Diagnosis and management of pyruvate kinase deficiency: international expert guidelines.

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.

Sickle cell disease landscape and challenges in the EU: the ERN-EuroBloodNet perspective.

Sickle cell disease is a hereditary multiorgan disease that is considered rare in the EU. In 2017, the Rare Diseases Plan was implemented within the EU and 24 European Reference Networks (ERNs) were created, including the ERN on Rare Haematological Diseases (ERN-EuroBloodNet), dedicated to rare haematological diseases. This EU initiative has made it possible to accentuate existing collaborations and create new ones. The project also made it possible to list all the needs of people with rare haematological diseases not yet covered health-care providers in the EU to allow optimised care of individuals with rare pathologies, including sickle cell disease. This Viewpoint is the result of joint work within 12 EU member states (ie, Belgium, Cyprus, Denmark, France, Germany, Greece, Ireland, Italy, Portugal, Spain, Sweden, and The Netherlands), all members of the ERN-EuroBloodNet. We describe the role of the ERN-EuroBloodNet to improve the overall approach to and the management of individuals with sickle cell disease in the EU through specific on the pooling of expertise, knowledge, and best practices; the development of training and education programmes; the strategy for systematic gathering and standardisation of clinical data; and its reuse in clinical research. Epidemiology and research strategies from ongoing implementation of the Rare Anaemia Disorders European Epidemiological Platform is depicted.

Combining microfluidics with machine learning algorithms for RBC classification in rare hereditary hemolytic anemia.

Combining microfluidics technology with machine learning represents an innovative approach to conduct massive quantitative cell behavior study and implement smart decision-making systems in support of clinical diagnostics. The spleen plays a key-role in rare hereditary hemolytic anemia (RHHA), being the organ responsible for the premature removal of defective red blood cells (RBCs). The goal is to adapt the physiological spleen filtering strategy for in vitro study and monitoring of blood diseases through RBCs shape analysis. Then, a microfluidic device mimicking the slits of the spleen red pulp area and video data analysis are combined for the characterization of RBCs in RHHA. This microfluidic unit is designed to evaluate RBC deformability by maintaining them fixed in planar orientation, allowing the visual inspection of RBC's capacity to restore their original shape after crossing microconstrictions. Then, two cooperative learning approaches are used for the analysis: the majority voting scheme, in which the most voted label for all the cell images is the class assigned to the entire video; and the maximum sum of scores to decide the maximally scored class to assign. The proposed platform shows the capability to discriminate healthy controls and patients with an average efficiency of 91%, but also to distinguish between RHHA subtypes, with an efficiency of 82%.

Usefulness of NGS for Diagnosis of Dominant Beta-Thalassemia and Unstable Hemoglobinopathies in Five Clinical Cases.

Unstable hemoglobinopathies (UHs) are rare anemia disorders (RADs) characterized by abnormal hemoglobin (Hb) variants with decreased stability. UHs are therefore easily precipitating, causing hemolysis and, in some cases, leading to dominant beta-thalassemia (dBTHAL). The clinical picture of UHs is highly heterogeneous, inheritance pattern is dominant, instead of recessive as in more prevalent major Hb syndromes, and may occur de novo. Most cases of UHs are not detected by conventional testing, therefore diagnosis requires a high index of suspicion of the treating physician. Here, we highlight the importance of next generation sequencing (NGS) methodologies for the diagnosis of patients with dBTHAL and other less severe UH variants. We present five unrelated clinical cases referred with chronic hemolytic anemia, three of them with severe blood transfusion dependent anemia. Targeted NGS analysis was performed in three cases while whole exome sequencing (WES) analysis was performed in two cases. Five different UH variants were identified correlating with patients' clinical manifestations. Four variants were related to the beta-globin gene (Hb Bristol-Alesha, Hb Debrousse, Hb Zunyi, and the novel Hb Mokum) meanwhile one case was caused by a mutation in the alpha-globin gene leading to Hb Evans. Inclusion of alpha and beta-globin genes in routine NGS approaches for RADs has to be considered to improve diagnosis' efficiency of RAD due to UHs. Reducing misdiagnoses and underdiagnoses of UH variants, especially of the severe forms leading to dBTHAL would also facilitate the early start of intensive or curative treatments for these patients.

Pathophysiology of Anemia in HIV-Infected Children Exposed to Malaria.

