Abstract 171: Cerebral Blood Flow and Oxygen Extraction Fraction are Age-dependent in Children and Young Adults with and without Sickle Cell Disease

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Kristin P Guilliams ◽  
Melanie E Fields ◽  
Michael M Binkley ◽  
Dustin K Ragan ◽  
Cihat Eldeniz ◽  
...  

Introduction: Children with sickle cell disease (SCD) are a high risk population for pediatric stroke. Young children with SCD have a higher stroke incidence than older children. Cerebral oxygen metabolism, the product of CBF, OEF and arterial oxygen content (CaO 2 , [oxygen saturation (SpO 2 ) x hemoglobin (Hb) x 1.36]) is age-dependent in healthy children, peaking at 5-9 years of age. CBF is age-dependent, but OEF variation across childhood is not well-studied. In non-SCD adults, elevated OEF confers higher stroke risk. Children with SCD have higher CBF and OEF than healthy controls, but also have lower CaO 2 . It is unknown if age independently influences CBF and OEF. We hypothesized that age, sex and CaO 2 influence components of cerebral oxygen metabolism, as measured by MRI. Methods: Subjects with SCD and sibling/relative controls without SCD underwent brain MRI with measurement of CBF and OEF by pseudocontinuous arterial spin labeling and asymmetric spin echo sequences, respectively. Blood samples were obtained for Hb and hematocrit values. A fast inversion recovery sequence measured T1 values in the superior sagittal sinus. A multiple regression model determined significant factors influencing CBF and OEF (age, sex, CaO 2 ). Results: We scanned 25 subjects without SCD (ages 6-27) and 56 subjects with SCD (ages 5-28). In multiple regression analysis, age (p=0.0009) and CaO 2 (p < 0.0001) were significantly predictive of CBF, controlling for sex. Age (p=0.027) and CaO 2 (p<0.0001), were also significantly predictive of OEF, controlling for sex. Conclusion: Age is an independent predictor of CBF and OEF. Younger children have higher CBF and OEF, even after controlling for the lower CaO 2 associated with SCD. This may explain the increased stroke incidence in young children with SCD.

HemaSphere ◽  
2019 ◽  
Vol 3 (S1) ◽  
pp. 324-325
Author(s):  
L. Vaclavu ◽  
E. Petersen ◽  
H. Mutsaerts ◽  
J. Petr ◽  
C. Majoie ◽  
...  

Author(s):  
Lena Václavů ◽  
Jan Petr ◽  
Esben Thade Petersen ◽  
Henri J.M.M. Mutsaerts ◽  
Charles B.L. Majoie ◽  
...  

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Andria L Ford ◽  
Kristin P Guilliams ◽  
Melanie E Fields ◽  
Dustin K Ragan ◽  
Cihat Eldeniz ◽  
...  

Background: While imaging biomarkers guide stroke prevention strategies in children with sickle cell (SC) disease, none have been adequately studied in adults. High oxygen extraction (OEF) predicts stroke in non-SC adults with carotid occlusion, while low oxygen metabolism (CMRO 2 ) predicts tissue at imminent risk in acute ischemic stroke. We hypothesized that metrics of cerebral metabolism: (1) differ between SC adults with and without stroke and (2) correlate with infarct burden. Methods: A prospective MRI study enrolled 37 adults (28 ± 8 yr) from SC clinic into 4 groups: (1) 9 age/race matched healthy controls, (2) 6 SC adults without infarcts, (3) 15 SC adults with infarcts (infarct volume 7.4 ± 17.5 ml), and (4) 7 SC adults on chronic transfusions (Tx) (infarct volume 3.6 ± 6.6 ml). Arterial spin labelling and asymmetric spin echo measured voxel-wise cerebral blood flow (CBF) and OEF. CMRO 2 = CBF x OEF x blood oxygen content. Infarcts were delineated on FLAIR. OEF, CBF, and CMRO 2 (excluding infarcted tissue) were compared: between groups 1-3 (Kruskal-Wallis) and in group 4 between pre- and post-tx scans (Signed Rank). An ROI defined by high OEF within the deep white matter (a region at high stroke risk in SC) was applied to group 3. OEF, CBF, and CMRO 2 within the ROI were correlated with hemispheric infarct volume (IV) (Spearman’s ρ ). Results: Whole brain OEF showed a stepwise increase from controls, to SC adults without stroke, to SC adults with stroke (P<.001). SC adults on chronic Tx had intermediate OEF, with lowering of OEF post-Tx (Fig A). CBF and CMRO 2 were similar for SC adults with and without stroke (Fig B, C). High OEF and low CBF/CMRO 2 in the ROI correlated with hemispheric infarct burden: IV vs. OEF ( ρ =.40, P=.043); IV vs. CBF ( ρ =-.61, P=.002); and IV vs. CMRO 2 ( ρ =-.50, P=.016). Conclusion: Global OEF holds promise to stratify stroke risk in SC disease. Regional metrics of cerebral oxygen metabolism may indicate tissue-specific metabolic stress at imminent risk of infarction.


