and Genetic Polymorphisms Associated with Alloimmunisation in Sickle Cell Disease.

Red blood cell (RBC) transfusion remains a critical component in caring for the acute and chronic complications of sickle cell disease (SCD). Patient alloimmunisation is the main limitation of transfusion, which can worsen anaemia and lead to delayed haemolytic transfusion reaction or transfusion deadlock. Although biological risk factors have been identified for immunisation, patient alloimmunisation remains difficult to predict.

Transfusion requirements and complication rate in β-thalassemia intermedia due to heterozygous β-globin gene mutation and triplicated α-globin genes.

Introduction: The heterozygous condition for β-thalassemia mutation associated with an extra functional α-globin gene can produce a Thalassemia Intermedia (TI) phenotype. This genotype is the second in frequency in the French Thalassemia Registry NaThalY that prospectively collects laboratory and clinical data.

Materials And Methods: The present report analyses transfusion needs, iron overload (ferritin, hepatic and cardiac iron concentrations), and complication rates in 45 patients included in NaThalY and presenting a heterozygous β or β -thalassemia mutation associated with a triplication at HBA locus.

Plasma levels of E-selectin are associated with retinopathy in sickle cell disease.

Background: The vascular endothelium is markedly disrupted in sickle cell disease (SCD) and is the converging cascade of the complex pathophysiologic processes linked to sickle cell vasculopathy. Circulating endothelial activation and/or apoptotic markers may reflect this endothelial activation/damage that contributes to the pathophysiology of the SCD vascular complications.

Methods: Plasmatic levels of circulating endothelial cells (CECs), E-selectin, progenitor's endothelial cells (EPCs), and circulating extracellular vesicles (EVs) were evaluated in 50 SCD patients, 16 with vasculopathy.

SARS-CoV-2 infection in patients with β-thalassemia: The French experience.

Introduction: Because of iron overload complications, thrombosis and infectious predisposition, patients with severe forms of thalassemia are likely to be at increased risk of COVID-19 complications.

Results: A national survey conducted during the year 2020 across the French reference centers for hemoglobinopathies identified 16 cases of COVID-19 confirmed by RT-PCR in beta-thalassemia patients. Their age ranged from 11 months to 60 years.

Late effects after hematopoietic stem cell transplantation for β-thalassemia major: the French national experience.

In this retrospective study, we evaluate long-term complications in nearly all β-thalassemia-major patients who successfully received allogeneic hematopoietic stem cell transplantation in France. Ninety-nine patients were analyzed with a median age of 5.9 years at transplantation.

Platelet and not erythrocyte microparticles are procoagulant in transfused thalassaemia major patients.

The level of circulating platelet-, erythrocyte-, leucocyte- and endothelial-derived microparticles detected by high-sensitivity flow cytometry was investigated in 37 β-thalassaemia major patients receiving a regular transfusion regimen. The phospholipid procoagulant potential of the circulating microparticles and the microparticle-dependent tissue factor activity were evaluated. A high level of circulating erythrocyte- and platelet-microparticles was found.

Variants in genetic modifiers of β-thalassemia can help to predict the major or intermedia type of the disease.

A cohort of 106 patients included in the French National Registry for Thalassemia were genotyped for 5 genetic modifiers of severity: i) β-thalassemia mutations; (ii) the XmnI SNP; (iii) the -3.7 kb α-thal deletion; (iv) the tag-SNP rs 11886868 in BCL11A exon 2; and (v) the tag-SNP rs9399137 in the HBSB1L-cMYB inter-region. Multivariate analysis was performed to study the risk of thalassemia Intermedia phenotype associated with the different combinations of alleles.

Analytical evaluation of the Tosoh HLC-723 G8 automated HPLC analyzer for hemoglobin analysis in beta-thalassemia mode.

Objectives: The analytical performances of a new kit conceived for Hb variants separation and measurement procedures on an HPLC instrument (Tosoh HLC-723 G8) were studied.

Results: Between-run and within-run precision tests were satisfactory for both HbA2 and HbF measurements. HbA2 and HbF values measured using the TOSOH HLC-723 G8 were correlated to those obtained using the Bio-Rad Variant II HPLC system (r=0.

The rare codon 24 (T>A) (beta+) mutation in association with the common codon 39 (C> T) (beta0) mutation causes transfusion-dependent beta-thalassemia in a Moroccan patient.

We present the rare codon 24 (T > A) (beta(+)) mutation causing transfusion-dependent beta-thalassemia (beta-thal) in combination with the common codon 39 (C > T) (beta(0)) defect in a Moroccan boy. We report the characterization of the mutation, phenotype, haplotype and possible origin of the first case in Morocco and discuss the significance of this genotype combination with a beta(0) defect.

Molecular basis of beta-thalassemia in Morocco: possible origins of the molecular heterogeneity.

We present the molecular spectrum of beta-thalassemia in the Moroccan population obtained by the identification of molecular defects responsible for this disease, and herewith we show that the Moroccan population is genetically heterogeneous; 18 different mutations have been found in the 158 beta-globin chromosomes studied. Eight mutations [codon 39 (C --> T), FSC-8 (-AA), IVS-II-745 (C --> G), -29 (A --> G), FSC-6 (-A), IVS-I-110 (G --> A), IVS-I-2 (T --> C), and IVS-I-1 (G --> A)] out of 18 beta-thalassemia mutations identified accounted for 76% of the Moroccan beta-thalassemia chromosomes. Restriction fragment length polymorphism (RFLP) haplotype analysis showed that the observed genetic diversity originated from both new mutational events and gene flow due to migration.

Beta-thalassemia intermedia due to two novel mutations in the promoter region of the beta-globin gene.

Two novel beta-thalassemia mutations affecting the promoter region of the beta-globin gene are described. The first mutation, found in a Moroccan family, is a G-->A substitution at position -190 relative to the beta-globin gene Cap site. The second, found in an Algerian patient, is a G-->C substitution at position -56 relative to the beta-globin Cap site.

Thalassemia intermedia due to a novel mutation in the second intervening sequence of the beta-globin gene.

We describe a new beta-thalassemia (thal) mutation in the beta-globin gene of an 8-year-old Moroccan boy. This homozygous mutation produces a phenotype of thalassemia intermedia and is associated with the Mediterranean haplotype IX. We discuss the pathophysiological consequences of this mutation which is located near the 3' end of the second intervening sequence (IVS-II) of the beta-globin gene.

Genotypic correlation between six common beta-thalassemia mutations and the XmnI polymorphism in the Moroccan population.

beta-Thalassemia (thal) is the most common recessive inherited disorder in Mediterranean populations. It is estimated that the frequency of this disease in the Moroccan population is between 1.5 and 3.