancies. Prior venous thromboembolism was present in 12 (27%) women/15 (25%) pregnancies and prior acute chest syndrome (ACS) in 33 (80%) women/41 (75%) pregnancies. In the year before pregnancy, 24 (56%) women were admitted at least once for VOC. There were no maternal deaths during pregnancy or up to 1 year postpartum. AHE (n = 171) occurred in 43 (73%) pregnancies (Figure A), with a median of 2 (range 0-13) AHE per pregnancy. AHE were more common with genotype SS, history of ACS, history of ³ 10 lifetime transfusions, admission for VOC in the year before pregnancy, tricuspid regurgitation velocity (TRV) >2.5 m/s on echocardiogram, and increased maternal age, and less common with increased hemoglobin (Figure B). ACE were rare (n = 3) (Figure A) and weakly associated with increased maternal age (Figure C). AOE (n = 37) occurred in 27 (45%) pregnancies (Figure A) and were associated with lower pre-pregnancy maternal BMI (Figure D). ANE (n = 54) occurred in 27 (46%) of pregnancies, and were associated with maternal hypertensive disorders of pregnancy (Figure E). Conclusions We found that AHE during pregnancy in women with SCD were associated with genotype SS, history of ACS, ³ 10 lifetime transfusions, admission for VOC in the year before pregnancy, higher maternal age, and inversely related to hemoglobin. In addition, AHE during pregnancy were associated with TRV >2.5 m/s on echocardiogram, which has not been previously shown in women with SCD. These data may be useful to identify women at increased risk during pregnancy. Data show that patients with sickle cell disease who have more disease-related complications including history of acute chest syndrome, frequent pain crisis, elevated TRV on echocardiogram, and lower hemoglobin are at greater risk for AHE. This suggests that disease severity is directly related to outcomes. The association between increased maternal age and ACE has been demonstrated in the past in women without SCD (DeViti et al). The same can be noted for the association of AOE with lower maternal BMI (Verma et al), and ANE being associated with maternal hypertensive disorders of pregnancy (Lugobe et al). In the future, prevention of these complications will be key. Future directions include determining the effect of disease-modifying therapy on these outcomes, though safety during pregnancy has not yet been demonstrated for more novel agents such as voxelotor and crizanlizumab. With more information on these risk factors, we hope that modification and treatment can result in better outcomes. Figure 1 Figure 1. Disclosures Desai: Pfizer: Other: Publication Fee, Research Funding; Foundation for Sickle Cell Research: Honoraria; Forma: Consultancy; Novartis: Research Funding, Speakers Bureau; Global Blood Therapeutics: Honoraria, Research Funding.

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COVID-19 and Sickle Cell Disease in the Province of Quebec: Morbidity and Mortality Rates Derived from the Provincial Registry

Blood ◽

10.1182/blood-2021-151361 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 4064-4064

Author(s):

Mathias Castonguay ◽

Nawar Dakhallah ◽

Marie-Laure Colaiacovo ◽

Camille Jimenez-Cortes ◽

Justin Desroches ◽

...

Keyword(s):

