Search

There is a group of beta (β)-thalassemia trait 'carriers' (with heterozygous mutations) who should be asymptomatic with minor abnormalities in their hematological parameters, but experience more severe disease manifestations than predicted based solely on their β-globin genotype. This review focuses on literature describing trans-acting genetic modifiers outside of the α- and β-globin gene clusters that could cause this phenomenon. These genetic modifiers are categorized into: mutations affecting the quantity of alpha-globin products, non-globin mutations affecting erythropoiesis, membranopathies, enzymopathies and erythrocyte-independent modifiers of complications relating to β-thalassemia. Although some genetic determinants seem to correlate more directly with β-thalassemia trait severity, such as mutations in SUPT5H, PIEZO1 and hereditary elliptocytosis, the difficulties of linking the contribution of other modulating factors are elucidated in this review. Targeted next generation sequencing of hemolytic anemias can be helpful but also raises another quandary in interpreting variants of uncertain significance. The accrual of knowledge, along with the increased availability of genetic testing for genetic modifiers has considerable potential for clinical applications such as genetic counselling, decision-making for clinical interventions and prognostication, and perhaps generating new therapeutic targets., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pyruvate kinase (PK) deficiency, a rare, congenital haemolytic anaemia caused by mutations in the PKLR gene, is associated with many clinical manifestations, but the full disease burden has yet to be characterised. The Peak Registry (NCT03481738) is an observational, longitudinal registry of adult and paediatric patients with PK deficiency. Here, we described comorbidities and complications in these patients by age at most recent visit and PKLR genotype. As of 13 May 2022, 241 patients were included in the analysis. In total, 48.3% had undergone splenectomy and 50.5% had received chelation therapy. History of iron overload (before enrolment/during follow-up) was common (52.5%), even in never-transfused patients (20.7%). Neonatal complications and symptoms included jaundice, splenomegaly and hepatomegaly, with treatment interventions required in 41.5%. Among adults, osteopenia/osteoporosis occurred in 19.0% and pulmonary hypertension in 6.7%, with median onset ages of 37, 33 and 22 years, respectively. Biliary events and bone health problems were common across PKLR genotypes. Among 11 patients who had thromboembolic events, eight had undergone prior splenectomy. Patients with PK deficiency may have many complications, which can occur early in and throughout life. Awareness of their high disease burden may help clinicians better provide appropriate monitoring and management of these patients., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

In this review, we provide a summary of evidence on iron overload in young children with transfusion-dependent β-thalassemia (TDT) and explore the ideal timing for intervention. Key data from clinical trials and observational studies of the three available iron chelators deferoxamine, deferiprone, and deferasirox are also evaluated for inclusion of subsets of young children, especially those less than 6 years of age. Evidence on the efficacy and safety of iron chelation therapy for children ≥2 years of age with transfusional iron overload is widely available. New data exploring the risks and benefits of early-start iron chelation in younger patients with minimal iron overload are also emerging., (© 2024 Wiley Periodicals LLC.)

Introduction: Membranopathies encompass haemolytic disorders arising from genetic variants in erythrocyte membrane proteins, including hereditary spherocytosis and stomatocytosis. Congenital dyserythropoietic anaemia type II (CDA II) is associated with the SEC23B gene and can exhibit phenotypic similarities to membranopathies. Current treatment options for these conditions, apart from splenectomy, are primarily supportive. Mitapivat, a novel pyruvate kinase (PK) activator, has demonstrated efficacy in increasing haemoglobin levels and reducing haemolysis in patients with PK deficiency, thalassemia, sickle cell disease and a mouse model of hereditary spherocytosis., Methods and Analyses: Sa fe t y and eff i cacy of mitapivat s ul f ate in adult patients with er y throcyte membranopathies (SATISFY) is a prospective, multicentre, single-arm phase two trial involving approximately 25 adult patients (≥18 years) diagnosed with a membranopathy or CDA II. During the 8-week dose escalation period, subjects will receive an initial dose of 50 mg mitapivat two times per day and may increase to 100 mg two times per day at week 4 based on the safety and changes in haemoglobin levels. Patients tolerating mitapivat well may be eligible to continue in two consecutive 24-week fixed dose periods.The primary objective of this study is to evaluate the safety of mitapivat, assessed through the occurrence of treatment-emergent adverse events. Secondary objectives include assessing the effects of mitapivat on haemoglobin levels, haemolysis, erythropoiesis, patient-reported outcome measures and spleen size.SATISFY aims to assess the safety and efficacy of mitapivat in adult patients with red blood cell membranopathies and CDA II, with the aim of establishing proof-of-concept in patients living with these rare conditions., Ethics and Dissemination: NCT05935202/CTIS:2023-503271-24-01. Findings will be published in peer-reviewed journals., Trial Registration Number: Clinicaltrials.gov, NCT05935202. CTIS:2023-503271-24-01. Registered 07-July-2023. Protocol number: 2.1. https://clinicaltrials.gov/study/NCT05935202., Competing Interests: Competing interests: AG: consultant for Agios Pharmaceuticals, Bristol Myers Squibb, Novartis Pharmaceuticals, Novo Nordisk A/S, Pharmacosmos UK Ltd and Vertex Pharmaceuticals; received research support from Agios Pharmaceuticals, Novo Nordisk A/S, Saniona and Sanofi. EJvB: advisory committee member for Agios Pharmaceuticals.; received research funding from Agios Pharmaceuticals, Novartis Pharmaceuticals, Pfizer and RR Mechatronics International B.V. KHMK: consultant for Agios Pharmaceuticals, Alexion Pharmaceuticals, Inc., Bristol Myers Squibb, Forma Therapeutics, Pfizer, Novo Nordisk A/S and Vertex Pharmaceuticals; received honoraria from Bristol Myers Squibb and Novo Nordisk A/S; member of the data safety monitoring board of Bioverativ; received research funding from Agios Pharmaceuticals and Pfizer. RvW: consultant for Agios Pharmaceuticals; research funding from Agios Pharmaceuticals and Pfizer. MAER: research funding from Agios Pharmaceuticals and Axcella Health., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Sickle cell disease (SCD) is an inherited hemoglobinopathy characterized by vaso-occlusion, hemolysis of red blood cells (RBC), and a predisposition for venous thromboembolism (VTE). The sickling and hemolysis of RBC culminate in coagulation system abnormalities, platelet activation, endothelial dysfunction, and impaired blood flow manifesting as a prothrombotic state. In addition, individuals with SCD are often exposed to extrinsic risk factors for VTE including recurrent hospitalizations, central venous catheters, and acute medical illnesses. The diagnosis is often challenging as symptoms may mimic other complications of SCD, and there is little data to guide diagnostic algorithms involving probability scoring in the SCD population. Non-anticoagulant strategies aimed at reducing disease severity may aid in lowering the risk of VTE, but data is limited. Furthermore, high quality evidence regarding anticoagulation in prevention and treatment of SCD is severely lacking, resulting in heterogeneity in clinical practice. In this narrative review we aim to review the prothrombotic pathophysiology of SCD, to describe the risk factors, high risk of mortality, and types of VTE in SCD, to develop an approach to the diagnosis of VTE in SCD, and to understand the limited available evidence for the prevention and treatment of VTE in SCD.

Clinically meaningful benefits in the signs, symptoms, and impacts of #PKDeficiency as assessed by disease-specific patient-reported outcome measures were observed in mitapivat-treated adult patients in two phase 3 clinical trials., (© 2024 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

Abstract: Pyruvate kinase (PK) deficiency is a rare, hereditary disease characterized by chronic hemolytic anemia. Iron overload is a common complication regardless of age, genotype, or transfusion history. Mitapivat, an oral, allosteric PK activator, improves anemia and hemolysis in adult patients with PK deficiency. Mitapivat's impact on iron overload and ineffective erythropoiesis was evaluated in adults with PK deficiency who were not regularly transfused in the phase 3 ACTIVATE trial and long-term extension (LTE) (#NCT03548220/#NCT03853798). Patients in the LTE received mitapivat throughout ACTIVATE/LTE (baseline to week 96; mitapivat-to-mitapivat [M/M] arm) or switched from placebo (baseline to week 24) to mitapivat (week 24 to week 96; placebo-to-mitapivat [P/M] arm). Changes from baseline in markers of iron overload and erythropoiesis were assessed to week 96. Improvements in hepcidin (mean, 4770.0 ng/L; 95% confidence interval [CI], -1532.3 to 11 072.3), erythroferrone (mean, -9834.9 ng/L; 95% CI, -14 328.4 to -5341.3), soluble transferrin receptor (mean, -56.0 nmol/L; 95% CI, -84.8 to -27.2), and erythropoietin (mean, -32.85 IU/L; 95% CI, -54.65 to -11.06) were observed in the M/M arm (n = 40) from baseline to week 24, sustained to week 96. No improvements were observed in the P/M arm (n = 40) to week 24; however, upon transitioning to mitapivat, improvements similar to those observed in the M/M arm were seen. Mean changes from baseline in liver iron concentration by magnetic resonance imaging at week 96 in the M/M arm and the P/M arm were -2.0 mg Fe/g dry weight (dw; 95% CI, -4.8 to -0.8) and -1.8 mg Fe/g dw (95% CI, -4.4 to 0.80), respectively. Mitapivat is the first disease-modifying pharmacotherapy shown to have beneficial effects on iron overload and ineffective erythropoiesis in patients with PK deficiency. This trial was registered at www.ClinicalTrials.gov as #NCT03548220 (ACTIVATE) and #NCT03853798 (LTE)., (© 2024 by The American Society of Hematology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

