Active spread of ß-thalassemia beyond the thalassemia belt: A study on a Russian population.

ß-Thalassemia is a disease traditionally associated with thalassemia belt countries. Nonetheless, as global migration intensifies, ß-thalassemia-causing variants spread far from their origin. We investigated this process to detect some patterns underlying its course. We analyzed ß-thalassemia-causing variants and the origin of 676 unrelated participants in Moscow, the largest city of Russia, far away from the thalassemia belt. Our analyses revealed that modern Russia has one of the broadest spectra of thalassemia-causing variants: 46 different variants, including two novel ß0 variants. Only a small proportion of the reported pathogenic variants likely originated in the resident subpopulation. Almost half of the variants that supposedly had emerged outside the Russian borders have already been assimilated by (were found in) the resident subpopulation. The primary modern source of immigration transferring thalassemia to a nonthalassemic part of Russia is the Caucasus region. We also found traces of ancient migration flows from non-Caucasus countries. Our data indicate that ß-thalassemia-causing variants are actively spilling over into resident populations of countries outside thalassemia belt regions. Therefore, viewing thalassemia as a disease exclusive to specific ethnic groups creates a mind trap that can complicate the diagnosis.

Marrow Fat-Cortical Bone Relationship in ß-Thalassemia: A Study Using MRI.

BACKGROUND: Growing evidence suggests that marrow adipocytes play an active role in the regulation of bone metabolism and hematopoiesis. However, research on the relationship between bone and fat in the context of hematological diseases, particularly ß-thalassemia, remains limited. PURPOSE: To investigate the relationship between marrow fat and cortical bone thickness in ß-thalassemia and to identify key determinants influencing these variables. STUDY TYPE: Prospective. SUBJECTS: Thirty-five subjects in four subject groups of increasing disease severity: 6 healthy control (25.0 ± 5.3 years, 2 male), 4 ß-thalassemia minor, 13 intermedia, and 12 major (29.1 ± 6.4 years, 15 male). FIELD STRENGTH/SEQUENCE: 3.0 T, 3D fast low angle shot sequence and T1-weighted turbo spin echo. ASSESSMENT: Analyses on proton density fat fraction (PDFF) and R2* values in femur subregions (femoral head, greater trochanter, intertrochanteric, diaphysis, distal) and cortical thickness (CBI) of the subjects' left femur. Clinical data such as age, sex, body mass index (BMI), and disease severity were also included. STATISTICAL TESTS: One-way analysis of variance (ANOVA), mixed ANOVA, Pearson correlation and multiple regression. P-values <0.05 were considered significant. RESULTS: Bone marrow PDFF significantly varied between the femur subregions, F(2.89,89.63) = 44.185 and disease severity, F(1,3) = 12.357. A significant interaction between subject groups and femur subregions on bone marrow PDFF was observed, F(8.67,89.63) = 3.723. Notably, a moderate positive correlation was observed between PDFF and CBI (r = 0.33-0.45). Multiple regression models for both PDFF (R2 = 0.476, F(13,151) = 10.547) and CBI (R2 = 0.477, F(13,151) = 10.580) were significant. Significant predictors for PDFF were disease severity (ßTMi = 0.36, ßTMa = 0.17), CBI (ß = 0.24), R2* (ß = -0.32), and height (ß = -0.29) while for CBI, the significant determinants were sex (ß = -0.27), BMI (ß = 0.55), disease severity (ßTMi = 2.15), and PDFF (ß = 0.25). DATA CONCLUSION: This study revealed a positive correlation between bone marrow fat fraction and cortical bone thickness in ß-thalassemia with varying disease severity, potentially indicating a complex interplay between bone health and marrow composition. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 3.

Importance of CD71+ Erythrocyte Cell Levels in Prognosis in Patients With ß-Thalassemia.

