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The North American Pediatric Aplastic Anemia Consortium (NAPAAC) is a group of pediatric hematologist-oncologists, hematopathologists, and bone marrow transplant physicians from 46 institutions in North America with interest and expertise in aplastic anemia, inherited bone marrow failure syndromes, and myelodysplastic syndromes. The NAPAAC Bone Marrow Failure Diagnosis and Care Guidelines Working Group was established with the charge of harmonizing the approach to the diagnostic workup of aplastic anemia in an effort to standardize best practices in the field. This document outlines the rationale for initial evaluations in pediatric patients presenting with signs and symptoms concerning for severe aplastic anemia.

Pyruvate kinase deficiency (PKD) is a rare, autosomal recessive red blood cell enzyme disorder, which leads to lifelong hemolytic anemia and associated complications from the disease and its management.An international, multicenter registry enrolled 124 individuals younger than 18 years old with molecularly confirmed PKD from 29 centers. Retrospective and prospective clinical data were collected.There was a wide range in the age at diagnosis from 0 to 16 years. Presentation in the newborn period ranged from asymptomatic to neonatal jaundice to fulminant presentations of fetal distress, myocardial depression, and/or liver failure. Children5 years old were significantly more likely to be transfused than children12 to18 years (53% vs. 14%, p = .0006), which correlated with the timing of splenectomy. Regular transfusions were most common in children with two severe PKLR variants. In regularly transfused children, the nadir hemoglobin goal varied considerably. Impact on quality of life was a common reason for treatment with regular blood transfusions and splenectomy. Splenectomy increased the hemoglobin and decreased transfusion burden in most children but was associated with infection or sepsis (12%) and thrombosis (1.3%) even during childhood. Complication rates were high, including iron overload (48%), perinatal complications (31%), and gallstones (20%).There is a high burden of disease in children with PKD, with wide practice variation in monitoring and treatment. Clinicians must recognize the spectrum of the manifestations of PKD for early diagnostic testing, close monitoring, and management to avoid serious complications in childhood.

The etiology of severe hemolytic anemia in most patients with recessive hereditary spherocytosis (rHS) and the related disorder hereditary pyropoikilocytosis (HPP) is unknown. Whole exome sequencing of DNA from probands of 24 rHS or HPP kindreds identified numerous mutations in erythrocyte membrane α-spectrin (SPTA1). Twenty-eight mutations were novel, with null alleles frequently found in trans to missense mutations. No mutations were identified in a third of SPTA1 alleles (17/48). Whole genome sequencing revealed linkage disequilibrium between the common rHS-linked α-spectrinBug Hill polymorphism and a rare intron 30 variant in all 17 mutation-negative alleles. In vitro minigene studies and in vivo splicing analyses revealed the intron 30 variant changes a weak alternate branch point (BP) to a strong BP. This change leads to increased utilization of an alternate 3' splice acceptor site, perturbing normal α-spectrin mRNA splicing and creating an elongated mRNA transcript. In vivo mRNA stability studies revealed the newly created termination codon in the elongated transcript activates nonsense mediated decay leading to spectrin deficiency. These results demonstrate a unique mechanism of human genetic disease contributes to the etiology of a third of cases of rHS, facilitating diagnosis and treatment of severe anemia, and identifying a new target for therapeutic manipulation.

Congenital dyserythropoietic anemias (CDAs) are characterized by ineffective erythropoiesis and distinctive erythroblast abnormalities; the diagnosis is often missed or delayed due to significant phenotypic heterogeneity. We established the CDA Registry of North America (CDAR) to study the natural history of CDA and create a biorepository to investigate the pathobiology of this heterogeneous disease. Seven of 47 patients enrolled so far on CDAR have CDA-I due to biallelic CDAN1 mutations. They all presented with perinatal anemia and required transfusions during infancy. Anemia spontaneously improved during infancy in three patients; two became transfusion-independent rapidly after starting interferon-α(2); and two remain transfusion-dependent at last follow-up at ages 5 and 30 y.o. One of the transfusion-dependent patients underwent splenectomy at 11 y.o due to misdiagnosis and returned to medical attention at 27 y.o with severe hemolytic anemia and pulmonary hypertension. All patients developed iron overload even without transfusions; four were treated with chelation. Genetic testing allowed for more rapid and accurate diagnosis; the median age of confirmed diagnosis in our cohort was 3 y.o compared to 17.3 y.o historically. In conclusion, CDAR provides an organized research network for multidisciplinary clinical and research collaboration to conduct natural history and biologic studies in CDA.

This book chapter appears in the CAMBRIDGE HANDBOOK ON INTERNATIONAL AND COMPARATIVE TRADEMARK LAW, edited by Jane C. Ginsburg and Irene Calboli (Cambridge Univ. Press 2020). The Chapter provides an overview of the defenses to trademark infringement, dilution, and false endorsement claims that serve the goals of free expression and fair competition. In particular, the Chapter covers the defenses of genericism, functionality, descriptive and nominative fair use, the Rogers test, statutory exemptions to dilution claims, and the questions of whether and how an independent First Amendment defense applies in light of recent Supreme Court decisions. In addition to providing a useful guide to each of these defenses in U.S. law, the Chapter makes several overarching observations about these speech and competition-related defenses. First, that the speech or competition values asserted by the defendants influence the likely success of the claims. Defenses are more successful when the uses are in creative or artistic works, convey relevant information to potential consumers (even in advertising), or are deemed a commercial necessity. Second, that the perceived “reasonableness” of the defendant’s use will determine the likely success of the asserted defense. This is true even when the particular defense does not explicitly include such a consideration. Finally, that these defenses serve as an important counterbalance to the broad scope of today’s trademark law, which has expanded dramatically over the last century, particularly in the last few decades with the addition of dilution claims to the federal regime. The defenses highlighted in this Chapter provide a powerful antidote to the potential for trademark and related laws to shut down speech and unduly limit competition. The First Amendment and its speech-protective penumbras incorporated into trademark law provide latitude to use others’ marks both in commercial and noncommercial speech, but this protection is not without limits. When a use exceeds what is appropriate under the circumstances, and is perceived as primarily profiting from another’s goodwill without a corresponding speech benefit, these defenses are unlikely to provide protective shade.

Background: Pyruvate kinase deficiency (PKD) is the most common cause of chronic hereditary non-spherocytic hemolytic anemia. The spectrum of disease in PKD is broad, ranging from an incidentally discovered mild anemia to a severe transfusion-dependent anemia. Splenectomy partially ameliorates the anemia and reduces the transfusion burden in the majority of patients. Because hemoglobin poorly correlates with symptoms in PKD, transfusion requirements are typically used clinically to classify disease severity with those who are regularly transfused despite splenectomy recognized as the most severely affected subgroup. Aim: To compare demographics, complications, and laboratory results between the most severely-affected PKD patients (those that are splenectomized and regularly transfused) with non-regularly transfused splenectomized PKD patients. Methods: After ethics committee approval, patients were enrolled on the PKD Natural History Study, a prospective 30 site international study. All patients had molecularly confirmed PKD. Only splenectomized patients were included in the analysis. Transfusion frequency was observed over a 3-year period. Patients were divided into two groups based on transfusion frequency: the severe phenotype group was defined as those who receive regular transfusions (≥6 discrete red cell transfusion episodes per year) and the control group did not receive regular transfusions. Phenotype stability over the 3-year period was also assessed. Results: 154 splenectomized patients with PKD were included: 30 patients in the severe PKD phenotype group and 124 patients in the comparison PKD group. Results of the analysis comparing the two groups are described in the Table. Severely affected patients were more likely to be female (77% versus 51%, p=0.013), older at the time of splenectomy (median age: 5 versus 3.6, p=0.011), have iron overload (93% vs. 51%, p Conclusions: Patients with PKD who are regularly transfused despite splenectomy appeared to have similar rates of PKD-associated complications (except for iron overload) and similar relevant laboratory values and genotypes when compared to those who are not regularly transfused after splenectomy. The similarity observed between severe phenotype patients and comparison patients with PKD may result from a protective effect of transfusion (e.g. reduction of bone fractures and extramedullary hematopoiesis) or could suggest transfusion-dependence is an artificial signifier of disease severity, reflective of provider practices and patient symptoms rather than an actual distinct phenotype. Transfusion requirements in severe PKD appear to fluctuate significantly over time. Download : Download high-res image (830KB) Download : Download full-size image Disclosures Al-Samkari: Dova: Consultancy, Research Funding; Agios: Consultancy, Research Funding; Moderna: Consultancy. van Beers: RR Mechatronics: Research Funding; Agios Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Research Funding. Barcellini: Agios: Consultancy, Other: Advisory board; Apellis: Consultancy; Incyte: Consultancy, Other: Advisory board; Bioverativ: Consultancy, Other: Advisory board; Novartis: Research Funding, Speakers Bureau; Alexion: Consultancy, Research Funding, Speakers Bureau. Eber: Agios Pharmaceuticals, Inc.: Consultancy. Glader: Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat: Alexion: Other: advisory board; Agios Pharmaceuticals, Inc.: Other: advisory board. Kuo: Pfizer: Consultancy; Novartis: Consultancy, Honoraria; Celgene: Consultancy; Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy. Despotovic: Dova: Honoraria; Novartis: Research Funding; Amgen: Research Funding. Kwiatkowski: Celgene: Consultancy; Terumo: Research Funding; Apopharma: Research Funding; bluebird bio, Inc.: Consultancy, Research Funding; Agios: Consultancy; Imara: Consultancy; Novartis: Research Funding. Thompson: Baxalta: Research Funding; Novartis: Consultancy, Research Funding; bluebird bio, Inc.: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Ravindranath: Agios Pharmaceuticals, Inc.: Other: I am site PI on several Agios-sponsored studies, Research Funding. Rothman: Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Agios: Honoraria, Research Funding. Verhovsek: Sickle Cell Awareness Group of Ontario: Membership on an entity's Board of Directors or advisory committees; Sickle Cell Disease Association of Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding; Canadian Haemoglobinopathy Association: Membership on an entity's Board of Directors or advisory committees; Vertex: Consultancy. Kunz: Novartis: Membership on an entity's Board of Directors or advisory committees. Sheth: CRSPR/Vertex: Other: Clinical Trial Steering committee; Apopharma: Other: Clinical trial DSMB; Celgene: Consultancy. London: United Therapeutics: Consultancy; ArQule, Inc: Consultancy. Grace: Novartis: Research Funding; Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