Anemia is a common condition in HIV-infected children; however, its pathophysiology and the contribution of frequent causes of anemia such as iron deficiency (ID) and malaria are poorly understood. We carried out an ancillary study on the effect of HIV on anemia as part of a case-control study on risk factors of anemia among Mozambican children aged 1-59 months with documented HIV status. Of them, 390 children were admitted to the hospital with anemia (hemoglobin [Hb] < 11 g/dL), whereas 272 children without anemia (Hb ≥ 11 g/dL) were recruited in the community. We assessed differences by HIV status in the presentation of anemia etiological factors and the effect of HIV infection on the association of each factor with anemia. Among the 99 HIV-infected and 563 uninfected children included, HIV-infected anemic children had an increased risk of undernutrition (P < 0.0001), Epstein-Barr virus infection (P < 0.0001), bacteremia (P = 0.0060), a decreased risk of malaria (P < 0.0001), and a similar risk of ID (P = 0.7371) compared with anemic-uninfected children. HIV-infected children were significantly less likely to have anemia associated with Plasmodium falciparum hyperparasitemia (P = 0.0444) and had a lower prevalence of parasitemia in the bone marrow (BM) (P < 0.0001) than anemic-uninfected children. Levels of BM erythropoiesis and dyserythropoiesis were comparable between groups. These findings suggest that the pathophysiology of anemia among HIV-infected malaria-exposed children is not related to HIV-specific effects. For unclear reasons, HIV-infected children had reduced risk of malaria infection, whereas ID prevalence was comparable in HIV-infected and uninfected children, suggesting that iron supplementation recommendations should not be different in HIV-infected children.

Time for Change? The Why, What and How of Promoting Innovation to Tackle Rare Diseases - Is It Time to Update the EU's Orphan Regulation? And if so, What Should be Changed?

Since developments are global in the healthcare arena, more should be done to align EU and other big markets' regulatory practices for rare disease patients. Notwithstanding efforts and cooperation between the US and EU aimed to harmonize their strategic plans in the field of orphan drugs, regulatory criteria and procedures to gain the designation, terms and classifications should be still harmonised. Aligning the criteria of prevalence and support to orphan medicines in the various jurisdictions internationally, would facilitate patient recruitment eventually at global level, so as to gain the data and the biological insights required to identify biomarkers and appropriate endpoints needed for progressing clinical development. A conducive regulatory environment can further support the development of medicines to treat rare diseases. Overall there is a need for joined-up regulatory process coordination. Better integration of regulatory pathways and better integration of regulatory systems, such as scientific tools and methods to generate evidence, would be helpful. There is a need to revise and agree the current frameworks to be improved which will take into account the considerations and challenges to diagnose and treat different rare diseases and improve quality of life. Deliberative processes with multi-stakeholders' involvement for reimbursement should be considered. This paper explores the successes and limitation of both the regulation and its implementation mechanisms in the current regulatory context, and suggests some improvements that could maximise its benefits and boost rare disease research even further.

Red Blood Cell Membrane Conductance in Hereditary Haemolytic Anaemias.

Congenital haemolytic anaemias are inherited disorders caused by red blood cell membrane and cytoskeletal protein defects, deviant hemoglobin synthesis and metabolic enzyme deficiencies. In many cases, although the causing mutation might be known, the pathophysiology and the connection between the particular mutation and the symptoms of the disease are not completely understood. Thus effective treatment is lagging behind. As in many cases abnormal red blood cell cation content and cation leaks go along with the disease, by direct electrophysiological measurements of the general conductance of red blood cells, we aimed to assess if changes in the membrane conductance could be a possible cause. We recorded whole-cell currents from 29 patients with different types of congenital haemolytic anaemias: 14 with hereditary spherocytosis due to mutations in α-spectrin, ß-spectrin, ankyrin and band 3 protein; 6 patients with hereditary xerocytosis due to mutations in Piezo1; 6 patients with enzymatic disorders (3 patients with glucose-6-phosphate dehydrogenase deficiency, 1 patient with pyruvate kinase deficiency, 1 patient with glutamate-cysteine ligase deficiency and 1 patient with glutathione reductase deficiency), 1 patient with ß-thalassemia and 2 patients, carriers of several mutations and a complex genotype. While the patients with ß-thalassemia and metabolic enzyme deficiencies showed no changes in their membrane conductance, the patients with hereditary spherocytosis and hereditary xerocytosis showed largely variable results depending on the underlying mutation.