BACKGROUND/OBJECTIVES: CD71+ erythroid cells (CECs) are immature red blood cells (proerythroblasts, erythroblasts, and reticulocytes). CECs play an important role in the development of sepsis and cancer by causing immunosuppression. We examined the CEC levels in the peripheral blood of beta thalassemia (ßThal) patients and investigated the relationship between CECs and the clinical status of the patients, especially splenectomy. METHODS: Sixty-eight patients with ßThal (46 splenectomized and 22 nonsplenectomized) and 15 healthy controls were included in this study. The hemogram parameters, ferritin, and CECs (flow cytometry method) were measured. RESULTS: It was observed that the CEC level in the patient group was significantly higher than the control group (p < 0.05). CEC levels were found to be significantly higher in patients with splenectomy than in patients with nonsplenectomy (p < 0.05). CEC levels were higher in patients with nontransfusion-dependent ßT (NTD-ßThal) than in patients with transfusion-dependent ßT (TD-ßThal) (p < 0.05). CEC levels were found to be significantly higher in patients with splenectomy than in patients with nonsplenectomy in both TD-ßThal and NTD-ßThal groups (p < 0.05). There was a moderate-negative correlation was detected between CECs and Hb levels (r = -0.467; p < 0.05). CONCLUSIONS: High CEC levels in ßThal patients develop as a result of ineffective erythropoiesis. We think that keeping CEC levels under control is important for prognosis, especially in patients with splenectomy.

Effects of Splenectomy on Natural Killer Cell Levels in ß-Thalassemia Major Patients.

AIM: In this study, we investigated how splenectomy affects natural killer (NK) cell levels in patients with ß-thalassemia major (ß-TM). MATERIALS AND METHODS: Seventy patients with ß-TM (38 splenectomized and 32 nonsplenectomized) and 25 healthy controls were included in this study. The hemogram parameters, ferritin, T lymphocyte, T-helper cell, T-suppressor cell, and NK cell numbers, were measured. RESULTS: The T lymphocyte (CD3+) level was found to be significantly higher in the patient group (p < 0.05). CD3+/CD4+ T lymphocytes were detected to be significantly higher in the patient group (p < 0.05). Although the CD3+/CD4+ T lymphocyte level was significantly higher in the nonsplenectomy group (p < 0.05), this was not the case in the splenectomy group. When the patient and control groups were compared, no significant difference was detected regarding CD3+/CD8+ T lymphocyte levels. CD3-/CD16+CD56+ NK cell level was found to be significantly lower only in the splenectomy group than in the control group (p < 0.05). We found that there was a significant negative correlation between serum ferritin levels and both total lymphocyte (r = -0.617) and CD3+ lymphocyte (r = -0.718) levels in the control group (p < 0.05). A significant negative correlation was detected between serum ferritin levels and CD3-/CD16+CD56+ NK cell levels in the patient group (r = -0.410) (p < 0.05). CONCLUSION: Splenectomy reduces NK cell levels in patients with ß-TM. The negative relationship between ferritin levels and NK cells indicates that ferritin levels should be kept under control in patients with ß-TM.

Spectrum of HBB gene mutations among 696 ß-thalassemia patients and carriers in Southern Vietnam.

BACKGROUND: Thalassemias are common inherited blood disorders that have been extensively studied in Asia. Thus far, data on mutations of the HBB gene in Vietnamese patients with ß-thalassemia are limited to small studies. METHODS: We recruited 696 ß-thalassemia patients and carriers in southern Vietnam and analyzed for the HBB gene mutations using Sanger sequencing technology. RESULTS: We documented 27 types of known mutations and 10 types of novel variants on 737 alleles out of 1392 surveyed alleles. The three most common mutations, which account for more than ¾ of all mutant alleles, were c.79G > A (HbE), c.124_127delTTCT, and c.52A > T. The novel variants were mainly located in 5' untranslated region (c.-92delC and c.-67A > G) and 3' untranslated region (c.*4C > T, c.*116_*117insA, c.*142 T > C, c.*156G > C, c.*176_*177insA, and c.*247 T > C), except for one in intron 2 (c.316-99 T > G) and one in exon 3 (c.385delG). CONCLUSION: We provide here a comprehensive mutation spectrum of the HBB gene in Southern Vietnam, which is crucial for carrier screening and prenatal diagnosis in the future.

