Direct Promoter Repression by BCL11A Controls the Fetal to Adult Hemoglobin Switch.

Fetal hemoglobin (HbF, α2γ2) level is genetically controlled and modifies severity of adult hemoglobin (HbA, α2ß2) disorders, sickle cell disease, and ß-thalassemia. Common genetic variation affects expression of BCL11A, a regulator of HbF silencing. To uncover how BCL11A supports the developmental switch from γ- to ß- globin, we use a functional assay and protein binding microarray to establish a requirement for a zinc-finger cluster in BCL11A in repression and identify a preferred DNA recognition sequence. This motif appears in embryonic and fetal-expressed globin promoters and is duplicated in γ-globin promoters. The more distal of the duplicated motifs is mutated in individuals with hereditary persistence of HbF. Using the CUT&RUN approach to map protein binding sites in erythroid cells, we demonstrate BCL11A occupancy preferentially at the distal motif, which can be disrupted by editing the promoter. Our findings reveal that direct γ-globin gene promoter repression by BCL11A underlies hemoglobin switching.

Co-transcriptional splicing regulates 3' end cleavage during mammalian erythropoiesis.

Pre-mRNA processing steps are tightly coordinated with transcription in many organisms. To determine how co-transcriptional splicing is integrated with transcription elongation and 3' end formation in mammalian cells, we performed long-read sequencing of individual nascent RNAs and precision run-on sequencing (PRO-seq) during mouse erythropoiesis. Splicing was not accompanied by transcriptional pausing and was detected when RNA polymerase II (Pol II) was within 75-300 nucleotides of 3' splice sites (3'SSs), often during transcription of the downstream exon. Interestingly, several hundred introns displayed abundant splicing intermediates, suggesting that splicing delays can take place between the two catalytic steps. Overall, splicing efficiencies were correlated among introns within the same transcript, and intron retention was associated with inefficient 3' end cleavage. Remarkably, a thalassemia patient-derived mutation introducing a cryptic 3'SS improved both splicing and 3' end cleavage of individual ß-globin transcripts, demonstrating functional coupling between the two co-transcriptional processes as a determinant of productive gene output.

Epigenetic inactivation of ERF reactivates γ-globin expression in ß-thalassemia.

The fetal-to-adult hemoglobin switch is regulated in a developmental stage-specific manner and reactivation of fetal hemoglobin (HbF) has therapeutic implications for treatment of ß-thalassemia and sickle cell anemia, two major global health problems. Although significant progress has been made in our understanding of the molecular mechanism of the fetal-to-adult hemoglobin switch, the mechanism of epigenetic regulation of HbF silencing remains to be fully defined. Here, we performed whole-genome bisulfite sequencing and RNA sequencing analysis of the bone marrow-derived GYPA+ erythroid cells from ß-thalassemia-affected individuals with widely varying levels of HbF groups (HbF ≥ 95th percentile or HbF ≤ 5th percentile) to screen epigenetic modulators of HbF and phenotypic diversity of ß-thalassemia. We identified an ETS2 repressor factor encoded by ERF, whose promoter hypermethylation and mRNA downregulation are associated with high HbF levels in ß-thalassemia. We further observed that hypermethylation of the ERF promoter mediated by enrichment of DNMT3A leads to demethylation of γ-globin genes and attenuation of binding of ERF on the HBG promoter and eventually re-activation of HbF in ß-thalassemia. We demonstrated that ERF depletion markedly increased HbF production in human CD34+ erythroid progenitor cells, HUDEP-2 cell lines, and transplanted NCG-Kit-V831M mice. ERF represses γ-globin expression by directly binding to two consensus motifs regulating γ-globin gene expression. Importantly, ERF depletion did not affect maturation of erythroid cells. Identification of alterations in DNA methylation of ERF as a modulator of HbF synthesis opens up therapeutic targets for ß-hemoglobinopathies.