BACKGROUND: Children with sickle cell disease (SCD) are at increased risk for bacterial infections including osteomyelitis (OM). Fever and bone pain, key presenting symptoms of OM, are common in SCD, thus complicating diagnosis. We reviewed presentation, imaging features, and microbiologic etiologies of children with SCD treated for OM. METHODS: The comprehensive SCD clinical database of children and adolescents with SCD followed at a single, large tertiary pediatric center was searched to identify all diagnostic coding for potential cases of osteomyelitis in children ages 6 months to 21 years from 2010 – 2019. Medical charts were reviewed to determine OM diagnostic probability based on radiographic and microbiologic findings and the duration of prescribed antibiotic treatment for OM. RESULTS: Review of 3,553 patients (18,039 person-years) identified 20 episodes of probable OM in 19 children. Magnetic resonance imaging (MRI) findings to support OM were definitive in 4/19 (21%), probable in 10/19 (53%), suspected in 5/19 (26%), based on blinded radiologist review. Blood and/or operative cultures from bone and tissue debridement isolated Salmonella species in 7 (35%) cases and Methicillin-susceptible Staphylococcus aureus (MSSA) in 2 (10%). Six patients received antibiotic treatment prior to obtainment of cultures. Of culture-positive cases, MRI findings for OM were definitive or probable in 6/9 (67%), suspected in 3/9 (33%). CONCLUSIONS: Distinction between OM and sickle-related bone infarct or vaso-occlusion is difficult based on imaging findings alone. Early attainment of blood and operative cultures increases the likelihood of identifying and adequately treating OM.

BACKGROUND: Total splenectomy (TS) and partial splenectomy (PS) are used for children with congenital hemolytic anemia (CHA), although the long-term outcomes of these procedures are poorly defined. This report describes long-term outcomes of children with CHA requiring TS or PS. PROCEDURE: We collected data from children ages 2-17 with hereditary spherocytosis (HS) or sickle cell disease (SCD) requiring TS or PS from 1996 to 2016 from 14 sites in the Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium using a prospective, observational patient registry. We summarized hematologic outcomes, clinical outcomes, and adverse events to 5 years after surgery. Hematologic outcomes were compared using mixed effects modeling. RESULTS: Over the study period, 110 children with HS and 97 children with SCD underwent TS or PS. From preoperatively compared to postoperatively, children with HS increased their mean hemoglobin level by 3.4 g/dL, decreased their mean reticulocyte percentage by 6.7%, and decreased their mean bilirubin by 2.4mg/dL. Hematologic improvements and improved clinical outcomes were sustained over 5 years of follow-up. For children with SCD, there was no change in hemoglobin after PS or TS following surgery, although all clinical outcomes were improved. Over 5 years, there was one child with HS and 5 children with SCD who developed post-splenectomy sepsis. CONCLUSIONS: For children with HS, there are excellent long-term hematologic and clinical outcomes following either PS or TS. Although hemoglobin levels do not change after TS or PS in SCD, the long-term clinical outcomes for children with SCD are favorable.

Diagnosis of pyruvate kinase deficiency (PKD), the most common cause of hereditary non-spherocytic haemolytic anaemia, remains challenging in routine practice and no biomarkers for clinical severity have been characterised. This prospective study enrolled 41 patients with molecularly confirmed PKD from nine North American centres to evaluate the diagnostic sensitivity of pyruvate kinase (PK) enzyme activity and PK:hexokinase (HK) enzyme activity ratio, and evaluate the erythrocyte PK (PK-R) protein level and erythrocyte metabolites as biomarkers for clinical severity. In this population not transfused for ≥90 days before sampling, the diagnostic sensitivity of the PK enzyme assay was 90% [95% confidence interval (CI) 77-97%], whereas the PK:HK ratio sensitivity was 98% (95% CI 87-100%). There was no correlation between PK enzyme activity and clinical severity. Transfusion requirements correlated with normalised erythrocyte ATP levels (r = 0·527, P = 0·0016) and PK-R protein levels (r = -0·527, P = 0·0028). PK-R protein levels were significantly higher in the never transfused [median (range) 40·1 (9·8-73·9)%] versus ever transfused [median (range) 7·7 (0·4-15·1)%] patients (P = 0·0014). The PK:HK ratio had excellent sensitivity for PK diagnosis, superior to PKLR exon sequencing. Given that the number of PKLR variants and genotype combinations limits prognostication based on molecular findings, PK-R protein level may be a useful prognostic biomarker of disease severity and merits further study.

Hereditary hemolytic anemias (HHA) are a heterogeneous group of anemias associated with decreased red cell survival. While there can be clinical benefit of splenectomy in many cases, splenectomy is not appropriate for all types of HHA. Additionally, there are significant risks during and following splenectomy including surgical risks, postsplenectomy sepsis, and thrombotic complications. This review discusses the diagnostic approach to HHA as well as the role of splenectomy in the management. Surgical approaches and outcomes for total and partial splenectomy are discussed.

Immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder which presents with isolated thrombocytopenia and risk of hemorrhage. While most children with ITP promptly recover with or without drug therapy, ITP is persistent or chronic in others. When needed, how to select second-line therapies is not clear. ICON1, conducted within the Pediatric ITP Consortium of North America (ICON), is a prospective, observational, longitudinal cohort study of 120 children from 21 centers starting second-line treatments for ITP which examined treatment decisions. Treating physicians reported reasons for selecting therapies, ranking the top three. In a propensity weighted model, the most important factors were patient/parental preference (53%) and treatment-related factors: side effect profile (58%), long-term toxicity (54%), ease of administration (46%), possibility of remission (45%), and perceived efficacy (30%). Physician, health system, and clinical factors rarely influenced decision-making. Patient/parent preferences were selected as reasons more often in chronic ITP (85.7%) than in newly diagnosed (0%) or persistent ITP (14.3%, P = .003). Splenectomy and rituximab were chosen for the possibility of inducing long-term remission (P < .001). Oral agents, such as eltrombopag and immunosuppressants, were chosen for ease of administration and expected adherence (P < .001). Physicians chose rituximab in patients with lower expected adherence (P = .017). Treatment choice showed some physician and treatment center bias. This study illustrates the complexity and many factors involved in decision-making in selecting second-line ITP treatments, given the absence of comparative trials. It highlights shared decision-making and the need for well-conducted, comparative effectiveness studies to allow for informed discussion between patients and clinicians.