Public Health ◽

Risk Factors ◽

Sickle Cell Disease ◽

General Population ◽

Sickle Cell ◽

Death Rate ◽

Research Funding ◽

Mortality Rates ◽

Cell Disease ◽

History Of

Abstract Introduction Approximately 1500 people live with sickle cell disease (SCD) in the province of Quebec, Canada. Public health has recognized these patients as immunocompromised. SCD patients may be at higher risk of developing severe COVID-19 infection due to their underlying pro-inflammatory and thrombogenic state, splenic dysfunction and secondary organopathies. Descriptions about disease severity and mortality rates in SCD vary widely. From the SECURE-SCD registry, Mucalo et al. recently reported a 0.3% and 4.7% mortality rate in children and adults, respectively. In the French registry, Arlet and colleagues reported a 2.4% death rate among those hospitalized with COVID-19 and SCD, not different from the general population. As a result, the COVID-19 morbidity and mortality rates among the SCD population remain uncertain. Objectives The primary objectives of our study are to describe the epidemiology, baseline characteristics and clinical outcomes of SCD patients with COVID-19 infection in the province of Quebec. In addition, we aim to identify risk factors for hospitalization and severe forms of COVID-19. Methods We built a web-based SCD-COVID-19 registry regrouping 7 adult and 4 paediatric tertiary care hospitals in the province of Quebec in June 2020. All SCD patients with a confirmed SARS-CoV-2 infection by PCR test were included in the study. We compared the prevalence of infection and hospitalization rates of SCD patients to the general population of Quebec using the epidemiological data from the INSPQ (National Institute of Public Health of Quebec) public database. We retrospectively analyzed data included between March 11, 2020 to March 1, 2021. Relative risk was calculated using bilateral association measures (exact fisher, mid-p or chi-squared tests, as appropriate) to compare the incidence of infection and hospitalization of SCD patients to the population of Quebec and to assess risk factors of hospitalization among SCD patients. Results During the first 12 months of the pandemic, 74 patients were included in the registry. The male to female ratio was 1:1.12. Median age was 23 years, ranging from 8 months to 68 years old. SS-Sbeta 0 genotypes were present in 51% of cases, while 49% were SC or Sbeta +. The majority of patients were on disease modifying therapy: 54% were on hydroxyurea and 17.5% on exchange transfusion therapy. The incidence of reported COVID-19 infection was significantly higher in SCD patients compared to the general population (4.9% vs. 3.5% p=0,002) (Table 1). Even more strikingly, SCD had rate of hospitalization 10-times greater than the general population (33.8 vs 3.2%, p<0,001). Nevertheless, the risk of admission to the intensive care unit was similar between SCD patients and the general population (24.0% vs. 24.1%, p=0.99). No death was recorded amongst SCD patients with COVID-19 compared to a death rate in the general population in Quebec of less than 70 years old of 48-78 for 100 000 infections (male-female). A history of acute chest syndrome (ACS) in the last year (OR 2.6 [1.5-4.6], p=0.04) and arterial hypertension (OR 3.3 [2.3-4.8], p=0.01) were associated with a higher risk of hospitalization (Table 2). On the other hand, there was no statistically significant association with age, sex, genotype, ABO blood group, baseline SCD therapy, or other comorbidities (chronic renal disease, obesity, pulmonary hypertension, chronic lung disease and previous admission to ICU) in our cohort. Conclusions Similar to other reports, we found that SCD patients were at much greater risk of hospitalization compared to the general population. We however found no increased risk of mortality or disease complication. This contrasts with results from other registries. A history of ACS and hypertension were associated with a higher risk of hospitalization. Whether social determinants of health could explain some of the outcome variability between different countries merit further investigation. Furthermore, we believe that registries are critical to monitor the impact of preventive measures. As vaccination is ongoing, it will be important to consider its impact on hospitalization and death rate among SCD population. Recruitment to the registry is ongoing and updated data will be presented at the meeting. Figure 1 Figure 1. Disclosures Soulieres: BMS: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding. Forté: Novartis: Honoraria; Canadian Hematology Society: Research Funding; Pfizer: Research Funding.

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Clinical and Biomarker Predictors for Avascular Necrosis in Sickle Cell Disease

Blood ◽

10.1182/blood-2021-147829 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3091-3091

Author(s):

Michael Rabaza ◽

Maria Armila Ruiz ◽

Liana Posch ◽

Faiz Ahmed Hussain ◽

Franklin Njoku ◽

...

Keyword(s):

Risk Factors ◽

Sickle Cell Disease ◽

Board Of Directors ◽

Avascular Necrosis ◽

Sickle Cell ◽

Research Funding ◽

Medical Attention ◽

Cell Disease ◽

Advisory Committees ◽

Early Management

Abstract Introduction Sickle cell disease (SCD) affects 1 in 365 African Americans and approximately 25 million people world-wide. A common skeletal system complication is avascular necrosis (AVN), which can cause substantial pain and a reduced quality of life. While early management of AVN is focused on increasing range of motion with physical therapy and pain relief, there are no clear predictors for who is more likely to develop AVN and earlier institution of these preventive measure could help decrease disease progression. Vascular endothelial growth factor (VEGF) is a biomarker of endothelial injury and may indicate reduced vascular supply to the femoral or humeral head. Here we describe potential risk factors and biologic pathways for AVN in SCD, as understanding these may lead to improvements in future monitoring, early detection, and early intervention practices. Methods We investigated clinical and laboratory risk factors associated with AVN in a cohort of 435 SCD patients from our center. Blood samples, clinical, and laboratory data were collected at the time of enrollment during a clinic visit. Genotyping for alpha thalassemia was performed by PCR and the serum concentration of VEGF was measured by ELISA. AVN status was confirmed by review of the medical record and available imaging. We conducted a cross-sectional analysis comparing categorical and linear variables by AVN status using the chi-square and Kruskal-Wallis test, respectively. The independent association of the clinical and laboratory variables with AVN status was determined by logistic regression analysis. The initial model included variables with a P-value < 0.1 on univariate analysis and the final model was ascertained by stepwise forward and backward selection. Median values and interquartile range (IQR) are provided. Results The median age of the cohort was 32 (IQR, 24 - 43) years, 57% (250/435) were female, and 46% (198/435) were on hydroxyurea. AVN was observed in 34% (149/435) of SCD patients. SCD patients with AVN were older, had more frequent vaso-occlusive crises requiring medical attention, and had a higher body mass index (Table I) (P ≤ 0.002). We measured VEGF in 241 of the SCD patients with serum samples available at the time of enrolment. Serum VEGF concentrations trended higher in SCD patients with versus without AVN (420 vs. 359 pg/mL, respectively; P = 0.078). In the multivariate analysis model, AVN was independently associated with increased number of vaso-occlusive crises (OR 1.1, 95% CI: 1.0 - 1.14; P = 0.02), AST concentration (natural log OR 0.5, 95% CI: 0.2 - 0.9; P = 0.03), VEGF concentration (natural log OR 1.4, 95% CI: 1.0 - 1.9; P = 0.047), and tobacco use (OR 1.9, 95% CI: 0.9 - 3.7; P = 0.078). Discussion In conclusion, we demonstrate a high prevalence of AVN in an adult cohort of SCD patients. The presence of AVN was independently associated with a greater frequency of vaso-occlusive pain episodes, which may demonstrate a shared pathophysiology between AVN and vaso-occlusion that merits further investigation. We demonstrate that serum VEGF concentrations are higher in SCD patients with AVN and may be a clinical tool to identify those at high-risk and for earlier intervention for this complication. Figure 1 Figure 1. Disclosures Gordeuk: Modus Therapeutics: Consultancy; Novartis: Research Funding; Incyte: Research Funding; Emmaus: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; CSL Behring: Consultancy. Saraf: Pfizer: Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Modifiable Cardiovascular Risk Factors in Adults with Sickle Cell Disease