Comparative histological analysis of spleens in pediatric patients with hemolytic anemias: Insights into the pathophysiological mechanisms of spleen destruction in sickle cell anemia.

While sickle cell anemia (SCA) and hereditary spherocytosis (HS) share common features of increased spleen erythrophagocytosis due to increased red blood cell (RBC) turnover, SCA is specifically characterized by susceptibility to infections. In this study, histological lesions in the spleens of pediatric patients with SCA were analyzed, in close correlation with past clinical history and comparatively to HS, healthy and transfused ß-thalassemia patients (TDT). An evaluation of red pulp elementary lesions (red pulp fibrosis, iron deposition, number of Gandy-Gamna, and RBC trapping) combined into a severity score was established, as well as B-cell follicles analysis. Quantification on digitalized slides of iron deposition, RBC trapping, and red pulp fibrosis was additionally performed. Spleens from 22 children with SCA, eight with HS, eight with TDT, and three healthy controls (HC) were analyzed. Median age at splenectomy was not different between SCA and HS patients, 6.05 years (range: 4.5-16.0) versus 4.75 (range: 2.2-9.5). Marked heterogeneity was found in SCA spleens in contrast to other conditions. Contrary to previous reports, B-cell follicles were generally preserved in SCA. While RBC trapping was significantly increased in both SCA and HS (compared to TDT and HC), quantitative fibrosis and overall red pulp severity score were significantly increased in SCA spleens compared to other conditions. Moreover, there was an inverse correlation between quantitative fibrosis and number of B-cell follicles, linking these two compartments as well as spleen fibrosis to infectious susceptibility in SCA, potentially through impaired red pulp macrophage scavenging and B-cell subpopulations defects.

Neutrophil Diversity (Immature, Aged, and Low-Density Neutrophils) and Functional Plasticity: Possible Impacts of Iron Overload in ß-Thalassemia.

Neutrophil dysfunction is a form of immune suppression in patients with ß-thalassemia (Beta-thal), although data on this are limited. In this study, blood from patients and healthy volunteers was analyzed. Flow cytometry analysis demonstrated an increase in immature neutrophils (CD16- CD62L+) and aged (senescent) neutrophils (CD16+ CD62L-) in Beta-thal patients compared to healthy volunteers. The Beta-thal neutrophils demonstrated less prominent chemotaxis and phagocytosis than healthy neutrophils at the baseline. With phorbol myristate acetate (PMA) or lipopolysaccharide (LPS) stimulations, some of the indicators, including the flow cytometry markers (CD11b, CD62L, CD66b, CD63, apoptosis, and reactive oxygen species) and neutrophil extracellular traps (NETs; detected by anti-citrullinated histone 3 immunofluorescence), were lower than the control. Additionally, low-density neutrophils (LDNs), which are found in the peripheral blood mononuclear cell (PBMC) fraction, were observed in Beta-thal patients but not in the control group. The expression of CD11b, CD66b, CD63, arginase I, and ROS in LDNs was higher than the regular normal-density neutrophils (NDNs). The proliferation rate of CD3+ T cells isolated from the PBMC fraction of healthy volunteers was higher than that of the cells from patients with Beta-thal. The incubation of red blood cell (RBC) lysate plus ferric ions with healthy NDNs transformed the NDNs into the aged neutrophils (decreased CD62L) and LDNs. In conclusion, iron overload induces neutrophil diversity along with some dysfunctions.

The association between steatosis and liver damage in transfusion-dependent beta thalassaemia patients.