Vaso-Occlusive Crises (VOCs) in patients with SCD cause acute and chronic morbidity including disabling pain, hospitalizations, missed school and work, end-organ damage, and early mortality. VOC prophylaxis, while beneficial, does not address the disabling pain and morbidity of breakthrough VOC events that still occur. E-selectin upregulation on vascular endothelium leads to leukocyte trapping, activation and aggregation and is a critical driver of acute VOC (Morikis et al, Blood 2017). Rivipansel, a pan-selectin inhibitor with potent activity against E-selectin, prevents interaction between leukocytes and vascular endothelium (Morikis et al, Blood 2017) and increases blood flow by reducing cell-cell aggregates and vascular occlusion in a SCD mouse model (Chang et al, Blood 2010). A phase 2 study of rivipansel in VOC demonstrated shorter hospital stays and reduced opioid use (Telen et al Blood, 2015). The RESET trial (NCT02187003) was a phase 3, randomized, double-blind, placebo-controlled, study of the efficacy and safety of rivipansel for VOC requiring hospitalization. Three hundred forty-five patients (204 patients ≥18 and 141 patients 6-17 years of age) were randomized to an intravenous rivipansel loading dose, followed by up to 14 additional doses Q 12 hr, or placebo, in addition to standard care. Overall, 320 were treated: 162 with rivipansel, 158 with placebo. Pre-treatment variables were well balanced, including concomitant hydroxyurea use, genotype, chronic opioid use, gender, and country. The primary endpoint was time to readiness for discharge (TTRFD), and key secondary endpoints were time to discharge (TTD), time to discontinuation of IV opioids (TTDIVO), and cumulative IV opioid use (CIVO). Hazard ratios or ratios of medians, and confidence intervals were calculated for each. Both study arms had comparable baseline soluble E-selectin (sE-sel) levels and inflammatory/coagulation biomarkers. Median sE-sel in the rivipansel group decreased by 59% from baseline after a loading dose while increasing by 9% in the placebo group. Although the RESET study did not show statistically significant improvements in outcomes for the total population, additional analysis demonstrated that rivipansel treatment within 26.4 hr of pain onset (earliest quartile of duration of VOC until treatment) reduced median TTRFD by 56.3 hrs (from 122.0 to 65.7 hrs), reduced median TTD by 41.5 hrs (from 112.8 to 71.3 hrs), and reduced median TTDIVO by 50.5 hrs (from 104.0 to 53.5 hrs), compared to placebo. There was also a consistent trend for lower hazard ratios for rivipansel treatment earlier during VOC (up to ~36 hr from onset) for all endpoints (Figure 1). Pediatric subjects (6-17 yrs, n = 141) were 41% of patients treated in the RESET trial (71 in rivipansel arm, 70 in placebo arm). As in the overall population the observed benefit with rivipansel in pediatric subjects depended on duration of VOC prior to treatment. Children 6-17 yrs of age treated with rivipansel within 30 hrs of onset of VOC experienced reduction in median TTRFD by 29.3 hrs (from 94.1 to 64.8 hrs), reduction in median TTD by 23.2 hrs (from 92.8 to 69.6 hrs), and reduction in median TTDIVO by 15.4 hrs (from 68.9 to 53.5 hrs). Early treatment with rivipansel decreased median TTRFD by more than one day and led to more children ready for discharge by 24, 48, and 72 hrs, compared to patients receiving placebo (Table 1). Additionally, pain scale assessments (VAS and Faces scale) showed a substantial reduction in the time to first clinically meaningful reduction in pain (data not shown). Thus, the hazard ratios for the efficacy endpoints favored early rivipansel treatment over placebo in the overall population and the pediatric population (Table 2). Summary: Rivipansel administered early in VOC results in clinically meaningful benefit for adults and children with SCD, shortening IV opioid use and hospital stay. Biomarker data confirm on-target effect, suggesting that the diminishing effect of later rivipansel treatment results from downstream pathophysiology. These findings suggest the utility of early treatment to shorten or interrupt acute VOCs, analogous to thrombolysis for heart attack or stroke. This could change the VOC treatment paradigm from deferral of hospitalization to one of early intervention to reduce length of hospitalization and IV opioid requirement, relieve VOC symptoms, and possibly mitigate end-organ damage from tissue ischemia. Disclosures Dampier: Merck: Research Funding; Hudson Publishing Company: Consultancy, Research Funding; CLS Behring: Consultancy, Other: DSMB Chair; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Micelle Biopharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cyclerion: Consultancy, Other: DSMB Chair; Novartis: Research Funding. Telen:GlycoMimetics Inc.: Consultancy; Forma Therapeutics: Research Funding; CSL Behring: 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; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Wun:GlycoMimetics, Inc.: Consultancy; Pfizer, Inc.: Other: Steering Committee for clinical study, Research Funding. Smith:Incyte: Other: Investigator; Pfizer: Consultancy; Ironwood: Consultancy; Novo Nordisk: Consultancy; Imara: Research Funding; Shire: Research Funding; NHLBI: Research Funding; Patient-Centered Outcomes Research Institute: Other: Investigator, Research Funding; Health Resources and Services Administration: Other: Investigator, Research Funding; Shire, Inc.: Other: Investigator, Research Funding; Global Blood Therapeutics, Inc.: Consultancy, Research Funding; Novartis, Inc.: Consultancy, Other: Investigator, Research Funding; Emmaeus Pharmaceuticals, Inc.: Consultancy; GlycoMimetics, Inc.: Consultancy. Brown:Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Forma Therapeutics, Inc,: Research Funding; Imara, Inc.: Consultancy, Research Funding; Novartis, Inc.: Consultancy, Research Funding. Desai:Pfizer, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; GBT, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ironwood Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees; Rockpointe Continuing Medical Education Company: Consultancy. El Rassi:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cyclerion: Research Funding; Pfizer: Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bluebird bio: Membership on an entity's Board of Directors or advisory committees. Kanter:Wells Fargo: Honoraria; Medscape: Honoraria; Guidepoint Global: Honoraria; NHLBI Sickle Cell Advisory Board: Membership on an entity's Board of Directors or advisory committees; SCDAA Medical and Research Advisory Board: Membership on an entity's Board of Directors or advisory committees; AGIOS: Membership on an entity's Board of Directors or advisory committees; BEAM: Membership on an entity's Board of Directors or advisory committees; Jeffries: Honoraria; GLG: Honoraria; Sanofi: Consultancy; bluebird bio, inc: Consultancy, Honoraria; Novartis: Consultancy; Cowen: Honoraria. Pastore:Pfizer: Honoraria. Rothman:Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Agios Pharmaceuticals: Honoraria, Research Funding. Readett:Pfizer, Inc.: Current Employment. Lozier:GlycoMimetics, Inc.: Current Employment, Current equity holder in publicly-traded company. Magnani:GlycoMimetics, Inc.: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Thackray:GlycoMimetics, Inc.: Current Employment. Hassell:Pfizer, Inc.: Other: RESET Study Steering Committee; Pfizer, Inc.: Research Funding.

Pyruvate kinase (PK) deficiency is the most common red cell glycolytic enzyme defect causing hereditary non-spherocytic hemolytic anemia. Current treatments are mainly supportive and include red cell transfusions and splenectomy.[1][1] Regular red cell transfusions are known to result in iron

Custom, including industry practices and social norms, has a tremendous influence on intellectual property (“IP”) law, from affecting what happens outside of the courts in the trenches of the creative, technology, and science-based industries, to influencing how courts analyze infringement and defenses in IP cases. For decades, many scholars overlooked or dismissed the impact of custom on IP law in large part because of a belief that the dominant statutory frameworks that govern IP left little room for custom to play a role. In the last ten years, however, the landscape has shifted and more attention has been given to considering how custom affects IP entitlements both outside and inside the courtroom. This book chapter in the Research Handbook on the Economics of Intellectual Property Law focuses on the theoretical frames that inform the incorporation of custom into the law, and documents some of the practices and norms of various communities that use IP. I criticize the frequent and unreflected reliance on custom to determine the scope of IP rights, suggesting guidelines for when it can nevertheless be a sometimes useful tool for providing insights about IP laws. This analysis is partially informed by traditional common law limits on the incorporation of custom into the law. The chapter concludes with some recommendations for future areas of research for scholars based on my framework for thinking about custom in the context of IP laws.

Research consistently indicates that children with sickle cell disease (SCD) face multiple risk factors for neurocognitive impairment. Despite this, no empirical research to date has examined the impact of neurocognitive functioning on quality of life for this pediatric group. Thus, the current study aims to examine the relationship between executive functioning and quality of life in a sample of children with SCD and further explore psychosocial and family/caregiver resources as moderators of this relationship. A total of 45 children with SCD aged 8 to 16 years and their caregivers completed measures of quality of life, behavioral ratings of executive functioning, and psychosocial functioning. Hierarchical linear regression models were utilized to determine the impact of executive functioning on quality of life and further test the interaction effects of proposed moderating variables. Controlling for age, pain, and socioeconomic status (SES), executive functioning was found to significantly predict child- and parent-reported quality of life among youth with SCD. Psychosocial resources of the primary caregiver or family was not found to moderate the relationship between executive functioning and quality of life. These results provide the first empirical evidence that lower executive skills negatively predict quality of life for children with SCD, supporting clinical and research efforts which aim to establish efficacious interventions that target cognitive decrements within this pediatric population.

