Abstract 89: Incidence and Characteristics of Hemorrhagic Stroke Among Post-STOP Participants

Introduction: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) changed standards of care for stroke screening and treatment of high-risk children with sickle cell anemia (SCA), reducing the risk of ischemic stroke. However, the incidence of hemorrhagic stroke in young patients with SCA in the post-STOP era remains poorly characterized. Methods: The Post-STOP multicenter cohort study collected follow-up data from prior participants (all with SCA) of the STOP or STOP II clinical trials. From 01/2012 – 05/2014, medical records analysts abstracted clinical, imaging and laboratory data collected after the STOP studies ended at 19 of the 26 original sites. Two stroke neurologists reviewed data to confirm hemorrhagic stroke, defined as primary spontaneous intracerebral, subarachnoid or intraventricular hemorrhage; we excluded traumatic hemorrhage or hemorrhagic conversion of ischemic infarcts. Incidence rates among those with no prior hemorrhagic stroke at the start of Post-STOP were calculated using survival analysis techniques. Results: Follow-up data were collected from 2,851 of 3,835 participants participated in the STOP trials. Patients (51% male) were a median age of 10.4 years (interquartile range [IQR] 6.8-14.1) at the start of Post-STOP. Over a median of 10.3 (IQR 7.3-11.4) years of follow-up, 35 patients with hemorrhagic stroke were identified (Table 1). The incidence rate was 63 per 100,000 person-years overall (95% CI 45-87). Stratified by age, the incidence rate per 100,00 person-years was 50 (95% CI 34-75) for children less than 18 years old and 134 (95% CI 74-243) for adults over the age of 50. Conclusion: In our cohort, we observed that the risk of hemorrhagic stroke in patients with SCA rises as patients age, most sharply after the first decade of life. Structural vascular abnormalities such as moyamoya syndrome and aneurysms are common etiologies for hemorrhage and screening may be warranted.

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Clinical and Laboratory Benefits of Early Initiation of Hydroxyurea with Pharmacokinetic Guided Dosing for Young Children with Sickle Cell Anemia

Blood ◽

10.1182/blood-2018-99-112909 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 507-507 ◽

Cited By ~ 1

Author(s):

Patrick T. McGann ◽

Omar Niss ◽

Min Dong ◽

Anu Marahatta ◽

Tomoyuki Mizuno ◽

...

Keyword(s):

