Monica L. Hulbert

Silent cerebral infarcts occur despite regular blood transfusion therapy after first strokes in children with sickle cell disease

Children with sickle cell disease (SCD) and strokes receive blood transfusion therapy for secondary stroke prevention; despite this, approximately 20% experience second overt strokes. Given this rate of second overt strokes and the clinical significance of silent cerebral infarcts, we tested the hypothesis that silent cerebral infarcts occur among children with SCD being transfused for secondary stroke prevention. A prospective cohort enrolled children with SCD and overt strokes at 7 academic centers. Magnetic resonance imaging and magnetic resonance angiography of the brain were scheduled approximately every 1 to 2 years; studies were reviewed by a panel of neuroradiologists. Eligibility criteria included regularly scheduled blood transfusion therapy. Forty children were included; mean pretransfusion hemoglobin S concentration was 29%. Progressive cerebral infarcts occurred in 45% (18 of 40 children) while receiving chronic blood transfusion therapy; 7 had second overt strokes and 11 had new silent cerebral infarcts. Worsening cerebral vasculopathy was associated with new cerebral infarction (overt or silent; relative risk = 12.7; 95% confidence interval, 2.65-60.5, P = .001). Children with SCD and overt strokes receiving regular blood transfusion therapy experience silent cerebral infarcts at a higher rate than previously recognized. Additional therapies are needed for secondary stroke prevention in children with SCD.

Primary Hemorrhagic Stroke in Children With Sickle Cell Disease Is Associated With Recent Transfusion and Use of Corticosteroids

OBJECTIVES. Primary hemorrhagic stroke is an uncommon complication of sickle cell disease, with reported mortality rates of 24% to 65%. Most reported cases are in adults; little is known about its occurrence in children. Proposed risk factors include previous ischemic stroke, aneurysms, low steady-state hemoglobin, high steady-state leukocyte count, acute chest syndrome, and hypertransfusion. We performed a retrospective case-control study to evaluate risk and prognostic factors for primary hemorrhagic stroke among children with sickle cell disease. PATIENTS AND METHODS. Case subjects (sickle cell disease and primary hemorrhagic stroke) and control subjects (sickle cell disease and ischemic stroke) were identified at 2 children’s hospitals from January 1979 to December 2004 by reviewing divisional records and the discharge databases. RESULTS. We identified 15 case subjects (mean age: 10.4 ± 1.3 years) and 29 control subjects (mean age: 5.2 ± 0.4 years). An increased risk of hemorrhagic stroke was associated with a history of hypertension and recent (in the last 14 days) transfusion, treatment with corticosteroids, and possibly nonsteroidal antiinflammatory drugs. Average blood pressures at well visits (adjusted for age and gender) were similar between the 2 groups, suggesting that hypertension was intermittent CONCLUSIONS. In this group of children with sickle cell disease, hemorrhagic stroke was associated with a history of hypertension or antecedent events including transfusion or treatment with corticosteroids. Improved understanding of risk and prognostic factors, especially those that are modifiable, may help prevent this devastating complication in children with sickle cell disease.

A multicenter randomized controlled trial of intravenous magnesium for sickle cell pain crisis in children

Magnesium, a vasodilator, anti-inflammatory, and pain reliever, could alter the pathophysiology of sickle cell pain crises. We hypothesized that intravenous magnesium would shorten length of stay, decrease opioid use, and improve health-related quality of life (HRQL) for pediatric patients hospitalized with sickle cell pain crises. The Magnesium for Children in Crisis (MAGiC) study was a randomized, double-blind, placebo-controlled trial of intravenous magnesium vs normal saline placebo conducted at 8 sites within the Pediatric Emergency Care Applied Research Network (PECARN). Children 4 to 21 years old with hemoglobin SS or Sβ(0) thalassemia requiring hospitalization for pain were eligible. Children received 40 mg/kg of magnesium or placebo every 8 hours for up to 6 doses plus standard therapy. The primary outcome was length of stay in hours from the time of first study drug infusion, compared using a Van Elteren test. Secondary outcomes included opioid use and HRQL. Of 208 children enrolled, 204 received the study drug (101 magnesium, 103 placebo). Between-group demographics and prerandomization treatment were similar. The median interquartile range (IQR) length of stay was 56.0 (27.0-109.0) hours for magnesium vs 47.0 (24.0-99.0) hours for placebo (P = .24). Magnesium patients received 1.46 mg/kg morphine equivalents vs 1.28 mg/kg for placebo (P = .12). Changes in HRQL before discharge and 1 week after discharge were similar (P > .05 for all comparisons). The addition of intravenous magnesium did not shorten length of stay, reduce opioid use, or improve quality of life in children hospitalized for sickle cell pain crisis. This trial was registered at www.clinicaltrials.gov as #NCT01197417.