Summary Background For children with sickle cell anaemia and high transcranial doppler (TCD) flow velocities, regular blood transfusions can effectively prevent primary stroke, but must be continued indefinitely. The efficacy of hydroxycarbamide (hydroxyurea) in this setting is unknown; we performed the TWiTCH trial to compare hydroxyurea with standard transfusions. Methods TWiTCH was a multicentre, phase 3, randomised, open-label, non-inferiority trial done at 26 paediatric hospitals and health centres in the USA and Canada. We enrolled children with sickle cell anaemia who were aged 4–16 years and had abnormal TCD flow velocities (≥200 cm/s) but no severe vasculopathy. After screening, eligible participants were randomly assigned 1:1 to continue standard transfusions (standard group) or hydroxycarbamide (alternative group). Randomisation was done at a central site, stratified by site with a block size of four, and an adaptive randomisation scheme was used to balance the covariates of baseline age and TCD velocity. The study was open-label, but TCD examinations were read centrally by observers masked to treatment assignment and previous TCD results. Participants assigned to standard treatment continued to receive monthly transfusions to maintain 30% sickle haemoglobin or lower, while those assigned to the alternative treatment started oral hydroxycarbamide at 20 mg/kg per day, which was escalated to each participant's maximum tolerated dose. The treatment period lasted 24 months from randomisation. The primary study endpoint was the 24 month TCD velocity calculated from a general linear mixed model, with the non-inferiority margin set at 15 cm/s. The primary analysis was done in the intention-to-treat population and safety was assessed in all patients who received at least one dose of assigned treatment. This study is registered with ClinicalTrials.gov, number NCT01425307. Findings Between Sept 20, 2011, and April 17, 2013, 159 patients consented and enrolled in TWiTCH. 121 participants passed screening and were then randomly assigned to treatment (61 to transfusions and 60 to hydroxycarbamide). At the first scheduled interim analysis, non-inferiority was shown and the sponsor terminated the study. Final model-based TCD velocities were 143 cm/s (95% CI 140–146) in children who received standard transfusions and 138 cm/s (135–142) in those who received hydroxycarbamide, with a difference of 4·54 (0·10–8·98). Non-inferiority (p=8·82 × 10 −16 ) and post-hoc superiority (p=0·023) were met. Of 29 new neurological events adjudicated centrally by masked reviewers, no strokes were identified, but three transient ischaemic attacks occurred in each group. Magnetic resonance brain imaging and angiography (MRI and MRA) at exit showed no new cerebral infarcts in either treatment group, but worsened vasculopathy in one participant who received standard transfusions. 23 severe adverse events in nine (15%) patients were reported for hydroxycarbamide and ten serious adverse events in six (10%) patients were reported for standard transfusions. The most common serious adverse event in both groups was vaso-occlusive pain (11 events in five [8%] patients with hydroxycarbamide and three events in one [2%] patient for transfusions). Interpretation For high-risk children with sickle cell anaemia and abnormal TCD velocities who have received at least 1 year of transfusions, and have no MRA-defined severe vasculopathy, hydroxycarbamide treatment can substitute for chronic transfusions to maintain TCD velocities and help to prevent primary stroke. Funding National Heart, Lung, and Blood Institute, National Institutes of Health.

Although hemoglobin SC (HbSC) disease is usually considered less severe than sickle cell anemia (SCA), which includes HbSS and HbS/β(0) -thalassemia genotypes, many patients with HbSC experience severe disease complications, including vaso-occlusive pain, acute chest syndrome, avascular necrosis, retinopathy, and poor quality of life. Fully 20 years after the clinical and laboratory efficacy of hydroxyurea was proven in adult SCA patients, the safety and utility of hydroxyurea treatment for HbSC patients remain unclear. Recent NHLBI evidence-based guidelines highlight this as a critical knowledge gap, noting HbSC accounts for ∼30% of sickle cell patients within the United States. To date, only 5 publications have reported short-term, incomplete, or conflicting laboratory and clinical outcomes of hydroxyurea treatment in a total of 71 adults and children with HbSC. We now report on a cohort of 133 adult and pediatric HbSC patients who received hydroxyurea, typically for recurrent vaso-occlusive pain. Hydroxyurea treatment was associated with a stable hemoglobin concentration; increased fetal hemoglobin (HbF) and mean corpuscular volume (MCV); and reduced white blood cell count (WBC), absolute neutrophil count (ANC), and absolute reticulocyte count (ARC). Reversible cytopenias occurred in 22% of patients, primarily neutropenia and thrombocytopenia. Painful events were reduced with hydroxyurea, more in patients >15 years old. These multicenter data support the safety and potentially salutary effects of hydroxyurea treatment for HbSC disease; however, a multicenter, placebo-controlled, Phase 3 clinical trial is needed to determine if hydroxyurea therapy has efficacy for patients with HbSC disease.

The purpose of this study was to define the hematologic response to total splenectomy (TS) or partial splenectomy (PS) in children with hereditary spherocytosis (HS) or sickle cell disease (SCD).The Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium registry collected hematologic outcomes of children with CHA undergoing TS or PS to 1 year after surgery. Using random effects mixed modeling, we evaluated the association of operative type with change in hemoglobin, reticulocyte counts, and bilirubin. We also compared laparoscopic to open splenectomy.The analysis included 130 children, with 62.3% (n=81) undergoing TS. For children with HS, all hematologic measures improved after TS, including a 4.1g/dl increase in hemoglobin. Hematologic parameters also improved after PS, although the response was less robust (hemoglobin increase 2.4 g/dl, p0.001). For children with SCD, there was no change in hemoglobin. Laparoscopy was not associated with differences in hematologic outcomes compared to open. TS and laparoscopy were associated with shorter length of stay.Children with HS have an excellent hematologic response after TS or PS, although the hematologic response is more robust following TS. Children with SCD have smaller changes in their hematologic parameters. These data offer guidance to families and clinicians considering TS or PS.

Transcranial Doppler (TCD) With Transfusions Changing to Hydroxyurea (TWiTCH) trial is a randomized, open-label comparison of hydroxycarbamide (also termed hydroxyurea) versus continued chronic transfusion therapy for primary stroke prevention in patients with sickle cell anaemia (SCA) and abnormal TCD. Severity and location of iron overload is an important secondary outcome measure. We report the baseline findings of abdominal organ iron burden in 121 participants. At enrollment, patients were young (9·8 ± 2·9 years), predominantly female (60:40), and previously treated with transfusions (4·1 ± 2·4 years) and iron chelation (3·1 ± 2·1 years). Liver iron concentration (LIC; 9·0 ± 6·6 mg/g dry weight) and serum ferritin were moderately elevated (2696 ± 1678 μg/l), but transferrin was incompletely saturated (47·2 ± 23·6%). Spleen R2* was 509 ± 399 Hz (splenic iron ~13·9 mg/g) and correlated with LIC (r(2) = 0·14, P = 0·0008). Pancreas R2* was increased in 38·3% of patients but not to levels associated with endocrine toxicity. Kidney R2* was increased in 80·7% of patients; renal iron correlated with markers of intravascular haemolysis and was elevated in patients with increased urine albumin-creatinine ratios. Extra-hepatic iron deposition is common among children with SCA who receive chronic transfusions, and could potentiate oxidative stress caused by reperfusion injury and decellularized haemoglobin.

Hydroxyurea (HU) is a crucial therapy for children with sickle cell anemia, but its off-label use is a barrier to widespread acceptance. We found HU exposure is not significantly altered by liquid vs capsule formulation, and weight-based dosing schemes provide consistent exposure. HU is recommended for all children starting as young as 9 months of age with sickle cell anemia (SCA; HbSS and HbSβspan(0) thalassemia); however; a paucity of pediatric data exists regarding the pharmacokinetics (PK) or the exposure-response relationship of HU. This trial aimed to characterize the PK of HU in children and to evaluate and compare the bioavailability of a liquid vs capsule formulation. This multicenter; prospective; open-label trial enrolled 39 children with SCA who provided 682 plasma samples for PK analysis following administration of HU. Noncompartmental and population PK models are described. We report that liquid and capsule formulations of HU are bioequivalent; weight-based dosing schemes provide consistent drug exposure; and age-based dosing schemes are unnecessary. These data support the use of liquid HU in children unable to swallow capsules and in those whose weight precludes the use of fixed capsule formulations. Taken with existing safety and efficacy literature; these findings should encourage the use of HU across the spectrum of age and weight in children with SCA; and they should facilitate the expanded use of HU as recommended in the National Heart; Lung; and Blood Institute guidelines for individuals with SCA.