α-Thalassemia is an inherited blood disorder characterized by decreased synthesis of α-globin chains that results in an imbalance of α and β globin and thus varying degrees of ineffective erythropoiesis, decreased red blood cell (RBC) survival, chronic hemolytic anemia, and subsequent comorbidities. Clinical presentation varies depending on the genotype, ranging from a silent or mild carrier state to severe, transfusion-dependent or lethal disease. Management of patients with α-thalassemia is primarily supportive, addressing either symptoms (eg, RBC transfusions for anemia), complications of the disease, or its transfusion-dependence (eg, chelation therapy for iron overload). Several novel therapies are also in development, including curative gene manipulation techniques and disease modifying agents that target ineffective erythropoiesis and chronic hemolytic anemia. This review of α-thalassemia and its various manifestations provides practical information for clinicians who practice beyond those regions where it is found with high frequency., Competing Interests: Declaration of competing interest K.M.M. reports consultancy fees from Novartis, Celgene Corp (Bristol Myers Squibb), Agios Pharmaceuticals, CRISPR Therapeutics, Vifor Pharma, and Pharmacosmos; and research funding from Agios Pharmaceuticals and Pharmacosmos. M.D.C. reports consultancy fees from Novartis, Celgene/Bristol Myers Squibb, Vifor Pharma, and Ionis Pharmaceuticals; and research funding from Novartis, Celgene/Bristol Myers Squibb, La Jolla Pharmaceutical Company, Roche, Protagonist Therapeutics, and CRISPR Therapeutics. T.D.C. provides advisory support to Agios Pharma, Bristol Meyers Squibb, and Chiesi. K.H.M.K. reports consultancy fees from Agios Pharmaceuticals, Alexion Pharmaceuticals, Bristol Myers Squibb, Forma Therapeutics, Pfizer, NovoNordisk, and Vertex Pharmaceuticals; honoraria from Agios Pharmaceuticals and Bristol Myers Squibb; membership on an advisory committee for Bioverativ/Sanofi/Sangamo; and research funding from Agios Pharmaceuticals and Pfizer. H.A-S. reports consultancy fees from Novartis, Forma Therapeutics, Agios Pharmaceuticals, argenx, Moderna, Pharmacosmos, and Sobi; and research funding from Agios Pharmaceuticals, Amgen, Sobi, Novartis, and Vaderis Therapeutics. S.S. reports consultancy fees from Agios Pharmaceuticals, bluebird bio, Fulcrum Therapeutics, Chiesi, Celgene Corp (Bristol Myers Squibb), and Vertex; honoraria for CME activities from Plexus, CCO, and Physicians' Education Resource; advisory board travel from Agios Pharmaceuticals, Celgene Corp (Bristol Myers Squibb), and bluebird bio; research funding from Celgene Corp (Bristol Myers Squibb), Agios Pharmaceuticals, and Forma Therapeutics; and serving on a clinical trial steering committee for CRISPR/Vertex CTX001 for thalassemia. V.V. reports consultancy fees from Celgene Corp (Bristol Myers Squibb), Agios Pharmaceuticals, Novartis, Vifor Pharma, Pharmacosmos, IONIS Pharmaceuticals, Inc., and DisperSol Technologies, LLC; and research funding from Celgene Corp (Bristol Myers Squibb), Agios Pharmaceuticals, Novartis, Vifor Pharma, Pharmacosmos, IONIS Pharmaceuticals, Inc., DisperSol Technologies, LLC, and The Government Pharmaceutical Organization (GPO). A.T.T. reports consultancy fees from Novartis, Celgene Corp (Bristol Myers Squibb), Agios Pharmaceuticals, Vifor Pharma, and Pharmacosmos; and research funding from Novartis, Celgene Corp (Bristol Myers Squibb), Agios Pharmaceuticals, Vifor Pharma, and Pharmacosmos., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In this retrospective cohort study of singleton pregnancies in people with sickle cell disease (SCD) delivered at two academic centres between 1990 and 2021, we collected demographic and SCD-related data, pregnancy outcomes, and the highest systolic and diastolic blood pressure (SBP and DBP) at seven time periods. We compared the characteristics of subjects with new or worsening proteinuria (NWP) during pregnancy to those without. We then constructed receiver operating characteristic (ROC) curves to determine the blood pressure (BP) that best identifies those with NWP. The SBP or DBP thresholds which maximized sensitivity and specificity were 120 mmHg SBP (sensitivity: 55.2%, specificity: 73.5%) and 70 mmHg DBP (sensitivity: 27.6%, specificity: 67.7%). The existing BP threshold of 140/90 mmHg lacked sensitivity in both genotype groups (HbSS/HbSβ 0 : SBP = 21% sensitive, DBP = 5.3% sensitive; HbSS/HbSβ + : SBP = 10% sensitive, DBP = 0% sensitive). Finally, percent change in SBP, DBP and MAP were all poor tests for identifying NWP. Existing BP thresholds used to diagnose hypertensive disorders of pregnancy (HDP) are not sensitive for pregnant people with SCD. For this population, lowering the BP threshold that defines HDP may improve identification of those who need increased observation, consideration of early delivery and eclampsia prophylaxis., (© 2023 British Society for Haematology and John Wiley & Sons Ltd.)

Pyruvate kinase (PK) deficiency is the most common cause of chronic congenital non-spherocytic haemolytic anaemia worldwide, with an estimated prevalence of one in 100 000 to one in 300 000 people. PK deficiency results in chronic haemolytic anaemia, with wide ranging and serious consequences affecting health, quality of life, and mortality. The goal of the International Guidelines for the Diagnosis and Management of Pyruvate Kinase Deficiency was to develop evidence-based guidelines for the clinical care of patients with PK deficiency. These clinical guidelines were developed by use of GRADE methodology and the AGREE II framework. Experts were invited after consideration of area of expertise, scholarly contributions in PK deficiency, and country of practice for global representation. The expert panel included 29 expert physicians (including adult and paediatric haematologists and other subspecialists), geneticists, laboratory specialists, nurses, a guidelines methodologist, patients with PK deficiency, and caregivers from ten countries. Five key topic areas were identified, the panel prioritised key questions, and a systematic literature search was done to generate evidence summaries that were used in the development of draft recommendations. The expert panel then met in person to finalise and vote on recommendations according to a structured consensus procedure. Agreement of greater than or equal to 67% among the expert panel was required for inclusion of a recommendation in the final guideline. The expert panel agreed on 31 total recommendations across five key topics: diagnosis and genetics, monitoring and management of chronic complications, standard management of anaemia, targeted and advanced therapies, and special populations. These new guidelines should facilitate best practices and evidence-based PK deficiency care into clinical practice., Competing Interests: Declaration of interests HA-S reports grants or contracts in research funding to their institution from Agios, Sobi, Vaderis, Novartis, and Amgen and reports consulting fees from Agios, Sobi, Novartis, Argenx, Rigel, Moderna, Forma, and Pharmacosmos. SWE reports receiving support for attending meetings, travel, or both from Agios and is on data safety monitoring boards or advisory boards for Agios. JAR reports grants or contracts from Pfizer, Agios, Novartis, Sanofi, Sobi, and Dova, and is on data safety monitoring boards or advisory boards for Agios, Global Blood Therapeutics, and Novartis. SS reports grants or contracts from Bristol-Myers Squibb/Celgene, Forma, and Agios; reports consulting fees from Agios, Bluebird Bio, Fulcrum, Chiesi, Bristol-Myers Squibb/Celgene, and Vertex); reports honoraria from Plexus, Clinical Care Options, and Physicians' Education Resource; reports receiving support for attending meetings, travel, or both from Agios, Bristol-Myers Squibb/Celgene and Bluebird Bio; and is on data safety monitoring boards or advisory boards for CRISPR/Vertex. KL-R reports funding provided to the Centre for Effective Practice (an independent not for profit corporation) to conduct the systematic literature review in this work. DCR is on data safety monitoring boards or advisory boards for Agios. AW reports receiving support for attending meetings, travel, or both from Agios and reports being in leadership in an advocacy group (the Pyruvate Kinase Deficiency Foundation). CL reports receiving support for attending meetings, travel, or both from Agios and reports being in leadership in an advocacy group (Metabolic Support UK). EJN reports consulting fees from Saliogen, reports receiving support for attending meetings, travel, or both from Agios; reports stock or stock options in Saliogen; and is on data safety monitoring boards or advisory boards for Agios, Imara, Merck/Acceleron, Sobi, and Pfizer. PB reports grants or contracts from Agios; reports honoraria from Rocket; reports support for attending meetings, travel, or both from Agios; and is on data safety monitoring boards or advisory boards for Agios. RFG reports grants or contracts from Agios, Novartis, and Sobi; reports consulting fees from Agios; is on data safety monitoring boards or advisory boards (Sanofi); and reports being in leadership in other boards, societies, committees, or advocacy groups (PK Deficiency Advocacy Advisory Council, Thrive with PK Deficiency, and Rare Anemias International Network). DPe reports receiving support for attending meetings, travel, or both from Eurobloodnet; is on data safety monitoring boards or advisory boards for Eurobloodnet; and reports being in a leadership role in an advocacy group (Stichting Zeldzame Bloedziekten). WB reports consulting fees from Alexion, Agios, Novartis, Sobi, and Sanofi; reports honoraria from Agios, Novartis, and Sanofi; reports receiving support for attending meetings, travel, or both from Sanofi; and is on data safety monitoring boards or advisory boards for Novartis. AJS is on data safety monitoring boards or advisory boards for Vertex and Bluebird Bio. NS reports receiving support for attending meetings, travel, or both from Agios. OA reports grants or contracts from Agios; reports honoraria from Agios; reports receiving support for attending meetings, travel, or both from the German, Austrian, and Swiss Society for Pediatric Oncology and Hematology, the German Society for Neonatology and Pediatric Intensive Care, and Agios; and is on data safety monitoring boards or advisory boards for Agios. AG reports grants or contracts from Agios, Bristol-Myers Squibb, Novo Nordisk, Saniona, and Sanofi; reports consulting fees from Agios, Novo Nordisk, Pharmacosmos, and Vertex; and reports receiving support for attending meetings, travel, or both from AbbVie. MDMMP reports grants or contracts from Agios and is on data safety monitoring boards or advisory boards for Agios. SC reports grants or contracts in research funding to their institution from Agios; reports consulting fees from Agios; and is on data safety monitoring boards or advisory boards for Agios. EJvB reports grants or contracts in research funding to their institution from Agios and Horizon Europe; reports consulting fees from Bristol-Myers Squibb and Agios; is on data safety monitoring boards or advisory boards for Imara Pharmaceuticals; and reports being in a leadership role in other boards (Sickle Cell Outcome Registry Research The Netherlands and Eurobloodnet). JLK reports consulting fees from Forma, Agios, and Chiesi and is on data safety monitoring boards or advisory boards for Agios. TAK reports grants to contracts in research funding to their institution from Agios, Forma, and Novo Nordisk); reports consulting fees from Forma and Novo Nordisk; and is on data safety monitoring boards or advisory boards for Agios, Forma, and Novo Nordisk). FG is on data safety monitoring boards or advisory boards for Addmedica, Vertex, Agios, Global Blood Therapeutics, and Novartis. KHMK reports grants or contracts from Agios and Pfizer; reports consulting fees from Alexion, Agios, Bristol-Myers Squibb, Forma, Pfizer, Novo Nordisk, and Vertex); reports honoraria from Agios and Bristol-Myers Squibb; and is on data safety monitoring boards or advisory boards for Bioverativ, Sanofi, and Sangamo. All other authors report no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Abstract: Advancements in orally bioavailable iron chelators and MRI methods have improved life expectancy and reproductive potential in thalassemia major (TM) and thalassemia intermedia (TI). Pregnancy is associated with adverse maternal and neonatal outcomes, frequency of which has not been well delineated. This systematic review aims to provide risk estimates of maternal and fetal outcomes in TM and TI and explore pregnancy's impact on iron homeostasis. Fifteen studies (429 participants, 684 pregnancies) were included. Meta-analysis revealed a higher thrombosis risk in TI (3.7%) compared to TM (0.92%), unchanged from prepregnancy. Heart failure risks in the earlier years appeared similar (TM 1.6% vs TI 1.1%), and maternal mortality in TM was 3.7%, but with current management, these risks are rare. Gestational diabetes and pre-eclampsia occurred in 3.9% and 11.3% of TM pregnancies, respectively. Caesarean section rates were 83.9% in TM and 67% in TI. No significant difference in stillbirth, small for gestational age neonates, or preterm birth incidence between TM and TI was observed. In TM pregnancies, red cell requirements significantly increased (from 102 to 139 ml/kg/year, P = 0.001), and 70% of TI pregnancies required blood transfusions. As expected, increased transfusion alongside chelation cessation led to a significant increase in serum ferritin during pregnancy (TM by 1005 ng/mL; TI by 332 ng/mL, P < 0.0001). Deterioration in iron status was further reflected by an increase in liver iron concentration (from 4.6 to 11.9 mg/g dry weight, P < 0.0001), and myocardial T2-star (T2∗) magnetic resonance imaging decreased (from 36.2 ± 2.5 ms to 31.1 ms) during pregnancy. These findings emphasize the elevated maternal risk of iron-related cardiomyopathy during pregnancy and labor, stressing the importance of cardiac monitoring and postpartum chelation therapy resumption., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