Health-related quality of life in children with sickle cell anemia: impact of blood transfusion therapy

The completion of the Multicenter Silent Infarct Transfusion Trial demonstrated that children with pre‐existing silent cerebral infarct and sickle cell anemia (SCA) who received regular blood transfusion therapy had a 58% relative risk reduction of infarct recurrence when compared to observation. However, the total benefit of blood transfusion therapy, as assessed by the parents, was not measured against the burden of monthly blood transfusion therapy. In this planned ancillary study, we tested the hypothesis that a patient centered outcome, health‐related quality of life (HRQL), would be greater in participants randomly assigned to the blood transfusion therapy group than the observation group. A total of 89% (175 of 196) of the randomly allocated participants had evaluable entry and exit HRQL evaluations. The increase in Change in Health, measured as the childs health being better, was significantly greater for the transfusion group than the observation group (difference estimate = −0.54, P ≤ 0.001). This study provides the first evidence that children with SCA who received regular blood transfusion therapy felt better and had better overall HRQL than those who did not receive transfusion therapy. Am. J. Hematol. 90:139–143, 2015.

Clinical course of postthrombotic syndrome in children with history of venous thromboembolism.

Postthrombotic syndrome (PTS) is a chronic morbidity of venous thromboembolism (VTE) in children. Information about the evolution of PTS is lacking in children. Present study was aimed to evaluate the time-course of extremity PTS in children who were serially followed in a hematology clinic. This retrospective cohort study included 69 consecutive children with documented VTEs that presented with symptoms of extremity VTE: 67 extremity VTEs with or without extension to vena cava, 2 inferior vena cava VTEs. Severity of PTS was assessed using modified Villalta scale. Median age of the cohort was 12.6 years (interquartile range 1.6–15 years) while median follow-up was 28.7 months (interquartile range 13.3–33.4 months. PTS prevalence was 46.8% [95% confidence interval (CI) 37.9–57.7%]. Lower extremity VTE was associated with development of PTS compared to upper extremity VTE regardless of catheter use (P = 0.002). The time-course of PTS fluctuated in 11 of 33 children (33%; 95% CI 20–47%) at a median interval of 12 months from diagnosis of VTE (range 4–14 months): three progressed from mild/moderate to severe, one improved from moderate to mild, seven fluctuated between mild and moderate. Recurrence and incomplete resolution of VTE were associated with variability in PTS severity (P < 0.05). In summary, this study suggested that almost 50% of study cohort developed PTS, and the time-course of PTS was not static in one third of children. Future research should focus on identifying the predictors contributing to the worsening of PTS and developing risk-stratified treatment interventions so as to improve the outcome of children with VTE.

Fluorosis because of prolonged voriconazole therapy in a teenager with acute myelogenous leukemia.

Introduction Voriconazole is a second-generation antifungal medication prescribed for the treatment of invasive fungal infections and for Aspergillus prophylaxis in high-risk populations. Voriconazole is generally well tolerated; however, it has recently been implicated in diffuse painful periostitis in adult solid organ and bone marrow transplant patients who received long-term voriconazole. Because voriconazole contains fluorine, the mechanism of toxicity is suspected to be the accumulation of fluoride. In this article, we report voriconazoleand posaconazole-associated fluorosis with diffuse periostitis and exostoses in a teenager with acute myelogenous leukemia. To our knowledge, this is the first pediatric nontransplant patient reported with this toxicity.