Background: Pyruvate Kinase (PK) deficiency is caused by mutations in the PKLR gene leading to chronic hereditary non-spherocytic hemolytic anemia. Diagnostic evaluation can be challenging with falsely normal PK enzyme activity levels in chronically transfused patients, in those with profound reticulocytosis, or in patients with mutations with unusual biochemical properties. Genetic testing can also be complex, as up to 20% of affected patients have new PKLR variants and up to 10% of patients have variants not routinely detected through exon sequencing. The phenotypic spectrum is broad, and biomarkers of clinical severity would be helpful for both prognosis and monitoring. Aims: To describe the correlation of PK enzyme activity, red cell PK (PK-R) protein level, and red cell metabolites [adenosine triphosphate (ATP), 2,3-diphosphoglycerate (2,3-DPG)] with clinical phenotype. To estimate the sensitivity of PK enzyme activity to diagnose PK deficiency in a cohort of patients with genetically confirmed PK deficiency. Methods: Blood samples were collected from a subset of 41 patients enrolled in the PK Deficiency Natural History Study, all with two confirmed PKLR mutations and no red cell transfusions for ≥3 months prior to the blood sample. PK and hexokinase (HK) enzyme activity testing were performed using standard biochemical assays (Beutler 1985) at the Stanford Red Blood Cell Special Studies Laboratory (normal ranges: PK activity: 3.2-6.5 EU/gm Hb, HK activity: 0.14-0.37 EU/gm Hb). Baseline PK-R protein was quantitated by antibody-based capture and detection using a Meso Scale assay and the signal normalized to a control sample without PK deficiency. ATP and 2,3-DPG concentrations (μg/ml) in blood were analyzed using qualified tandem mass spectrometry methods and then normalized for individual hemoglobin (Hb) values (ATP and 2,3-DPG concentrations were converted to g/dL and divided by Hb (g/dL)). Spearman correlation coefficients were calculated to estimate the correlation between continuous variables, and Wilcoxon rank-sum testing was used to assess the association of continuous and binary variables. Results: The median age was 25.3 years (range 1.4-60.4) and 80% of patients were splenectomized (Table). The mean PK enzyme activity level was 1.1 EU/gm Hb with 90% (37/41) of patients with low PK activity. Normal PK activity was observed in 4 patients, 3 of whom had high HK activity and a low PK/HK ratio (normal mean PK/HK ratio 15.6, range: 8.7-22.5), with a sensitivity of 98% (40/41) when both PK activity and PK/HK ratio were used together. There were no correlations between PK enzyme activity and clinical severity indicators, including transfusion status (p=0.3), splenectomy status (p=0.4), or post-splenectomy Hb (r=0.109). Normalized ATP levels were significantly correlated with normalized 2,3-DPG levels (r=0.93) and higher in ever transfused (median=0.0022, range=0.0011-0.0029) compared with never transfused patients (median=0.0012 , range=0.0008-0.0020), (p=0.004). PK-R protein level was inversely correlated with the total number of transfusions prior to enrollment (r= -0.53) and was higher in never transfused (median=40.1%, range=9.8-73.9%) compared with ever transfused patients (median=7.7%, range=0.4%-15.1%), (p=0.0014). Conclusions: In this cohort with a molecularly confirmed diagnosis, PK deficiency was detected by enzyme testing with 98% sensitivity by utilizing both the PK activity and the PK/HK ratio. Although these assays cannot distinguish between heterozygotes and affected patients, the combination of PK activity and the PK/HK ratio is useful as a screening test to determine which patients require genetic testing. There was no correlation between PK enzyme activity and clinical phenotype. PK-R protein and ATP levels were inversely correlated with clinical severity and may be a helpful marker of disease phenotype. Disclosures Al-Samkari: Agios: Consultancy, Research Funding; Moderna: Consultancy; Dova: Consultancy, Research Funding. Glader:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat:Alexion: Other: advisory board; Agios Pharmaceuticals, Inc.: Other: advisory board. Thompson:bluebird bio, Inc.: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Baxalta: Research Funding. Kuo:Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy; Celgene: Consultancy; Novartis: Consultancy, Honoraria; Pfizer: Consultancy. Ravindranath:Agios Pharmaceuticals, Inc.: Other: I am site PI on several Agios-sponsored studies, Research Funding. Rothman:Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Agios: Honoraria, Research Funding. Kwiatkowski:Celgene: Consultancy; Terumo: Research Funding; Imara: Consultancy; Apopharma: Research Funding; Novartis: Research Funding; bluebird bio, Inc.: Consultancy, Research Funding; Agios: Consultancy. Kung:Agios Pharmaceuticals, Inc: Employment, Other: Stakeholder. Kosinski:Agios Pharmaceuticals, Inc: Employment, Other: Stakeholder. London:United Therapeutics: Consultancy; ArQule, Inc: Consultancy. Grace:Novartis: Research Funding; Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Introduction: Pyruvate kinase (PK) deficiency causes a defect in the glycolytic pathway, leading to a hereditary hemolytic anemia. Management is supportive and consists of splenectomy, transfusions, and chelation therapy. Aim: To better understand the comorbidity and complication profile of adults with PK deficiency, and the extent to which transfusion frequency contributes, the objectives of this study were to (1) quantify the prevalence of comorbidities and complications according to transfusion history and (2) compare the types and rates of select comorbidities and complications with the general population. Methods: Data were obtained from the enrollment survey of the PK Deficiency Natural History Study (NHS), a longitudinal, retrospective and prospective cohort study in which clinical, laboratory, transfusion, and radiologic data were collected; all participants were confirmed to have 2 mutations in the PKLR gene. Patients (n=122) were eligible for this analysis if they were ≥18 years of age and had sufficient data on transfusion history to enable classification into 1 of 3 cohorts: "Ever Regularly Transfused" (ERT, defined as ≥6 transfusions in any 12-month period), "Never Regularly Transfused" (NRT, defined as having ≥1 lifetime transfusion but never having >4 transfusions in any 12-month period), or "Never Transfused" (NT). To contextualize the findings, the frequencies of select conditions were compared with an age- and gender-matched cohort of individuals from the insured, general US population who did not have any hemolytic anemia diagnoses and had ≥5 years of continuous enrollment in the Truven MarketScan administrative claims database. The NHS reported lifetime prevalence rates, whereas rates obtained from the MarketScan data were based on diagnosis and procedure codes over varying look-back periods; therefore, to minimize bias, we limited PK deficiency vs. general population comparisons to (1) chronic conditions that require lifetime management and would thus still be recorded in claims data years after initial diagnosis, and/or (2) conditions for which a diagnosis/procedure date was available in the NHS and could be matched in time to the average 8-year look-back period for the general population. Frequencies were compared across mutually exclusive cohorts using Fisher's exact 2-tailed tests of significance. Results: ERT (n=65), NRT (n=30), and NT patients (n=27) had a mean age of 34.2, 39.5, and 37.2 years at enrollment, respectively (not significant [ns]), with 46.2%, 56.7%, and 59.3%, respectively, being male (ns). ERT patients trended toward being more likely than NT patients to be Amish and have the homozygous R479H splice variant (30.8% vs 11.1% [p=0.064]) but were significantly less likely to have a missense/missense PKLR genotype (32.3% vs 70.4% [p=0.001]). Compared with the general population, patients with PK deficiency had significantly higher rates of splenectomy, cholecystectomy, osteoporosis, liver cirrhosis, pulmonary hypertension, and current prophylactic antibiotic and anticoagulant use (Table). Rates of splenectomy, cholecystectomy, and osteoporosis were significantly higher in patients with PK deficiency, regardless of transfusion cohort, and both ERT and NRT patients had significantly higher rates of liver cirrhosis than individuals from the general population. A gradient was seen across transfusion cohorts for other conditions. Notably, 83.1% of ERT patients, 50.0% of NRT patients, and 25.9% of NT patients had a history of liver iron overload. ERT patients were also significantly more likely than NRT and NT patients to have had a splenectomy, cholecystectomy, and/or thrombosis, and to currently use prophylactic antibiotics. Findings were consistent when the analysis was restricted to non-Amish patients with PK deficiency. Conclusions: Patients with PK deficiency have higher rates of select comorbidities and complications than age- and gender-matched individuals who do not have PK deficiency. Even patients with PK deficiency who have never been transfused are at increased risk of complications of the disease and its treatment. Disclosures Boscoe: Agios Pharmaceuticals, Inc.: Employment, Equity Ownership. Yan:Agios Pharmaceuticals, Inc.: Consultancy. Hedgeman:IBM Watson Health: Employment. van Beers:Agios Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Research Funding; RR Mechatronics: Research Funding. Al-Samkari:Agios: Consultancy, Research Funding; Dova: Consultancy, Research Funding; Moderna: Consultancy. Barcellini:Incyte: Consultancy; Alexion: Consultancy, Speakers Bureau; Agios Pharmaceuticals, Inc.: Consultancy; Novartis: Speakers Bureau; Apellis: Consultancy; bioverativ: Consultancy. Eber:Agios Pharmaceuticals, Inc.: Consultancy. Glader:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat:Alexion: Other: advisory board; Agios Pharmaceuticals, Inc.: Other: advisory board. Rothman:Agios: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding. Kuo:Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy; Celgene: Consultancy; Novartis: Consultancy, Honoraria; Pfizer: Consultancy. Kwiatkowski:Agios: Consultancy; bluebird bio, Inc.: Consultancy, Research Funding; Imara: Consultancy; Apopharma: Research Funding; Novartis: Research Funding; Celgene: Consultancy; Terumo: Research Funding. Ravindranath:Agios Pharmaceuticals, Inc.: Other: I am site PI on several Agios-sponsored studies, Research Funding. Neufeld:Octapharma, Shire Pharmaceuticals (Baxalta), Novo Nordisk, Celgene, NHLBI/NIH: Research Funding; Octapharma, Agios, Acceleron, Grifols, Pfizer, CSL Behring, Shire Pharmaceuticals (Baxalta), Novo Nordisk, ApoPharma, Genentech, Novartis, Bayer Healthcare: Consultancy; Octapharma: Other: study investigator, NuProtect study (Octapharma-sponsored). Holzhauer:Agios Pharmaceuticals, Inc.: Consultancy. Verhovsek:Sickle Cell Disease Association of Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding; Canadian Haemoglobinopathy Association: Membership on an entity's Board of Directors or advisory committees; Vertex: Consultancy; Sickle Cell Awareness Group of Ontario: Membership on an entity's Board of Directors or advisory committees. Kunz:Novartis: Membership on an entity's Board of Directors or advisory committees. Sheth:Apopharma: Other: Clinical trial DSMB; Celgene: Consultancy; CRSPR/Vertex: Other: Clinical Trial Steering committee. Despotovic:Novartis: Research Funding; Dova: Honoraria. Grace:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding.