In this retrospective cohort study of singleton pregnancies in people with sickle cell disease (SCD) delivered at two academic centres between 1990 and 2021, we collected demographic and SCD-related data, pregnancy outcomes, and the highest systolic and diastolic blood pressure (SBP and DBP) at seven time periods. We compared blood pressure values and trajectories in the composite cohort and in each genotype group to control values in a non-SCD pregnancy dataset. There were 290 pregnancies among 197 patients with SCD. Sixteen per cent (n = 47) of pregnancies had a hypertensive disorder of pregnancy (HDP); the rates did not differ by genotype. The mean SBP and DBP were lower in the HbSS/HbSβ 0 group than in the non-SCD control group at all timepoints. Mean SBP and DBP trajectories were similar between the HbSS/HbSβ 0 group and non-SCD controls, whereas the mean SBP and DBP in the HbSC/HbSβ + group decreased between the first and second trimesters and plateaued between the second and third trimesters. There were no differences in blood pressure trajectory by haemoglobin >/< 10 gm/dL or by chronic transfusion status. Overall, pregnant people with SCD have lower blood pressure than unaffected pregnant people, raising the possibility that HDP are underdiagnosed, particularly in people with HbSS/HbSβ 0 ., (© 2023 British Society for Haematology and John Wiley & Sons Ltd.)

Introduction: Individuals with sickle cell disease (SCD) and central venous catheters (CVC) are at high risk for venous thromboembolism (VTE). Minimal data exist regarding the use of anticoagulation as thromboprophylaxis of VTE in this demographic, and as a result, clinical equipoise exists. Prophylactic dose rivaroxaban, a direct oral anticoagulant, is efficacious and safe as thromboprophylaxis in other demographics, and may be an optimal agent in SCD with CVC. Prior to conducting a full clinical trial to assess rivaroxaban as thromboprophylaxis in SCD with CVC, a pilot study is needed to gauge its feasibility., Methods and Analysis: THromboprophylaxis In Sickle Cell Disease pilot trial is an investigator-initiated, multicentre, double-blinded, randomised controlled trial (RCT) assessing if it is feasible and safe to conduct an adequately powered RCT comparing rivaroxaban to matching placebo as thromboprophylaxis in those with SCD and CVC. Fifty adult patients with SCD and CVC will be randomised to receive either rivaroxaban 10 mg daily or matching placebo for the duration of the CVC in situ for up to 1 year. After randomisation, follow-up visits will occur every 3 months. The primary outcomes pertain to the feasibility of a full trial and include numbers of eligible and recruited participants. Exploratory outcomes include overall incidence of VTE and bleeding complications, as well as quality of life. If the full trial is feasible, blinding will be maintained and patients in the pilot study will be included in the full trial., Ethics and Dissemination: The trial was initially approved by the University Health Network Research Ethics Board (REB) in Toronto, Canada. All sites will obtain approval from their respective REB prior to commencement of study activities. Study results will be disseminated through presentations at medical conferences and peer-reviewed publications., Trial Registration Number: NCT05033314., Competing Interests: Competing interests: SF has received research funding from the Canadian Hematology Society, and PFIZER; Honoraria from Novartis; and Consultancy fees from Novo Nordisk and Vertex. PB has received research funding from Bluebird, NOVARTIS, ROCHE Fabre Foundation and ADDMEDICA; Consultancy fees from AGIOS, EMMAUS, GBT, ROCHE, HEMANEXT, Bluebird, NOVARTIS, and ADDMEDICA; lecture fees from Jazz Pharma, NOVARTIS, and ADDMEDICA; is the cofounder of INNOVHEM, is on steering committees for NOVARTIS, ROCHE, ADDMEDICA, and PFIZER. KHMK has received research funding from AGIOS and PFIZER; Consulting fees from Alexion Pharmaceuticals, AGIOS, Bristol Myers Squibb, Forma Therapeutics, Pfizer, Novo Nordisk, and Vertex; Honoraria for speaking from AGIOS, and Bristol Myers Squibb; and is a member of a Data Safety Monitoring Board or Advisory Board for Bioverativ/Sanofi/Sangamo. The other authors have no competing interests to declare., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Thalassemia is an inherited red blood cell disorder whereby the qualitative and/or quantitative imbalance in α- to β-globin ratio results in hemolysis and ineffective erythropoiesis. Oxidative stress, from the precipitated excess globin and free iron, is a major factor that drives hemolysis and ineffective erythropoiesis. Pyruvate kinase activity and adenosine triphosphate availability are reduced due to the overwhelmed cellular antioxidant system from the excessive oxidative stress. Mitapivat, a pyruvate kinase activator in development as a treatment for thalassemia, was shown to increase hemoglobin and reduce hemolysis in a small phase 2 single-arm trial of patients with α- and β-thalassemia. The ongoing phase 3 studies with mitapivat and the phase 2 study with etavopivat will examine the role of pyruvate kinase activators as disease modifying agents in thalassemia., (Copyright © 2023 by The American Society of Hematology.)

Neurovascular disease such as symptomatic stroke, silent brain infarcts and vascular cognitive impairment are common complications of sickle cell disease (SCD) that can have devastating consequences on quality of life, employment, and social functioning.  Early recognition of neurovascular disease is a prerequisite for the timely optimization of medical care and to connect patients to adaptive resources. While cognitive impairment has been well described in children, currently available data are limited in adults. As a result, guidance on the optimal cognitive screening strategies in adults is scarce. We conducted a systematic review to identify the different screening tools that have been evaluated in SCD. A meta-analysis was performed to estimate the prevalence of suspected cognitive impairment in this population. In this qualitative synthesis, we present 8 studies that evaluated 6 different screening tools. Patient characteristics that impacted on cognitive screening performance included age, education level, and a prior history of stroke. We report a pooled prevalence of 38% [14-62%] of suspected cognitive impairment. We discuss the relative benefits and limitations of the different screening tools to help clinicians select an adapted approach tailored to their specific patients' needs. Further studies are needed to establish and validate cognitive screening strategies in patients with diverse cultural and educational backgrounds., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Competing Interests: LHP is funded through the National Institutes of Health (NIH) and National Heart, Lung, and Blood Institute (NHLBI; K23HL146841 and U01 HL156620–01), the American Society of Hematology, Doris Duke Charitable Foundation Grant (2020147), the Mellon Foundation, and Alexion and served as a consultant for Global Blood Therapeutics and Novo Nordisk. CPC serves as a consultant for DimeRx. SL receives research funding from Imara, Novartis, Global Blood Therapeutics, Takeda, CSL-Behring, Health Resources and Services Administration, Patient-Centered Outcomes Research Institiute and Maryland Community Health Resources Commission; consultancy for Bluebird bio, Novo Nordisk, Pfizer, and Magenta; and owns stock in Pfizer and Teva. AMA declares no competing interests. MH has research funding to the institution from Novo Nordisk, consultancy for Bluebird bio, and family member employment at Pfizer. ES has served as a consultant for Bluebird bio. KHMK is funded through NIH and NHLBI (1R33HL147845), Thalassemia Foundation Canada, Peter Munk Cardiac Centre, University of Toronto, Canadian Hematology Society, Agios Pharmaceuticals, and Pfizer and served as a consultant for Alexion Pharmaceuticals, Agios Pharmaceuticals, Bristol Myers Squibb, Forma Therapeutics, Pfizer, Novo Nordisk, and Vertex Pharmaceuticals. DSD serves as consultant for Pfizer, Novonordisk, Novartis, Agios Pharmaceuticals and Bluebird bio.