Blood ◽

10.1182/blood-2018-99-115595 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1088-1088

Author(s):

Foluso Joy Ogunsile ◽

Kerry Stewart ◽

Hang Wang ◽

Sophie Lanzkron

Keyword(s):

Risk Factors ◽

Body Composition ◽

Sickle Cell Disease ◽

Body Fat ◽

Sickle Cell ◽

Exercise Testing ◽

Research Funding ◽

Knee Extension ◽

Normative Values ◽

Cell Disease

Abstract Introduction: Body composition, cardiorespiratory fitness (CRF) and muscular strength(MusS) are important predictors of cardiovascular (CV) mortality and morbidity. Poor CRF, body composition and MusS are each associated with higher rates of musculoskeletal injury, inflammation, heart disease, and all-cause mortality. Fortunately, these parameters in the general population, are partly influenced by lifestyle habits and can improve with modifying unhealthy behaviors such as increasing activity levels. Few studies have examined fitness parameters, in particularly MusS, in adults with sickle cell disease (SCD). As cardiopulmonary disease is a leading cause of death in SCD, we sought to better characterize fitness and body composition in adults with SCD. The objective of this study is to describe modifiable CV risk factors of fitness along with other risk factors of smoking, hypertension, and cholesterol in a population of adults with SCD. Methods: Forty-six participants (ages 21-66 yrs.; 74% female; sickle cell anemia n =29, sickle variant genotype n=17) were recruited from a comprehensive adult sickle center. Non-pregnant adults in steady-state SCD disease without an absolute contraindications to exercise were eligible to participate. CRF was measured using symptom-limited exercise testing performed on a cycle ergometer following an incremental ramp protocol. Maximal oxygen uptake (VO2 max), a key measure of CRF, was calculated during exercise testing. MusS was assessed using an isokinetic dynamometer, the Biodex system 3, the gold standard to measure MusS in rehabilitative medicine. Peak isokinetic torques of knee extension and flexion were determined at 60 degrees per second, and adjusted for body weight on the Biodex system 3. A medical history, fitness assessments, anthropometric testing, and laboratory testing were completed on all SCD participants. Sixteen SCD participants had dual energy x-ray absorptiometry imaging to assess fat, lean, and bone mass. The remaining 30 SCD patients underwent isokinetic CRF and MusS testing. Lean muscle mass and body fat of participants were compared to US national guidelines, VO2max was compared to predicted norms. As there are no well-established normative values for MusS, we compared values to a cohort of 60 adults without SCD (age 21-40 yrs.; 63% female) who underwent MusS testing as a part of a separate study. For muscle strength, multivariate regression was performed to control for the effects of age, BMI, gender, and SCD status on peak torques. Results: All SCD and control participants were able to complete testing safely without any adverse events. 34.7% of SCD participants (n=16) had a smoking history with a mean pack year history of 9 years (Table 1). 18% of participants (n=10) received medical treatment for hypertension (Table 1). 64% (n=32) of participants had reduced HDL levels and 8% (n=3) had elevated triglycerides. Median (IQR) waist-hip circumference (F=0.89(0.14), M=0.93 (0.11)) and total percent body fat (F=37.7(11.5), M=22.3(11.5)) for SCD participants were higher than national normative values and 66% were classified as obese (Table 1). SCD participants had reduced mean (SD) VO2max, 16.77 (3.29) and 19.56 (7.27) ml/min/kg for females and males respectively compared with norms. In 90% of SCD participants (n=28), percent-predicted VO2max was less than normal (i.e. < 84 percent-predicted) with 4 adults having markedly reduced VO2max with a percent-predicted value less than 50%. Hemoglobin, hydroxyurea use and SCD genotype were not predictive of VO2max. Compared to controls, mean (SD) peak torque values for knee extension (82.7 Nm (19) vs 44.33 Nm (18.85), p<0.0001) and flexion ( 38.6 Nm (9.03)vs 19.19 Nm (13.2), p<0.0001) at 60 degrees were lower in SCD participants even after adjusting for age, sex, and body mass index (BMI) (Table1). Limitations: Study limitations include a small sample size, and the lack of controls matched for race, age, BMI, and hemoglobin. Conclusion: In this pilot study we show that both CRF and MusS are decreased in adults with SCD. Additionally, this cohort had a number of CV risk factors including smoking, hypertension and reduced HDL levels. As we know these are important predictors of poor CV outcomes additional research is needed to determine whether a carefully designed exercise and diet program can improve these modifiable CV risk factors and ultimately health status in adults living with SCD. Disclosures Wang: PCORI: Research Funding. Lanzkron:Pfizer: Consultancy, Research Funding; NHLBI: Research Funding; Ironwood: Research Funding; PCORI: Research Funding; GBT: Consultancy, Research Funding; Selexys: Research Funding; Prolong: Research Funding.