Young Children ◽

Sickle Cell ◽

Cystatin C ◽

Sickle Cell Anemia ◽

Research Funding ◽

Laboratory Data ◽

Advisory Board ◽

Young Cohort

Abstract Background: Hydroxyurea is now the standard of care for children with sickle cell anemia (SCA). Results from the BABY HUG study and recommendations from the 2014 NHLBI Guidelines have led to early initiation (increasingly before 1 year of age) of hydroxyurea for many patients. Given the known variability in hydroxyurea pharmacokinetics (PK), treatment response (HbF%), and maximum tolerated dose (MTD), we hypothesized that individualized dosing would provide the optimal treatment approach. Methods: The Therapeutic Response Evaluation and Adherence Trial (TREAT, ClinicalTrials.gov NCT02286154) is a prospective study of a personalized, PK-guided dosing model of hydroxyurea for children with SCA. Using population PK model-based Bayesian estimation, each participant's PK data are used to generate an individualized starting hydroxyurea dose that targets an area under the curve associated with actual MTD. Clinical follow-up and subsequent dose adjustments target MTD, usually defined by ANC<3.0x109/L. We analyzed clinical and laboratory data for TREAT participants who started hydroxyurea before 2 years of age, to allow for comparison to published results from BABY HUG, which included a similar young cohort but with conservative weight-based dosing of 20 mg/kg/day. TREAT participants had ongoing clinical and research evaluations of organ function, including transcranial doppler (TCD) studies, RBC pit counts, and cystatin C measurements. Results:The analysis of children starting hydroxyurea before 2 years of age included 33 participants (of 47 total TREAT enrollments), who contributed a total of 59.5 patient-years of hydroxyurea therapy. The mean age (±SD) at hydroxyurea initiation was 1.0±0.4 years of age. The average PK-guided, individualized starting dose was 27.8±5.3 mg/kg/day, higher than conventional and BABY HUG initial dosing (20 mg/kg/day). For children who have completed 12 months of therapy (n=24), effects in hematologic laboratory data are remarkable with average 35.9±8.9% HbF and hemoglobin concentration of 10.2±1.1 g/dL after 12 months of therapy (compared to 29.3±8.8% and 9.2±1.3 g/dL at baseline). The majority (70%) of these participants have HbF>30% and almost half achieved HbF>40% after 12 months of hydroxyurea. This hematological response is more robust than what was observed in BABY HUG (HbF=22.4%, Hb=9.1 g/dL after two years of therapy, Wang WC et al. Lancet 2011). In the TREAT cohort, there were no episodes of dactylitis, acute splenic sequestration, or stroke. There were 111 emergency room or sick outpatient clinic visits for this young cohort; 107 ED/clinic visits (without subsequent hospitalization) were for fever, URI symptoms, GI illness, or other non-specific complaints unrelated to SCA, while only 4 (3.6%) visits were for pain. There were 38 hospitalizations in 17 participants, mostly for routine evaluation of fever (66%), but no positive blood cultures and no admissions for febrile neutropenia. The average length of hospitalization was 2.8±2.4 days with 81% of participants discharged within 72 hours of admission. There were 3 episodes of acute chest syndrome in 2 patients, two of whom required PRBC transfusion. Including all types of visits, there were only 6 pain events, equivalent to 10.1 pain events per 100 patient-years, which is much lower than the published 94 events per 100 patient-years in the hydroxyurea treatment arm of BABY HUG (Thornburg CD et al. Blood 2012). There were 37 TCD exams performed in 16 participants, all normal except for one patient with conditional velocities that normalized with hydroxyurea. There were no significant differences from baseline to month 12 in either RBC pit counts or cystatin C values. Conclusions: Hydroxyurea initiation at an early age using PK-guided dosing provides significant clinical benefits for young children with sickle cell anemia. These TREAT study data suggest that initiating hydroxyurea around one year of life using a personalized dosing strategy can provide better clinical and laboratory benefits than starting at the conventional 20 mg/kg/day weight-based dose. Very high HbF levels are observed at modest and well-tolerated doses of hydroxyurea, perhaps because treatment was initiated before the process of HbF inactivation is complete. Continued long-term follow-up of these patients will determine whether these will be sustained and able to prevent both short- and long-term complications of SCA. Disclosures Malik: CSL Behring: Patents & Royalties. Quinn:Silver Lake Research Corporation: Research Funding; Global Blood Therapeutics: Research Funding; Amgen: Research Funding. Ware:Biomedomics: Research Funding; Nova Laboratories: Consultancy; Bristol Myers Squibb: Research Funding; Addmedica: Research Funding; Global Blood Therapeutics: Other: advisory board; Agios: Other: advisory board; Novartis: Membership on an entity's Board of Directors or advisory committees.

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Hydroxyurea Treatment of Young Children with Sickle Cell Anemia: Safety and Efficacy of Continued Treatment – the BABY HUG Follow-up Study

Blood ◽

10.1182/blood.v118.21.7.7 ◽

2011 ◽

Vol 118 (21) ◽

pp. 7-7 ◽

Cited By ~ 1

Author(s):

Zora R. Rogers ◽

Billie Fish ◽

Zhaoyu Luo ◽

Rathi V. Iyer ◽

Courtney D. Thornburg ◽

...

Keyword(s):