Introduction: Allogeneic hematopoietic stem cell transplant (HSCT) and gene therapy (GT) are two potentially curative approaches for sickle cell disease (SCD), but they have never been compared in clinical trials., Objective: To compare the safety and efficacy of HSCT and GT to assist clinicians and patients in making informed treatment decisions., Methods: Phase I-III clinical trials and case reports/series were included. Regimens included HSCT from all stem cell sources, lentiviral gene therapy, and gene editing, with any conditioning regimen. We searched Medline and EMBASE databases as of 1st June 2020 for studies reporting HSCT and GT outcomes in SCD. The Newcastle-Ottawa scale was used to assess the risk of bias. Descriptive statistics and post-hoc imputation for standard deviations of mean change in FEV1 and FVC were performed., Results: In total, 56 studies (HSCT, n  = 53; GT, n  = 3) representing 1,198 patients met inclusion criteria (HSCT, n  = 1,158; GT, n  = 40). Length of follow-up was 3,881.5 and 58.7 patient-years for HSCT and GT, respectively. Overall quality of evidence was low, with no randomized controlled trials identified. Two-year overall survival for HSCT was 91%; mortality was 2.5% for GT. Acute chest syndrome and vaso-occlusive episodes were reduced post-HSCT and GT. Meta-analysis was not possible due to lack of comparator and heterogeneity in outcome measures reporting. Very few studies reported post-transplant end-organ function. Six secondary malignancies (5 post-HSCT, 1 post-GT) were reported., Discussion: Reporting of SCD-related complications and patient-important outcomes is lacking for both strategies. We advocate for standardized reporting to better compare outcomes within and between treatment groups.

Novel developments in therapies for various hereditary hemolytic anemias reflect the pivotal role of pyruvate kinase (PK), a key enzyme of glycolysis, in red blood cell (RBC) health. Without PK catalyzing one of the final steps of the Embden-Meyerhof pathway, there is no net yield of adenosine triphosphate (ATP) during glycolysis, the sole source of energy production required for proper RBC function and survival. In hereditary hemolytic anemias, RBC health is compromised and therefore lifespan is shortened. Although our knowledge on glycolysis in general and PK function in particular is solid, recent advances in genetic, molecular, biochemical, and metabolic aspects of hereditary anemias have improved our understanding of these diseases. These advances provide a rationale for targeting PK as therapeutic option in hereditary hemolytic anemias other than PK deficiency. This review summarizes the knowledge, rationale, (pre)clinical trials, and future advances of PK activators for this important group of rare diseases., Competing Interests: Declaration of Competing Interest M.v.D., J.d.W., K.K., A.G., M.R., E.v.B. and R.v.W. receive research funding from Agios Pharmaceuticals Inc. K.K., E.v.B. and R.v.W. are consultants for Agios Pharmaceuticals Inc. K.K., M.R. and R.v.W. receive research funding from Pfizer. K.K. and R.v.W. are consultants for Pfizer. K.K. is also consultant for Alexion Pharmaceuticals, Celgene/Bristol Myers Squibb, Forma Therapeutics, Novo Nordisk, and chair of the Data Safety Monitoring Board for Bioverativ/Sanofi and Sangamo. A.G. receives research funding from Bristol Myers Squibb, Saniona and Sanofi and has done consulting for Agios, Bluebird Bio, Bristol Myers Squibb, Novartis, Novo Nordisk, Pharmacosmos. M.R. and R.v.W. receive research funding from Axcella Health Inc. The remaining author declares no conflict of interest., (Crown Copyright © 2023. Published by Elsevier Ltd. All rights reserved.)

Background: Therapeutic plasma exchange (TPE) and red blood cell exchange (RBCX) are life-saving apheresis procedures offered in 7 Ontario hospitals. Most referrals are directed by CritiCall Ontario (CritiCall), a 24/7 service funded by the Ontario Ministry of Health and Long-Term Care. We used CritiCall data to examine referral requests, acceptances, and transfers for urgent apheresis to our centre., Methods: Retrospective CritiCall referral and transfer data for urgent apheresis between October 2013 and December 2018 were included. Continuous variables were analyzed by linear regression. Categorical variables were analyzed using nonparametric tests., Results: Eighty-five cases (52 TPE, 33 RBCX) were identified. Median patient age was 52 years (interquartile range [IQR] 32) for TPE, 29 years (IQR 18) for RBCX. Most patients (58%) were female. Total time from referral to arrival at our centre was 243 (IQR 166) minutes. The greatest proportion of this total was from patient acceptance to arrival (169 [IQR 112] minutes). Median distance between referring and accepting centres was 39 (IQR 30) kilometres, with ground transportation used most often. Multiple linear regression examining factors that contribute to total time demonstrated that the number of physicians contacted prior to patient acceptance and inter-hospital distance were independently associated (p = 0.007 and p = 0.048, respectively)., Interpretation: Addressing modifiable factors to reduce time is important given that time to initiate treatment is associated with better outcomes. Quality improvement strategies should be aimed at coordinated provincial resource sharing, pairing referrals with nearest available apheresis centres, and creating efficiency in the interval between patient acceptance and arrival., Competing Interests: Declaration of Competing Interest K.M: Educational and/or research grants: Canadian Hematology Society, University Health Network Blood Disorders Program, Royal College of Physicians and Surgeons Canada. K.H.M.K: Educational and/or research grants: NHLBI/NIH, Thalassemia Foundation Canada, Peter Munk Cardiac Centre, University of Toronto, Canadian Hematology Society, Pfizer. Consulting fees: Agios, Alexion, Apellis, Aruvant, Bluebirdbio, Celgene/BMS, Forma, Novarits, Pfizer. Lecture Honoraria: Agios, Alexion, Apellis, Bluebirdbio, Celgene/BMS, Forma. Data Safety Monitoring Board: Bioreativ/Sanofi. C.J.P: Advisory board/consultancy honouraria: Alexion, Apellis, BioCryst, Octapharma, Sanofi, Sobi, Takeda. Speaking honouraria: Alexion, Octapharma, Sobi. Educational and/or research grants: Alexion, Octapharma, Sanofi. A.B. and D.B. No competing interests to declare., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Over the past decade, evidence has been mounting on the detrimental clinical sequelae of untreated anemia in patients with non-transfusion-dependent β-thalassemia (NTDT). There are no pharmacologic agents that are specifically approved for the management of anemia in NTDT, and available options such as splenectomy, transfusion therapy, and hydroxyurea each come with their own shortcomings, especially for long-term use. Luspatercept is an erythroid maturation agent that has been evaluated in a Phase 2, randomized trial and showed a significant benefit in raising hemoglobin level by at least 1 g/dL in adults with NTDT and a baseline hemoglobin level ≤10 g/dL. These data led to luspatercept's approval by the European Commission for the treatment of anemia in adults with NTDT and presents the first evidence-based approach for a novel agent that is able to ameliorate anemia in this patient population., Competing Interests: K.M.M. reports consultancy fees from Novartis, Celgene/Bristol Myers Squibb, Agios Pharmaceuticals, CRISPR Therapeutics, Vifor Pharma, and Pharmacosmos; and research funding from Agios Pharmaceuticals and Pharmacosmos. A.T.T. reports consultancy fees Novartis, Celgene/Bristol Myers Squibb, Vifor Pharma, Silence Therapeutics and Ionis Pharmaceuticals; and research funding from Novartis, Celgene/Bristol Myers Squibb, La Jolla Pharmaceutical Company, Roche, Protagonist Therapeutics, and Agios Pharmaceuticals. A.K. reports receiving advisory board fees and consulting fees from Agios Pharmaceuticals, Amgen, Celgene/Bristol Myers Squibb, CRISPR Therapeutics/Vertex, Ionis Pharmaceuticals, Novartis, and Vifor Pharma; and research support, paid to his institution, from Celgene/Bristol Myers Squibb and Novartis; honoraria for lectures, presentations or speakers’ bureau from Bristol Myers Squibb, Chiesi Farmaceutici, CRISPR Therapeutics/Vertex, and Novartis; and personal fees from Bristol Myers Squibb. K.H.M.K. reports consultancy fees from Agios Pharmaceuticals, Alexion, Apellis, bluebird bio, Celgene/Bristol Myers Squibb, Forma, Pfizer, Novo Nordisk, Vertex, and Novartis; honoraria from Alexion and Novartis; membership on an advisory committee for Agios Pharmaceuticals and Bioverativ/Sanofi/Sangamo; and research funding from Pfizer. S.S. reports consultancy fees from Agios Pharmaceuticals, Bluebird bio, Bristol Myers Squibb, Forma, and Chiesi; and serving on a clinical trial steering committee for CRISPR/Vertex CTX001 for thalassemia. M.D.C. reports consultancy fees from Novartis, Celgene/Bristol Myers Squibb, Vifor Pharma and Ionis Pharmaceuticals; and research funding from Novartis, Celgene/Bristol Myers Squibb, La Jolla Pharmaceutical Company, Roche, Protagonist Therapeutics, and CRISPR Therapeutics. The authors report no other conflicts of interest in this work., (© 2023 Musallam et al.)

