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Blood Reviews Jan 2024Gene modification of haematopoietic stem cells (HSCs) is a potentially curative approach to sickle cell disease (SCD) and offers hope for patients who are not eligible... (Review)
Review
Gene modification of haematopoietic stem cells (HSCs) is a potentially curative approach to sickle cell disease (SCD) and offers hope for patients who are not eligible for allogeneic HSC transplantation. Current approaches require in vitro manipulation of healthy autologous HSC prior to their transplantation. However, the health and integrity of HSCs may be compromised by a variety of disease processes in SCD, and challenges have emerged in the clinical trials of gene therapy. There is also concern about increased susceptibility to haematological malignancies during long-term follow up of patients, and this raises questions about genomic stability in the stem cell compartment. In this review, we evaluate the evidence for HSC deficits in SCD and then discuss their potential causation. Finally, we suggest several questions which need to be addressed in order to progress with successful HSC manipulation for gene therapy in SCD.
Topics: Humans; Anemia, Sickle Cell; Hematopoietic Stem Cells; Hematologic Diseases; Stem Cell Transplantation; Hematopoietic Stem Cell Transplantation
PubMed: 37919142
DOI: 10.1016/j.blre.2023.101137 -
Blood Advances Aug 2023
Topics: Humans; Child; Hydroxyurea; Anemia, Sickle Cell; Antisickling Agents
PubMed: 37171600
DOI: 10.1182/bloodadvances.2023010099 -
Balkan Medical Journal Jul 2023Hemoglobinopathies are the most common inherited diseases in humans resulting from impaired globin chain synthesis of hemoglobin. The progression of thalassemia rates is...
BACKGROUND
Hemoglobinopathies are the most common inherited diseases in humans resulting from impaired globin chain synthesis of hemoglobin. The progression of thalassemia rates is prevented with prenatal screening methods.
AIMS
To evaluate the hematological parameters of α- and β-thalassemia and normal fetuses aged 17-25 weeks of gestation.
STUDY DESIGN
A cross-sectional study.
METHODS
Pregnant women who underwent cordocentesis in the second trimester because of the risk of having a baby with thalassemia were included in the study. Hematological indices and molecular DNA methods were analyzed from the cord blood samples of 129 women who were 17-25 weeks into pregnancy. The HPLC method was used for Hb fraction analysis. Amplification refractory mutation system, restriction enzyme analysis, multiplex polymerase chain reaction, and sequencing methods were used for the molecular analysis. Maternal contamination was eliminated by the short tandem repeat method.
RESULTS
In total, 112 of the fetuses carry α- and β-thalassemia heterozygous or homozygous (α: 37, β: 58, mixed: 17) and 17 fetuses had a normal genotype for thalassemia. Significant differences in adult hemoglobin (HbA), fetal hemoglobin (HbF), Hb Barts, MCV, MCH, and RDW were detected in three groups compared with the normal group (p < 0.001, except for RBC, Hb, HCT, and MCHC). Differences in HbF, Hb Barts, MCV, MCH, and RDW were observed in the α-thalassemia groups compared with the normal group (p < 0.001). Among the five β-thalassemia subgroups, only HbA and RDW were different from the normal group (p < 0.001).
CONCLUSION
This study could be a good reference for future studies and prenatal diagnostic applications in emphasizing the importance of changes in the blood parameters of fetuses before molecular genotyping. These hematological data give valuable information to clinicians about the fetus to enlighten families in making appropriate decisions during prenatal diagnosis.
Topics: Female; Pregnancy; Humans; beta-Thalassemia; Pregnancy Trimester, Second; Fetal Blood; Cross-Sectional Studies; alpha-Thalassemia; Genotype; Fetus
PubMed: 37154826
DOI: 10.4274/balkanmedj.galenos.2023.2023-1-86 -
Nature Communications Apr 2023Haemoglobin E (HbE) β-thalassaemia causes approximately 50% of all severe thalassaemia worldwide; equating to around 30,000 births per year. HbE β-thalassaemia is due...