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Use of Thromboprophylaxis for Central Venous Access Devices in Patients with Sickle Cell Disease: A Survey of Canadian Providers

Blood ◽

10.1182/blood-2021-145889 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 4173-4173

Author(s):

Kristine Matusiak ◽

Stephanie Forte ◽

Jameel Abdulrehman ◽

Madeleine Verhovsek ◽

Kevin H.M. Kuo

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Research Funding ◽

Central Venous Access ◽

Venous Access ◽

Cell Disease ◽

Central Venous ◽

Advisory Committees ◽

History Of

Abstract Background: Sickle cell disease (SCD) induces a chronic prothrombotic state, with a cumulative incidence of venous thromboembolism (VTE) reported to be 11% by age 40. Central venous access devices (CVAD) are commonly used for chronic transfusions and iron chelation in this patient population.The presence of a CVAD is an additional risk factor for venous thromboembolism (VTE), with a catheter related thrombosis rate of 24%. Despite this high risk of VTE, the role of thromboprophylaxis in this setting is uncertain due to a lack of high quality data. Methods: A survey was administered in March 2021 to physicians caring for adult sickle cell disease patients via the Canadian Haemoglobinopathy Association (CanHaem), covering nine SCD comprehensive care centers in Canada. One reminder email was distributed after 3 weeks to encourage participation. Questions were directed at characterizing the practice size, number of patients with CVADs, and the role of thromboprophylaxis for CVADs. Physicians were also surveyed about their willingness to enroll their SCD patients with CVADs in a randomized trial of thromboprophylaxis versus placebo. Items were generated and selected based on face and content validity. Results are reported in medians and percentages, where applicable. Results: Responses were collected from 14 physicians who care for a median of 100 (IQR 185) adult sickle cell disease patients in practices across Canada. Physicians reported approximately 5% of their patients currently require a CVAD, and physicians estimated no CVAD patients are lost to follow up. Respondents use a variety of CVADs, including port-a-caths (75%), followed by PICC lines (58%), tunneled (25%) and non-tunneled CVCs (25%) (Figure 1). Duration of venous access was reported to be <1 month (17%), 1-3 months (8%), 3-6 months (0%), 6-12 months (8%), and >12 months (67%). Fifty percent of respondents indicated they do not use thromboprophylaxis for CVADs. Responses varied with respect to choice and dose of antiplatelet or anticoagulant in cases where thromboprophylaxis is used (Figure 2). Forty-two percent of physicians indicated they were not very confident or not at all confident in choice of prophylaxis. Past history of VTE was the most cited factor influencing the choice to use thromboprophylaxis. Physicians were generally in favour of enrolling patients in an RCT using thromboprophylaxis for CVADs. The exception was that 69% answered "No" when asked about enrolling patients with a prior history of VTE who are not currently on anticoagulation. One-hundred percent of physicians agreed that an RCT would improve their confidence in decision-making around thromboprophylaxis in their patients with CVADs. Conclusions: While there is evidence for an increased risk of VTE for SCD patients with CVADs, our results suggest there remains clinical equipoise with respect to the use of thromboprophylaxis. Thromboprophylaxis options were variable when physicians chose to use them, as there is no evidence to support specific antithrombotic regimens. All physicians surveyed are supportive of an RCT to clarify this management approach, and many would enroll their patients. As a result of this survey, a Canadian multicenter pilot RCT addressing this question is currently underway. Figure 1 Figure 1. Disclosures Forte: Pfizer: Research Funding; Canadian Hematology Society: Research Funding; Novartis: Honoraria. Verhovsek: Vertex: Consultancy. Kuo: Alexion: Consultancy, Honoraria; Celgene: Consultancy; Bluebird Bio: Consultancy; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Research Funding; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria; Apellis: Consultancy. OffLabel Disclosure: This survey explored the use of LMWH, direct oral anticoagulants, warfarin and ASA for prophylaxis among patients with sickle cell disease using a central venous access device.

