Moyamoya syndrome in childhood sickle cell disease: a predictive factor for recurrent cerebrovascular events

Abstract We conducted a retrospective study to determine whether the presence of moyamoya collaterals influenced the risk of recurrence of cerebrovascular events (CVEs: stroke or transient ischemic attack) in patients with sickle cell disease placed on chronic transfusions after a stroke. Forty-three patients with homozygous sickle cell anemia (HbSS) and 1 with HbSOArab (16 females, 28 males) who had suffered strokes while under the age of 18 were studied. All patients had been on transfusions aimed at maintaining the sickle hemoglobin (HbS) level below 30%. They were followed for a mean of 6.6 years (2.2 to 20.4 years). The presence of collaterals was diagnosed based on either magnetic resonance angiography or conventional angiography. Eighteen (41%) of the 44 patients suffered recurrent CVEs. Nineteen (43%) (6 females, 13 males) patients had moyamoya collaterals. Eleven (58%) of these 19 experienced 21 total recurrent CVEs, including 4 strokes in 4 patients (21%). In comparison, 7 (28%) of 25 patients without moyamoya collaterals experienced 9 recurrent CVEs (P < .05) with only 1 recurrent stroke (4%). Moyamoya patients were also more likely to have 2 recurrent CVEs (42% vs 8%,P < .05) as well as poorer neuropsychological testing results. A proportional hazards regression analysis indicated that patients with moyamoya were more than twice as likely to incur a subsequent CVE (hazard ratio, 2.40; 95% confidence interval, 0.85, 6.75). We conclude that up to 41% of patients with sickle cell disease experience recurrent CVEs after an initial stroke despite chronic transfusions and that the risk of recurrence is significantly higher for those who have moyamoya collaterals.

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A modified transfusion program for prevention of stroke in sickle cell disease

Blood ◽

10.1182/blood.v79.7.1657.1657 ◽

1992 ◽

Vol 79 (7) ◽

pp. 1657-1661 ◽

Cited By ~ 127

Author(s):

AR Cohen ◽

MB Martin ◽

JH Silber ◽

HC Kim ◽

K Ohene-Frempong ◽

...

Keyword(s):

Sickle Cell Disease ◽

Cerebral Infarction ◽

Sickle Cell ◽

Recurrent Stroke ◽

High Rate ◽

First Year ◽

Cell Disease ◽

Red Blood Cell Transfusions ◽

Major Reduction

Abstract Regular red blood cell transfusions reduce the rate of recurrent cerebral infarction in sickle cell disease but lead to accumulation of excessive iron. We studied the effect on the prevention of recurrent stroke and the volume of blood transfused of a modified transfusion program in which the pretransfusion percentage of hemoglobin S (HbS) was maintained at 50%, rather than the conventional 30%. Fifteen patients with sickle cell disease and cerebral infarction who had been free of recurrent stroke for at least 4 years during which the pretransfusion HbS was maintained below 30% were assigned to a transfusion program in which the HbS was allowed to increase to 50%. Transfusion regimens included simple transfusion and manual and automated partial exchange transfusion. The duration of follow-up was 14 to 130 months with a median duration of 84 months. None of the 15 patients had a recurrent cerebral infarction during 1,023 patient- months in which the target pretransfusion HbS was 50%. Analysis of this finding, using a binomial distribution, indicates that there is less than a 5% chance that the risk per patient of recurrent stroke in the first year of the modified transfusion program is greater than 18%. One 23-year-old patient had a fatal intraventricular hemorrhage when the HbS was 30% and a 21-year-old patient had a fatal subarachnoid hemorrhage in the 40th week of pregnancy when the HbS was 29%. Blood requirements with simple transfusions decreased by 17% to 48% (mean 31%) when the target pretransfusion HbS level was increased from 30% to 50% (P less than .001). Manual or automated partial exchange transfusions and a target HbS level of 50% in eight patients reduced blood requirements by 33% to 99% (mean 67%) in comparison with simple transfusion and a target HbS level of 30% (P less than .001). This study offers evidence that a target pretransfusion HbS level of 50% affords a continuing high rate of protection against recurrent cerebral infarction in sickle cell disease after 4 years of a conventional transfusion program. Increasing the target HbS level from 30% to 50% provides a major reduction in blood requirements and lowers the rate of iron accumulation.