Advances in understanding the underlying pathophysiology of β-thalassemia have enabled efforts toward the development of novel therapeutic modalities. These can be classified into three major categories based on their ability to target different features of the underlying disease pathophysiology: correction of the α/β globin chain imbalance, targeting ineffective erythropoiesis, and targeting iron dysregulation. This article provides an overview of these different emerging therapies that are currently in development for β-thalassemia., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Pyruvate kinase (PK) deficiency is a rare, under-recognised, hereditary condition that leads to chronic haemolytic anaemia and potentially serious secondary complications, such as iron overload, cholecystitis, pulmonary hypertension and extramedullary haematopoiesis. It is an autosomal recessive disease caused by homozygous or compound heterozygous mutations in the PKLR gene. Due to its rarity and clinical heterogeneity, information on the natural history and long-term clinical course of PK deficiency is limited, presenting major challenges to patient management, the development of new therapies and establishing disease-specific treatment recommendations. The Pyruvate Kinase Deficiency Global Longitudinal (Peak) Registry is an initiative to address the gaps in the knowledge of PK deficiency. This manuscript describes the objectives, study design and methodology for the Peak Registry., Methods and Analysis: The Peak Registry is an observational, longitudinal, global registry of adult and paediatric patients with a genetically confirmed diagnosis of PK deficiency. The Peak Steering Committee is composed of 11 clinicians and researchers with experience in the diagnosis and management of PK deficiency from 10 countries, a patient representative and representatives from the sponsor (Agios Pharmaceuticals). The registry objective is to foster an understanding of the longitudinal clinical implications of PK deficiency, including its natural history, treatments and outcomes, and variability in clinical care. The aim is to enrol up to 500 participants from approximately 60 study centres across 20 countries over 7 years, with between 2 and 9 years of follow-up. Data will include demographics, diagnosis history, genotyping, transfusion history, relevant clinical events, medications, emergency room visits and hospitalisations., Ethics and Dissemination: Registry protocol and informed consent forms are approved by institutional review boards/independent ethics committees at each study site. The study is being conducted in accordance with the Declaration of Helsinki. Registry data will be published in peer-reviewed journal articles and conference publications., Trial Registration Number: NCT03481738., Competing Interests: Competing interests: RFG receives research funding from Agios Pharmaceuticals, Novartis Pharmaceuticals and Sobi, and is a consultant for Agios Pharmaceuticals and Sanofi. EJvB is an advisory committee member for Agios Pharmaceuticals and receives research funding from Agios Pharmaceuticals, Novartis Pharmaceuticals, Pfizer and RR Mechatronics International B.V. BG is a consultant for Agios Pharmaceuticals. AG is a consultant for Agios Pharmaceuticals, bluebird bio, Bristol Myers Squibb, Novartis Pharmaceuticals, Novo Nordisk A/S and Pharmacosmos UK and receives research support from Agios Pharmaceuticals, Saniona, and Sanofi. KHMK is a consultant for Agios Pharmaceuticals, Alexion Pharmaceuticals, Apellis Pharmaceuticals, bluebird bio, Celgene Corporation, Novartis Pharmaceuticals and Pfizer, receives honoraria from Alexion Pharmaceuticals and Novartis Pharmaceuticals, is a member of the data safety monitoring board of Bioverativ and receives research funding from Agios Pharmaceuticals and Pfizer. CL receives payment as a patient representative on the Agios Pharmaceuticals PK Deficiency Patient Advocacy Advisory Council. DML is a consultant and advisory committee member for Agios Pharmaceuticals and Novartis Pharmaceuticals and is a member of the data safety monitoring board of Cerus Corporation. HK, J-LVC, DP and VV have no conflicts of interest to disclose. JL, ANB and YY are employees of Agios Pharmaceuticals and are shareholders in the company. CB is a former employee of Agios Pharmaceuticals. PB is a scientific advisor for Agios Pharmaceuticals., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Insulin resistance (IR) with associated compensatory hyperinsulinemia (HI) are early abnormalities in the etiology of prediabetes (preT2D) and type 2 diabetes (T2D). IR and HI also associate with increased erythrocytosis. Hemoglobin A1c (HbA1c) is commonly used to diagnose and monitor preT2D and T2D, but can be influenced by erythrocytosis independent of glycemia., Methods: We undertook bidirectional Mendelian randomization (MR) in individuals of European ancestry to investigate potential causal associations between increased fasting insulin adjusted for BMI (FI), erythrocytosis and its non-glycemic impact on HbA1c. We investigated the association between the triglyceride-glucose index (TGI), a surrogate measure of IR and HI, and glycation gap (difference between measured HbA1c and predicted HbA1c derived from linear regression of fasting glucose) in people with normoglycemia and preT2D., Results: Inverse variance weighted MR (IVWMR) suggested that increased FI increases hemoglobin (Hb, b=0.54 ± 0.09, p=2.7 x 10 -10 ), red cell count (RCC, b=0.54 ± 0.12, p=5.38x10 -6 ) and reticulocyte (RETIC, b=0.70 ± 0.15, p=2.18x10 -6 ). Multivariable MR indicated that increased FI did not impact HbA1c (b=0.23 ± 0.16, p=0.162) but reduced HbA1c after adjustment for T2D (b=0.31 ± 0.13, p=0.016). Increased Hb (b=0.03 ± 0.01, p=0.02), RCC (b=0.02 ± 0.01, p=0.04) and RETIC (b=0.03 ± 0.01, p=0.002) might modestly increase FI. In the observational cohort, increased TGI associated with decreased glycation gap, (i.e., measured HbA1c was lower than expected based on fasting glucose, (b=-0.09 ± 0.009, p<0.0001)) in people with preT2D but not in those with normoglycemia (b=0.02 ± 0.007, p<0.0001)., Conclusions: MR suggests increased FI increases erythrocytosis and might potentially decrease HbA1c by non-glycemic effects. Increased TGI, a surrogate measure of increased FI, associates with lower-than-expected HbA1c in people with preT2D. These findings merit confirmatory studies to evaluate their clinical significance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Nguyen, Khafagy, Hashemy, Kuo, Roshandel, Paterson and Dash.)

This study sought to link neurocognitive profiles in sickle cell disease (SCD) patients with clinical characteristics. We conducted a prospective cohort study of adults with SCD who underwent comprehensive neuropsychological assessment at the UMGGR clinic at Henri Mondor Hospital, Créteil (France). A cluster analysis was performed based on neuropsychological testing scores. The association between clusters and clinical profiles was assessed. Between 2017 and 2021, 79 patients with a mean age of 36 [range 19-65] years were included. On principal component analysis, a 5-factor model presented the best fit (Bartlett's sphericity test [χ 2 (171) = 1345; p < 0.001]), explaining 72% of the variance. The factors represent distinct cognitive domains and anatomical regions. On hierarchical classification, three clusters emerged. Cluster 1 ( n = 24) presented deficits in all five factors compared to Cluster 3 ( n = 33). Cluster 2 ( n = 22) had deficits in all factors, but to a lesser extent than Cluster 1. MoCA scores mirrored the severity of these cognitive deficits. Age, genotype and stroke prevalence did not differ significantly between clusters. However, the time of first stroke occurrence differed significantly between Cluster 1 and 2-3: 78% of strokes occurred during childhood, whereas 80% and 83% occurred during adulthood in Clusters 2 and 3, respectively. Educational attainment was also reduced in Cluster 1. SCD patients with childhood stroke seem to be at increased risk of a global cognitive deficit profile. In addition to existing methods of primary and secondary stroke prevention, early neurorehabilitation should be prioritized in order to reduce the long-term cognitive morbidity of SCD.

Objectives: Obstructive sleep apnea (OSA) is reported to be a cause of secondary polycythemia. The present study (i) reviewed the literature reporting the prevalence of secondary polycythemia in patients with OSA and (ii) determined the effect of continuous positive airway pressure (CPAP) therapy on hemoglobin and hematocrit levels in patients with OSA., Methods: We searched MEDLINE, Embase and Cochrane for studies of adult patients with OSA that reported hemoglobin and/or hematocrit levels. We performed summary estimates of (i) polycythemia prevalence and a subgroup analysis according to OSA severity, and (ii) change in hemoglobin and hematocrit levels following treatment with CPAP., Results: Synthesis of seven studies including 3,654 patients revealed an overall polycythemia prevalence of 2% (95% CI 1-4%); 2% (95% CI 1-3%) in mild-to moderate and 6 % (95% CI 3-12%) in severe OSA. In the pooled analysis of ten single-arm trials including 434 patients, CPAP treatment reduced hemoglobin by 3.76 g/L (95% CI -4.73 to -2.80 g/L). Similarly, pooled analysis of ten single-arm trials including 356 patients without baseline polycythemia showed that CPAP treatment reduced hematocrit by 1.1% (95% CI -1.4 to -0.9%)., Conclusion: Our pooled analysis supports an increased prevalence of secondary polycythemia in OSA. This estimated prevalence is likely underestimated due to the change in the polycythemia diagnostic criteria in 2016. Future randomized controlled trials are needed to evaluate the effect of CPAP in patients with baseline polycythemia., Highlights: Pooled analysis shows OSA is associated with an increased prevalence of secondary polycythemiaPrevalence of polycythemia is greater in severe OSACPAP treatment for OSA reduces both the hemoglobin and hematocrit.