2020 ◽  
Vol 67 (5) ◽  
Author(s):  
Corinna L. Schultz ◽  
Trudy Tchume‐Johnson ◽  
Tannoa Jackson ◽  
Henrietta Enninful‐Eghan ◽  
Marilyn M. Schapira ◽  
...  

Blood ◽  
2010 ◽  
Vol 115 (17) ◽  
pp. 3447-3452 ◽  
Author(s):  
Charles T. Quinn ◽  
Zora R. Rogers ◽  
Timothy L. McCavit ◽  
George R. Buchanan

Abstract The survival of young children with sickle cell disease (SCD) has improved, but less is known about older children and adolescents. We studied the Dallas Newborn Cohort (DNC) to estimate contemporary 18-year survival for newborns with SCD and document changes in the causes and ages of death over time. We also explored whether improvements in the quality of medical care were temporally associated with survival. The DNC now includes 940 subjects with 8857 patient-years of follow-up. Most children with sickle cell anemia (93.9%) and nearly all children with milder forms of SCD (98.4%) now live to become adults. The incidence of death and the pattern of mortality changed over the duration of the cohort. Sepsis is no longer the leading cause of death. All the recent deaths in the cohort occurred in patients 18 years or older, most shortly after the transition to adult care. Quality of care in the DNC has improved over time, with significantly more timely initial visits and preventive interventions for young children. In summary, most children with SCD now survive the childhood years, but young adults who transition to adult medical care are at high risk for early death.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1677-1677
Author(s):  
Masoud Nahavandi ◽  
Fatemeh Tavakkoli ◽  
Melville Q. Wyche ◽  
Syed P. Hasan ◽  
Oswaldo Castro

Abstract Recently we reported the use of a non-invasive near-infrared optical spectroscopy technique to measure cerebral oxygenation (cerebral oximetry, rSO2%) in agroup of 27 adult patients with sickle cell disease (Eur J Clin Invest, 34:143,2004). The sickle cell patients’ rSO2 values were significantly lower (mean 47.7%) than those in normal subjects (mean 61.3%) even though none of the patients had clinical evidence of stroke or cerebral ischemia. We included patients with all Hb phenotypes, and regardless of hydroxyurea (HU) treatment. Transfusions improved cerebral oxygen saturation but the post-transfusion values still did not reach normal levels. Our findings were corroborated independently by Raj et al. who studied 25 children with sickle cell disease (J Pediat Hematol Oncol 26:279,2004). In order to determine if long-term HU treatment affects rSO2, we analyzed cerebral oximetry results in a subset of 31 patients with sickle cell anemia (Hb SS). Eleven of them were on long-term (more than 6 months) HU treatment at stable doses (1000–1500 mg/day). The table shows that the mean rSO2, Hb, Hct, and MCV in HU-treated patients were significantly higher than those in sickle cell anemia (SCA) patients not on HU. The rSO2 in HU-treated patients was 12.5% higher than in SS patients not on this drug. By comparison, we previously reported a 24% increment in rSO2 following transfusions. A group of 8 patients who were on long-term HU treatment were given also single 1000 mg oral doses of HU and their rSO2 was measured for 12 hours without noticeable change in cerebral oxygenation. Nor did rSO2 change after oxygen inhalation (3L/min). The cause of the low rSO2 in sickle cell patients is unknown and still under investigation. It is probably not related exclusively to the anemia, since, as previously reported, anemic subjects without sickle cell disease appear to have normal rSO2. These preliminary results indicate that chronic HU treatment is associated with higher rSO2 values in SCA. If validated in a larger number of patients, our findings suggest that cerebral oximetry could be a useful, non-invasive method for assessing a new in vivo effect of HU and red cell transfusion in sickle cell disease: increased blood oxygen saturation in the cerebral vasculature. HYDROXYUREA AND CEREBRAL OXYGEN SATURATION IN PATIENTS WITH SICKLE CELL DISEASE NO HYDROXYUREA (N=20) HYDROXYUREA (N=11) P value* rSO2 = cerebral oxygen saturation. *= t-test. Plus/minus figures represent SD Mean rSO2 (%) 41 ± 6.6 46 ± 7.6 0.025 Mean Hb (g/dl) 8.4 ± 1.4 9.68 ± 1.2 0.029 Mean Hct (%) 24± 3.4 28± 4.4 0.027 Mean MCV (fl) 89± 8 102± 7 0.028