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High risk of recurrent stroke after discontinuance of five to twelve years of transfusion therapy in patients with sickle cell disease

The Journal of Pediatrics ◽

10.1016/s0022-3476(05)82150-x ◽

1991 ◽

Vol 118 (3) ◽

pp. 377-382 ◽

Cited By ~ 119

Author(s):

Winfred C. Wang ◽

Edward H. Kovnar ◽

Ina L. Tonkin ◽

Raymond K. Mulhern ◽

James W. Langston ◽

...

Keyword(s):

High Risk ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Recurrent Stroke ◽

Cell Disease ◽

Transfusion Therapy

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Hydroxyurea as an Alternative to Blood Transfusions for the Prevention of Recurrent Stroke in Children With Sickle Cell Disease

Blood ◽

10.1182/blood.v94.9.3022 ◽

1999 ◽

Vol 94 (9) ◽

pp. 3022-3026 ◽

Cited By ~ 111

Author(s):

Russell E. Ware ◽

Sherri A. Zimmerman ◽

William H. Schultz

Keyword(s):

Sickle Cell Disease ◽

Iron Overload ◽

Sickle Cell ◽

Recurrent Stroke ◽

Fetal Hemoglobin ◽

Hemoglobin Concentration ◽

Stroke Recurrence ◽

Hematologic Toxicity ◽

Cell Disease ◽

F Cells

Abstract Children with sickle cell disease (SCD) and stroke receive chronic transfusions to prevent stroke recurrence. Transfusion risks including infection, erythrocyte allosensitization, and iron overload suggest a need for alternative therapies. We previously used hydroxyurea (HU) and phlebotomy in two young adults with SCD and stroke as an alternative to transfusions. We have now prospectively discontinued transfusions in 16 pediatric patients with SCD and stroke. Reasons to discontinue transfusions included erythrocyte alloantibodies or autoantibodies, recurrent stroke on transfusions, iron overload, noncompliance, and deferoxamine allergy. HU was started at 15 mg/kg/d and escalated to 30 mg/kg/d based on hematologic toxicity. Patients with iron overload underwent phlebotomy. The children have been off transfusions 22 months, (range, 3 to 52 months). Their average HU dose is 24.9 ± 4.2 mg/kg/d, hemoglobin concentration is 9.4 ± 1.3 g/dL, and mean corpuscular volume (MCV) is 112 ± 9 fL. Maximum percentage fetal hemoglobin (%HbF) is 20.6% ± 8.0% and percentage HbF-containing erythrocytes (%F cells) is 79.3% ± 14.7%. Fourteen patients underwent phlebotomy with an average of 8,993 mL (267 mL/kg) removed. Serum ferritin has decreased from 2,630 to 424 ng/mL, and 4 children have normal ferritin values. Three patients (19%) had neurological events considered recurrent stroke, each 3 to 4 months after discontinuing transfusions, but before maximal HU effects. These preliminary data suggest some children with SCD and stroke may discontinue chronic transfusions and use HU therapy to prevent stroke recurrence. Phlebotomy is well-tolerated and significantly reduces iron overload. Modifications in HU therapy to raise HbF more rapidly might increase protection against stroke recurrence.

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Natriuretic Peptide Levels Correlate with Pulmonary Pressures and Prospective Mortality in SCD: Use of This Biomarker To Identify Prevalence and Mortality of Pulmonary Hypertension in the MSH Cohort.

Blood ◽

10.1182/blood.v106.11.1.1 ◽

2005 ◽

Vol 106 (11) ◽

pp. 1-1

Author(s):

Roberto Machado ◽

Martin Steinberg ◽

Duane Bonds ◽

Samir Ballas ◽

William Blackwelder ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Sickle Cell Disease ◽