This overview of reproductive and sexual health care concerns for people with sickle cell disease (SCD) addresses clinical concerns that can be complex and are inherently multidisciplinary. Clinicians must be prepared to initiate reproductive health care discussions, as these intimate concerns may not be volunteered by patients. SCD is associated with delayed onset of puberty, sickle pain during menstruation, disease-specific contraceptive considerations, high-risk pregnancy, priapism, erectile dysfunction, and offspring who inherit a hemoglobinopathy trait from affected parents. Reproductive health considerations are underrecognized, undertreated, and understudied. They need attention in primary care and specialty SCD, urology, and obstetrics and gynecology clinics., Competing Interests: Disclosure L.H Pecker is supported by grants from NIH/NHLBI K23HL146841, the American Society of Hematology, the Doris Duke Charitable Foundation Grant: 2020147, and the Mellon Foundation, and is a co-founder of the Sickle Cell Reproductive Health Education Directive; consultancy with Global Blood Therapeutics. KHM Kuo received grants from NIH/NHLBI: 1R33HL147845, Thalassemia Foundation of Canada, Peter Munk Cardiac Centre, University of Toronto, Canadian Hematology Society, Pfizer; consultancy with Agios, Alexion, Apellis, Aruvant, Bluebirdbio, Celgene/BMS, Forma, Novartis, Pfizer; chair of a data safety monitoring board: Bioverativ/Sanofi/Sangamo; research collaboration: Phoenicia Biosciences., (Published by Elsevier Inc.)

Background: Mitapivat, an oral activator of pyruvate kinase (PK) in red blood cells (RBCs), has shown significant improvements in haemoglobin and haemolysis among patients with pyruvate kinase deficiency who were not receiving regular transfusions. We aimed to evaluate the efficacy and safety of mitapivat in adults with pyruvate kinase deficiency receiving regular transfusions., Methods: ACTIVATE-T was an open-label, single-arm, phase 3 trial conducted in 20 centres across Europe, North America, and Asia. Eligible participants were adults (aged ≥18 years) with a clinical laboratory confirmation of pyruvate kinase deficiency receiving regular transfusions (at least six episodes in the previous year). Participants received oral mitapivat during a 16-week dose-optimisation period (5 mg, 20 mg, 50 mg twice daily) and 24-week fixed-dose period. The primary endpoint was a reduction in transfusion burden (≥33% reduction in number of RBC units transfused during the fixed-dose period, compared with the participant's individual historical transfusion burden, standardised to 24 weeks). Efficacy and safety were assessed in all participants who received at least one dose of mitapivat. This trial is registered with ClinicalTrials.gov, NCT03559699, and is complete., Findings: Between June 26, 2018, and Feb 4, 2020, 27 participants (20 [74%] female and seven [26%] male; 20 [74%] White, three [11%] Asian, and four [15%] not reported) were enrolled and received at least one dose of mitapivat. Median duration of exposure to mitapivat was 40·3 weeks (IQR 40·0-41·3). A reduction in transfusion burden by at least 33% was found in ten (37%) participants (95% CI 19-58; p=0·0002). The most common treatment-emergent adverse events were increase in alanine aminotransferase (ten [37%] participants), headache (ten [37%]), increase in aspartate aminotransferase (five [19%]), fatigue (five [19%]), and nausea (five [19%]). Two grade 3 treatment-emergent adverse events were related to study treatment: joint swelling (one participant [4%]) and an increase in aspartate aminotransferase (one participant [4%]). Three participants had serious treatment-emergent adverse events, none related to the study treatment: increased blood triglycerides, ovarian cyst, and renal colic (each in one participant [4%]). No treatment-related deaths were observed., Interpretation: Mitapivat represents a novel therapy that can reduce transfusion burden in some adults with pyruvate kinase deficiency receiving regular transfusions, and is the first disease-modifying agent approved in this disease., Funding: Agios Pharmaceuticals., Competing Interests: Declaration of interests EZ, RX, AO, PH, SG, and VB are employees and shareholders of Agios Pharmaceuticals. AG has received fees for consultancy work and as a member of advisory boards from Agios Pharmaceuticals, bluebird bio, Celgene, Novartis, and Novo Nordisk; and research grants from Alexion, Saniona, and Sanofi. EJvB has received fees as a member of advisory board from Agios Pharmaceuticals; and research funding from Agios Pharmaceuticals, Novartis, Pfizer, and RR Mechatronics. HA-S has received fees for consultancy work from Agios Pharmaceuticals, argenx, Dova–Sobi, Novartis, Rigel, Forma Therapeutics, and Moderna; and research funding from Agios Pharmaceuticals, Dova, and Amgen. VV has received fees for consultancy work, honoraria, research funding, and speakers bureau from Bristol-Myers Squibb; and fees for consultancy work and research funding from Agios Pharmaceuticals, Ionis, La Jolla Pharmaceuticals, Protagonist Therapeutics, and Vifor Pharma. KHMK has received fees for consultancy work from Agios Pharmaceuticals, Alexion, Apellis, bluebird bio, Celgene, Pfizer, and Novartis; honoraria from Alexion and Novartis; research funding from Pfizer; and membership on an entity's Board of Directors or advisory committees from Bioverativ. FG has been on board membership or advisory committee for Addmedica. SC has received fees for consultancy work from Agios Pharmaceuticals, Alexion, Daiichi Sankyo, Novartis, and Takeda; and research funding from Agios Pharmaceuticals, Alexion, Apellis, Global Blood Therapeutics, Novartis, and Takeda. WB has received honoraria from Agios Pharmaceuticals, Alexion, and Novartis; and been on board membership or advisory committee for Bioverativ and Incyte. JP declares no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In patients with sickle cell disease (SCD), the delivery of oxygen to the brain is compromised by anemia, abnormal rheology, and steno-occlusive vascular disease. Successful compensation depends on an increase in oxygen supply such as that provided by an increase in cerebral blood flow (CBF). We used magnetic resonance imaging to provide a high-resolution assessment of the ability of SCD patients to respond to a vasoactive stimulus in middle, anterior, and posterior cerebral artery territories for both white and gray matter. Cerebrovascular reactivity (CVR) was measured as the blood oxygen level dependent signal (a surrogate for CBF) response to an increase in the end tidal partial pressure of CO 2 (P ET CO 2 ). The dynamic aspect of the response was measured as the time constant of the first order response kinetics (tau). To confirm and support these findings we used an alternative examination of the response, transfer function analysis (TFA), to measure the responsiveness (gain), the speed of response (phase), and the consistency of the response over time (coherence). We tested 34 patients with SCD and compared the results to those of 24 healthy controls participants. The results from a three-way ANOVA showed that patients with SCD have reduced CVR (p < 0.001) and lower coherence (p < 0.001) in gray matter and white matter and reduced gain in gray matter only (p < 0.001). In terms of the speed of the response to CO 2 , tau (p < 0.001) and TFA phase (p < 0.001) were increased in SCD patients compared to healthy control subjects. These findings show that the cerebrovascular responsiveness to CO 2 in patients with SCD is both decreased and slowed compared to healthy controls., (© 2022 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Background: Despite increased cerebral blood flow (CBF), cerebral infarcts occur in patients with sickle cell disease (SCD). This suggests increased CBF does not meet metabolic demand possibly due to compromised cerebral vasodilatory response. Hypothesis: In adult SCD patients, cerebrovascular reactivity (CVR) and speed of vasodilatory response (tau) to a standardized vasodilatory stimulus, are reduced compared to normal subjects. Methods: Functional brain imaging performed as part of routine care in adult SCD patients without known large vessel cerebral vasculopathy was reviewed retrospectively. CVR was calculated as the change in CBF measured as the blood-oxygenation-level-dependent (BOLD)-magnetic resonance imaging signal, in response to a standard vasoactive stimulus of carbon dioxide (CO 2 ). The tau corresponding to the best fit between the convolved end-tidal partial pressures of CO 2 and BOLD signal was defined as the speed of vascular response. CVR and tau were normalized using a previously generated atlas of 42 healthy controls. Results: Fifteen patients were included. CVR was reduced in grey and white matter (mean Z-score for CVR -0.5 [-1.8 to 0.3] and -0.6 [-2.3 to 0.7], respectively). Tau Z-scores were lengthened in grey and white matter (+0.9 [-0.5 to 3.3] and +0.8 [-0.7 to 2.7], respectively). Hematocrit was the only significant independent predictor of CVR on multivariable regression. Conclusion: Both measures of cerebrovascular health (CVR and tau) in SCD patients were attenuated compared to normal controls. These findings show that CVR represents a promising tool to assess disease state, stroke risk, and therapeutic efficacy of treatments in SCD and merits further investigation., Competing Interests: JF and DM contributed to the development of the automated end-tidal targeting device, RespirAct™ (Thornhill Research Inc., TRI) used in this study and have equity in the company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Forté, Sobczyk, Poublanc, Duffin, Hare, Fisher, Mikulis and Kuo.)