Diagnostic performance of classification trees and hematological functions in hematologic disorders: an application of multidimensional scaling and cluster analysis.

BACKGROUND: Several hematological indices have been already proposed to discriminate between iron deficiency anemia (IDA) and ß-thalassemia trait (ßTT). This study compared the diagnostic performance of different hematological discrimination indices with decision trees and support vector machines, so as to discriminate IDA from ßTT using multidimensional scaling and cluster analysis. In addition, decision trees were used to determine the diagnostic classification scheme of patients. METHODS: Consisting of 1178 patients with hypochromic microcytic anemia (708 patients with ßTT and 470 patients with IDA), this cross-sectional study compared the diagnostic performance of 43 hematological discrimination indices with classification tree algorithms and support vector machines in order to discriminate IDA from ßTT. Moreover, multidimensional scaling and cluster analysis were used to identify the homogeneous subgroups of discrimination methods with similar performance. RESULTS: All the classification tree algorithms except the LOTUS tree algorithm showed acceptable accuracy measures for discrimination between IDA and ßTT in comparison with other hematological discrimination indices. The results indicated that the CRUISE and C5.0 tree algorithms had better diagnostic performance and efficiency among other discrimination methods. Moreover, the AUC of CRUISE and C5.0 tree algorithms indicated more precise classification with values of 0.940 and 0.999, indicating excellent diagnostic accuracy of such models. Moreover, the CRUISE and C5.0 tree algorithms showed that mean corpuscular volume can be considered as the main variable in discrimination between IDA and ßTT. CONCLUSIONS: CRUISE and C5.0 tree algorithms as powerful methods in data mining techniques can be used to develop accurate differential methods along with other laboratory parameters for the discrimination of IDA and ßTT. In addition, the multidimensional scaling method and cluster analysis can be considered as the most appropriate techniques to determine the discrimination indices with similar performance for future hematological studies.

A ß-Thalassemia Trait with Two Mutations in Cis in a Chinese Family.

A female of Chinese origin carried the codon 43 (G>T) (HBB: c.130G > T) and codons 71/72 (+A) (HBB: c.216_217insA) mutations of the ß-globin gene in cis, identified during prenatal thalassemia screening. The double in cis mutations were inherited from her mother. Both of the two carriers behave as a traditional heterozygote for ß-thalassemia (ß-thal) with microcytosis and a high Hb A2 level. This case report indicates that the possibility of multiple mutations in cis in a fetus with thalassemia trait has to be considered in a prenatal screening program.

Antioxidative effects of N-acetylcysteine in patients with ß-thalassemia: A quick review on clinical trials.

Background and Aims: Several studies have highlighted the potent antioxidant properties of N-acetyl cysteine (NAC). This review aimed to assess the impact of NAC on oxidative stress biomarkers in patients with ß-thalassemia. Methods: The review included articles published before 2024 that investigated the effects of NAC on oxidative stress in individuals with ß-thalassemia. A comprehensive search was conducted across various databases, including Scopus, PubMed, Web of Science, Trip, and CENTRAL. Only English-language clinical trials were considered for inclusion in this review. Besides, the number needed to treat (NNT) was calculated based on the included studies. Results: Ninety-nine articles were retrieved from electronic databases, and after a thorough review, eight articles were selected for comprehensive text analysis. The highest dose of NAC administered was 10 mg/kg/day (equivalent to 600 mg/day) over a period of 3-6 months. All the studies assessing the impact of NAC on oxidative stress indicators in ß-thalassemia patients demonstrated positive effects during the 3-month follow-up period. Most estimated NNTs fell into 1-5, suggesting significant clinical therapeutic value in this context. Conclusion: The current potency of NAC alone appears to be effective in ameliorating oxidative stress in patients with ß-thalassemia major. While a 3-month duration seems adequate to demonstrate the antioxidant properties of NAC in this population, larger and well-designed clinical trials are warranted. Current clinical evidence possesses a high risk of bias.