Addressing the diagnostic gaps in pyruvate kinase deficiency: Consensus recommendations on the diagnosis of pyruvate kinase deficiency.

Pyruvate kinase deficiency (PKD) is the most common enzyme defect of glycolysis and an important cause of hereditary, nonspherocytic hemolytic anemia. The disease has a worldwide geographical distribution but there are no verified data regarding its frequency. Difficulties in the diagnostic workflow and interpretation of PK enzyme assay likely play a role. By the creation of a global PKD International Working Group in 2016, involving 24 experts from 20 Centers of Expertise we studied the current gaps in the diagnosis of PKD in order to establish diagnostic guidelines. By means of a detailed survey and subsequent discussions, multiple aspects of the diagnosis of PKD were evaluated and discussed by members of Expert Centers from Europe, USA, and Asia directly involved in diagnosis. Broad consensus was reached among the Centers on many clinical and technical aspects of the diagnosis of PKD. The results of this study are here presented as recommendations for the diagnosis of PKD and used to prepare a diagnostic algorithm. This information might be helpful for other Centers to deliver timely and appropriate diagnosis and to increase awareness in PKD.

A Previously Unrecognized Ca2+-inhibited Nonselective Cation Channel in Red Blood Cells.

Supplemental Digital Content is available in the text.

Heterogeneity of G6PD deficiency prevalence in Mozambique: a school-based cross-sectional survey in three different regions.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked hereditary enzymatic abnormality that affects more than 400 million people worldwide. Most deficient individuals do not manifest any symptoms; however, several precipitant agents-such as fava intake, infections, or several drugs-may trigger acute haemolytic anaemia. Countries should be informed of the prevalence of this enzymatic anomaly within their borders, in order to make safe and appropriate national decisions regarding the use of potentially unsafe drugs for G6PD deficient individuals. METHODS: A school-based cross-sectional survey was conducted in three districts in Mozambique, namely Manhiça, located in the south; Mocuba in the centre; and Pemba in the northern tip of the country. G6PD deficiency was evaluated using the CareStart™ diagnostic test, and enzyme activity levels were measured through fluorescence spectrophotometry in deficient individuals. Chi squared and ANOVA tests were used to assess prevalence and mean enzyme activity differences, and logistic regression was used to identify risk factors associated to the deficiency. RESULTS: G6PD deficiency prevalence estimates were lowest in the northern city of Pemba (8.3%) and among Emakhuwas and Shimakondes, and higher in the centre and southern regions of the country (16.8 and 14.6%, respectively), particularly among Elomwes and Xichanganas. G6PD deficiency was significantly more prevalent among male students than females (OR = 1.4, 95% CI 1.0-1.8, p = 0.02), although enzyme activity levels were not different among deficient individuals from either gender group. Finally, median deficiency levels were found to be more severe among the deficient students from the north (0.7 U/gHg [0.2-0.7] p < 0.001) and south (0.7 U/gHg [0.5-2.5]), compared to those from the centre (1.4 U/gHg [0.6-2.1]). CONCLUSION: These findings suggest that Mozambique, as a historically high malaria-endemic country has considerable levels of G6PD deficiency, that vary significantly across the country. This should be considered when planning national strategies for the use of licensed drugs that may be associated to haemolysis among G6PD individuals, or prior to the performance of future trials using primaquine and other 8-aminoquinolines derivatives. Registration Number CISM local ethics committee (CIBS-25/013, 4th of December 2013), and the National Ethics Committee of Mozambique (IRB00002657, 28th of February 2014).

Déficit de piruvato cinasa eritrocitaria en España: estudio de 15 casos / Red cell pyruvate kinase deficiency in Spain: A study of 15 cases

Antecedentes y objetivo: El déficit de piruvato cinasa (DPK) es una enfermedad hereditaria rara, que cursa con hemólisis crónica y anemia de intensidad variable. Su heterogeneidad genética es elevada, habiéndose descrito unas 240 mutaciones diferentes. Pacientes y metodología: Se han estudiado 15 pacientes con DPK en los que se ha secuenciado la totalidad del gen PKLR, incluyendo las regiones promotora, exónicas, intrónicas flanqueantes y 3’UTR. Resultados: Según la intensidad del cuadro clínico, los pacientes se han clasificado en 3 grandes grupos: I) grave y muy grave (8 pacientes); II) moderado (2 pacientes), y III) leve (5 pacientes). Se han identificado 18 alelos diferentes, de los que 6 son mutaciones nuevas, no descritas con anterioridad, siendo la mutación PKLRc.721G > T la más prevalente (26,67%), seguida de la mutación PKLR c.1456C > T (13,33%). Trece de los 15 pacientes mostraron un genotipo doble heterocigoto y 2 homocigoto. Conclusiones: En España, la heterogeneidad del patrón genético de la PKLR continúa siendo elevada, aunque algo diferente a la observada en un estudio anterior (1998). Se concluye que la secuenciación total del gen PKLR es imprescindible tanto para la caracterización de los pacientes como para la realización del consejo genético (AU)

