Limited access to transcranial Doppler screening and stroke prevention for children with sickle cell disease in Europe: Results of a multinational EuroBloodNet survey.

BACKGROUND: Ensuring equitable access to adequate standard of care for patients with rare hematological disease is one of the aims of the European Reference Network (ERN) EuroBloodNet. Stroke is one of the most devastating complications for children with sickle cell disease (SCD). For effective prevention of stroke risk, annual transcranial Doppler (TCD) according to a defined protocol is recommended for patients aged 2-16 years, with red blood cell transfusion therapy for those at risk. There is no information regarding screening for stroke risk and stroke prevention programs in Europe. METHODS: Seven SCD experts of five healthcare providers (HCPs) of ERN EuroBloodNet developed an online survey to assess the access to TCD screening and stroke prevention programs for children with SCD in Europe. RESULTS: Eighty-one experts in 77 HCPs from 16 European countries responded to 16 online questions. Thirty-two of 77 (51%) HCPs were EuroBloodNet reference centers, and 36% physicians reported not having a dedicated TCD/TCD imaging service for children with SCD. Only 30% of physicians provided estimates that all their patients received annual TCD according to the standard protocol due to lack of trained staff (43%), lack of TCD instruments (11%), refusal of patients due to logistical difficulties (22%), and lack of funds for dedicated staff or equipment (11%). CONCLUSIONS: This multinational European survey provides the first comprehensive picture of access to TCD screening and stroke prevention in European countries. Identifying the potential underlying causes of the lack of effective standardized screening, this survey also addresses possible dedicated actions to cover these needs.

HK1 haemolytic anaemia in association with a neurological phenotype and co-existing CEP290 Meckel-Gruber in a Romani family.

HK1 deficient Haemolytic Anaemia in association with a Neurological Phenotype & co-existing Meckel-Gruber due to CEP290 in a Romani family.

Newborn screening for sickle cell disease in Europe: recommendations from a Pan-European Consensus Conference.

Sickle Cell Disease (SCD) is an increasing global health problem and presents significant challenges to European health care systems. Newborn screening (NBS) for SCD enables early initiation of preventive measures and has contributed to a reduction in childhood mortality from SCD. Policies and methodologies for NBS vary in different countries, and this might have consequences for the quality of care and clinical outcomes for SCD across Europe. A two-day Pan-European consensus conference was held in Berlin in April 2017 in order to appraise the current status of NBS for SCD and to develop consensus-based statements on indications and methodology for NBS for SCD in Europe. More than 50 SCD experts from 13 European countries participated in the conference. This paper aims to summarise the discussions and present consensus recommendations which can be used to support the development of NBS programmes in European countries where they do not yet exist, and to review existing programmes.

A case of parvovirus B19-induced pure red cell aplasia in a child following heart transplant.

We describe a case of an 11-year-old boy who underwent orthotopic heart transplant for dilated cardiomyopathy. He developed a normocytic, normochromic anaemia with a low reticulocyte count 1 month after transplant. A bone marrow biopsy was performed, which showed a mildly hypocellular bone marrow with few red blood cell precursors with giant pro-erythroblasts indicative of a pure red cell aplasia. Parvovirus B19 polymerase chain reaction in the blood was positive 2 months after transplant. Intravenous immunoglobulin administration resulted in a resolution of the anaemia over several months. Unexplained pure red cell aplasia in immunosuppressed patients should alert one to the possibility of parvovirus B19 infection.

The correlation of ultrasonographic placental architecture with placental histology in the low-risk primigravid population.

AIM: To determine the association, if any, between placental architecture findings assessed ultrasonographically at 22 and 36 weeks and placental histology. METHODS: There was prospective recruitment of 1011 low-risk primigravids from the antenatal clinic at the Rotunda Hospital, Dublin, Ireland. Ultrasound of the placenta was performed at 22 and 36 weeks and histological assessment was made of the placenta of all participants. RESULTS: Complete data pertaining to ultrasound and placental histology was available for 810 women (80%). Placental calcification on ultrasound in the third trimester was associated with a higher incidence of placental infarction identified following placental histology (80.0% vs. 21.5%; P=0.009: r=0.115). The placental thickness on ultrasound in the second trimester was less in cases complicated by chorioamnionitis (2.62 cm vs. 3.07 cm; P=0.039: r=-0.176). Chronic villitis was associated with a statistically significant increased incidence of antenatal placental infarction identified on ultrasound in the third trimester (10.7% vs. 1.9%; P=0.020: r=0.113). Intervillous thrombi occurred more frequently in cases with reduced placental thickness on ultrasound in the second trimester (3.0 cm vs. 3.3 cm; P=0.035: r=-0.171). CONCLUSIONS: Antenatal ultrasound of the placenta may aid detection of placental disease, particularly in the identification of placental infarction.