Sickle Cell ◽

Sickle Cell Anemia ◽

Hospital Admissions ◽

Controlled Trial ◽

Laboratory Data ◽

Acute Chest Syndrome ◽

Follow Up Study ◽

Hydroxyurea Treatment ◽

The Impact

Abstract Abstract 7 BABY HUG [Clinical Trials #NCT00006400], an NIH-NICHD sponsored randomized placebo-controlled trial showed that hydroxyurea (HU) administered to 9–18 month old children with sickle cell anemia (SCA) provides substantial clinical benefit. Benefits include a decrease in pain crises, acute chest syndrome events, need for transfusion and hospital admission; hematologic improvement include higher total and fetal hemoglobin concentration, larger red cell size, and lower WBC counts with toxicity limited to transient reduction in absolute neutrophil count (ANC) [Lancet 2011; 377:1663–72]. The parent or guardian of all 176 children who completed at least 18 months of randomized treatment were offered participation in an initial observational BABY HUG Follow-Up Study and 163 (93%) consented to participate. Clinical and laboratory data were collected every 6 months by structured abstraction of the medical record regarding use of clinically prescribed HU (dose escalation recommended), blood counts, clinical imaging, and sickle cell-related events. At the time of enrollment the family did not know their child's randomized study treatment assignment; 133 (82%) initially chose clinical prescription of open-label HU. Acceptance of HU has remained high through 36 months of follow-up; during each 6 month data collection period 68–75% of participants reported having taken HU. Only 2 patients have left the study (due to relocation) and more than 93% of expected data have been collected. Preliminary analyses as of May 2011, including 417 patient years (pt-yrs) of follow up, demonstrate that in comparison to participants not taking HU, children who continue to take HU have statistically lower rates of pain crises requiring emergency department (ED) visits, episodic transfusions, and hospital admissions for any reason, including acute chest syndrome or febrile illness (see table). The substantial decrease in acute chest syndrome episodes is similar to the effect demonstrated with HU use in the randomized BABY HUG trial in younger infants and consistent with published trials detailing the benefit of HU therapy in older children and adults. The decrease in the rate of admission for febrile events in HU-treated patients is also comparable to that in the randomized trial, but the reason for this benefit is uncertain. There was no difference in hospitalization rates for painful events including dactylitis. Two patients in the non-HU group had a stroke. There were no differences between groups in the frequency of a palpable spleen or rate of acute splenic sequestration crises. Through 36 months of follow up children taking HU had persistently higher hemoglobin and MCV, and lower WBC and ANC than those not taking HU. Results of these analyses including growth and development assessments will enhance our understanding of the impact of HU use in children with SCA starting at a very young age. The accruing data from the BABY HUG Follow-Up Study demonstrate a continuation of the substantial benefits of early HU therapy with no discernable additional toxicities. Ongoing follow up of this cohort is essential to fully define these benefits as children grow, and to observe for late toxicity.Event Rate per 100 pt-yrsHUNo HUp valueED visit for Pain Crisis28.853.60.004Episodic Transfusion18.334.00.010Hospital Admission (any cause)74.9133.20.001Acute Chest Syndrome (admission)9.522.30.0001Febrile Illness (admission)30.764.3<.001Pain Crisis (admission)18.630.40.102 Disclosures: Off Label Use: Hydroxyurea is not indicated for treatment of children with sickle cell disease. Use of this medication was for clinical indications and not mandated by this observational study.

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Impact of TCD Screening Protocol on the Incidence of Hemorrhagic Stroke in Children and Young Adults with Sickle Cell Disease

Blood ◽

10.1182/blood.v126.23.3402.3402 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3402-3402 ◽

Cited By ~ 2

Author(s):

Julie Kanter ◽

Janet Kwiatkowski ◽

Heather J. Fullerton ◽

Jenifer Voeks ◽

Ellen Debenham ◽

...