Background: Pyruvate kinase deficiency (PKD) is the most common cause of chronic hereditary non-spherocytic hemolytic anemia. The spectrum of disease in PKD is broad, ranging from an incidentally discovered mild anemia to a severe transfusion-dependent anemia. Splenectomy partially ameliorates the anemia and reduces the transfusion burden in the majority of patients. Because hemoglobin poorly correlates with symptoms in PKD, transfusion requirements are typically used clinically to classify disease severity with those who are regularly transfused despite splenectomy recognized as the most severely affected subgroup. Aim: To compare demographics, complications, and laboratory results between the most severely-affected PKD patients (those that are splenectomized and regularly transfused) with non-regularly transfused splenectomized PKD patients. Methods: After ethics committee approval, patients were enrolled on the PKD Natural History Study, a prospective 30 site international study. All patients had molecularly confirmed PKD. Only splenectomized patients were included in the analysis. Transfusion frequency was observed over a 3-year period. Patients were divided into two groups based on transfusion frequency: the severe phenotype group was defined as those who receive regular transfusions (≥6 discrete red cell transfusion episodes per year) and the control group did not receive regular transfusions. Phenotype stability over the 3-year period was also assessed. Results: 154 splenectomized patients with PKD were included: 30 patients in the severe PKD phenotype group and 124 patients in the comparison PKD group. Results of the analysis comparing the two groups are described in the Table. Severely affected patients were more likely to be female (77% versus 51%, p=0.013), older at the time of splenectomy (median age: 5 versus 3.6, p=0.011), have iron overload (93% vs. 51%, p Conclusions: Patients with PKD who are regularly transfused despite splenectomy appeared to have similar rates of PKD-associated complications (except for iron overload) and similar relevant laboratory values and genotypes when compared to those who are not regularly transfused after splenectomy. The similarity observed between severe phenotype patients and comparison patients with PKD may result from a protective effect of transfusion (e.g. reduction of bone fractures and extramedullary hematopoiesis) or could suggest transfusion-dependence is an artificial signifier of disease severity, reflective of provider practices and patient symptoms rather than an actual distinct phenotype. Transfusion requirements in severe PKD appear to fluctuate significantly over time. Disclosures Al-Samkari: Dova: Consultancy, Research Funding; Agios: Consultancy, Research Funding; Moderna: Consultancy. van Beers:RR Mechatronics: Research Funding; Agios Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Research Funding. Barcellini:Agios: Consultancy, Other: Advisory board; Apellis: Consultancy; Incyte: Consultancy, Other: Advisory board; Bioverativ: Consultancy, Other: Advisory board; Novartis: Research Funding, Speakers Bureau; Alexion: Consultancy, Research Funding, Speakers Bureau. Eber:Agios Pharmaceuticals, Inc.: Consultancy. Glader:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat:Alexion: Other: advisory board; Agios Pharmaceuticals, Inc.: Other: advisory board. Kuo:Pfizer: Consultancy; Novartis: Consultancy, Honoraria; Celgene: Consultancy; Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy. Despotovic:Dova: Honoraria; Novartis: Research Funding; Amgen: Research Funding. Kwiatkowski:Celgene: Consultancy; Terumo: Research Funding; Apopharma: Research Funding; bluebird bio, Inc.: Consultancy, Research Funding; Agios: Consultancy; Imara: Consultancy; Novartis: Research Funding. Thompson:Baxalta: Research Funding; Novartis: Consultancy, Research Funding; bluebird bio, Inc.: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Ravindranath:Agios Pharmaceuticals, Inc.: Other: I am site PI on several Agios-sponsored studies, Research Funding. Rothman:Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Agios: Honoraria, Research Funding. Verhovsek:Sickle Cell Awareness Group of Ontario: Membership on an entity's Board of Directors or advisory committees; Sickle Cell Disease Association of Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding; Canadian Haemoglobinopathy Association: Membership on an entity's Board of Directors or advisory committees; Vertex: Consultancy. Kunz:Novartis: Membership on an entity's Board of Directors or advisory committees. Sheth:CRSPR/Vertex: Other: Clinical Trial Steering committee; Apopharma: Other: Clinical trial DSMB; Celgene: Consultancy. London:United Therapeutics: Consultancy; ArQule, Inc: Consultancy. Grace:Novartis: Research Funding; Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Introduction: The incidence of venous thromboembolism (VTE) in hospitalized pediatric patients is increasing secondary to the growing medical complexity of pediatric patients and the increasing use of central venous catheters. Pediatric patients diagnosed with VTE have up to 2% mortality associated directly with their thromboses. While incidence, risk factor identification and preventive strategies are well established in hospitalized adults, this information is limited in the pediatric population. There are currently no standardized VTE risk screening tools or thromboprophylaxis guidelines for children at Duke Children's Hospital. The incidence of hospital acquired VTE (HA-VTE), as well as their associated risk factors were investigated in a retrospective review. Methods: Medical records of pediatric patients hospitalized at Duke Children's Hospital during June 2018 through November 2018 were reviewed. The EPIC SlicerDicer tool was used to identify patients with ICD-10 diagnoses codes related to thrombosis or treated with anticoagulants. Included patients were diagnosed with HA-VTE during their hospitalization or within 14 days of discharge. Data collected included demographics, thrombosis characteristics, family history, mobility, and acute or chronic co-morbid conditions. The characteristics of the study population were described by median (with 25th and 75th percentiles) for continuous variables and frequencies (with percentages) for binary or categorical variables. Results: Out of 4,176 total pediatric admissions to all units of Duke Children's Hospital (ages 0-18.99 years) during the inclusion timeframe, 33 VTE events were identified. The incidence of VTE events per 1000 patient days was 0.98. The complete patient and VTE event characteristics are listed in Tables 1 and 2. The median age of patients with VTE events was 0.4 years. Of the identified cohort, 73% had an associated central venous line (CVL). Neonates with congenital cardiac disease comprised the majority of the cohort. Other common patient characteristics observed in this cohort included impaired mobility, recent major surgery, and recent mechanical ventilation. Of the 33 VTE diagnoses, 70% received therapeutic anticoagulation with enoxaparin or unfractionated heparin. Only 2 patients (8%) received prophylactic anticoagulation prior to their diagnosis of VTE. Conclusions: The retrospective review of HA-VTE events at Duke Children's Hospital identified that the majority of the events occurred in neonates with congenital cardiac disease and the presence of CVLs. It was also noted that there was no standardization among the use of anticoagulation agents that were initiated for treatment of VTE. Furthermore, few patients received VTE prophylaxis during the hospitalization. A limitation of this review was that it was retrospective and the documentation of family history of thrombosis was inconsistent. It is also possible that several VTE events were missed due to inadequate ICD-10 coding. Based on the results of this review, there is a need to implement a risk stratification tool and develop standardized recommendations of VTE prophylaxis and treatments for pediatric patients admitted to Duke Children's Hospital. There is an additional quality improvement phase of this project and the goal is to implement a risk calculator that is based on information learned from the retrospective review. Ultimately, this risk calculator will help to decrease the incidence of VTE events at Duke Children's Hospital. Disclosures Rothman: Agios: Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding.

An international, multicenter registry was established to collect retrospective and prospective clinical data on patients with pyruvate kinase (PK) deficiency, the most common glycolytic defect causing congenital nonspherocytic hemolytic anemia. Medical history and laboratory and radiologic data were retrospectively collected at enrollment for 254 patients with molecularly confirmed PK deficiency. Perinatal complications were common, including anemia that required transfusions, hyperbilirubinemia, hydrops, and prematurity. Nearly all newborns were treated with phototherapy (93%), and many were treated with exchange transfusions (46%). Children age 5 years and younger were often transfused until splenectomy. Splenectomy (150 [59%] of 254 patients) was associated with a median increase in hemoglobin of 1.6 g/dL and a decreased transfusion burden in 90% of patients. Predictors of a response to splenectomy included higher presplenectomy hemoglobin (P 5 .007), lower indirect bilirubin (P 5 .005), and missense PKLR mutations (P 5 .0017). Postsplenectomy thrombosis was reported in 11% of patients. The most frequent complications included iron overload (48%) and gallstones (45%), but other complications such as aplastic crises, osteopenia/bone fragility, extramedullary hematopoiesis, postsplenectomy sepsis, pulmonary hypertension, and leg ulcers were not uncommon. Overall, 87 (34%) of 254 patients had both a splenectomy and cholecystectomy. In those who had a splenectomy without simultaneous cholecystectomy, 48% later required a cholecystectomy. Although the risk of complications increases with severity of anemia and a genotype-phenotype relationship was observed, complications were common in all patients with PK deficiency. Diagnostic testing for PK deficiency should be considered in patients with apparent congenital hemolytic anemia and close monitoring for iron overload, gallstones, and other complications is needed regardless of baseline hemoglobin. This trial was registered at www.clinicaltrials.gov as #NCT02053480.