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Increased Prevalence of Asthma Symptoms in Nigerian Children with Sickle Cell Disease Compared to Children without Sickle Cell Disease

Blood ◽

10.1182/blood.v120.21.4760.4760 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4760-4760 ◽

Cited By ~ 1

Author(s):

Najibah Aliyu Galadanci ◽

Wayne Liang ◽

Muktar Aliyu ◽

Binta Wudil Jibir ◽

Ibraheem Karaye ◽

...

Keyword(s):

Risk Factors ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Mode Of Delivery ◽

Cell Disease ◽

Parental History ◽

Nigerian Children ◽

Asthma Symptoms ◽

History Of ◽

Physician Diagnosis

Abstract Abstract 4760 Background: Nigeria has the largest population of children and adults with sickle cell disease (SCD) in the world. Approximately 150,000 children are born with SCD each year (incident cases) in Nigeria, compared to a total of approximately 100,000 children and adults living with SCD in the United States (prevalent cases). Pulmonary complications, including asthma and asthma-like symptoms are leading causes of morbidity and mortality in SCD. However, the natural history, risk factors and biological basis of asthma and SCD-associated asthma-like symptoms in SCD are poorly defined. The primary aim of this study is to determine the prevalence of asthma and asthma-like symptoms among children with and without SCD in Nigeria. In a 1:1 case-control study design, we tested the hypothesis that children with SCD would have a higher rate of asthma-like symptoms when compared to children without SCD. Methods: We enrolled 250 cases with SCD and controls, children without SCD, from patients presenting for routine medical care at the Murtala Mohammed Specialist Hospital (MMSH) in Kano, Nigeria over a 4-month period (12/2011 to 04/2012). A structured questionnaire was employed to capture participants' demographic information, medical history (including history of asthma symptoms and allergies), environmental factors (e.g., cooking, presence of animals in the home) and parental behavior (e.g., smoking). Asthma symptoms were identified based on responses to questions adapted from the American Thoracic Society Division of Lung Disease (ATS-DLD-78) questionnaire. Chi-square test of association was used for categorical variables; Wilcoxon rank-sum tests and Kruskal-Wallis U test were used for continuous and ordinal variables. Results: No differences in sex, ethnicity, or place of residence were noted between cases and controls. The average age for the cases was 5.7 years and for controls was 2.8 years (P<0.01). In both cases and controls, affirmative responses to ATS-DLD questions were unrelated to age. Cases were more likely than controls to report a history of cough that worsens with a cold (28.0% vs. 16.8%, P<0.01), cough without a cold (16.0% vs. 9.6%, P=0.03), chest congestion that worsens with a cold (8.0% vs. 1.2%, P<0.01), wheezing that worsens with a cold (19.6% vs. 6.4%, P<0.01), and wheezing without a cold (5.6% vs. 1.6%, P=0.02). Participants with SCD were more likely to have eczema (4.4% vs. 0.4%, P<0.01). Surprisingly, despite the high prevalence of asthma-like symptoms in cases when compared to controls, the prevalence of physician diagnosis of asthma was low in both groups. Only two children were reported as having asthma among cases, compared to none in the control group. No participant reported a history of wheezing attacks with shortness of breath. No difference between cases and controls existed in the distribution of risk factors for asthma, namely: mode of delivery, gestational age at delivery, parental history of asthma, maternal smoking during pregnancy, and exposure to smoking as a child. No association was observed between respiratory symptoms in either group and age, household income, household size, mode of delivery, gestational age, parental history of asthma, or use of firewood/charcoal. Subgroup analysis was performed on participants 4 years of age and older (163 cases and 96 controls). No substantial differences in the results were noted when compared to the entire cohort of 250 cases and controls (results not shown). Conclusions/Recommendation: Nigerian children with SCD have a much higher prevalence of asthma-like symptoms when compared to controls. Despite asthma symptoms being common, a diagnosis of asthma is rare in both cases and controls, suggesting under-ascertainment of an asthma diagnosis. Future work in low income countries directed towards improving co-morbid respiratory disease in children with SCD should focus on the presence of asthma-like symptoms and not a physician diagnosis of asthma. Better understanding of the biological basis for why children with SCD have a higher rate of asthma-like symptoms and atopy may lead to targeted therapy. Disclosures: No relevant conflicts of interest to declare.