Background and objective: Pyruvate kinase deficiency (PKD) is a rare, inherited disease causing chronic hemolysis and anemia of varying intensity. The genetic heterogeneity of PKD is high and, to this day, over 240 different mutations have been identified. Patients and methods: 15 unrelated patients affected by PKD have been studied. PKLR gene sequencing was performed by SANGER, including the determination of promoter regions, exonic, intronic flanking and 3’UTR. Results: Patients were classified into 3 groups based on the intensity of their clinical symptoms: I) severe and very severe (8 patients); II) moderate (2 patients), and III) mild (5 patients). Six out of the 18 alleles found were new mutations which had not been described previously, with the PKLR c.721G>T mutation being the most prevalent (26.67%), followed by the PKLR c.1456C>T mutation (13.33%). Conclusions: In Spain, the genetic heterogeneity of PKLR is still high but differs from that observed in the previous study carried out in 1998. Total PKLR gene sequencing is necessary for the characterization of all patients with PKD and for genetic counseling (AU)

Red cell pyruvate kinase deficiency in Spain: A study of 15 cases. / Déficit de piruvato cinasa eritrocitaria en España: estudio de 15 casos.

BACKGROUND AND OBJECTIVE: Pyruvate kinase deficiency (PKD) is a rare, inherited disease causing chronic hemolysis and anemia of varying intensity. The genetic heterogeneity of PKD is high and, to this day, over 240 different mutations have been identified. PATIENTS AND METHODS: 15 unrelated patients affected by PKD have been studied. PKLR gene sequencing was performed by SANGER, including the determination of promoter regions, exonic, intronic flanking and 3'UTR. RESULTS: Patients were classified into 3 groups based on the intensity of their clinical symptoms: I) severe and very severe (8 patients); II) moderate (2 patients), and III) mild (5 patients). Six out of the 18 alleles found were new mutations which had not been described previously, with the PKLR c.721G>T mutation being the most prevalent (26.67%), followed by the PKLR c.1456C>T mutation (13.33%). CONCLUSIONS: In Spain, the genetic heterogeneity of PKLR is still high but differs from that observed in the previous study carried out in 1998. Total PKLR gene sequencing is necessary for the characterization of all patients with PKD and for genetic counseling.

Red Cell Properties after Different Modes of Blood Transportation.

Transportation of blood samples is unavoidable for assessment of specific parameters in blood of patients with rare anemias, blood doping testing, or for research purposes. Despite the awareness that shipment may substantially alter multiple parameters, no study of that extent has been performed to assess these changes and optimize shipment conditions to reduce transportation-related artifacts. Here we investigate the changes in multiple parameters in blood of healthy donors over 72 h of simulated shipment conditions. Three different anticoagulants (K3EDTA, Sodium Heparin, and citrate-based CPDA) for two temperatures (4°C and room temperature) were tested to define the optimal transportation conditions. Parameters measured cover common cytology and biochemistry parameters (complete blood count, hematocrit, morphological examination), red blood cell (RBC) volume, ion content and density, membrane properties and stability (hemolysis, osmotic fragility, membrane heat stability, patch-clamp investigations, and formation of micro vesicles), Ca(2+) handling, RBC metabolism, activity of numerous enzymes, and O2 transport capacity. Our findings indicate that individual sets of parameters may require different shipment settings (anticoagulants, temperature). Most of the parameters except for ion (Na(+), K(+), Ca(2+)) handling and, possibly, reticulocytes counts, tend to favor transportation at 4°C. Whereas plasma and intraerythrocytic Ca(2+) cannot be accurately measured in the presence of chelators such as citrate and EDTA, the majority of Ca(2+)-dependent parameters are stabilized in CPDA samples. Even in blood samples from healthy donors transported using an optimized shipment protocol, the majority of parameters were stable within 24 h, a condition that may not hold for the samples of patients with rare anemias. This implies for as short as possible shipping using fast courier services to the closest expert laboratory at reach. Mobile laboratories or the travel of the patients to the specialized laboratories may be the only option for some groups of patients with highly unstable RBCs.