Non-alcoholic fatty liver disease (NAFLD) is a global health problem. Iron is the leading cause of liver damage in patients with transfusion-dependent thalassaemia (TDT), and data on the contribution of NAFLD to liver damage in TDT is lacking. Forty-five heavily transfused TDT patients who did not have biochemical or ultrasonic evidence of liver cirrhosis were evaluated for effects of iron overload, including the presence of diabetes mellitus, hypogonadism, serum ferritin, R2-MRI-liver, and liver enzymes alanine aminotransferase and aspartate aminotransferase. Liver fibrosis and steatosis were estimated using transient elastography (TE). Nine (20%) patients had significant steatosis (S1), and their body mass index (BMI) and liver fibrosis scores were higher than in patients without significant steatosis (S0) (p = 0.03 and p = 0.004, respectively). On regression analysis, the controlled attenuation parameter (CAP) score (i.e., degree of liver steatosis) was associated only with increasing BMI. The TE score (i.e., degree of liver fibrosis) was associated with increasing age, CAP score, male gender, and presence of diabetes. Neither liver steatosis nor fibrosis showed significant association with the liver iron concentration or iron-related organ damage (hypogonadism). In this cohort of TDT patients, steatosis of the liver, which is associated with increasing BMI, appeared to increase the risk of liver fibrosis.

Endocrinopathies in Hemoglobinopathies: What Is the Role of Iron?

Hemoglobinopathies, including ß-thalassemia and sickle cell disease (SCD), are common genetic blood disorders. Endocrine disorders are frequent manifestations of organ damage observed mainly in patients with ß-thalassemia and rarely in SCD. Iron overload, oxidative stress-induced cellular damage, chronic anemia, and HCV infection contribute to the development of endocrinopathies in ß-thalassemia. The above factors, combined with vaso-occlusive events and microcirculation defects, are crucial for endocrine dysfunction in SCD patients. These endocrinopathies include diabetes mellitus, hypothyroidism, parathyroid dysfunction, gonadal and growth failure, osteoporosis, and adrenal insufficiency, affecting the quality of life of these patients. Thus, we aim to provide current knowledge and data about the epidemiology, pathogenesis, diagnosis, and management of endocrine disorders in ß-thalassemia and SCD. We conducted a comprehensive review of the literature and examined the available data, mostly using the PubMed and Medline search engines for original articles. In the era of precision medicine, more studies investigating the potential role of genetic modifiers in the development of endocrinopathies in hemoglobinopathies are essential.

Stroke propensity in the Th3+/ mouse model of ß-thalassemia intermedia.

ß-thalassemia is associated with multiple hematological and cerebrovascular symptoms linked to a hypercoagulable state that has not been fully replicated in animal models for the development of stroke treatments. Herein we compared the physiological properties and responses to transient cerebral hypoxia-ischemia (tHI) between six-month-old wildtype and heterozygous Th3/+ mice, a model of non-transfusion-dependent ß-thalassemia intermedia (ß-TI). We found that Th3/+ mice developed microcytic anemia, splenomegaly, higher platelet counts, and increased platelet-erythrocyte plus erythrocyte-leukocyte aggregates. Furthermore, Th3/+ mice showed diminished cerebrovascular reactivity (CVR) and cortical oxygen saturation under repetitive hypercapnic challenges. When subjected to a sub-threshold tHI insult, platelets and leukocytes in Th3/+ mice adhered to the cerebrovascular wall or formed aggregates, while their counterparts flew through smoothly in wildtype mice. Subsequently, Th3/+ mice showed increased fibrin deposition around cerebral blood vessels and larger infarction than wildtype mice, especially in female Th3/+ mice. Collectively these results showed that Th3/+ mice mimic key clinical features and a propensity to thromboembolism in ß-TI patients. The hypercoagulable state in Th3/+ mice is likely caused by multiple hematological and CVR anomalies that are similar, but are not identical to those in the mouse model of sickle cell anemia. As such, we suggest that Th3/+ mice are a useful model to study the pathological mechanisms and prophylactic stroke treatments in thalassemia patients.

Hematopoietic stem cell function in ß-thalassemia is impaired and is rescued by targeting the bone marrow niche.