Recent evidence has implicated EFL1 in a phenotype overlapping Shwachman–Diamond syndrome (SDS), with the functional interplay between EFL1 and the previously known causative gene SBDS accounting for the similarity in clinical features. Relatively little is known about the phenotypes associated with pathogenic variants in the EFL1 gene, but the initial indication was that phenotypes may be more severe, when compared with SDS. We report a pediatric patient who presented with a metaphyseal dysplasia and was found to have biallelic variants in EFL1 on reanalysis of trio whole-exome sequencing data. The variant had not been initially reported because of the research laboratory's focus on de novo variants. Subsequent phenotyping revealed variability in her manifestations. Although her metaphyseal abnormalities were more severe than in the original reported cohort with EFL1 variants, the bone marrow abnormalities were generally mild, and there was equivocal evidence for pancreatic insufficiency. Despite the limited number of reported patients, variants in EFL1 appear to cause a broader spectrum of symptoms that overlap with those seen in SDS. Our report adds to the evidence of EFL1 being associated with an SDS-like phenotype and provides information adding to our understanding of the phenotypic variability of this disorder. Our report also highlights the value of exome data reanalysis when a diagnosis is not initially apparent.

The outcomes of children with congenital hemolytic anemia (CHA) undergoing total splenectomy (TS) or partial splenectomy (PS) remain unclear. In this study, we collected data from 100 children with CHA who underwent TS or PS from 2005–2013 at 16 sites in the Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium using a patient registry. We analyzed demographics and baseline clinical status, operative details, and outcomes at 4, 24, and 52 weeks after surgery. Results were summarized as hematologic outcomes, short-term adverse events (AEs) (≤ 30 days after surgery), and long-term AEs (31–365 days after surgery). For children with hereditary spherocytosis, after surgery there was an increase in hemoglobin (baseline 10.1 ± 1.8 gm/dl, 52 week 12.8 ± 1.6 gm/dl; mean ± SD), decrease in reticulocyte and bilirubin as well as control of symptoms. Children with sickle cell disease had control of clinical symptoms after surgery, but had no change in hematologic parameters. There was an 11% rate of short-term AEs and 11% rate of long-term AEs. As we accumulate more subjects and longer follow-up, use of a patient registry should enhance our capacity for clinical trials and engage all stakeholders in the decision-making process.

Background Pediatric patients undergoing liver transplant are at significant risk for bleeding and thrombotic complications due to the complex nature of rebalanced hemostasis in patients with liver disease. Methods/objectives We reviewed records of 92 pediatric liver and multivisceral transplant cases at Duke University Medical Center between January 2009 and December 2015. The goal was to define the nature and incidence of bleeding and thrombotic complications in this cohort and define potential risk factors. Results There were 24 major bleeding events in 19 transplants (incidence 20.7%) and 30 thrombotic events in 23 transplants (incidence 25%). Five of the 10 retransplantations were for vascular thrombotic complications. Thirty-day mortality was 4.9%, and three of these four deaths were due to vascular thrombosis. No bleeding events led to retransplantation or mortality. Prophylactic aspirin was associated with decreased risk of thrombosis without increased bleeding. Prophylactic heparin did not increase bleeding risk. Laboratory assays predicted events poorly, apparently failing to capture the nuanced and dynamic interplay between pro- and anticoagulant factors in the posttransplant patient. Conclusions Both bleeding and thrombosis are frequent in this population, but only thrombotic complications contributed to retransplantation and mortality. A standardized approach to coagulation testing and antithrombotic therapy may be useful in predicting and reducing adverse outcomes. Alternative approaches to monitoring hemostasis need to be prospectively investigated in this complex patient population.

Background: Pyruvate Kinase (PK) deficiency is the most common enzyme defect of the glycolytic pathway causing hereditary non-spherocytic hemolytic anemia. Patients have a broad phenotypic spectrum, ranging from mild anemia to transfusion dependence, and there is wide variation in transfusion practices and decisions about splenectomy. No prior studies have reported on the use of validated health related quality of life (HRQoL) measures in this population. Aim: To describe patient reported outcomes including general HRQoL and fatigue in adults with PK deficiency and the correlation with clinical and laboratory features. Methods: Patients were enrolled on the PK Deficiency Natural History Study, a prospective 30 site international study. All patients had molecularly confirmed PK deficiency. Adults (n=132), ages ≥18 years, completed the EuroQol-5D (high index equivalent to better QoL), PROMIS Fatigue Short Form 7a (high scores equivalent to higher fatigue), and the Functional Assessment of Cancer Therapy-Anemia (FACT-An, high scores equivalent to less fatigue) surveys at enrollment and annually. Timing of administration was convenience based. Survey data were analyzed according to proprietary scoring guidelines. Tests of association were performed using Fisher's exact test (categorical) and Wilcoxon rank sum test (continuous). Regular transfusions were defined as ≥6 transfusions in 12 months. Genotypes were grouped as two missense mutations (M/M), one missense/one non-missense (M/NM), or two non-missense mutations (NM/NM)); non-missense included deletions or other drastic variants. The minimal important difference (MID) for the FACT-An has been reported as 7 points (Cella et al, J Pain Symptom Manage 2002). P-values Results: At enrollment, 128 adults completed the FACT-An with a median total score of 156 (IQR 122-190). Patients receiving regular transfusions reported significantly lower FACT-An scores than those who were not regularly transfused (median 129 vs 156, p=0.004) with significantly lower scores for physical, emotional, and functional well-being and anemia sub-scores (Table). This difference also surpassed the MID. However, non- regularly transfused patients with hemoglobin (Hb) 1000 ng/dL or chelation), higher number of lifetime transfusions, and two missense mutations. Females reported significantly lower scores than males (median 143 vs. 160, p=0.006) with significantly lower anemia sub-scores (p=0.0009). FACT-An surveys completed at the one year follow-up time point validated these findings. EuroQol-5D scores (n=124) at enrollment were similar to the healthy population (median PK deficiency index score 0.88; healthy population index mean 0.88, Shaw et al, Medical Care 2005). No significant differences were found by Hb level, splenectomy status, transfusion status, or genotype group. The median PROMIS fatigue T score (n=66) was 52.1 (IQR 40.5-63.7). Similar to the FACT-An survey data, PROMIS fatigue scores were significantly worse in patients who were regularly transfused (67.0 vs 52.4, p=0.02). PROMIS fatigue scores were also significantly worse in patients ≥40 years old (p=0.05) and females (p=0.01). Conclusions: Using the FACT-An and PROMIS Fatigue measures, patients with PK deficiency who are regularly transfused report significantly more fatigue and worse HRQoL compared with those who are not transfused. Important differences were also seen by iron status and mutation group using the FACT-An. Patients report similar fatigue levels regardless of Hb level, which suggests that symptoms, rather than Hb value alone, should be factored into clinical decision making. In contrast to anemia related HRQoL scores, overall HRQoL scores using validated generic measures in patients with PK deficiency show no differences compared with the healthy population, suggesting that disease-specific measures may better detect the effects of PK deficiency on HRQoL. Disclosures Van Beers: Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Glader:Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat:Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Despotovic:AmGen: Research Funding; Novartis: Research Funding; Sanofi: Consultancy. Kwiatkowski:bluebird bio: Consultancy, Honoraria, Research Funding; Agios Pharmaceuticals: Consultancy, Research Funding; Novartis: Research Funding; Apopharma: Research Funding; Terumo: Research Funding. Thompson:La Jolla Pharmaceutical: Research Funding; Baxalta/Shire: Research Funding; Novartis: Research Funding; Celgene: Research Funding; bluebird bio: Consultancy, Research Funding; Biomarin: Research Funding; Amgen: Research Funding. Newburger:TransCytos LLC: Consultancy; Janssen Research & Development, LLC: Consultancy, Honoraria; X4 Pharmaceutics: Consultancy, Honoraria. Ravindranath:AGIOS: Other: Site Investigator for Pyruvate Kinase Deficiency. Sheth:Terumo Corporation: Research Funding; Novartis: Research Funding; La Jolla Pharmaceutical Company: Research Funding; Celgene Corporation: Consultancy, Research Funding; Bluebird Bio: Consultancy. Grace:Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Research Funding; Agios Pharmaceuticals: Consultancy.

Research consistently indicates that children with sickle cell disease (SCD) face multiple risk factors for neurocognitive impairment. Despite this, no empirical research to date has examined the impact of neurocognitive functioning on quality of life for this pediatric group. Thus, the current study aims to examine the relationship between executive functioning and quality of life in a sample of children with SCD and further explore psychosocial and family/caregiver resources as moderators of this relationship. A total of 45 children with SCD aged 8 to 16 years and their caregivers completed measures of quality of life, behavioral ratings of executive functioning, and psychosocial functioning. Hierarchical linear regression models were utilized to determine the impact of executive functioning on quality of life and further test the interaction effects of proposed moderating variables. Controlling for age, pain, and socioeconomic status (SES), executive functioning was found to significantly predict child- and parent-reported quality of life among youth with SCD. Psychosocial resources of the primary caregiver or family was not found to moderate the relationship between executive functioning and quality of life. These results provide the first empirical evidence that lower executive skills negatively predict quality of life for children with SCD, supporting clinical and research efforts which aim to establish efficacious interventions that target cognitive decrements within this pediatric population.

Hemoglobin S/Black ((A)γδβ)(0)-thalassemia is a rare sickle cell disease (SCD) variant. Based on limited descriptions in the literature, the disease is reported as a mild microcytic anemia with an uncomplicated course. We report the clinical and laboratory data of nine patients whose diagnoses were confirmed by DNA-based techniques. Despite having mild anemia and high fetal hemoglobin level post-infancy, these patients developed many of the classic complications of SCD, including vaso-occlusive crisis, acute chest syndrome, avascular necrosis, and cholelithiasis. Based on these findings, we recommend that patients with this rare disorder receive specialized hematology care according to SCD guidelines.