Impacts of ß-thalassemia/hemoglobin E disease on pregnancy outcomes.

OBJECTIVE: To compare obstetric outcomes between women with ß-thalassemia/hemoglobin E (ß-thal/HbE) disease and those of low-risk pregnancies, and also between the two subgroups, ß-thal0/HbE and ß-thal+/HbE disease. METHODS: A retrospective cohort study was undertaken on pregnant women with ß-thal/HbE disease and low-risk pregnancies, which were randomly selected with a case-to-control ratio of 1:10. RESULTS: Pregnancies with ß-thal/HbE disease were identified in 0.19% of 59 152 pregnancies, including 104 women in the study group and 1040 women in the control group. The mean gestational age and mean birth weight were significantly lower in the study group. The prevalence of fetal growth restriction, preterm birth and low birth weight were significantly increased in the study group based on both univariate and multivariate analysis. The impacts were more striking in the ß-thal0/HbE subgroup than in the ß-thal+/HbE subgroup. The cesarean rate was significantly higher in the study group. No maternal death or serious complication was found in this cohort. CONCLUSION: Based on this cohort, the largest ever published, ß-thal/HbE disease is significantly associated with increased incidence of fetal growth restriction, preterm birth and low birth weight. The impacts were more pronounced in the ß-thal0/HbE subgroup. Pregnancy may be relatively safer for women with ß-thal/HbE disease.

HLA haplotype frequencies and diversity in patients with hemoglobinopathies.

The genetic diversity of the human leukocyte antigen (HLA) system was shaped by evolutionary constraints exerted by environmental factors. Analyzing HLA diversity may allow understanding of the underlying pathways and offer useful tools in transplant setting. The aim of this study was to investigate the HLA haplotype diversity in patients with sickle cell disease (SCD, N = 282) or ß-thalassemia (ß-Thal, N = 60), who received hematopoietic cell transplantation (HCT) reported to Eurocord and the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC). We identified 405 different HLA-A-B-DRB1 haplotypes in SCD and 108 in ß-Thal patients. Using data from African and European populations of the "1000 Genomes Project" for comparison with SCD and ß-Thal, respectively, we found that the haplotypes HLA-A*30-B*14-DRB1*15 (OR 7.87, 95% CI: 1.66-37.3, p b = 0.035), HLA-A*23-B*08 (OR 6.59, 95% CI: 1.8-24.13, p b = 0.023), and HLA-B*14-DRB1*15 (OR 10.74, 95% CI: 3.66-31.57, p b = 0.000) were associated with SCD, and the partial haplotypes HLA-A*30-B*13 and HLA-A*68-B*53 were associated with ß-Thal (OR 4.810, 95% CI: 1.55-14.91, p b = 0.033, and OR 17.52, 95% CI: 2.81-184.95, p b = 0.011). Our results confirm the extreme HLA genetic diversity in SCD patients likely due to their African ancestry. This diversity seems less accentuated in patients with ß-Thal. Our findings emphasize the need to expand inclusion of donors of African descent in HCT donor registries and cord blood banks.

Clinical outcome and humoral immune responses of ß-thalassemia major patients with severe iron overload to SARS-CoV-2 infection and vaccination: a prospective cohort study.