Haemoglobin E (HbE) β-thalassaemia causes approximately 50% of all severe thalassaemia worldwide; equating to around 30,000 births per year. HbE β-thalassaemia is due to a point mutation in codon 26 of the human HBB gene on one allele (GAG; glutamatic acid → AAG; lysine, E26K), and any mutation causing severe β-thalassaemia on the other. When inherited together in compound heterozygosity these mutations can cause a severe thalassaemic phenotype. However, if only one allele is mutated individuals are carriers for the respective mutation and have an asymptomatic phenotype (β-thalassaemia trait). Here we describe a base editing strategy which corrects the HbE mutation either to wildtype (WT) or a normal variant haemoglobin (E26G) known as Hb Aubenas and thereby recreates the asymptomatic trait phenotype. We have achieved editing efficiencies in excess of 90% in primary human CD34 + cells. We demonstrate editing of long-term repopulating haematopoietic stem cells (LT-HSCs) using serial xenotransplantation in NSG mice. We have profiled the off-target effects using a combination of circularization for in vitro reporting of cleavage effects by sequencing (CIRCLE-seq) and deep targeted capture and have developed machine-learning based methods to predict functional effects of candidate off-target mutations.
Topics: Humans; Animals; Mice; beta-Thalassemia; Hemoglobin E; Thalassemia; Mutation; Point Mutation
PubMed: 37076455
DOI: 10.1038/s41467-023-37604-8 -
Blood Apr 2022Excessive intravascular release of lysed cellular contents from damaged red blood cells (RBCs) in patients with sickle cell anemia (SCA) can activate the inflammasome, a... (Randomized Controlled Trial)
Randomized Controlled Trial
Excessive intravascular release of lysed cellular contents from damaged red blood cells (RBCs) in patients with sickle cell anemia (SCA) can activate the inflammasome, a multiprotein oligomer promoting maturation and secretion of proinflammatory cytokines, including interleukin-1β (IL-1β). We hypothesized that IL-1β blockade by canakinumab in patients with SCA would reduce markers of inflammation and clinical disease activity. In this randomized, double-blind, multicenter phase 2a study, patients aged 8 to 20 years with SCA (HbSS or HbSβ0-thalassemia), history of acute pain episodes, and elevated high-sensitivity C-reactive protein >1.0 mg/L at screening were randomized 1:1 to received 6 monthly treatments with 300 mg subcutaneous canakinumab or placebo. Measured outcomes at baseline and weeks 4, 8, 12, 16, 20, and 24 included electronic patient-reported outcomes, hospitalization rate, and adverse events (AEs) and serious AEs (SAEs). All but 1 of the 49 enrolled patients were receiving stable background hydroxyurea therapy. Although the primary objective (prespecified reduction of pain) was not met, compared with patients in the placebo arm, patients treated with canakinumab had reductions in markers of inflammation, occurrence of SCA-related AEs and SAEs, and number and duration of hospitalizations as well as trends for improvement in pain intensity, fatigue, and absences from school or work. Post hoc analysis revealed treatment effects on weight, restricted to pediatric patients. Canakinumab was well tolerated with no treatment-related SAEs and no new safety signal. These findings demonstrate that the inflammation associated with SCA can be reduced by selective IL-1β blockade by canakinumab with potential for therapeutic benefits. This trial was registered at www.clinicaltrials.gov as #NCT02961218.
Topics: Anemia, Sickle Cell; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Biomarkers; Child; Double-Blind Method; Humans; Inflammation; Young Adult
PubMed: 35226723
DOI: 10.1182/blood.2021013674 -
European Heart Journal. Quality of Care... May 2022To explore the impact of incorporating a faster cardiac magnetic resonance (CMR) imaging protocol in a low-middle-income country (LMIC) and using the result to guide...
AIMS
To explore the impact of incorporating a faster cardiac magnetic resonance (CMR) imaging protocol in a low-middle-income country (LMIC) and using the result to guide chelation in transfusion-dependent patients.