Background: Patients with non-transfusion-dependent thalassaemia (NTDT), although they do not require regular blood transfusions for survival, can still accrue a heavy burden of comorbidities. No approved disease-modifying therapies exist for these patients. We aimed to investigate the safety and efficacy of mitapivat (Agios Pharmaceuticals, Cambridge, MA, USA), a pyruvate kinase activator, in adults with non-transfusion-dependent (NTD) α-thalassaemia or NTD β-thalassaemia., Methods: In this open-label, multicentre, phase 2 study, patients were recruited from four academic clinical study sites in Oakland, CA, and Boston, MA, USA; Toronto, ON, Canada; and London, UK. Patients were eligible if they were aged 18 years or older, with NTDT (including β-thalassaemia with or without α-globin gene mutations, haemoglobin E β-thalassaemia, or α-thalassaemia), and a baseline haemoglobin concentration of 10·0 g/dL or lower. During a 24-week core period, mitapivat was administered orally at 50 mg twice daily for the first 6 weeks followed by an escalation to 100 mg twice daily for 18 weeks thereafter. The primary endpoint was haemoglobin response (a ≥1·0 g/dL increase in haemoglobin concentration from baseline at one or more assessments between weeks 4 and 12). Efficacy and safety were assessed in the full analysis set (ie, all patients who received at least one dose of study drug). This study is registered with ClinicalTrials.gov, NCT03692052, and is closed to accrual., Findings: Between Dec 28, 2018, and Feb 6, 2020, 27 patients were screened, of whom 20 were enrolled (15 [75%] with β-thalassaemia and five [25%] with α-thalassaemia) and received mitapivat. The median age of patients was 44 years (IQR 35-56), 15 (75%) of 20 patients were female, five (25%) were male, and ten (50%) identified as Asian. 16 (80% [90% CI 60-93]) of 20 patients had a haemoglobin response (p<0·0001), five (100%) of five with α-thalassaemia and 11 (73%) of 15 with β-thalassaemia. 17 (85%) patients had a treatment-emergent adverse event, and 13 had a treatment-emergent event that was considered to be treatment related. One serious treatment-emergent adverse event occurred (grade 3 renal impairment), which was considered unrelated to study drug, resulting in discontinuation of treatment. The most commonly reported treatment-emergent adverse events were initial insomnia (ten [50%] patients), dizziness (six [30%]), and headache (five [25%]). No patients died during the 24-week core period., Interpretation: These efficacy and safety results support the continued investigation of mitapivat for the treatment of both α-thalassaemia and β-thalassaemia., Funding: Agios Pharmaceuticals., Competing Interests: Declaration of interests KHMK reports consultancy fees from Agios Pharmaceuticals, Alexion, Apellis, bluebird bio, Celgene, Forma, Pfizer, and Novartis; honoraria from Alexion and Novartis; membership on an advisory committee for Agios Pharmaceuticals and Bioverativ/Sanofi/Sangamo; and research funding from Pfizer. DML reports consultancy fees from Agios Pharmaceuticals and membership on the Board of Directors or advisory committee for Agios Pharmaceuticals and Cerus. AL reports research funding from bluebird bio, Celgene, Insight Magnetics, La Jolla Pharmaceutical Company, Novartis, Protagonist Therapeutics, Terumo Corporations, and Forma; consultancy fees from Agios Pharmaceuticals and Chiesi USA; and membership on the Board of Directors or advisory committee for Celgene and Protagonist Therapeutics. HA-S reports consultancy fees from Agios Pharmaceuticals, argenx, Dova/Sobi, Moderna, Novartis, Rigel, and Forma and research funding from Agios Pharmaceuticals, Amgen, and Dova. JB, PAK, BT, ML, and KU are employees and shareholders of Agios Pharmaceuticals. EPV reports consultancy fees and research funding from Agios Pharmaceuticals, bluebird bio, Global Blood Therapeutics, Novartis, and Pfizer., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In patients with sickle cell disease (SCD) the delivery of oxygen to the brain is compromised by anemia, abnormal rheology, and steno-occlusive vascular disease. Meeting demands for oxygen delivery requires compensatory features of brain perfusion. The cerebral vasculature's regulatory function and reserves can be assessed by observing the flow response to a vasoactive stimulus. In a traditional approach we measured voxel-wise change in Blood Oxygen-Level Dependent (BOLD) MRI signal as a surrogate of cerebral blood flow (CBF) in response to a linear progressive ramping of end-tidal partial pressure of carbon dioxide (PETCO 2 ). Cerebrovascular reactivity (CVR) was defined as ΔBOLD/ΔPETCO 2 . We used a computer model to fit a virtual sigmoid resistance curve to the progressive CBF response to the stimulus, enabling the calculation of resistance parameters: amplitude, midpoint, range response, resistance sensitivity and vasodilatory reserve. The quality of the resistance sigmoid fit was expressed as the r 2 of the fit. We tested 35 patients with SCD, as well as 24 healthy subjects to provide an indication of the normal ranges of the resistance parameters. We found that gray matter CVR and resistance amplitude, range, reserve, and sensitivity are reduced in patients with SCD compared to healthy controls, while resistance midpoint was increased. This study is the first to document resistance measures in adult patients with SCD. It is also the first to score these vascular resistance measures in comparison to the normal range. We anticipate these data will complement the current understanding of the cerebral vascular pathophysiology of SCD, identify paths for therapeutic interventions, and provide biomarkers for monitoring the progress of the disease., Competing Interests: JF and DM contributed to the development of the automated end-tidal targeting device, RespirAct™ (Thornhill Research Inc., TRI) used in this study and have equity in the company. OS and JD receive salary support from TRI. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sayin, Sobczyk, Poublanc, Mikulis, Fisher, Kuo and Duffin.)

Pyruvate kinase deficiency (PKD) is the most common cause of congenital nonspherocytic hemolytic anemia. Although recognition of the disease spectrum has recently expanded, data describing its impact on health-related quality of life (HRQoL) are limited. In this prospective international cohort of 254 patients (131 adults and 123 children) with PKD, we used validated measures to assess the impact of disease on HRQoL (EuroQol 5-Dimension Questionnaire, Pediatric Quality of Life Inventory Generic Core Scale version 4.0, and Functional Assessment of Cancer Therapy-Anemia) and fatigue (Patient Reported Outcomes Measurement Information System Fatigue and Pediatric Functional Assessment of Chronic Illness Therapy-Fatigue). Significant variability in HRQoL and fatigue was reported for adults and children, although individual scores were stable over a 2-year interval. Although adults who were regularly transfused reported worse HRQoL and fatigue compared with those who were not (EuroQol-visual analog scale, 58 vs 80; P = .01), this difference was not seen in children. Regularly transfused adults reported lower physical, emotional, and functional well-being and more anemia symptoms. HRQoL and fatigue significantly differed in children by genotype, with the worst scores in those with 2 severe PKLR mutations; this difference was not seen in adults. However, iron chelation was associated with significantly worse HRQoL scores in children and adults. Pulmonary hypertension was also associated with significantly worse HRQoL. Additionally, 59% of adults and 35% of children reported that their jaundice upset them, identifying this as an important symptom for consideration. Although current treatments for PKD are limited to supportive care, new therapies are in clinical trials. Understanding the impact of PKD on HRQoL is important to assess the utility of these treatments. This trial was registered at www.clinicaltrials.gov as #NCT02053480., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Sickle cell disease (SCD) induces a chronic prothrombotic state. Central venous access devices (CVADs) are commonly used for chronic transfusions and iron chelation in this population. CVADs are an additional venous thromboembolism (VTE) risk factor. The role of thromboprophylaxis in this setting is uncertain. The objectives are: (1) to determine whether thromboprophylaxis reduces VTE risk in SCD patients with CVAD and (2) to explore characteristics associated with VTE risk. We identified adults with SCD and CVAD intended for chronic use (≥3 months) at two comprehensive SCD centers. Thromboprophylaxis presence; type; intensity; and patient-, catheter-, and treatment-related VTE risk factors were recorded. Among 949 patients, 49 had a CVAD (25 without and 24 with VTE prophylaxis). Thromboprophylaxis type and intensity varied widely. Patients without thromboprophylaxis had higher VTE rates (rate ratio (RR) = 4.0 (95% confidence interval: 1.2−12.6), p = 0.02). Hydroxyurea was associated with lower VTE rates (RR = 20.5 (6.4−65.3), p < 0.001). PICC lines and Vortex and Xcela Power implantable devices were associated with higher rates compared with Port-a-Cath (RR = 5.8 (1.3−25.9), p = 0.02, and RR = 58.2 (15.0−225.0), p < 0.001, respectively). Thromboprophylaxis, hydroxyurea, and CVAD subtype were independently associated with VTE. The potentially protective role of thromboprophylaxis and hydroxyurea for VTE prevention in patients with SCD and CVAD merits further exploration.

Objectives: MRI quantification of liver iron concentration (LIC) using R 2 or R 2 * relaxometry requires offline post-processing causing reporting delays, administrative overhead, and added costs. A prototype 3D multi-gradient-echo pulse sequence, with inline post-processing, allows immediate calculation of LIC from an R 2 * map (inline R 2 *-LIC) without offline processing. We compared inline R 2 *-LIC to FerriScan and offline R 2 * calibration methods., Methods: Forty patients (25 women, 15 men; age 18-82 years), prospectively underwent FerriScan and the prototype sequence, which produces two R 2 * maps, with and without fat modeling, as well as an inline R 2 *-LIC map derived from the R 2 * map with fat modeling, with informed consent. For each map, the following contours were drawn: ROIs, whole-axial-liver contour, and an exact copy of contour utilized by FerriScan. LIC values from the FerriScan report and those calculated using an alternative R 2 calibration were the reference standards. Results were compared using Pearson and interclass correlation coefficients (PCC, ICC), linear regression, Bland-Altman analysis, and estimation of area under the receiver operator curve (ROC-AUC)., Results: Inline R 2 *-LIC demonstrated good agreement with the reference standards. Compared to FerriScan, inline R 2 *-LIC with whole-axial-liver contour, ROIs, and FerriScan contour demonstrated PCC of 94.8%, 94.8%, and 92%; ICC 93%, 92.7%, and 90.2%; regression slopes 1.004, 0.974, and 1.031; mean bias 5.54%, 10.91%, and 0.36%; and ROC-AUC estimates 0.903, 0.906, and 0.890 respectively. Agreement was maintained when adjusted for sex, age, diagnosis, liver fat content, and fat-water swap., Conclusion: Inline R 2 *-LIC provides robust and comparable quantification of LIC compared to FerriScan, without the need for offline post-processing., Key Points: • In patients being treated for iron overload with chelation therapy, liver iron concentration (LIC) is regularly assessed in order to monitor and adjust therapy. • Magnetic resonance imaging (MRI) is commonly used to quantify LIC. Several R 2 and R 2 * methods are available, all of which require offline post-processing. • A novel R 2 * MRI method allows for immediate calculation of LIC and provides comparable quantification of LIC to the FerriScan and recently published alternative R 2 * methods., (© 2021. European Society of Radiology.)