Background: COVID-19 has raised special concern for patients with ß-thalassemia major (ß-TM) due to frequent comorbidities, regular blood transfusions, and iron overload. However, the exact implications of COVID-19 for patients with ß-TM remain uncertain. We aimed to explore the COVID-19 incidence and severity, and the serological response to SARS-CoV-2 infection and vaccination in patients with ß-TM. Methods: Patients with ß-TM (n = 105) and age-matched healthy controls, all individuals of all control groups were health care workers of the hospital, were prospectively enrolled at the haematology department of Al-Shifa hospital in the Gaza Strip from January 1st, 2021 to December 31st, 2021. Data on COVID-19 incidence and severity were analysed, with Alpha, Beta, and Delta SARS-CoV-2 variants dominating at that time. Anti-SARS-CoV-2 IgG antibody levels were measured and compared between study groups. Findings: Patients with ß-TM showed a higher incidence of SARS-CoV-2 infection than the general population (61.9% vs. 7.1%, p < 0.0001). Most patients with ß-TM had asymptomatic (70.8%) or mild disease (26.1%), with no fatalities recorded. COVID-19 illness was more severe among female than male patients with ß-TM. Anti-SARS-CoV-2 IgG antibodies were significantly higher in symptomatic patients with ß-TM than controls post-infection (geometric mean ÷ geometric standard deviation 1299.0 ÷ 3.3 vs. 555.7 ÷ 2.4 AU/mL, p = 0.009) and post-vaccination (8404.0 ÷ 3.9 vs. 2785.6 ÷ 5.0 AU/mL, p = 0.015). Similar responses were observed when comparing splenectomised to non-splenectomised (both asymptomatic and symptomatic) patients with ß-TM post-infection (595.4 ÷ 3.9 vs. 280.7 ÷ 3.5 AU/mL, p = 0.005) and post-vaccination (13,778.2 ÷ 3.2 vs. 4961.8 ÷ 4.1 AU/mL, p = 0.045). Interpretation: This distinctive ß-TM cohort exhibited a high susceptibility to SARS-CoV-2 infection but mild disease course. Our findings support favourable serological responses to SARS-CoV-2 infection and to vaccination in patients with ß-TM, indicating a potential interplay between iron availability and COVID-19-related immunity. Funding: This study was funded by Mr. Hosam and Wasim s. El Helou.

Possible effects of sirolimus treatment on the long­term efficacy of COVID­19 vaccination in patients with ß­thalassemia: A theoretical perspective.

The pandemic caused by the severe acute respiratory syndrome coronavirus (SARS­CoV­2), responsible for coronavirus disease 2019 (COVID­19) has posed a major challenge for global health. In order to successfully combat SARS­CoV­2, the development of effective COVID­19 vaccines is crucial. In this context, recent studies have highlighted a high COVID­19 mortality rate in patients affected by ß­thalassemia, probably due to their co­existent immune deficiencies. In addition to a role in the severity of SARS­CoV­2 infection and in the mortality rate of COVID­19­infected patients with thalassemia, immunosuppression is expected to deeply affect the effectivity of anti­COVID­19 vaccines. In the context of the interplay between thalassemia­associated immunosuppression and the effectiveness of COVID­19 vaccines, the employment of immunomodulatory molecules is hypothesized. For instance, short­term treatment with mammalian target of rapamycin inhibitors (such as everolimus and sirolimus) has been found to improve responses to influenza vaccination in adults, with benefits possibly persisting for a year following treatment. Recently, sirolimus has been considered for the therapy of hemoglobinopathies (including ß­thalassemia). Sirolimus induces the expression of fetal hemoglobin (and this may contribute to the amelioration of the clinical parameters of patients with ß­thalassemia) and induces autophagy (thereby reducing the excessive levels of α­globin). It may also finally contribute to the mobilization of erythroid cells from the bone marrow (thereby reducing anemia). In the present study, the authors present the hypothesis that sirolimus treatment, in addition to its beneficial effects on erythroid­related parameters, may play a crucial role in sustaining the effects of COVID­19 vaccination in patients with ß­thalassemia. This hypothesis is based on several publications demonstrating the effects of sirolimus treatment on the immune system.

Epigenetic Insights and Potential Modifiers as Therapeutic Targets in ß-Thalassemia.