Hematopoietic stem cells (HSCs) are regulated by signals from the bone marrow (BM) niche that tune hematopoiesis at steady state and in hematologic disorders. To understand HSC-niche interactions in altered nonmalignant homeostasis, we selected ß-thalassemia, a hemoglobin disorder, as a paradigm. In this severe congenital anemia, alterations secondary to the primary hemoglobin defect have a potential impact on HSC-niche cross talk. We report that HSCs in thalassemic mice (th3) have an impaired function, caused by the interaction with an altered BM niche. The HSC self-renewal defect is rescued after cell transplantation into a normal microenvironment, thus proving the active role of the BM stroma. Consistent with the common finding of osteoporosis in patients, we found reduced bone deposition with decreased levels of parathyroid hormone (PTH), which is a key regulator of bone metabolism but also of HSC activity. In vivo activation of PTH signaling through the reestablished Jagged1 and osteopontin levels correlated with the rescue of the functional pool of th3 HSCs by correcting HSC-niche cross talk. Reduced HSC quiescence was confirmed in thalassemic patients, along with altered features of the BM stromal niche. Our findings reveal a defect in HSCs in ß-thalassemia induced by an altered BM microenvironment and provide novel and relevant insight for improving transplantation and gene therapy approaches.

Lentiviral vector ALS20 yields high hemoglobin levels with low genomic integrations for treatment of beta-globinopathies.

Ongoing clinical trials for treatment of beta-globinopathies by gene therapy involve the transfer of the beta-globin gene, which requires integration of three to four copies per genome in most target cells. This high proviral load may increase genome toxicity, potentially limiting the safety of this therapy and relegating its use to total body myeloablation. We hypothesized that introducing an additional hypersensitive site from the locus control region, the complete sequence of the second intron of the beta-globin gene, and the ankyrin insulator may enhance beta-globin expression. We identified a construct, ALS20, that synthesized significantly higher adult hemoglobin levels than those of other constructs currently used in clinical trials. These findings were confirmed in erythroblastic cell lines and in primary cells isolated from sickle cell disease patients. Bone marrow transplantation studies in beta-thalassemia mice revealed that ALS20 was curative at less than one copy per genome. Injection of human CD34+ cells transduced with ALS20 led to safe, long-term, and high polyclonal engraftment in xenograft experiments. Successful treatment of beta-globinopathies with ALS20 could potentially be achieved at less than two copies per genome, minimizing the risk of cytotoxic events and lowering the intensity of myeloablation.

Long-read sequencing on the SMRT platform enables efficient haplotype linkage analysis in preimplantation genetic testing for ß-thalassemia.

PURPOSE: This study aimed to evaluate the value of long-read sequencing for preimplantation haplotype linkage analysis. METHODS: The genetic material of the three ß-thalassemia mutation carrier couples was sequenced using single-molecule real-time sequencing in the 7.7-kb region of the HBB gene and a 7.4-kb region that partially overlapped with it to detect the presence of 17 common HBB gene mutations in the Chinese population and the haplotypes formed by the continuous array of single-nucleotide polymorphisms linked to these mutations. By using the same method to analyze multiple displacement amplification products of embryos from three families and comparing the results with those of the parents, it could be revealed whether the embryos carry disease-causing mutations without the need for a proband. RESULTS: The HBB gene mutations of the three couples were accurately detected, and the haplotype linked to the pathogenic site was successfully obtained without the need for a proband. A total of 68.75% (22/32) of embryos from the three families successfully underwent haplotype linkage analysis, and the results were consistent with the results of NGS-based mutation site detection. CONCLUSION: This study supports long-read sequencing as a potential tool for preimplantation haplotype linkage analysis.

Interrelationship between liver T2*-weighted magnetic resonance imaging and acoustic radiation force impulse elastography measurement results and plasma ferritin levels in children with ß-thalassemia major.