From ENERCA to the establishment of a European Reference Network of centres of expertise in Rare Hematological diseases: potential ethical issues impacting on its implementation

Due to the scarcity of patients and knowledge, rare diseases, affecting less than 1 in 2000 individuals, are the area in public health in which joint efforts among European Member States is most justified and crucial. The Directive 2011/24/EU on cross border health establishes the creation of European Reference Network (ERN) based on national recognized Centres of Expertise aiming to ensure the same level of access to health services of European citizens affected by a rare disease. Haematological diseases involve a large group of complex rare diseases affecting the normal process of blood cell growth and development. From these, rare anaemias are leading to chronic complications that severely undermine the quality of life of patients or lead to an early death. ENERCA, the European Network for Rare and Congenital Anaemias was established in 2002 and recognized by the EC as one of the ten pilots ERNs in 2008 for the tackle of rare anaemias (RAs) by promoting policies leading to reduce inequalities in the medical care across EU. Based on this networking experience, EuroBloodNet proposal was submitted to the first call for interest to establish a ERN launched by the EC last March 2016. The final outcome of EuroBloodNet is to guarantee that European citizens affected by a RHD benefit from the same level of highly specialised care, thereby improving their overall quality of life independently from the patient's country of origin or country of professional practice. In the process of development of an ERN such as EuroBloodNet, one of the main concerns is the legal issues that may arise when establishing cross border health services and ensuring their accessibility across the EU. Crucial fields requiring legal and ethical action have been identified within EuroBloodNet proposal as cornerstone for its success: Patients' rights and access to cross border health services, data protection and safe and security exchange of data, rights and duties of health professionals involved in cross border health services, health services suitable for reimbursement at the Member State level and the need of a pan European framework for the exchange of human samples for diagnosis and research

Debido a la escasez de pacientes y de conocimiento, las enfermedades raras, que afectan a menos de 1 de cada 2000 personas, son el área de la salud pública en la que el trabajo conjunto entre los Estados miembros de la UE está más justificada y resulta crucial. La Directiva 2011/24/UE sobre asistencia sanitaria transfronteriza establece la creación de una Red de Referencia Europea en base a los Centros nacionales reconocidas de referencia con el objetivo de garantizar el mismo nivel de acceso a los servicios de salud de los ciudadanos europeos afectados por una enfermedad rara. Las enfermedades hematológicas comprenden un gran grupo de enfermedades raras complejas que afectan el proceso normal de crecimiento de las células de la sangre y al desarrollo. De éstas, las anemias raras están dando lugar a complicaciones crónicas que socavan gravemente la calidad de vida de los pacientes o llevan a una muerte temprana. ENERCA, la Red Europea para la Anemia Rara y Congénita, fue fundada en 2002 y reconocida por la CE como una de las diez Redes piloto de Referencia Europeas en 2008 para tartar las anemias raras mediante la promoción de políticas que lleven a reducir las desigualdades en la atención médica en toda la UE. En base a esta experiencia en creación de redes, la propuesta EuroBloodNet se presentó a la primera convocatoria de interés para establecer una Red de Referencia Europea impulsada por la Comisión Europea en marzo de 2016. El propósito final de EuroBloodNet es garantizar que los ciudadanos europeos afectados por una Enfermedad Hematológica Rara se beneficien del mismo nivel de atención altamente especializada, mejorando así su calidad de vida en general independientemente del país de origen del paciente o de la práctica professional del país. En el proceso de desarrollo de una Red de Referencia Europea como EuroBloodNet, una de las principales preocupaciones es la referente a los problemas legales que pueden surgir cuando se establecen servicios de salud transfronterizos y cuando se garantiza su accesibilidad en toda la UE. Son áreas cruciales que requieren una acción legal y ética y que han sido identificadas dentro de la propuesta EuroBloodNet como piedra angular de su éxito: los derechos de los pacientes y el acceso a los servicios transfronterizos de salud, la protección de datos y el intercambio seguro y la seguridad de los datos, los derechos y deberes de los profesionales sanitarios implicados en los servicios de salud transfronterizos, servicios de salud adecuados para el reembolso en los Estados miembros y la necesidad de un marco paneuropeo para el intercambio de muestras humanas para el diagnóstico y la investigación