Thalassemia, an inherited quantitative globin disorder, consists of two types, α- and ß-thalassemia. ß-thalassemia is a heterogeneous disease that can be asymptomatic, mild, or even severe. Considerable research has focused on investigating its underlying etiology. These studies found that DNA hypomethylation in the ß-globin gene cluster is significantly related to fetal hemoglobin (HbF) elevation. Histone modification reactivates γ-globin gene expression in adults and increases ß-globin expression. Down-regulation of γ-globin suppressor genes, i.e., BCL11A, KLF1, HBG-XMN1, HBS1L-MYB, and SOX6, elevates the HbF level. ß-thalassemia severity is predictable through FLT1, ARG2, NOS2A, and MAP3K5 gene expression. NOS2A and MAP3K5 may predict the ß-thalassemia patient's response to hydroxyurea, a HbF-inducing drug. The transcription factors NRF2 and BACH1 work with antioxidant enzymes, i.e., PRDX1, PRDX2, TRX1, and SOD1, to protect erythrocytes from oxidative damage, thus increasing their lifespan. A single ß-thalassemia-causing mutation can result in different phenotypes, and these are predictable by IGSF4 and LARP2 methylation as well as long non-coding RNA expression levels. Finally, the coinheritance of ß-thalassemia with α-thalassemia ameliorates the ß-thalassemia clinical presentation. In conclusion, the management of ß-thalassemia is currently limited to genetic and epigenetic approaches, and numerous factors should be further explored in the future.

Hemochromatosis in a ß-thalassemia minor patient with H63D homozygous mutation: A case report.

ß-thalassemia heterozygosity can cause significant iron overload when accompanied by HFE gene mutations and inappropriate iron supplementation.

A Cell-free DNA Barcode-Enabled Single-Molecule Test for Noninvasive Prenatal Diagnosis of Monogenic Disorders: Application to ß-Thalassemia.

Noninvasive prenatal testing of common aneuploidies has become routine over the past decade, but testing of monogenic disorders remains a challenge in clinical implementation. Most recent studies have inherent limitations, such as complicated procedures, a lack of versatility, and the need for prior knowledge of parental genotypes or haplotypes. To overcome these limitations, a robust and versatile next-generation sequencing-based cell-free DNA (cfDNA) allelic molecule counting system termed cfDNA barcode-enabled single-molecule test (cfBEST) is developed for the noninvasive prenatal diagnosis (NIPD) of monogenic disorders. The accuracy of cfBEST is found to be comparable to that of droplet digital polymerase chain reaction (ddPCR) in detecting low-abundance mutations in cfDNA. The analytical validity of cfBEST is evidenced by a ß-thalassemia assay, in which a blind validation study of 143 at-risk pregnancies reveals a sensitivity of 99.19% and a specificity of 99.92% on allele detection. Because the validated cfBEST method can be used to detect maternal-fetal genotype combinations in cfDNA precisely and quantitatively, it holds the potential for the NIPD of human monogenic disorders.

Sensorineural Hearing Loss and Its Relationship with Duration of Chelation Among Major ß-Thalassemia Patients.