VWF-ADAMTS13 axis dysfunction in children with sickle cell disease treated with hydroxycarbamide vs blood transfusion.

Previous studies have reported elevated von Willebrand factor (VWF) levels in patients with sickle cell disease (SCD) and demonstrated a key role for the VWF-ADAMTS13 axis in the pathobiology of SCD vaso-occlusion. Although blood transfusion is the gold standard for stroke prevention in SCD, the biological mechanisms underpinning its improved efficacy compared with hydroxycarbamide are not fully understood. We hypothesized that the improved efficacy of blood transfusion might relate to differences in VWF-ADAMTS13 axis dysfunction. In total, 180 children with a confirmed diagnosis of SCD (hemoglobin SS) on hydroxycarbamide (n = 96) or blood transfusion (n = 84) were included. Despite disease-modifying treatment, plasma VWF and VWF propeptide were elevated in a significant proportion of children with SCD (33% and 47%, respectively). Crucially, all VWF parameters were significantly higher in the hydroxycarbamide compared with the blood transfusion cohort (P < .05). Additionally, increased levels of other Weibel-Palade body-stored proteins, including factor VIII (FVIII), angiopoietin-2, and osteoprotegerin were observed, indicated ongoing endothelial cell activation. Children treated with hydroxycarbamide also had higher FVIII activity and enhanced thrombin generation compared with those in the blood transfusion cohort (P < .001). Finally, hemolysis markers strongly correlated with VWF levels (P < .001) and were significantly reduced in the blood transfusion cohort (P < .001). Cumulatively, to our knowledge, our findings demonstrate for the first time that despite treatment, ongoing dysfunction of the VWF-ADAMTS13 axis is present in a significant subgroup of pediatric patients with SCD, especially those treated with hydroxycarbamide.

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.

Adherence to hydroxyurea, health-related quality of life domains and attitudes towards a smartphone app among Irish adolescents and young adults with sickle cell disease.

INTRODUCTION: SCD patients experience declines in health-related quality of life (HRQOL) domains compared with healthy controls. Despite evidence supporting the benefits of hydroxyurea, medication non-adherence remains problematic, especially in adolescents and young adults (AYA). Adherence barriers include forgetfulness and lack of knowledge. Recently, increased interest in technology-based strategies to improve medication adherence has emerged. No data currently exists on hydroxyurea adherence, HRQOL or perceptions of technology-based tools in the Irish SCD population. METHODS: In order to interrogate these domains among Irish AYA SCD patients we administered an anonymous survey at two tertiary referral centres in Dublin, Ireland, in July 2019. RESULTS: Sixty-three patients participated; 63% female and 37% male, with a median and mean age of 17 and 19 years, respectively. Average monthly adherence was 76% using a visual analogue scale. Recall barriers were present in 62% while 26% omit hydroxyurea for reasons other than forgetting. Reviewing HRQOL; only 36.5% felt always physically able to engage in recreational activities, while 51% experienced disruption to school/college/work due to pain. Eighty-one percent reported that anxiety about health interferes with their lives and non-adherence correlated with worse HRQOL outcomes. Interest in a smartphone app was expressed by the majority, with daily medication reminders being the most popular feature. Sharing adherence data with doctors and discussion forums were less appealing. CONCLUSIONS: Representing over 10% of the Irish SCD population, our survey provides novel and valuable insights into medication adherence and HRQOL domains. Preferred app features may inform future technology-based interventions to improve medication adherence in SCD and other chronic health conditions.

South-east Asian ovalocytosis and the cryohydrocytosis form of hereditary stomatocytosis show virtually indistinguishable cation permeability defects.