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Immunophenotypes and Clinical Outcomes in Adult Patients with Sickle Cell Disease: Lymphopenia Correlates with End Organ Damage

Blood ◽

10.1182/blood-2020-142634 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 12-13

Author(s):

Stephen Zachary Peeke ◽

Qi Gao ◽

Jaeun Choi ◽

Khadijah Abdallah ◽

Ashley Buscetta ◽

...

Keyword(s):

T Cells ◽

Sickle Cell Disease ◽

Clinical Outcomes ◽

Sickle Cell ◽

Research Funding ◽

Organ Damage ◽

Cell Disease ◽

History Of ◽

Leukocyte Populations ◽

Lymphocyte Populations

Introduction: Sickle cell disease (SCD) is the most prevalent inherited hemoglobinopathy in the United States. While the primary event is polymerization of HbS under deoxygenation in red cells, the contribution of white blood cells and inflammation to SCD pathology has been increasingly recognized. Prior investigations of lymphocytes in SCD revealed varied abnormalities some of which have been shown to be corrected by hydroxyruea (HU) though not uniformly (Nickel 2015, Allali 2019). Alterations in lymphocyte subsets have previously been correlated with survival in elderly populations (Ferguson 1995) and with non-AIDS related mortality in HIV (Helleberg 2014). The aim of this study was to analyze alterations of leukocyte populations in relation to different clinical outcomes in a large set of adult patients with sickle cell disease at steady state. Methods: Patients were consented and data was obtained as part of the INSIGHTS study (NCT02156102). Only patients with HBSS/Sβ0 from whom lymphocyte subset panels had been prospectively collected were included in this analysis. Panels consisted of total CD3+ T cells, CD4+/CD8- (CD4+) and CD8+/CD4- (CD8+) T cells, CD19+ B cells and CD16/56+ NK cells; absolute neutrophil count (ANC), white blood cell count (WBC), CD4/CD8 and ANC/ALC (absolute lymphocyte count) ratios were examined as well. Patients were classified as having cardiovascular events (CVE) if they reported prior stroke, pulmonary embolism, deep vein thrombosis, myocardial infarction, arrhythmia, cardiomyopathy, coronary artery bypass or stent. Ulcer status was defined as history of, or current active cutaneous lower extremity ulcer. Also analyzed were self-reported pulmonary hypertension (pHTN), diabetes mellitus (DM), and a combined End Organ Damage Score (EODS) consisting of one point for each of the following clinical outcomes: CVA, Any Ulcer, pHTN, CAD (MI/CABG/stent), cardiomyopathy, PE/DVT, DM. Multivariate analysis was performed controlling for age, gender and active HU use and Spearman correlation coefficients were calculated using SAS software. Results: 170 patients were included in this analysis, 54.7% female, mean age of 38.7 years, 95.3% HbSS, 64.1% on active HU treatment, and 15.9% chronically transfused. Mean leukocyte counts were within reference ranges except for CD19+ cells (666 c/uL) which were double the upper limit of normal (ULN 321 c/uL) consistent with prior reports. The 40% of patients with a CVE history showed an overall decrease in their lymphocyte populations (CD3+, CD4+, CD8+, CD19+) and WBC compared to those without (Table 1). Patients with a pHTN history (15.3%) had lower total CD3+, CD8+, CD19+, ANC's and WBC's. This resulted, somewhat surprisingly, in a significantly lower ANC/ALC ratio than in those patients without pHTN. No significant correlations with organ damage outcomes were noted for CD4/CD8 ratios or NK cells. Similar to the CVE findings, increased EODS was associated with significantly lower total T lymphocytes, CD4+, CD8+, and CD19+ cells while ANC/ALC ratio was significantly increased (Tables 2 & 3). DM is very rare overall in SCD and was in our adult population (2/170) as well (Morrison 1979). It is notable that these 2 patients had significantly lower overall T and B cells and elevated ANC/ALC ratios. Compared to patients without any history of cutaneous ulcer, those with active ulcers had significantly lower total T cells (CD3+) and CD8+ cells (Table 4) while higher total WBC was seen in patients with a history of but no active ulcer compared to those without an ulcer history. Discussion: Our analysis of a large cohort of adult SCD patients at steady state revealed significant alterations in leukocyte populations in relation to a variety of clinical events. The salient finding was that B and T cell lymphocyte populations were significantly decreased in relation to clinical outcomes such as CVE and pHTN. The potential impact of this finding is highlighted by the adverse survival outcomes associated with lymphopenia seen in studies of general adult populations and in those with other medical problems such as cancer (Zidar 2019, Ray-Coquard 2009). While the interpretation of this study is limited to correlations further follow-up and study of SCD immunophenotypes may reveal important prognostic information that could enhance future care strategies. Disclosures Minniti: Bluebird bio: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; CLS Bering: Consultancy; Roche: Consultancy, Research Funding; TauTona: Consultancy, Research Funding; Emmaus: Consultancy, Research Funding; Novartis: Consultancy, Research Funding.