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Stroke Prevention ◽

Hemorrhagic Stroke ◽

Cell Disease ◽

Increased Risk ◽

The Mean ◽

The Impact

Abstract Background: Primary hemorrhagic stroke is a rare complication of sickle cell disease (SCD) that usually occurs in adults. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) screening with indefinite chronic red cell transfusions (CRCT) for patients with abnormal TCD as standard of care. Despite a notable improvement in the incidence of infarctive stroke in children with SCD after the introduction of TCD screening protocols, it is unclear how this protocol will affect the rate of hemorrhagic stroke. Presumably, early TCD screening and subsequent initiation of CRCT in high risk patients will prevent the progression of cerebral vasculopathy, which should decrease the risk of hemorrhagic stroke; however this has not been proven. Using the large multicenter cohort of children who participated in STOP and/or STOP 2 trials, we sought to assess whether the rate of hemorrhagic stroke was impacted by the use of TCD screening and/or CRCT. Subjects and Methods: Between 1995 and 2005, STOP and STOP 2 (STOP/2) were conducted at 26 sites in the US and Canada. These studies included 3835 children, ages 2 to 16 y with SCD type SS or S-beta-0-thalassemia. Participation in STOP/2 required at least a single screening TCD for randomization. Patients on STOP 2 also had an observational arm for children started on CRCT who had an abnormal TCD. The Post-STOP study was designed to follow-up the outcomes of children who participated in one or both of trials. For all participants the date of their last encounter in STOP/2 was defined as the start of their Post-STOP period. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3539 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 including follow-up TCD and brain imaging results, clinical information, and laboratory results. Two separate neurologists, blinded to STOP/2 status and prior TCD and neuroimaging results adjudicated all suspected strokes. Results: Follow-up data were available for 2850 of the 3539 subjects (81%). Twelve children who had a stroke during the STOP study period were further excluded from this analysis resulting 2838 subjects. The mean age at the start of Post-STOP was 10.5 years and mean duration of follow-up after exiting STOP/2 until time of last medical encounter was 9.1 years. A total of 31 patients had a primary hemorrhagic stroke during the Post-STOP observation period (incidence 0.12 per 100 pt years). The mean age at time of stroke was 16.2+5.6 (median 15.3 range (4.8-30.2) years of age. Of those 31 patients, only 52% had a TCD during Post-STOP prior to the event. Seven of those children who underwent screening had documentation of an abnormal TCD prior to the event (5 during STOP era and/or 3 Post-STOP). However, only 1/7 patients (14%) were documented on CRCT at the time of the stroke (4 patients were receiving HU and 2 patients had unknown treatment). Discussion: Although less common than infarctive stroke, patients with SCD are at increased risk for hemorrhagic stroke. There is an increased risk of mortality for patients who suffer from hemorrhagic stroke (up to 26% in some reports in the 2 weeks after the event). It is unclear if TCD screening and subsequent initiation of CRCT will impact the rate of hemorrhagic stroke in the long term. In our results, a similar incidence of primary hemorrhagic stroke was noted although the patients were overall younger than previously reported (16.5+/- 5.5 years versus 20-29 years in Cooperative Study of Sickle Cell Disease). Many patients who had a hemorrhagic stroke (48%) had not undergone TCD screening during the Post-Stop period. Additionally, although a safe stopping point for CRCT has not been established in patients who have had an abnormal TCD, only 1 patient was documented on CRCT at the time of the event (14%). Thus, it is unclear at this time whether TCD screening and subsequent, lifelong continuation of CRCT could have prevented these other events. Clearly, these results demonstrate that improved implementation of STOP protocol is needed as well as further evaluation of the impact of this protocol on the incidence of hemorrhagic stroke. Disclosures No relevant conflicts of interest to declare.

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Long-term (>10-year) clinical follow-up after young embolic stroke/TIA of undetermined source

International Journal of Stroke ◽

10.1177/1747493019884520 ◽

2019 ◽

pp. 174749301988452 ◽

Cited By ~ 2

Author(s):

M Nassif ◽

ME Annink ◽

H Yang ◽

TCD Rettig ◽

YBWEM Roos ◽

...

Keyword(s):

Incidence Rate ◽

Recurrent Stroke ◽

Young Patients ◽

Incidence Rates ◽

Embolic Stroke ◽

Vascular Events ◽

Tertiary Center ◽

New Onset

Background To date, the pathophysiology of first-ever and recurrent stroke/TIA still remains unclear in young patients with embolic stroke/TIA of undetermined source (ESUS). Clinical studies with long-term follow-up in young ESUS patients are necessary to investigate the underlying pathophysiology of first-ever and recurrent stroke/TIA in this patient population, in particular the role of new-onset atrial fibrillation. Aims Our aim was to study the long-term (>10-year) clinical outcome of young patients (<50 years) with ESUS. Methods This cohort study included all patients aged ≤ 50 years who underwent transoesophageal echocardiography for diagnostic work-up of ESUS during 1996–2008 from one tertiary center. All patients were contacted by telephone between September–November 2018 to update clinical information from medical records. The clinical outcomes of this study were incidence rates of all-cause and cardiovascular mortality, recurrent stroke/TIA, new-onset clinical AF, and ischemic vascular events. Results In total, 108 patients (57% female, mean age 40 ± 7.2 years [range 19–50 years], n = 72 stroke) were included. Across clinical follow-up (median 13[IQR 10–16] years), 24 patients died ( n = 14 cardiovascular). The 15-year incidence rate of recurrent stroke/TIA was 15% (incidence rate = 1.09[95%CI 0.54–1.65]/100 patient-years) and a 5.5% incidence of new-onset clinical AF (incidence rate = 0.44[95%CI 0.09–0.79]/100 patient-years) following ESUS. Conclusions The incidence of recurrent stroke/TIA is relatively high during long-term clinical follow-up of young patients with ESUS. In contrast, new-onset clinical AF is relatively low and therefore may not play an important part in the pathophysiology of first-ever and recurrent stroke/TIA of these patients.