METHODS AND RESULTS
A prospective UK-India collaborative cohort study was conducted in two cities in India. Two visits 13 months apart included clinical assessment and chelation therapy recommendations based on rapid CMR results. Participants were recruited by the local patient advocate charity, who organized the patient medical camps. The average scanning time was 11.3 ± 2.5 min at the baseline and 9.8 ± 2.4 min (P < 0.001) at follow-up. The baseline visit was attended by 103 patients (mean age 25 years) and 83% attended the second assessment. At baseline, 29% had a cardiac T2* < 20 ms, which represents significant iron loading, and 12% had left ventricular ejection fraction <60%, the accepted lower limit in this population. Only 3% were free of liver iron (T2* ≥ 17 ms). At 13 months, more patients were taking intensified dual chelation therapy (43% vs. 55%, P = 0.002). In those with cardiac siderosis (baseline T2* < 20 ms), there was an improvement in T2*-10.9 ± 5.9 to 13.5 ± 8.7 ms, P = 0.005-and fewer were classified as having clinically important cardiac iron loading (T2* < 20 ms, 24% vs. 16%, P < 0.001). This is the first illustration in an LMIC that incorporating CMR results into patient management plans can improve cardiac iron loading.
CONCLUSION
For thalassaemia patients in an LMIC, a simplified CMR protocol linked to therapeutic recommendation via the patient camp model led to enhanced chelation therapy and a reduction in cardiac iron in 1 year.
Topics: Adult; Chelation Therapy; Cohort Studies; Humans; Iron; Magnetic Resonance Imaging; Prospective Studies; Stroke Volume; Thalassemia; Ventricular Function, Left; beta-Thalassemia
PubMed: 34849707
DOI: 10.1093/ehjqcco/qcab089 -
Orphanet Journal of Rare Diseases Jul 2021Thalassaemia, a hereditary haemoglobin disorder, is a major public health concern in some parts of the world. Although Bangladesh is in the world's thalassaemia belt,...
BACKGROUND
Thalassaemia, a hereditary haemoglobin disorder, is a major public health concern in some parts of the world. Although Bangladesh is in the world's thalassaemia belt, the information on this disease is scarce. Additionally, the awareness of this life threatening, but potentially preventable disease is surprisingly poor. However, mass awareness is pivotal for the development of an effective preventive strategy. In this context, the understanding of parental perspectives is essential to grasp the magnitude of the problem. Therefore, this study aimed to investigate the parental knowledge gaps and perceptions regarding thalassemia, the barriers confronted by the parents for caring for their thalassaemic children and their attitude to prenatal screening and prenatal diagnosis.
METHODS
This cross-sectional study was conducted between January 2018 and December 2018 at a dedicated thalassemia hospital located in Dhaka. A structured questionnaire was used for face-to-face interviews with parents of thalassaemic children. Descriptive statistics were used to analyse data.
RESULTS
Of 365 respondents, nearly all respondents (97%) had not heard about the term, 'thalassemia' before the disease was diagnosed in their children; all (100%) were unscreened for carrier status prior to marriage. Mean knowledge scores were significantly higher in respondents with higher income and education. Most respondents (~ 91%) had a guilty feeling for not undergoing premarital screening. Only around 36% of them had heard about prenatal diagnosis. Approximately 25% participants would consider prenatal diagnosis in a future pregnancy, while 70% of them were unsure and only ~ 5% would decline prenatal diagnosis. Only 9.3% mothers had prenatal diagnosis in a previous pregnancy. Nearly 80% of the parents faced difficulty for obtaining blood donors regularly and a similar proportion (~ 81%) of them did not receive support from any organized blood clubs. More than 40% of the parents reported they felt socially stigmatized.
CONCLUSION
This study suggests poor parental knowledge regarding thalassaemia including prenatal diagnosis and the challenges faced while caring for their children. These findings would be of paramount importance in planning and devising effective prevention and intervention strategies in Bangladesh as well as other countries with similar sociocultural setting.
Topics: Bangladesh; Child; Cross-Sectional Studies; Emotions; Female; Health Knowledge, Attitudes, Practice; Humans; Parents; Pregnancy; Prenatal Diagnosis; Thalassemia
PubMed: 34271949
DOI: 10.1186/s13023-021-01947-6 -
Indian Journal of Hematology & Blood... Jul 2021Screening of newborns for the presence of sickle hemoglobin (HbS) is aimed at reducing the morbidity and mortality associated with sickle cell disease in early...
Screening of Dry Blood Spots from Newborns by Two High Performance Liquid Chromatography (HPLC) Systems: A Comparison of Their Ability to Diagnose Both Sickle and Non-sickle Hemoglobinopathies.