Intravenous magnesium for pediatric sickle cell vaso‐occlusive crisis: Methodological issues of a randomized controlled trial

Multiple recent Sickle Cell Disease studies have been terminated due to poor enrollment. We developed methods to overcome past barriers and utilized these to study the efficacy and safety of intravenous magnesium for vaso‐occlusive crisis (VOC). We describe the methods of the Intravenous Magnesium in Sickle Vaso‐occlusive Crisis (MAGiC) trial and discuss methods used to overcome past barriers. MAGiC was a multi‐center randomized double‐blind placebo‐controlled trial of intravenous magnesium versus normal saline for treatment of VOC. The study was a collaboration between Pediatric Hematologists and Emergency Physicians in the Pediatric Emergency Care Applied Research Network (PECARN). Eligible patients were randomized within 12 hours of receiving intravenous opioids in the Emergency Department (ED) and administered study medication every 8 hours. The primary outcome was hospital length of stay. Associated plasma studies elucidated magnesiums mechanism of action and the pathophysiology of VOC. Health‐related quality of life was measured. Site‐, protocol‐, and patient‐related barriers from prior studies were identified and addressed. Limited study staff availability, lack of collaboration with the ED, and difficulty obtaining consent were previously identified barriers. Leveraging PECARN resources, forging close collaborations between Sickle Cell Centers and EDs of participating sites, and approaching eligible patients for prior consent helped overcome these barriers. Participation in the PECARN network and establishment of collaborative arrangements between Sickle Cell Centers and their affiliated EDs are major innovative features of the MAGiC study that allowed improved subject capture. These methods could serve as a model for future studies of VOCs. Pediatr Blood Cancer 2014;61:1049–1054.

Cerebral vasculopathy in children with sickle cell anemia

Sickle cell anemia (SCA)-associated cerebral vasculopathy and moyamoya is a unique entity reflecting the abnormal interactions between sickled red blood cells (RBCs) and the cerebral arterial endothelium. Endothelial injury, coagulation activation, and the inflammatory response generated by sickled RBCs are implicated in the development of cerebral vasculopathy, but the pathophysiology remains incompletely understood. SCA-specific screening and treatment guidelines have successfully reduced the incidence of overt strokes in this high-risk population. However, despite aggressive hematological management, many children with cerebral vasculopathy due to SCA have progressive vasculopathy and recurrent strokes; therefore, more effective therapies, such as revascularization surgery and curative hematopoietic stem cell transplant, are urgently needed.

Unrelated Umbilical Cord Blood Transplantation for Sickle Cell Disease Following Reduced-Intensity Conditioning: Results of a Phase I Trial

Hematopoietic stem cell transplantation from HLA-matched sibling donors results in disease-free survival of >90% in patients with sickle cell disease (SCD); however, only approximately 18% of these patients have suitable donors available. Unrelated cord blood transplantation (UCBT) is one way to expand donor options for patients with severe SCD, but historically has been associated with high graft rejection rates (50% to 62%). We hypothesized that the addition of thiotepa to a previously tested reduced-intensity conditioning (RIC) regimen would support engraftment after UCBT in patients with SCD. Nine children (age 3 to 10 years) with cerebrovascular complications of SCD underwent 5-6/6 HLA-matched (A, B, and DRB1 loci) UCBT after conditioning with hydroxyurea, alemtuzumab, fludarabine, thiotepa, and melphalan. A calcineurin inhibitor and mycophenolate mofetil were used for graft-versus-host-disease (GVHD) prophylaxis. With median follow up of 2.1 years (range, 1 to 4.2 years), 7 patients had sustained donor cell engraftment and are free of SCD, and 2 patients had autologous recovery. Acute GVHD (grade II-IV) and mild and moderate chronic GVHD developed in 3 patients, 2 patients, and 1 patient, respectively. At >2 years post-UCBT, 4 of 5 patients discontinued systemic immunosuppression. Seven patients had viral infections (cytomegalovirus, Epstein-Barr virus, respiratory syncytial virus, or adenovirus) and recovered. The 1-year overall survival and disease-free survival rates were 100% and 78%, respectively. Thus, this RIC regimen was able to achieve donor engraftment in the majority of patients. Future efforts will focus on further reducing rates of acute GVHD and viral infection.

Higher-than-expected prevalence of silent cerebral infarcts in children with hemoglobin SC disease

To the editor: Individuals with hemoglobin (Hb) SC disease have fewer vaso-occlusive events and greater life expectancy than those with Hb SS, and they have been excluded from most interventional clinical trials. Although the 10% prevalence of overt stroke and >35% prevalence of silent cerebral