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.

Early-onset indicators of a hypercoagulable state and clinical complications in a cohort of children with sickle cell trait.

Adults with sickle cell trait (SCT) have a procoagulant state with increased risk of thromboembolism, but limited data are available for children. We compared the coagulation profile of children with SCT, different sickle cell disease (SCD) genotypes, and healthy controls. Compared to controls and similarly to HbSC patients, 41 SCT children (mean age 6.85 years; 20 males; 88% Africans) had a characteristic procoagulant profile: higher levels of factor VIII, von Willebrand factor (VWF) Ag and CBA, D-dimer; lower levels of ADAMTS 13 activity, ADAMTS13 activity: VWFAg, plasminogen activator inhibitor, tissue plasminogen activator. Moreover, 13/41 had clinical complications of SCD, five requiring hospitalization.

Hematological characteristics and hepatobiliary complications of hereditary spherocytosis in a tertiary care pediatric center: optimizing diagnosis and care through local and international networks.

Background: Hereditary Spherocytosis (HS) is a rare, congenital red blood cell disorder presenting with variable clinical manifestations ranging from mild hemolytic anemia to severe anemia with hypersplenism and hepatobiliary complications. Methods: The objectives of the study were to evaluate the diagnostic pathway of HS, the presence and management of hepatobiliary complications in pediatric patients with HS followed in a tertiary care center. The demographic, clinical, hematological information were retrieved from medical records of patients having at least 1 hematology visit between 2010 and 2020. Results: Forty-two patients were enrolled, 23 M. Mean age at onset of symptoms was 2.8 years, at diagnosis was 3.5 years. Anemia was the first manifestation in 73%; suspect of HS arose for all patients in first or second level outpatient clinics. Only 64% of patients performed two confirmation tests in the reference center. 28/42 had familiarity for HS; of the 13/42 who did not, only 47% performed further analysis. Sixteen patients developed gallbladder stones (40%), visible at the first ultrasound (5.6 years). Hemolytic crises and parvovirus infections were more frequent in patients with stones (53.6% vs. 26.1% and 63.6% vs. 28.6%, respectively). 10/16 (62.5%) underwent elective cholecystectomy: 8 had concomitant splenectomy. Conclusions: our study highlights the need to optimize the diagnostic pathway in networks of care involving general and specialized centers in order to reduce time to diagnosis and ensure that all patients receive confirmatory tests. A high frequency of hepatobiliary complications since young age was observed suggesting that screening with ultrasound should begin earlier.

CK2ß Regulates Hematopoietic Stem Cell Biology and Erythropoiesis.

The Ser-Thr kinase CK2 plays important roles in sustaining cell survival and resistance to stress and these functions are exploited by different types of blood tumors. Yet, the physiological involvement of CK2 in normal blood cell development is poorly known. Here, we discovered that the ß regulatory subunit of CK2 is critical for normal hematopoiesis in the mouse. Fetal livers of conditional CK2ß knockout embryos showed increased numbers of hematopoietic stem cells associated to a higher proliferation rate compared to control animals. Both hematopoietic stem and progenitor cells (HSPCs) displayed alterations in the expression of transcription factors involved in cell quiescence, self-renewal, and lineage commitment. HSPCs lacking CK2ß were functionally impaired in supporting both in vitro and in vivo hematopoiesis as demonstrated by transplantation assays. Furthermore, KO mice developed anemia due to a reduced number of mature erythroid cells. This compartment was characterized by dysplasia, proliferative defects at early precursor stage, and apoptosis at late-stage erythroblasts. Erythroid cells exhibited a marked compromise of signaling cascades downstream of the cKit and erythropoietin receptor, with a defective activation of ERK/JNK, JAK/STAT5, and PI3K/AKT pathways and perturbations of several transcriptional programs as demonstrated by RNA-Seq analysis. Moreover, we unraveled an unforeseen molecular mechanism whereby CK2 sustains GATA1 stability and transcriptional proficiency. Thus, our work demonstrates new and crucial functions of CK2 in HSPC biology and in erythropoiesis.