We aimed to identify risk factors for adverse outcomes in pregnancies of women with sickle cell disease (SCD) and develop risk prediction models. Models were derived from a retrospective cohort of pregnant women with SCD and constructed using generalised estimating equation logistic regression, with clustering by woman. Maternal event(s) consisted of acute anaemia; cardiac, pulmonary, hepatobiliary, musculoskeletal, skin, splenic, neurological or renal complications, multi-organ failure, venous thromboembolism, admission-requiring vaso-occlusive events (VOE), red cell transfusion, mortality or hypertensive disorder of pregnancy. Fetal events included preterm birth, small-for-gestational-age or perinatal mortality. Of 199 pregnancies, 71% and 45% resulted in adverse maternal and fetal outcomes respectively. Low first-trimester haemoglobin, admission-requiring VOE in the year before pregnancy, multiple transfusions before pregnancy, SCD genotype and previous cardiac complications predicted maternal risk. Younger age and SCD genotype allowed early prediction of fetal risk (model-F1). Adding maternal event(s) and high lactate dehydrogenase enabled re-assessment of fetal risk with advancing gestation (model-F2). Models were well calibrated and moderately discriminative for maternal outcome (c-statistic 0·81, cross-validated value 0·79) and fetal outcome (model-F1 c-statistic 0·68, cross-validated value 0·65; model-F2 c-statistic 0·72, cross-validated value 0·68). The models will allow early identification of women with SCD at high risk of adverse events, permitting early targeted interventions and ongoing fetal risk re-assessment enabling intensification of surveillance and optimisation of delivery timing., (© 2021 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Importance: Adults with sickle cell disease (SCD) disproportionally experience early cognitive decline; however, guidance on the optimal screening strategy for cognitive dysfunction is lacking, and several available tools are biased by language, educational level, socioeconomic status, and race/ethnicity. The Rowland Universal Dementia Assessment Scale (RUDAS) was specifically designed for cognitive screening in multicultural populations., Objective: To ascertain the prevalence of suspected dementia in adults with SCD using the RUDAS, and to identify whether age, sex, educational level, several biological variables, and SCD complications were associated with RUDAS scores., Design, Setting, and Participants: This multicenter, bilingual, cross-sectional study was conducted in 2 SCD comprehensive care centers in Canada (Centre Hospitalier de l'Université Montréal in Montréal and University Health Network in Toronto). Participants were adults aged 18 years or older and were enrolled in the study between July 1, 2018, and July 30, 2019. All outpatients were eligible and offered study participation, unless they had an acute medical condition that required inpatient care or they were unable to follow study instructions., Interventions: The RUDAS was administered by trained personnel in either French or English, according to the patient's language preference. A questionnaire on social determinants of health was also administered, and participants underwent screening for anxiety and depression., Main Outcomes and Measures: Proportion of participants with RUDAS scores that were suggestive of dementia and the RUDAS score. Any score lower than 23 points was suggestive of dementia, a score between 23 and 27 points indicated a possible association with mild neurocognitive disorder, and a score higher than 27 points was normal., Results: A total of 252 adult patients with SCD were included (136 women [54.0%]; mean [range] age, 34.8 [18-75] years). Overall, 29 patients (11.5%) had RUDAS scores that were suggestive of dementia, and this proportion increased with age (15 [8.7%] in the 18-39 years age group, 10 [14.5%] in the 40-59 years age group, and 4 [36.4%] in the ≥60 years age group). The RUDAS scores were not associated with sex, language, SCD genotype, and SCD complications. The highest level of education was significantly associated with the RUDAS score; however, the association was small (η2 = 0.02; 95% CI, 0.00-0.07; P = .02). In a multivariable analysis, lower glomerular filtration rate (r = 0.40; 95% CI, 0.29-0.50; P < .001) and increasing age (r = -0.37; 95% CI, -0.47 to -0.26; P < .001), but not SCD genotype or disease severity, were associated with lower RUDAS scores., Conclusions and Relevance: This study found that using the RUDAS revealed a high prevalence of suspected dementia in adult patients with SCD that was associated with worsening kidney function and age. Cognition should be screened in all adult patients with SCD, regardless of age, disease severity, and SCD genotype; further validation of the RUDAS is ongoing.

Objectives: Pyruvate kinase (PK) deficiency is caused by PKLR gene mutations, leading to defective red blood cell glycolysis and hemolytic anemia. Rates of comorbidities and complications by transfusion history and relative to the general population remain poorly quantified., Methods: Data for patients aged ≥ 18 years with two confirmed PKLR mutations were obtained from the PK deficiency Natural History Study (NCT02053480). Frequencies of select conditions were compared with an age- and sex-matched cohort from a general insured US population without PK deficiency., Results: Compared with the matched population (n = 1220), patients with PK deficiency (n = 122) had significantly higher lifetime rates of osteoporosis, liver cirrhosis, and pulmonary hypertension; splenectomy and cholecystectomy rates were also significantly higher in the 8 years before the index date. Sixty-five (53.3%) patients with PK deficiency were classified as regularly transfused, 30 (24.6%) as occasionally transfused, and 27 (22.1%) as never transfused. Regularly transfused patients were significantly more likely than never transfused patients to have had splenectomy, cholecystectomy, and/or thrombosis. Liver iron overload was reported in 62% of patients and occurred regardless of transfusion cohort., Conclusions: Even never transfused patients with PK deficiency had higher rates of select comorbidities and complications than individuals without PK deficiency., (© 2020 Agios Pharmaceuticals, Inc. European Journal of Haematology Published by John Wiley & Sons Ltd.)

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., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

Pyruvate kinase deficiency (PKD) is the most common cause of chronic hereditary non-spherocytic hemolytic anemia and results in a broad spectrum of disease. The diagnosis of PKD requires a high index of suspicion and judicious use of laboratory tests that may not always be informative, including pyruvate kinase enzyme assay and genetic analysis of the PKLR gene. A significant minority of patients with PKD have occult mutations in non-coding regions of PKLR which are missed on standard genetic tests. The biochemical consequences of PKD result in hemolytic anemia due to red cell pyruvate and ATP deficiency while simultaneously causing increased red cell 2,3-diphosphoglycerate, which facilitates oxygen unloading. This phenomenon, in addition to numerous other factors such as genetic background and differences in splenic function result in a poor correlation between symptoms and degree of anemia from patient to patient. Red cell transfusions should, therefore, be symptom-directed and not based on a hemoglobin threshold. Patients may experience specific complications, such as paravertebral extramedullary hematopoiesis and chronic debilitating icterus, which require personalized treatment. The decision to perform splenectomy or hematopoietic stem cell transplantation is nuanced and depends on disease burden and long-term outlook given that targeted therapeutics are in development. In recognition of the complicated nature of the disease and its management and the limitations of the PKD literature, an international working group of ten PKD experts convened to better define the disease burden and manifestations. This article summarizes the conclusions of this working group and is a guide for clinicians and investigators caring for patients with PKD.

Indications for therapeutic and donor apheresis continue to increase and expand into new domains of therapy. The level and amount of apheresis education in residency programs remains heterogeneous, which may translate into varying degrees of clinical confidence in providing care. The purpose of this study was to assess Canadian clinicians' perceptions of their apheresis training in order to help demonstrate a need for a concrete apheresis education in residency curricula. A 22-question survey was distributed to Canadian graduates who recently completed training (2013-2017) in the following specialties: hematology, nephrology, transfusion medicine, and hematologic pathology. Questions regarding clinician perception of their training were asked using a Likert scale. Fifty-seven survey responses (32% response rate) were obtained from recent graduates from hematology (29/57, 51%), nephrology (21/57, 37%), hematologic pathology (4/57, 7%) and transfusion medicine (3/57, 5%). Although most respondents (68%) received some form of apheresis exposure during residency, only 23% reported a formal apheresis rotation. Only 40% felt that the amount of time devoted to apheresis education was sufficient, and only four respondents (7%) felt confident providing independent apheresis care at the end of training. Overall, these findings suggest that a common, dedicated apheresis curriculum in these training programs could possibly increase knowledge and competence of trainees, and provide a more solid foundation in apheresis for future practice., Competing Interests: Declaration of Competing Interest None., (Crown Copyright © 2020. Published by Elsevier Ltd. All rights reserved.)

Pyruvate kinase (PK) deficiency is a rare recessive congenital hemolytic anemia caused by mutations in the PKLR gene. This study reports the molecular features of 257 patients enrolled in the PKD Natural History Study. Of the 127 different pathogenic variants detected, 84 were missense and 43 non-missense, including 20 stop-gain, 11 affecting splicing, five large deletions, four in-frame indels, and three promoter variants. Within the 177 unrelated patients, 35 were homozygous and 142 compound heterozygous (77 for two missense, 48 for one missense and one non-missense, and 17 for two non-missense variants); the two most frequent mutations were p.R510Q in 23% and p.R486W in 9% of mutated alleles. Fifty-five (21%) patients were found to have at least one previously unreported variant with 45 newly described mutations. Patients with two non-missense mutations had lower hemoglobin levels, higher numbers of lifetime transfusions, and higher rates of complications including iron overload, extramedullary hematopoiesis, and pulmonary hypertension. Rare severe complications, including lower extremity ulcerations and hepatic failure, were seen more frequently in patients with non-missense mutations or with missense mutations characterized by severe protein instability. The PKLR genotype did not correlate with the frequency of complications in utero or in the newborn period. With ICCs ranging from 0.4 to 0.61, about the same degree of clinical similarity exists within siblings as it does between siblings, in terms of hemoglobin, total bilirubin, splenectomy status, and cholecystectomy status. Pregnancy outcomes were similar across genotypes in PK deficient women. This report confirms the wide genetic heterogeneity of PK deficiency., (© 2020 Wiley Periodicals, Inc.)