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 255-255
Author(s):  
Suzette O. Oyeku ◽  
Nancy S. Green ◽  
Farzana Pashankar ◽  
Patricia Giardina ◽  
Craig A. Mullen ◽  
...  

Abstract Abstract 255 Despite proven efficacy in clinical trials, hydroxyurea (HU) has not been uniformly adopted into the care of children with sickle cell disease (SCD). In 2008, the NIH Consensus Development Conference on Hydroxyurea Treatment for Sickle Cell Disease postulated that barriers to HU use may occur at the provider level. Limited evidence exists on barriers to the use of HU, and prior studies have largely focused on use in adults. HU use is rapidly expanding to different indications, to use in patients with less common hemoglobin genotypes and to young children. Initial data from the Pediatric Hydroxyurea Phase III Trial (BABY HUG) in very young children (ages 9–18 months) is also now becoming available. To better understand current provider barriers to effective translation of efficacy trial results into “real-world” clinical care of children with SCD, we surveyed pediatric hematology providers within several regional consortiums of pediatric hematology programs in the eastern US. The objectives of our study were to: 1) describe practice patterns related to HU use among providers of children and adolescents with SCD; 2) identify provider level barriers to HU use among SCD children; and 3) solicit provider recommendations to overcome the perceived barriers. A close-ended, self-administered web-based survey was sent to 230 pediatric hematology providers in June 2010. Provider demographics, practice characteristics, clinical indications to prescribe HU, concerns related to HU use and suggestions to improve HU use were assessed by this survey. Forty-two percent (N=97) of 230 surveys were completed by hematologists (84%), nurse practitioners (12%) and physician assistants (3.7%). The number of SCD patients in provider practices ranged from 2 to 1,200 patients. 57% of respondents were female. 42% of respondents were in practice for more than 20 years. The majority (72%) of providers were white. Many providers (83%) were somewhat/very familiar with the NHLBI guidelines about HU use in SCD. Among those surveyed, the most frequent indications to start HU were: 1) history of 3 painful episodes, 2) acute chest syndrome, 3) chronic pain use requiring narcotics, 4) priapism and 5) symptomatic anemia. A majority of providers (82%) reported using HU in children ages 3–5 years of age, with 41% of providers indicated using HU in children less than 3 years of age. Fewer than half of providers (28%) prescribe HU to patients with Hgb SC or other Hgb S variants. Only 74% of providers attempted to titrate HU to maximal tolerated dose. This goal dose ranged from 20 to 40mg/kg/day among our respondents. Major provider concerns about HU in children are: 1) patient compliance with taking HU, 2) compliance with attending drug monitoring visits, 3) compliance with taking contraception, 4) effects of HU on fertility and 5) long term side effects. Almost 50% of clinicians were concerned about the age of the patient when starting HU: 48.5% of clinicians considered patients less than 1 years of age too young to start HU, while 40% of clinicians felt patients' ages 1–2 years were too young. Some providers (39%) had concerns about the efficacy of HU in patients with Hgb SC, while 24.1% were concerned about efficacy in patients with Hgb S variants. Providers' suggestions to improve HU use included: 1) developing updated evidence based practice guidelines for HU use (89%), 2) developing culturally appropriate patient educational materials about HU (84%), 3) extending FDA approval for HU to children (80%), and 4) developing a national registry of patients on HU to monitor clinical outcomes and adverse events (74%). Our survey highlights that HU use varies among pediatric providers with respect to: 1) the broader clinical indications for HU use, 2) optimal maximal tolerated dose of HU, 3) appropriate lower age limit to prescribe HU, and 4) sickle cell genotype in which to use HU. Updated national evidence- based guidelines to assist clinicians in using HU in pediatric sickle cell care are indicated given the efficacy of HU for SCD over a wide range of indications, the logistical limits and tempo of clinical studies, the paucity of other widely available treatments, and persistent barriers to HU use at the provider level. Additional studies are warranted to examine alternative indications for HU, HU use in younger ages, optimum dosing, potential impact on fertility, teratogenicity and possible carcinogenicity, and use of HU for other sickle cell genotypes. Disclosures: Off Label Use: Hydroxyurea has not been FDA approved for use in children and adolescents with sickle cell disease, the topic of the submitted abstract.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 841-841
Author(s):  
Carlton Dampier ◽  
Elizabeth Ely ◽  
Leela Aertker ◽  
Darcy Brodecki ◽  
Karen Kesler ◽  
...  