The hereditary stomatocytoses are a group of dominantly inherited conditions in which the osmotic stability of the red cell is compromised by abnormally high cation permeability. This report demonstrates the very marked similarities between the cryohydrocytosis form of hereditary stomatocytosis and the common tropical condition south-east Asian ovalocytosis (SAO). We report two patients, one showing a novel cryohydrocytosis variant (Ser762Arg in SLC4A1) and a case of SAO. Both cases showed a mild haemolytic state with some stomatocytes on the blood film, abnormal intracellular sodium and potassium levels which were made markedly abnormal by storage of blood at 0°C, increased cation 'leak' fluxes at 37°C and increased Na(+) K(+) pump activity. In both cases, the anion exchange function of the mutant band 3 was destroyed. Extensive electrophysiological studies comparing the cation leak and conductance in Xenopus laevis oocytes expressing the two mutant genes showed identical patterns of abnormality. These data are consistent with the cryohydrocytosis form of hereditary stomatocytosis and we conclude that the cation leak in SAO is indistinguishable from that in cryohydrocytosis, and that SAO should be considered to be an example of hereditary stomatocytosis.

Esophageal strictures during treatment for acute lymphoblastic leukemia.

Esophageal stricture is a rare complication of paediatric cancer treatment that usually occurs after esophageal exposure to radiotherapy. We describe 4 cases of esophageal stricture during chemotherapy for acute lymphoblastic leukemia. All patients presented with refractory vomiting and were diagnosed with radiologic contrast studies. None of the patients had received radiotherapy. Esophageal candidiasis was seen in 2 patients but the remaining 2 patients had earlier systemic candidiasis. High-dose dexamethasone may predispose these children to both esophageal candidiasis and peptic esophagitis. The etiology of esophageal strictures during treatment for acute leukemia is likely to be multifactorial but systemic candidiasis may play a significant role.

Newborn Screening for Sickle Cell Disease in Europe.

The history of newborn screening (NBS) for sickle cell disease (SCD) in Europe goes back almost 40 years. However, most European countries have not established it to date. The European screening map is surprisingly heterogenous. The first countries to introduce sickle cell screening on a national scale were France and England. The French West Indies started to screen their newborns for SCD as early as 1983/84. To this day, all countries of the United Kingdom of Great Britain and Northern Ireland have added SCD as a target disease to their NBS programs. The Netherlands, Spain and Malta also have national programs. Belgium screens regionally in the Brussels and Liège regions, Ireland has been running a pilot for many years that has become quasi-official. However, the Belgian and Irish programs are not publicly funded. Italy and Germany have completed several pilot studies but are still in the preparatory phase of national NBS programs for SCD, although both countries have well-established concepts for metabolic and endocrine disorders. This article will give a brief overview of the situation in Europe and put a focus on the programs of the two pioneers of the continent, England and France.

Sickle cell disease and dental treatment.

Sickle cell disease (SCD) and sickle cell trait (SCT) are found most frequently in individuals of African, Middle Eastern and Indian ethnicity. Population migration has made this disease more common worldwide, including Ireland. We present an overview of this disease, focusing on management and practical implications for dental practitioners.

Prevalence of left ventricular hypertrabeculation/noncompaction among children with sickle cell disease.

OBJECTIVES: Incidence of sickle cell disease (SCD) in Ireland has dramatically increased. Disease survival has also steadily improved however cardiovascular manifestations remain important causes of morbidity. These include reports of left ventricular hypertrabeculation (LVHT)/noncompaction. We sought to investigate the prevalence of LVHT among a large cohort of children with SCD. METHODS: We retrospectively reviewed the records of all patients with a diagnosis of SCD who had undergone surveillance echocardiography at Our Lady's Children's Hospital Crumlin (OLCHC) from 1998 to 2015. Demographics, hemoglobin phenotype and treatment information was recorded. LV systolic function, evidence of LVHT, and possible pulmonary arterial hypertension was assessed. RESULTS: Two hundred thirty-six patients had echocardiograms available for interpretation. One hundred twenty-one (51.3%) were female; mean age was 11.3 years (± 4.1 years). Twenty-six patients (11%) had features of LVHT on echocardiography. Eleven patients (4.7%) had borderline features of LVHT. Mean LVEDD across the whole cohort was 4.2 ± 0.69 cm, LVEDD z-score of 1.44 ± 1.9, and mean LVSF was 37.3% ±15.7%. There were no significant differences in terms of age, LVEDD, LVEDD z-score, or LVSF between patients with and those without LVHT. CONCLUSIONS: The prevalence of LVHT/noncompaction in children with SCD is lower than the adult population and LV systolic function is well preserved throughout our patient group. The mechanism behind the development of LVHT in this population remains speculative. Further work is required in this field. Sickle cell patients require longitudinal evaluation to ascertain changes in left ventricular function and the presence of LVHT/noncompaction.