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Ischemic Stroke in Children and Young Adults with Sickle Cell Disease (SCD) in the Post-STOP Era

Blood ◽

10.1182/blood.v126.23.68.68 ◽

2015 ◽

Vol 126 (23) ◽

pp. 68-68 ◽

Cited By ~ 3

Author(s):

Janet L. Kwiatkowski ◽

Julie Kanter ◽

Heather J. Fullerton ◽

Jenifer Voeks ◽

Ellen Debenham ◽

...

Keyword(s):

Ischemic Stroke ◽

High Risk ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Stroke Prevention ◽

Cell Disease ◽

Clinical Series ◽

The Mean

Abstract Background: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) screening with indefinite chronic red cell transfusions (CRCT) for children with abnormal TCD as standard of care. To identify children at high-risk of stroke, annual TCD screening is recommended from ages 2 to 16 years, with more frequent monitoring if the result is not normal. A reduction in stroke incidence in children with SCD has been reported in several clinical series and analyses utilizing large hospital databases when comparing rates before and after the publication of the STOP study in 1998. We sought to determine the rate of first ischemic stroke in a multicenter cohort of children who had previously participated in the STOP and/or STOP 2 trials and to determine whether these strokes were screening or treatment failures. Subjects and Methods: Between 1995 and 2005, STOP and STOP 2 (STOP/2) were conducted at 26 sites in the US and Canada. These studies included 3,835 children, ages 2 to 16 y with SCD type SS or S-beta-0-thalassemia. Participation in STOP/2 ranged from a single screening TCD to randomization. STOP 2 also had an observational arm for children on CRCT for abnormal TCD whose TCD had not reverted to normal. The Post-STOP study was designed to follow-up the outcomes of children who participated in one or both trials. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3,539 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 (depending on site) including follow-up TCD and brain imaging results, clinical information, and laboratory results. Two vascular neurologists, blinded to STOP/2 status and prior TCD and neuroimaging results, reviewed source records to confirm all ischemic strokes, defined as a symptomatic cerebral infarction; discordant opinions were resolved through discussion. For the first Post-STOP ischemic stroke, prior TCD result and treatment history subsequently were analyzed. Results: Of the 3,539 subjects, follow-up data were available for 2,850 (81%). Twelve children who had a stroke during STOP or STOP2 were excluded from these analyses resulting in data on 2,838 subjects. The mean age at the start of Post-STOP was 10.5 y and mean duration of follow-up after exiting STOP/2 was 9.1 y. A total of 69 first ischemic strokes occurred in the Post-STOP observation period (incidence 0.27 per 100 pt years). The mean age at time of stroke was 14.4±6.2 (median 13.8, range 3.5-28.9) y. Twenty-five of the 69 patients (36%) had documented abnormal TCD (STOP/2 or Post-STOP) prior to the stroke; 15 (60%) were receiving CRCT and 9 (36%) were not (treatment data not available for 1 subject). Among the 44 subjects without documented abnormal TCD, 29 (66%) had not had TCD re-screen in the Post-STOP period prior to the event; 7 of these 29 (24%) were 16 y or older at the start of Post-STOP, which is beyond the recommended screening age. Four of the 44 (9%) patients had inadequate TCD in Post-STOP (1 to 10.7 y prior to event). Six (14%) had normal TCD more than a year before the event (1.2 - 4 y); all but one of these children were younger than 16 y at the time of that TCD. Only 5 (11%) had a documented normal TCD less than 1 year prior to the event. Conclusions: In the Post-STOP era, the rate of first ischemic stroke was substantially lower than that reported in the Cooperative Study of Sickle Cell Disease, prior to implementation of TCD screening. Many (39%) of the Post-STOP ischemic strokes were associated with a failure to re-screen according to current guidelines, while only 11% occurred in children who had had recent low-risk TCD. Among those known to be at high risk prior to stroke, treatment refusal or inadequate treatment may have contributed. While TCD screening and treatment are effective at reducing ischemic stroke in clinical practice, significant gaps in screening and treatment, even at sites experienced in the STOP protocol, remain to be addressed. Closing these gaps should provide yet further reduction of ischemic stroke in SCD. Disclosures No relevant conflicts of interest to declare.