Introduction Thalassemia is a common genetic disorder worldwide, also occurring frequently in Karachi, Pakistan. Beta (ß)-thalassemia major patients need repeated transfusions which cause iron overload. Patients are treated with chelating agents to reduce the high serum ferritin level and to decrease morbidity and mortality due to increased iron levels. This combined therapy also leads to some complications. One of them is the sensorineural hearing loss (SNHL). To date, no data is available in Pakistan regarding SNHL among major ß-thalassemia patients on chelating therapy.  Methods A cross-sectional study was performed in collaboration with the Thalassemia Center and Dr. Ruth Pfau at the Department of Ear, Nose, and Throat, Civil Hospital, Karachi, Pakistan. The variable to detect hearing was pure tone air and bone conduction thresholds at the frequencies of 250 - 4,000 Hz. Clinical data, such as chelating agent dose, duration, and hearing status, were recorded. Demographic characteristics, like age, gender, height, and weight, were noted. The hemoglobin and serum ferritin levels of the subjects were also included. Results Forty-five percent of cases of thalassemia were suffering from SNHL. In the right ear, the Pearson correlation of chelating agent dose (mg) with SNHL was mildly positive and statistically significant (r = 0.261, p < 0.001), (r = 0.337, p < 0.001), (r = 0.198, p = 0.005), and (r = 0.207, p = 0.003) at the frequencies of 250, 500, 1,000, and 2,000 Hz, respectively, and the Pearson correlation of chelating agent used (in months) with SNHL was mildly positive and statistically significant (r = 0.232, p = 0.001), and (r = 0.301, p < 0.001) at frequencies 250 to 500 Hz, respectively. In the left ear, the Pearson correlation of chelating agent dose (mg) with SNHL was mildly positive and statistically significant, (r = 0.191, p = 0.007), (r = 0.202, p = 0.004), (r = 0.297, p < 0.001), (r = 0.183, p = 0.010) and (r = 0.221, p = 0.002) at frequencies 250, 500, 1,000, 2,000, and 4,000 Hz, respectively, and Pearson correlation of chelating agent used (months) with SNHL was mildly positive and statistically significant only at the frequency of 2,000 Hz (r = 140, p = 0.049).  Conclusion Chelation therapy and regular blood transfusions, apart from prolonging the life of thalassemic patients, also leads to some complications. With this survey, it was concluded that almost half of the patients had normal hearing, while the other half had sensorineural hearing loss after the use of deferasirox. It is inferred that the incidence of SNHL is not only dose-related but the duration of use of a chelating agent is also a contributing factor.

Cytomegalovirus infection in a splenectomized with ß-thalassemia major: immunocompetent or immunosuppressed?

We should possibly revise our knowledge about risk assessment of splenectomized individuals with ß-thalassemia major. Besides their known risk of certain bacterial infection, they might be also in a risk of life-threatening primary cytomegalovirus (CMV) infection and end-, multi-organ disease, in the context of their immunosuppression status. Prompt and appropriate treatment initiation can be life saving.

Upregulation of miR­6747­3p affects red blood cell lineage development and induces fetal hemoglobin expression by targeting BCL11A in ß­thalassemia.

In ß­thalassemia, excessive α­globin chain impedes the normal development of red blood cells resulting in anemia. Numerous miRNAs, including miR­6747­3p, are aberrantly expressed in ß­thalassemia major (ß­TM), but there are no reports on the mechanism of miR­6747­3p in regulating red blood cell lineage development and fetal hemoglobin (HbF) expression. In the present study, RT­qPCR was utilized to confirm miR­6747­3p expression in patients with ß­TM and the healthy controls. Electrotransfection was employed to introduce the miR­6747­3p mimic and inhibitor in both HUDEP­2 and K562 cells, and red blood cell lineage development was evaluated by CCK­8 assay, flow cytometry, Wright­Giemsa staining and Benzidine blue staining. B­cell lymphoma/leukemia 11A (BCL11A) was selected as a candidate target gene of miR­6747­3p for further validation through FISH assay, dual luciferase assay and Western blotting. The results indicated that miR­6747­3p expression was notably higher in patients with ß­TM compared with healthy controls and was positively related to HbF levels. Functionally, miR­6747­3p overexpression resulted in the hindrance of cell proliferation, promotion of cell apoptosis, facilitation of cellular erythroid differentiation and γ­globin expression in HUDEP­2 and K562 cells. Mechanistically, miR­6747­3p could specifically bind to the 546­552 loci of BCL11A 3'­UTR and induce γ­globin expression. These data indicate that upregulation of miR­6747­3p affects red blood cell lineage development and induces HbF expression by targeting BCL11A in ß­thalassemia, highlighting miR­6747­3p as a potential molecular target for ß­thalassemia therapy.