PURPOSE: To evaluate correlation and agreement between T2*-weighted magnetic resonance imaging (T2*-wMRI), acoustic radiation force impulse elastography (ARFI-e) measurement results of liver and plasma ferritin levels (PFLs) in children with ß-thalassemia major (ß-TM). METHODS: The study included 40 pediatric patients (aged 64-216 months; 14 girls, 26 boys) receiving blood transfusion and chelation therapy. To detect the severity of liver iron overload (LIO) and concomitant parenchymal fibrosis, T2*-wMRI and ARFI-e measurements were performed from the right lobe segments. Student's t-test, Mann-Whitney U, ANOVA, Spearman's test and ICC were used for statistical analysis. RESULTS: After the measurements of T2*-wMRI, patients were grouped as normal in 4 (10%), mild in 11 (27.5%), moderate in 21 (52.5%), and severe in 4 (10%) cases in terms of LIO. Combined moderate and severe groups had significantly higher ARFI-e and PFL values than the combination of other groups (p = .001, p = .040). The ARFI-e measurements of boys were found to be significantly higher than those of girls (p = .023). A strong negative correlation between T2*-wMRI and ARFI-e and a moderate negative correlation between T2*-wMRI and PFL were detected (p;r = 0.001;-0.606, p;r = 0.009; -0.407). A strong positive correlation was found between ARFI-e values and PFL (p;r = 0.001; 0.659). The optimal cut-off value of ARFI-e to predict liver fibrosis because of moderate&severe LIO was determined to be 1.29 M/s (80% sensitivity and 88% specificity). A moderate agreement was observed between the T2*-wMRI and ARFI-e methods [ICC: 0.680, 95% CI: (0.470 to 0.817)]. CONCLUSION: Given the strong correlation and moderate agreement between ARFI-e and T2*-wMRI, ARFI -e could be used to monitor LIO in children with ß-TM.

Netrin-1 and clusterin: Innovative potential diagnostic biomarkers for early renal damage in ß-thalassemia major children.

BACKGROUND: Children with ß-thalassemia major (ß-TM) suffer from tubular dysfunction even before the onset of any renal impairment symptoms and/or clinical signs. Therefore, identifying innovative biomarkers allowing early renal damage detection has focused attention. AIM: This study aims to preliminary assess Netrin-1(NTN-1) and clusterin (CLU) in ß-TM children and explore their possible roles as surrogate noninvasive biomarkers of renal tubular dysfunction. SUBJECTS AND METHODS: In this study, 40 ß-TM children and 30 healthy children were enrolled. Routine serum and urinary biochemical variables were determined. Urinary NTN-1 and CLU levels were measured using ELISA and their mRNA expression in PBMCs were assayed using real-time PCR. Serum TNF-α, MDA levels and GST activity were measured. RESULTS: Urinary NTN-1 and CLU concentrations and mRNA relative expression levels in PBMCs were significantly increased in ß-TM children relative to controls. Oxidative stress and inflammatory markers revealed significant elevation in ß-TM children compared to controls. The change in these parameters correlated significantly with other renal parameters. ROC curves analysis showed that urinary NTN-1 and CLU levels are of promising diagnostic performance. CONCLUSION: Our results suggest that NTN-1 and CLU are qualified as new noninvasive biomarker panels for early detection of renal injury in ß-TM children. Moreover, urinary NTN-1 is recommended as a precise one during the clinical practices.

Iron metabolism under conditions of ineffective erythropoiesis in ß-thalassemia.

ß-Thalassemia (BT) is an inherited genetic disorder that is characterized by ineffective erythropoiesis (IE), leading to anemia and abnormal iron metabolism. IE is an abnormal expansion of the number of erythroid progenitor cells with unproductive synthesis of enucleated erythrocytes, leading to anemia and hypoxia. Anemic patients affected by BT suffer from iron overload, even in the absence of chronic blood transfusion, suggesting the presence of ≥1 erythroid factor with the ability to modulate iron metabolism and dietary iron absorption. Recent studies suggest that decreased erythroid cell differentiation and survival also contribute to IE, aggravating the anemia in BT. Furthermore, hypoxia can also affect and increase iron absorption. Understanding the relationship between iron metabolism and IE could provide important insights into the BT condition and help to develop novel treatments. In fact, genetic or pharmacological manipulations of iron metabolism or erythroid cell differentiation and survival have been shown to improve IE, iron overload, and anemia in animal models of BT. Based on those findings, new therapeutic approaches and drugs have been proposed; clinical trials are underway that have the potential to improve erythrocyte production, as well as to reduce the iron overload and organ toxicity in BT and in other disorders characterized by IE.