Screening of newborns for the presence of sickle hemoglobin (HbS) is aimed at reducing the morbidity and mortality associated with sickle cell disease in early childhood. The high cost and limited availability of dedicated high performance liquid chromatography (HPLC) systems specially designed for screening of dry blood spots (DBS), however, restrict a wider application of this preventive approach. Therefore, we examined the ability of a commonly used HPLC system for detection of hemoglobinopathies in DBS samples in order to find an alternative for the dedicated newborn screening (NBS) HPLC system. DBS samples from 7522 newborns were first examined by Variant NBS HPLC system (Bio Rad, USA) for the presence of hemoglobinopathies. Positive samples were then analysed by Variant II system (Bio Rad, USA), another platform commonly used for hemoglobinopathy screening of anticoagulated blood samples. Eighty six newborns (1.1%) showed the presence of hemoglobinopathies (HbS 28, HbE 21, HbD 27, HbQ India 9 and Hb Barts 1) by Variant NBS system-all in heterozygous state. There was 100% correlation between the two sets of results obtained by the two HPLC systems. Newborns with HbQ India showed an additional Hb peak in HPLC resulting from combination of the abnormal alpha globin chain of HbQ India with the normal gamma chain of HbF-'HbF Q India'. Variant II HPLC system, used for routine hemoglobinopathy screening in anticoagulated , can also be used for screening samples. This obviates the need for a dedicated NBS system for hemoglobinopathy screening in newborns. We also demonstrated that both the systems are equally competent in detecting non-sickle Hb variants in DBS samples.
PubMed: 34267462
DOI: 10.1007/s12288-020-01352-2 -
Haematologica Nov 2020
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anemia; Betacoronavirus; COVID-19; Child; Child, Preschool; Coronavirus Infections; Female; Hemoglobinopathies; Humans; Infant; Male; Middle Aged; Pandemics; Pneumonia, Viral; SARS-CoV-2; Surveys and Questionnaires; Young Adult
PubMed: 33054122
DOI: 10.3324/haematol.2020.259440 -
BMC Medical Genetics Aug 2020The frequency of the alpha thalassemia trait is approximately 40% in the Kuwaiti population, but there has been no comprehensive study of the prevalent alleles. This is...
BACKGROUND
The frequency of the alpha thalassemia trait is approximately 40% in the Kuwaiti population, but there has been no comprehensive study of the prevalent alleles. This is a report of patients who were referred for molecular diagnosis over a 20-year period.
METHODS
This is a retrospective study of the α-globin genotypes obtained in the Hemoglobin Research Laboratory of the Department of Pediatrics, Kuwait University from 1994 to 2015. Genotyping was performed by a combination of PCR, allele-specific oligonucleotide hybridization and reverse dot blot hybridization (Vienna Lab Strip Assay).
RESULTS
Four hundred samples were characterized and analyzed from individuals aged < 1 month to 80 years, with a median of 6 years from 283 unrelated families. Most (90.8%) were Kuwaiti nationals. The commonest genotype was homozygosity for the polyadenylation-1 mutation (αα/α α) in 33.3% of the samples, followed by heterozygosity (αα/α α) for the same mutation in 32.3%. PA-1 was therefore the most frequent allele (0.59). The frequency of the α (--) allele was 0.017. Rare alleles that were found in very low frequencies included α (--) in a Filipino child, Hb Constant Spring, Hb Adana, and Hb Icaria.
CONCLUSION
There is a wide variety of alpha thalassemia alleles among Kuwaitis, but nondeletional PA-1 is by far the most common cause of the moderate to severe HbH (β4 tetramer) disease phenotype. The α (-) allele is also encountered, which has implications for premarital counseling, especially for the possibility of having babies with alpha thalassemia major (Barts hydrops fetalis).
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alleles; Child; Child, Preschool; Female; Gene Frequency; Genotype; Humans; Infant; Infant, Newborn; Kuwait; Male; Middle Aged; Retrospective Studies; Young Adult; alpha-Globins; alpha-Thalassemia
PubMed: 32831051
DOI: 10.1186/s12881-020-01105-y