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HMOX1 and Acute Kidney Injury in Sickle Cell Anemia

Blood ◽

10.1182/blood.v130.suppl_1.686.686 ◽

2017 ◽

Vol 130 (Suppl_1) ◽

pp. 686-686

Author(s):

Santosh L. Saraf ◽

Maya Viner ◽

Ariel Rischall ◽

Binal Shah ◽

Xu Zhang ◽

...

Keyword(s):

Chronic Kidney Disease ◽

Acute Kidney Injury ◽

Risk Factor ◽

Kidney Disease ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Kidney Injury ◽

Ckd Progression ◽

Kdigo Guidelines

Abstract Acute kidney injury (AKI) is associated with tubulointerstitial fibrosis and nephron loss and may lead to an increased risk for subsequently developing chronic kidney disease (CKD). In adults with sickle cell anemia (SCA), high rates of CKD have been consistently observed, although the incidence and risk factors for AKI are less clear. We evaluated the incidence of AKI, defined according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines as a rise in serum creatinine by ≥0.3mg/dL within 48 hours or ≥1.5 times baseline within seven days, in 158 of 299 adult SCA patients enrolled in a longitudinal cohort from the University of Illinois at Chicago. These patients were selected based on the availability of genotyping for α-thalassemia, BCL11A rs1427407, APOL1 G1/G2, and the HMOX1 rs743811 and GT-repeat variants. Median values and interquartile range (IQR) are provided. With a median follow up time of 66 months (IQR, 51-74 months), 137 AKI events were observed in 63 (40%) SCA patients. AKI was most commonly observed in the following settings: acute chest syndrome (25%), an uncomplicated vaso-occlusive crisis (VOC)(24%), a VOC with pre-renal azotemia determined by a fractional excretion of sodium <1% or BUN-to-creatinine ratio >20:1 (14%), or a VOC with increased hemolysis, defined as an increase in serum LDH or indirect bilirubin level >1.5 times over the baseline value at the time of enrollment (12%). Compared to individuals who did not develop AKI, SCA adults who developed an AKI event were older (AKI: median and IQR age of 35 (26-46) years, no AKI: 28 (23 - 26) years; P=0.01) and had a lower estimated glomerular filtration rate (eGFR) (AKI: median and IQR eGFR of 123 (88-150) mL/min/1.73m2, no AKI: 141 (118-154) mL/min/1.73m2; P=0.02) by the Kruskal-Wallis test at the time of enrollment. We evaluated the association of a panel of candidate gene variants with the risk of developing an AKI event. These included loci related to the degree of hemolysis (α-thalassemia, BCL11A rs1427407), to chronic kidney disease (APOL1 G1/G2 risk variants), and to heme metabolism (HMOX1) . Using a logistic regression model that adjusted for age and eGFR at the time of enrollment, the risk of an AKI event was associated with older age (10-year OR 2.6, 95%CI 1.4-4.8, P=0.002), HMOX1 rs743811 (OR 3.1, 95%CI 1.1-8.7, P=0.03), and long HMOX1 GT-repeats, defined as >25 repeats (OR 2.5, 95%CI 1.01-6.1, P=0.04). Next, we assessed whether AKI is associated with a more rapid decline in eGFR and with CKD progression, defined as a 50% reduction in eGFR, on longitudinal follow up. Using a mixed effects model that adjusted for age and eGFR at the time of enrollment, the rate of eGFR decline was significantly greater in those with an AKI event (β = -0.51) vs. no AKI event (β = -0.16) (P=0.03). With a median follow up time of 66 months (IQR, 51-74 months), CKD progression was observed in 21% (13/61) of SCA patients with an AKI event versus 9% (8/88) without an AKI event. After adjusting for age and eGFR at the time of enrollment, the severity of an AKI event according to KDIGO guidelines (stage 1 if serum creatinine rises 1.5-1.9 times baseline, stage 2 if the rise is 2.0-2.9 times baseline, and stage 3 if the rise is ≥3 times baseline or ≥4.0 mg/dL or requires renal replacement therapy) was a risk factor for CKD progression (unadjusted HR 1.6, 95%CI 1.1-2.3, P=0.02; age- and eGFR-adjusted HR 1.6, 95%CI 1.1-2.5, P=0.03). In conclusion, AKI is commonly observed in adults with sickle cell anemia and is associated with increasing age and the HMOX1 GT-repeat and rs743811 polymorphisms. Furthermore, AKI may be associated with a steeper decline in kidney function and more severe AKI events may be a risk factor for subsequent CKD progression in SCA. Future studies understanding the mechanisms, consequences of AKI on long-term kidney function, and therapies to prevent AKI in SCA are warranted. Disclosures Gordeuk: Emmaus Life Sciences: Consultancy.