2021 update on clinical trials in ß-thalassemia.

The treatment landscape for patients with ß-thalassemia is witnessing a swift evolution, yet several unmet needs continue to persist. Patients with transfusion-dependent ß-thalassemia (TDT) primarily rely on regular transfusion and iron chelation therapy, which can be associated with considerable treatment burden and cost. Patients with non-transfusion-dependent ß-thalassemia (NTDT) are also at risk of significant morbidity due to the underlying anemia and iron overload, but treatment options in this patient subgroup are limited. In this review, we provide updates on clinical trials of novel therapies targeting the underlying pathology in ß-thalassemia, including the α/non-α-globin chain imbalance, ineffective erythropoiesis, and iron dysregulation.

Global loss of Tfr2 with concomitant induced iron deficiency greatly ameliorates the phenotype of a murine thalassemia intermedia model.

ß-thalassemias result from mutations in ß-globin, causing ineffective erythropoiesis and secondary iron overload due to inappropriately low levels of the iron regulatory hormone hepcidin. Mutations in transferrin receptor 2 (TFR2) lead to hereditary hemochromatosis (HH) as a result of inappropriately increased iron uptake from the diet, also due to improperly regulated hepcidin. TFR2 is also thought to be required for efficient erythropoiesis through its interaction with the erythropoietin receptor in erythroid progenitors. Transmembrane serine protease 6 (TMPRSS6), a membrane serine protease expressed selectively in the liver, participates in regulating hepcidin production in response to iron stores by cleaving hemojuvelin (HJV). We have previously demonstrated that inhibiting TMPRSS6 expression with a hepatocyte-specific siRNA formulation, induces hepcidin, mitigates anemia, and reduces iron overload in murine models of ß-thalassemia intermedia and HH. Here, we demonstrate that Tmprss6 siRNA treatment of double mutant Tfr2Y245X/Y245X HH Hbbth3/+ thalassemic mice induces hepcidin and diminishes tissue and serum iron levels. Importantly, treated double mutant animals produce more mature red blood cells and have a nearly 50% increase in hemoglobin compared to untreated ß-thalassemic mice. Furthermore, we also show that treatment of Tfr2Y245X/Y245X HH mice leads to increased hepcidin expression and reduced total body iron burden. These data indicate that siRNA suppression of Tmprss6, in conjunction with the targeting of TFR2, may be superior to inhibiting Tmprss6 alone in the treatment of the anemia and secondary iron loading in ß-thalassemia intermedia and may be useful as a method of suppressing the primary iron overload in TFR2-related (type 3) hereditary hemochromatosis.

Association of the Degree of Erythroid Expansion and Maturation Arrest with the Clinical Severity of ß0-Thalassemia/Hemoglobin E Patients.

INTRODUCTION: ß-Thalassemia/hemoglobin E represents one-half of all the clinically severe ß-thalassemias worldwide. Despite similar genetic backgrounds, patients show clinical heterogeneity ranging from nearly asymptomatic to transfusion-dependent thalassemia. The underlying disease modifying factors remain largely obscure. METHODS: To elucidate the correlation between ineffective erythropoiesis and ß0-thalassemia/hemoglobin E (HbE) disease severity, in vitro culture of erythroid cells derived from patients with different clinical symptoms was established. Cell proliferation, viability, and differentiation were investigated. To identify potential molecular mechanisms leading to the arrested erythroid maturation, the expression levels of erythropoiesis modifying factors were measured. RESULTS: The ß0-thalassemia/HbE cells exhibited enhanced proliferation, limited differentiation, and impaired erythroid terminal maturation but did not show accelerated erythroblast differentiation and increased cell death. Erythroblasts derived from mild patients showed the highest proliferation rate with a faster cell division time, while erythroblasts derived from severe patients displayed extremely delayed erythroid maturation. Downregulation of growth differentiation factor 11 and FOXO3a was observed in mild ß0-thalassemia/HbE erythroblasts, while upregulation of heat shock protein 70 and activin receptor 2A was revealed in severe erythroblasts. DISCUSSION/CONCLUSION: The degree of erythroid expansion and maturation arrest contributes to the severity of ß0-thalassemia/HbE patients, accounting for the disease heterogeneity. The findings suggest a restoration of erythroid maturation as a promising targeted therapy for severe patients.