Abstract Abstract 841 Pain is the hallmark symptom of vaso-occlusion in sickle cell disease (SCD), but has not been well studied, particularly in children. Previous studies of pain in very young children with SCD have largely been limited to episodes sufficiently severe as to require acute care visits or hospitalizations. Our previous studies in school-aged children and adolescents (Dampier CD et al. J Pediatr Hematol Oncol 2004), as well as those in adults (Smith W et al Ann Inter Med 2009) suggest that vaso-occlusive pain is frequently managed at home outside of acute care medical settings. We sought to obtain similar data about the home pain experience of infants and young children with SCD as reported by parents or guardians, and to explore the relationship between the pain experience and hematological biomarkers. Enrollment and data collection was conducted from Jan 1999-Mar 2008 at the Marian Anderson Sickle Cell Center as part of the Comprehensive Sickle Cell Centers program. Families with SCD infants identified by newborn screening were first approached about the study after completion of confirmatory diagnosis and initial SCD-related education, usually between 4 to 6 months of age. After informed consent, parents/guardians were trained in pain assessment and daily reporting. When sickle cell related pain events occurred, parents/guardians reported pain occurrence, location, associated symptoms and the treatment that they provided. Daily paper diaries were generally used in the first year of life to familiarize families with pain assessment and reporting. Subsequently a novel daily pager system was used to provide a method allowed daily reporting, but with reduced participant burden. A monthly telephone system in conjunction with a daily calendar was used for those families unable to effectively comply with providing daily reports. All pain reports were adjudicated by consensus of study staff and PI/Co-PI. Children were removed from the study for any period of chronic transfusion for clinical events (splenic sequestration, recurrent acute chest syndrome, surgery). Over the study period, 103 children (58% male) were enrolled beginning at a median age of 7.3 months (range 1.5, 65.2 months). This represented about 50% of SCD children referred to the Center by newborn screening during these time periods; the most common reasons for refusal were inability to complete daily reporting and geographic distance from the Center. An SS genotype was present in 50 children (48.5%), SC in 32 (31.1%), SB0thalassemia in 6 (5.8%), SB+thalassemia in 15 (14.6%). Children were actively followed for a median of 3.8 years (range 0.3–7.6 years). The total number of days children were assessed for pain was 141,197 days with an additional 28,079 days of missing data (16%). The total number of days that children had reported pain was 2,288 days (1.6%), which represented 768 distinct episodes of pain. Over 80% of children reported to have pain in the 0–12 month age interval had pain locations (hands/feet) and characteristics (swelling or tenderness) consistent with dactylitis, which became progressively less prevalent in older age intervals. Significantly more SS/SB0 patients (58%) had >2 days of average dactylitis pain during 0–12 months or 12–24 months (53%) intervals compared to SC/SB+ patients (0%) (p=0.04). The timing of the first reported dactylitis event (<2 years or ≥2 years) significantly predicted the frequency of SCD pain events per person year, with earlier onset associated with more frequent pain events during the study period (p=0.02), for both the SS/SB0 and SC/SB+ (P=0.03) groups. Our study demonstrates the feasibility of initial recruitment and subsequent daily reporting of clinical events by families of infants and young children with SCD over many years, particularly when careful consideration is given to enhance family support and minimizing respondent burden. The onset of an initial dactylitis episode prior 2 years of age, even if treated at home, was associated with more frequent pain throughout childhood, irrespective of hemoglobinopathy type. Such children may be appropriate for interventions, such as oral hydroxyurea, that reduce excessive pain frequency. Supported by NIHHL-051495 and HL-083705. Disclosures: Dampier: Anthera Pharmaceuticals Inc:; Glycomimetics Inc: .


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