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Hypoxia Enhanced Red Cell Adhesion in Vitro May Identify Patients at Risk for Vasculopathy

Blood ◽

10.1182/blood-2018-99-120207 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3672-3672

Author(s):

Charlotte Yuan ◽

Erina Quinn ◽

Sargam Kapoor ◽

Myeongseop Kim ◽

Erdem Kucukal ◽

...

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Research Funding ◽

Cell Disease ◽

Hypoxic Conditions ◽

Significant Difference ◽

History Of ◽

Male Subjects

Abstract Background: Priapism is a serious complication associated with Sickle Cell Disease (SCD) that may be a manifestation of underlying vasculopathy. The Centers for the Study of Complex Diseases of Childhood (CSCCD), comprising independent Comprehensive Sickle Cell Centers, demonstrated an association of priapism with hemolysis.1 Previously, we identified two groups of people with SCD based on red blood cell (RBC) adhesion under hypoxic conditions: those patients whose RBCs showed hypoxia-enhanced adhesion (HEA) and those whose did not (non-HEA).2 Patients with HEA had evidence for more hemolysis in vivo. Here, we aimed to examine (1) the association of HEA with hypoxia in vivo, and (2) RBC adhesion in normoxic and hypoxic conditions in male patients with or without a history of priapism. Methods: This retrospective study was conducted at the Adult Sickle Cell Disease Clinic at the University Hospitals Seidman Cancer Center, in Cleveland, OH between 2015 to 2018. Blood samples were obtained from 26 male subjects (29 samples, 25 HbSS and 1 HbSS HPFH). Adhesion experiments were performed as previously reported by passing surplus whole blood through LN-immobilized microchannels at physiological conditions under both normoxic and hypoxic conditions.2,3 Adherent RBCs were then quantified with microscope after a wash step. The median value was used for data analyses from multiple samples obtained from an individual. Chart review was conducted to examine results of hypoxia testing obtained in vivo as part of routine clinical care. Results: Male subjects with HbSS and a history of priapism had higher HEA in comparison to subjects without a history of priapism (3268 ± 5647 vs. 122 ± 1218, p=0.016). However, there was no significant difference between RBC adhesion of the two groups under normoxic conditions (529 ± 1528 vs. 402 ± 280). More male subjects with priapism had hypoxia in vivo (10 out of 14) than subjects without priapism (5 out of 12). Compared to male subjects with a history of priapism, those without a history of priapism had lower lactate dehydrogenase levels (474 ± 267 vs. 290 ± 215, p=0.008). Conclusions: Our data showed that subjects with a history of priapism had a higher HEA and tended to have more evidence for hypoxia in vivo than did subjects without a history of priapism. Further, male subjects with hypoxia in vivo had more HEA than did those without hypoxia in vivo (not shown). Hypoxia in vivo may cause increased RBC damage (reflected by HEA), hemolysis, nitric oxide depletion, and consequent vasculopathy, resulting in priapism. Hypoxia may be treatable, when identified in subjects with a history priapism in vivo or possibly with HEA in vitro. This could plausibly modify disease severity in some cases. References: Nolan VG, Wyszynski DF, Farrer LA, Steinberg MH. Blood. 20015 Nov;106(9):3264-7. doi: 10.1182/blood-2005-04-1594 Kim M, Alapan Y, Adhikari A, Little JA, Gurkan Microcirculation. 2017 Jul;24(5). doi: 10.1111/micc.12374. Alapan Y, Kim C, Adhikari A, Gray KE, Gurkan-Cavusoglu E, Little JA, Gurkan Transl Res. 2016 Jul;173:74-91.e8. doi: 10.1016/j.trsl.2016.03.008. Epub 2016 Mar 19. Disclosures Little: NHLBI: Research Funding; PCORI: Research Funding; Hemex: Patents & Royalties: Patent, no honoraria; Doris Duke Charitable Foundations: Research Funding.

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Implementation of Escort-HU Extension: European Sickle Cell Disease Cohort - Hydroxyurea - Extension Study : Interests and Methodology

Blood ◽

10.1182/blood-2021-152525 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 3098-3098

Author(s):

Mariane de Montalembert ◽

Ersi Voskaridou ◽

Lena Oevermann ◽

Giovanna Cannas ◽

Anoosha Habibi ◽

...