Sickle Cell ◽

Proportional Hazards ◽

Cox Proportional Hazards ◽

Cell Disease ◽

Risk Of Death ◽

Cox Proportional Hazards Regression ◽

Proportional Hazards Regression

Abstract Pulmonary hypertension [PH-tricuspid regurgitant jet velocity (TRV) ≥2.5 m/s] is a common complication of sickle cell disease associated with high mortality. Identification of biomarkers of PH and mortality could facilitate screening and risk stratification in this population. Validated biomarkers would provide methods for retrospective evaluation of the prevalence and prognosis of PH in large historical cohorts of patients such as the Multicenter Study of Hydroxyurea in Sickle Cell Anemia(MSH). Because brain natriuretic peptide(BNP) is released from the ventricles during pressure strain, we hypothesized that BNP levels would correlate with the severity of PH and prospective risk of death in patients with SCD. BNP was measured in 45 African-American control subjects and 230 patients with SCD. Median (interquartile range) BNP(pg/ml) was higher in patients with PH than patients without PH or controls[+PH: 206(81–701),-PH: 47(26–104), C: 29, P<0.001]. BNP levels directly correlated with age (R=0.32, P<0.001), creatinine (R=0.22, P<0.001), LDH(R=0.31, P<0.001), TRV (R=0.5, P<0.001), pulmonary vascular resistance (R=0.5, P=0.001); and inversely with hemoglobin(R=0.41, P<0.001), cardiac output(R=0.47, P= 0.003) and 6-minute walk distance(R=0.51, P=0.001). The area under the ROC for BNP and the diagnosis of pulmonary hypertension was 0.84 (P<0.001). A cutoff value of 160 pg/ml (corresponding to the 75th percentile for the population) had 58% sensitivity and 98% specificity for the diagnosis of PH. Cox proportional hazards regression identified BNP as an independent predictor of mortality(RR 2.17,95% CI 1.2–3.8, P =0.001) with clear mortality break point at the 75th percentile(160 pg/ml). To independently explore the prevalence and associated risk of PH in patients with sickle cell disease, a BNP value of 160 pg/ml was used as an indicator of PH. BNP levels were then measured in plasma samples collected in 121 patients who were enrolled in the MSH patient’s follow-up study that started in 1996. These patients had received hydroxyurea or placebo for two years, had moderately severe disease based on study entry criteria, and had 9-years of comprehensive follow-up. An abnormal BNP level ≥160 pg/ml was present in 30% of patients in the MSH cohort. BNP levels correlated directly with age(R=0.35, P<0.001) and creatinine (R=0.24, P<0.001), and inversely with hemoglobin(R=−0.54, P<0.001). There was no correlation between BNP and rate of painful episodes or acute chest syndrome, use of hydroxyurea or leukocyte count. A high BNP level in the MSH cohort was associated with mortality by logistic regression(OR 3.04,95% CI 1.2–7.6, P = 0.018) and Cox proportional hazards regression analysis(RR 2.87, P=0.017). The relationship remained significant for continuous log- transformed BNP values and after adjustment for other covariates. These studies confirm that PH is common, mechanistically linked to hemolytic anemia and the major risk factor for death in SCD. Provocatively, the MSH analysis suggests that rates of pain episodes in this small sample of seriously ill patients were unrelated to risk of death: this risk was largely determined by a high BNP level, which is probably explained by undiagnosed hemolysis-associated PH.

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Polymorphisms in TNFα Are Associated with Cerebrovascular Events in Sickle Cell Disease.

Blood ◽

10.1182/blood.v114.22.1540.1540 ◽

2009 ◽

Vol 114 (22) ◽

pp. 1540-1540 ◽

Cited By ~ 1

Author(s):