GDF-15 negatively regulates excess erythropoiesis and its overexpression is involved in erythroid hyperplasia.

Growth differentiation factor-15 (GDF-15) is a member of TGF-ß superfamily. Among hematopoietic cells, this factor is mainly produced by erythroid series and is recently considered a biomarker of ineffective erythropoiesis (IE). Whether IE induces enhanced GDF-15 expression or is prompted by it, has remained elusive. In this study we investigated how high levels of GDF-15 contribute to IE-associated erythroid dysplasia. We assessed mRNA levels of GDF-15 during erythroid maturation as well as in patients with IE using qRT-PCR. Later, the erythroid colony-forming capacity of GDF-15-treated hematopoietic stem cells (HSCs) was evaluated by CFC assay. Any effect of elevated levels of GDF-15 on erythroid maturation was ultimately examined by expression analysis of erythroid-associated transcription factors and flow cytometry analysis of CD235a expression. GDF-15 mRNA expression increased during erythroid differentiation and also in ß-thalassemia and MDS patients which was directly correlated with erythropoiesis severity. Treating the cells with high GDF-15 concentration (50 ng/ml) resulted in an approximate 30% decline in the capacity of erythroid colony formation of HSCs and CD235a positive cells. Additionally, erythroid-specific transcription factors showed significant down-regulation in the early stages of erythroid differentiation. According to the expression level of GDF-15 and the role it plays in the erythroid system, high-levels of this factor could be an auto-modulatory mechanism to control the excessive production of erythroid cells.

COVID-19 Pandemic and Thalassemia Major Patients: Transfusion Practice and Treatment Assessment.

BACKGROUND: When the COVID-19 epidemic occurred for the first time in December 2019, the governments worldwide took some restriction measures for slowing the spread of novel coronavirus. Eventually, there was a considerable decrease in volunteer blood donations. Regular transfusions and follow-up of patients with thalassemia major (TM) should be maintained during this period. It is possible that the treatment of the patients with TM may hinder due to the difficulty of reaching the treatment center and the difficulty of blood supply. Thus, in this study, we aimed to investigate whether there were any differences in the follow-up and treatment of the patients with TM during the outbreak. MATERIALS AND METHODS: Sixty-one patients with TM who were followed up in our center without COVID-19 contact history and symptoms were included in this study. The demographic features and red blood cell volume per kilogram they received, pretransfusion hemoglobin, serum ferritin (SF) level, biochemical parameters, and transfusion interval were recorded. The difference between the arithmetic mean of the data before and during the pandemic was evaluated. RESULTS: In this study, 61 patients with TM (32 males/29 females, mean age 13.9±6.8 y) were evaluated. The mean pretransfusion hemoglobin value was 9.14±0.77 g/dL and 8.87± 0.80 g/dL before and during the pandemic, respectively (P=0.023). There was no difference between before and during the pandemic concerning transfusion interval and transfusion volume. However, SF levels increased above 1000 ng/mL in 16.6% of patients. CONCLUSION: Although blood donation decreased significantly during the pandemic, it was observed in this study that the blood needs of patients with TM could be provided. The results of the SF level showed that the management of chelation therapy should be more meticulous. However, we should be ready for the challenges in the transfusion practice of patients with TM due to fluctuations in the COVID-19 pandemic.