Keyword(s):

Sickle Cell Disease ◽

Board Of Directors ◽

Sickle Cell ◽

Research Funding ◽

Steering Committee ◽

Leg Ulcers ◽

Cell Disease ◽

Advisory Committees ◽

History Of

Abstract The efficacy and long-term effectiveness of hydroxycarbamide/hydroxyurea (HU) in the prevention of painful crises and in the decrease of mortality and morbidity in sickle cell disease (SCD) patients have been established (Charache et al. 1992; Steinberg et al 2010, Voskaridou et al 2010). From January 2009 to March 2019, the non-interventional prospective cohort study ESCORT-HU was conducted to evaluate the use of HU in real-life conditions and to collect information on the long-term safety of HU when used in current practice for the prevention or treatment of symptomatic complications in patients with sickle cell disease (SCD) (Montalembert et al 2021). A total of 1906 patients, 55% of adults, were enrolled in this study in 62 centres (Germany, Greece, Italy and France). The mean exposure to HU in this cohort was 30 months, for a cumulative exposure of 7310 patient-per year. The main objectives of ESCORT-HU have been fulfilled as regards the collection of data on the most common concerns associated with the use of HU in SCD patients: myelosuppression, child growth, concomitant administration of live vaccines, safety in population with renal and hepatic impairment and frequency of SCD events (painful crises, acute chest syndrome, stroke, acute splenic sequestration, infections, blood transfusions and hospitalizations) (Montalembert et al 2021). In order to better identify potential long-term risks and specific concerns of HU therapy, ESCORT-HU extension is being implemented in Europe with the goal of 2500 patients enrolled. Main risks targeted by the study are leg ulcers, one of the most limiting factors to continue a treatment with HU. Patients will be recruited over a 5-year period. In addition to patients already involved in the first ESCORT-HU study, new at-risk patients might be added such as patients with a history of HU exposure of at least 5 years, to allow a follow-up of patients treated with long-term HU to fully estimate the incidence of potential risk of malignancies prepubescent children aged more than 10 years for girls and more than 13 years for boys in order to document impact or not of HU on puberty and realisation of cryopreservation,patients with a history of leg ulcers, to search for discriminating criteria between leg ulcer caused by the disease and HU-induced leg ulcer,pregnant women without interruption of HU 3 months before the beginning of the pregnancy and males treated with HU whose partner is pregnant and without discontinuation of HU 3 months before the beginning of the pregnancy. To date, there is a limited number of pregnancies exposed to HU with documented outcome. Despite no adverse effects on pregnancy or on the health of the foetus/new-born have been registered, an increase of the number of pregnancies with documented outcomes will allow for meaningful assessment of foetal outcome following exposure to HU during pregnancy, 10 months after the beginning of ESCORT-HU extension, 818 patients have been enrolled in 70 investigational sites in 4 countries (Greece, Italy, Germany and France) (see Graph below). A first steering committee was hold in June 2021. Its conclusions were that distribution of patients (genotype, sex, age) was consistent with the first study and the number of events reported until now was coherent with what was expected per year, with no occurrence of major concern. This extension study involves most of competence centres which manage SCD patients. SC patients have become increasingly well cared for in recent decades and have seen their life expectancy increase. HU treatment is now a chronic treatment possibly for life in many patients with SCD, better its knowledge of its efficiency and tolerance, better patient adherence to treatment will be. Figure 1 Figure 1. Disclosures de Montalembert: Addmedica: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bluebird Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Vertex: Consultancy. Voskaridou: ADDMEDICA: Consultancy, Research Funding; BMS: Consultancy, Research Funding; GENESIS: Consultancy, Research Funding; NOVARTIS: Research Funding; PROTAGONIST: Research Funding; IMARA: Research Funding. Oevermann: NOVARTIS: Consultancy; GBT: Consultancy. Joseph: bluebird bio: Consultancy. Colombatti: BlueBirdBio: Membership on an entity's Board of Directors or advisory committees, Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Membership on an entity's Board of Directors or advisory committees. Bartolucci: INNOVHEM: Other: Co-founder; Jazz Pharma: Other: Lecture fees; AGIOS: Consultancy; Addmedica: Consultancy, Other: Lecture fees, Research Funding; Fabre Foundation: Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Lecture fees, Steering committee, Research Funding; Bluebird: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy; GBT: Consultancy; Emmaus: Consultancy; Hemanext: Consultancy. Brousse: BLUEBIRDBIO: Consultancy; ADDMEDICA: Consultancy. Galactéros: Addmedica: Membership on an entity's Board of Directors or advisory committees.

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