Latorya A Barber ◽

Allison E Ashley-Koch ◽

Melanie E. Garrett ◽

Karen L Soldano ◽

Marilyn J. Telen

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Conflicts Of Interest ◽

Umbilical Vein ◽

Acute Chest Syndrome ◽

Cell Disease ◽

Data Set ◽

Clinical Complications ◽

Cerebrovascular Events ◽

Increased Risk

Abstract Abstract 1540 Poster Board I-563 Tumor necrosis factor alpha (TNFα) is a pro-inflammatory cytokine that stimulates phagocytosis, neutrophil recruitment, and expression of adhesion molecule VCAM-1. Plasma levels of TNFα have been found to be increased in sickle cell disease (SCD), and in vitro studies show that TNFα causes increased adherence of sickle red blood cells to human umbilical vein endothelial cells. A polymorphism in the promoter region of the TNFα gene has previously been associated with stroke in children with SCD (Hoppe et al., 2007). The current study was designed to identify associations of additional TNFα single nucleotide polymorphisms (SNPs) with SCD clinical complications. We analyzed five SNPs in the TNFα gene in 509 DNA samples of SCD patients from Duke University, University of North Carolina at Chapel Hill, and Emory University. In our data set, cerebrovascular events (CVEs), including overt stroke, seizures, and transient ischemic attacks, occurred in 133 out of 509 SCD patients (26.1%). SNP genotyping was performed using Taqman genotyping assays from Applied Biosystems. Due to low minor allele frequencies (<0.05) for all the SNPs examined, genetic associations with SCD clinical complications were examined by using allele tests. After controlling for age, gender, and use of hydroxyurea, two of the five TNFα SNPs, rs2228088 and rs3093665, were significantly associated with CVEs (p=0.013 and 0.029, respectively). The odds that SCD patients with a G allele at rs2228088 suffered from CVEs were 0.485 times that for patients with the T allele, suggesting that the G allele had a protective effect. The odds of having the A allele at rs3093665 and suffering from CVEs was also reduced, at 0.45 compared to the C allele. Neither SNP was found to be in linkage disequilibrium (LD) with any of the other SNPs analyzed (r2≤0.002). There was also strong association of SNP rs2228088 with acute chest syndrome (ACS; p=0.003), occurring in 382 out of 509 SCD patients (75%). However, in this analysis, the G allele was associated with increased risk for ACS (OR=2.313). In addition to the association with CVEs, the SNP rs3093665 was also significantly associated with priapism (p=0.03), reported by 86 of 223 male SCD patients (38.6%). In this analysis, the A allele was protective, as had been observed for CVE (OR=0.188). Additionally, we found no difference in steady state plasma TNFα levels between genotypes for the two SNPs. The functional significance of these SNPs is presently unknown. SNP rs2228088 is a synonymous SNP located in the coding region, and rs3093665 is located in the 3' untranslated region of the TNFα gene. While the G to T change at SNP rs2228088 does not translate to a change in amino acid sequence, the A to C change at SNP rs3093665 may affect mRNA stability due to its location. It is also possible that one or both of these SNPs is in LD with another functionally relevant SNP. Our findings thus support previous data implicating TNFα polymorphisms in risk for central nervous system events. Interestingly, ACS has been previously associated with seizures, stroke and altered mental status in adults and children with SCD (Vinchinsky et al., 2000) and with silent cerebral infarcts and reversible posterior leukoencephalopathy syndrome in children with SCD (Henderson et al., 2003). However, in our dataset, ACS and the occurrence of CVEs were not associated (p=0.24). Further studies are required to elucidate these and other factors that potentially correlate with SCD clinical complications. Disclosures No relevant conflicts of interest to declare.

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Five years of experience with hydroxyurea in children and young adults with sickle cell disease

Blood ◽

10.1182/blood.v97.11.3628 ◽

2001 ◽

Vol 97 (11) ◽

pp. 3628-3632 ◽

Cited By ~ 132

Author(s):

Alina Ferster ◽

Parvine Tahriri ◽

Christiane Vermylen ◽

Geneviève Sturbois ◽

Francis Corazza ◽

...

Keyword(s):

Sickle Cell Disease ◽

Sickle Cell ◽

Laboratory Data ◽

Acute Chest Syndrome ◽

Cell Disease ◽

Significant Difference ◽

History Of ◽

Ischemic Attack

The short-term beneficial effect of hydroxyurea (HU) in sickle cell disease (SCD) has been proven by randomized studies in children and adults. The Belgian registry of HU-treated SCD patients was created to evaluate its long-term efficacy and toxicity. The median follow-up of the 93 patients registered is 3.5 years; clinical and laboratory data have been obtained for 82 patients at 1 year, 61 at 2 years, 44 at 3 years, 33 at 4 years, and 22 after 5 years. On HU, the number of hospitalizations and days hospitalized dropped significantly. Analysis of the 22 patients with a minimum of 5 years of follow-up confirm a significant difference in the number of hospitalizations (P = .0002) and days in the hospital (P < .01), throughout the treatment when compared to prior to HU therapy. The probabilities of not experiencing any event or any vaso-occlusive crisis requiring hospitalization during the 5 years of treatment were, respectively, 47% and 55%. On HU, the rate per 100 patient-years of severe events was estimated to be 3.5% for acute chest syndrome, 1.2% for aplastic crisis, 0.4% for splenic sequestration; it was 0% for the 9 patients with a history of stroke or transient ischemic attack followed for an average of 4 years. No important adverse effect occurred. Long-term chronic treatment with HU for patients with SCD appears feasible, effective, and devoid of any major toxicity; in patients with a history of stroke, HU may be a valid alternative to chronic transfusion support.

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