To define rates of priapism diagnosis and inpatient admission among males with sickle cell disease (SCD).We retrospectively reviewed the Pediatric Health Information System database for males aged21 years treated 2004-2012. We identified patients with SCD and priapism based on the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. Logistic regression and generalized estimating equation models were used to control for confounding and to adjust for within-hospital clustering of similar patients.We identified 17,186 males who were admitted 137,710 times during the study period. Of these, 362 (2.1%) were diagnosed with priapism on 748 admissions. There was a significant decrease in the number of priapism admissions among patients with SCD over time (0.81% in 2004 to 0.44% in 2012, P .001). The number of patients diagnosed with SCD-related priapism varied over time without a statistically significant trend (2.3% in 2004, 2.69% in 2008, 1.01% in 2012, P = .34). Rates of priapism admissions (0-4.4%) varied widely between hospitals. Older patient age was associated with an increased likelihood of a priapism admission in the multivariate logistic regression model after adjusting for treatment year, hospital region, and for hospital-level clustering of similar patients.From 2004 to 2012, the number of admissions for SCD-related priapism declined whereas the number of individual patients diagnosed with SCD-related priapism did not. Rates of priapism-related admissions in males with SCD vary widely among PHIS hospitals.

Background: The impact of second line therapies on health related quality of life (HRQoL) and fatigue in pediatric patients with ITP is not well studied. Objective: To describe the impact of second line therapies on HRQoL and fatigue in North American pediatric patients with ITP. Methods: A longitudinal observational cohort of 120 children with ITP starting second line treatments was enrolled from 2013-2015 at 21 ICON centers. Enrollment requirements included age 1-17y and starting a second line treatment (not IVIG, corticosteroids or anti-D immunoglobulin) as monotherapy. HRQoL (Kids ITP Tool - KIT) and fatigue (Hockenberry Fatigue Scale - FS) surveys were completed prior to starting treatment (baseline) and 1 and 12 months after starting treatment by patient/caregiver. KIT is scored from 0 (worst) to 100 (best), and the FS scores were re-scaled so that 0 is no fatigue and 100 is highest fatigue. At the same time points as the patient/caregiver surveys, physicians assessed the perceived effect of treatment on patient HRQoL using a 7-point scale. ANOVA was used to compare the baseline means of the treatment groups. This study specifically compared change from baseline to 1 month in the KIT and FS using paired t-tests within each treatment group. The 12 month timepoint was not used in the paired analysis of individual treatments due to attrition between 1 and 12 months. Results: The median age at enrollment was 11.3 y (1.2-17.8), and 16% (19/120) had newly diagnosed ITP, 31% (37/120) had persistent ITP, and 53% (64/120) had chronic ITP. The median number of prior treatments was 3 (range: 1-9). Fifty-eight (48%) patients had received at least one prior second line treatment. Treatments selected for second line treatment included: rituximab (n=43), romiplostim (n=31), eltrombopag (n=20), oral immunosuppressants (n=19), splenectomy (n=4), and dapsone (n=3). The child and parent proxy KIT scores significantly improved on rituximab (p As previously described, at enrollment, physicians reported that ITP had impacted the patients' HRQoL severely in 15%, significantly in 45%, moderately in 38%, and almost not at all in 3%. Physicians reported that HRQoL improved in 68% (range: 64-75%) of patients while on treatment from baseline to 1 month with no significant difference by treatment group (p=0.46). The physician's assessment of the patient's baseline HRQoL significantly correlated with the child and parent proxy KIT report (p At enrollment, the median FS-Child score (n=54) was 18.5 (range 0-85), the median FS-Adolescent score (n=42) was 20.2 (0-73), and the median FS-Parent (n= 100) score was 35 (7-81). One month FS-Child improved for those who were treated with rituximab (p=0.03); there was no significant change in fatigue on the other treatments. One month FS-Parent significantly improved for those treated with rituximab (p=0.015) and eltrombopag (p=0.009). Conclusions: In this pediatric cohort, all second line treatments appear to significantly improve HRQoL in ITP. Rituximab had the greatest impact in decreasing fatigue at one month. Physician assessment of patient HRQoL did not correlate well with patient assessment after treatment was started, suggesting there may be challenges in ascertaining the effect of treatment on HRQoL. Future analysis of ICON1 will consider the impact of treatment on HRQoL and fatigue while also accounting for the treatment effect on bleeding and platelet count. Disclosures Grace: Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Klaassen: Amgen: Consultancy; Hoffman-La Roche LTD: Consultancy; Octapharma: Honoraria; Baxalta: Honoraria; Biogen Canada LTD: Consultancy; Agios Pharmaceuticals: Consultancy. Despotovic: Sanofi: Consultancy; Schell Cooley LLP: Other: Expert witness. Bussel: Protalex: Membership on an entity's Board of Directors or advisory committees, Research Funding; Momenta: Membership on an entity's Board of Directors or advisory committees; Rigel: 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; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Rothman: Pfizer: Consultancy; Agios Pharmaceuticals: Honoraria. Haley: Genentech: Honoraria; Baxalta: Honoraria; CSL Behring: Honoraria. Neufeld: Octapharma: Consultancy, Honoraria; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Lambert: Educational Concepts in Medicine: Honoraria; Novartis: Honoraria; AstraZeneca: Research Funding.

Objective.Raynaud’s phenomenon (RP) is an important clinical feature of systemic sclerosis (SSc) for which consistently effective therapies are lacking. The study was designed to assess the safety, tolerability, and efficacy of tadalafil, a selective, long acting type V cyclic GMP phosphodiesterase (PDE-5) inhibitor, in this clinical syndrome.Methods.We performed a prospective, randomized, double-blind, placebo-controlled, crossover study comparing oral tadalafil at a fixed dose of 20 mg daily for a period of 4 weeks versus placebo in women with RP secondary to SSc.Results.Thirty-nine subjects completed the study and were evaluable. There were no statistically significant differences in Raynaud Condition Score (RCS), frequency of RP episodes, or duration of RP episodes between treatment groups. Placebo response was a confounding factor. Tadalafil was well tolerated.Conclusion.Tadalafil appears to be safe and well tolerated but lacks efficacy in comparison to placebo as a treatment for RP secondary to SSc.

X-linked lymphoproliferative disease (XLP) is an immunodeficiency caused by defects in the adaptor molecule SAP. The manifestations of XLP generally occur following Epstein-Barr virus (EBV) infection and include fulminant mononucleosis, hypogammaglobulinemia and lymphoma. In this report, we describe two unrelated patients with fatal T cell-mediated central nervous system vasculitis for whom repeated serologic and molecular testing for EBV was negative. In both patients, clonal T cell populations were observed, but neither demonstrated evidence of lymphoma. Thus, loss of SAP function can lead to dysregulated immune responses characterized by the uncontrolled expansion and activation of T cells independent of EBV infection.

Hemoglobin S/Black (Aγδβ)0-thalassemia is a rare sickle cell disease (SCD) variant. On the basis of limited descriptions in the literature, the disease is reported as a mild microcytic anemia with an uncomplicated course. We report the clinical and laboratory data of nine patients whose diagnoses were confirmed by DNA-based techniques. Despite having mild anemia and high fetal hemoglobin level postinfancy, these patients developed many of the classic complications of SCD, including vaso-occlusive crisis, acute chest syndrome, avascular necrosis, and cholelithiasis. On the basis of these findings, we recommend that patients with this rare disorder receive specialized hematology care according to SCD guidelines.

There are numerous malignant conditions that place the pediatric patient at great risk requiring the need of critical care services. Therefore, it is essential that the pediatric critical care provider possess a sound understanding of these conditions such that they may be anticipated, recognized and treated effectively. Of these conditions, perhaps none requires the prompt, well conceived care of a pediatric intensivist as much as a malignant mediastinal mass. A definitive diagnosis must be established balancing the likelihood of a definitive result with the risk of the diagnostic procedure and the associated sedation. A clear understanding of the findings that suggest a patient is at high risk for airway compromise is essential. Hyperleukocytosis is another malignant condition associated with significant morbidity and mortality as a result of leukostasis. Leukostasis is a clinical condition characterized by progressive and potentially severe neurologic or respiratory disease attributable to small vessel infiltration and occlusion by leukemic blasts. Hypercalcemia is another disorder that may be associated with a variety of malignant processes. Although relatively rare in children, it may result in a number of life-threatening conditions including cardiac dysrhythmias, neurologic impairment, and renal failure. Additionally, it is well-established that varying degrees of coagulopathy are present in most patients with advanced malignancy. Perhaps most notable, acute promyelocytic leukemia is associated with such a high incidence of death near the time of presentation secondary to intracranial and pulmonary hemorrhages that it is viewed as a medical emergency. Other forms of leukemia may be associated with other pathophysiological consequences that may also be life-threatening. For example, lactic acidosis resulting from a high rate of glycolysis is a very rare, but life-threatening complication of hematologic malignancies. A heightened sense of alertness for these rare conditions may result in earlier detection, more effective therapy, and better outcomes for these children.