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Barriers to Pediatric Sickle Cell Disease Guideline Recommendations

Global Pediatric Health ◽

10.1177/2333794x19847026 ◽

2019 ◽

Vol 6 ◽

pp. 2333794X1984702 ◽

Cited By ~ 3

Author(s):

Michael D. Cabana ◽

Julie Kanter ◽

Anne M. Marsh ◽

Marsha J. Treadwell ◽

Michael Rowland ◽

...

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Sickle Cell Anemia ◽

Support Staff ◽

Cell Disease ◽

National Guidelines ◽

Convenience Sample ◽

Different Types ◽

Pediatric Sickle Cell Disease

National guidelines recommend that providers counsel all patients with sickle cell anemia about hydroxyurea (HU) therapy and screen children with sickle cell anemia annually for the risk of stroke with transcranial Doppler (TCD). We surveyed a national convenience sample of sickle cell disease clinicians to assess factors associated with low adherence. Adherence was 46% for TCD screening. Low adherence was associated with a lack of outcome expectancy (eg, a belief that there would be poor patient follow-up to TCD testing; P < .05). Adherence was 72% for HU counseling. Practice barriers (eg, lack of support staff or time) and a lack of agreement with HU recommendations were associated with low adherence ( P < .05). This study demonstrates that different types of strategies are needed to improve TCD screening (to address follow-up and access to testing) versus HU counseling (to address physician agreement and practice barriers).

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An objective sign in painful crisis in sickle cell anemia: the concomitant reduction of high density red cells

Blood ◽

10.1182/blood.v64.2.559.559 ◽

1984 ◽

Vol 64 (2) ◽

pp. 559-563 ◽

Cited By ~ 45

Author(s):

ME Fabry ◽

L Benjamin ◽

C Lawrence ◽

RL Nagel

Keyword(s):

Sickle Cell ◽

Sickle Cell Anemia ◽

State Level ◽

Red Cells ◽

Average Decrease ◽

Concomitant Reduction ◽

Objective Sign ◽

The Stability ◽

Painful Crisis

Abstract The etiopathologic basis of painful crisis in sickle cell anemia is largely unknown, and no objective criteria for its diagnosis and follow- up exist at present. We have studied 11 patients through 14 painful crises and observed a significant decrease of the densest fraction of red cells in 12 of the 14 crises as determined by isopycnic Percoll- Stractan continuous density gradients. If the first observation is normalized to 100%, the average decrease in dense cells was 77% with a range of 36% to 94%. The time needed for the percentage of dense cells to return to the steady-state level varied from seven to more than 30 days. These findings were in sharp contrast to the stability of the density pattern observed in another group of sickle cell patients, who were studied during crisis-free periods. The mechanism of the disappearance of dense cells could involve selective destruction by the reticuloendothelial (RE) system, selective sequestration in the areas of vasoocclusion, or a combination of both factors.

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