Investigating the Efficacy and Safety of Thalidomide for Treating Patients With ß-Thalassemia: A Meta-Analysis.
ABSTRACT: At present, the main therapies for ß-thalassemia patients include regular blood transfusion and iron chelation, associating with a number of limitations. Thalidomide, a fetal hemoglobin (HbF) inducer that promotes γ-globin gene expression, has been reported to be effective for ß-thalassemia. Thus, this meta-analysis was conducted to assess the efficacy and safety of thalidomide for treating patients with ß-thalassemia. We searched the related studies from eight databases published from inception until December 1, 2021. The R 4.0.5 language programming was used to perform meta-analysis. After screening of retrieved articles, 12 articles were included that enrolled a total of 451 patients. The Cochrane Collaboration risk assessment tool was used to evaluate the quality and the bias risk of the randomized controlled trials (RCTs), and non randomized trials were assessed using Newcastle-Ottawa Scale (NOS). After treatment with thalidomide, the pooled overall response rate (ORR) was 85% (95% confidence interval (CI): 80-90%), and the pooled complete response rate (CRR) was 54% (95% confidence interval: 31-76%). Compared with the placebo group, the thalidomide group had higher odds of overall response rate (odds ratio = 20.4; 95% CI: 6.75-61.64) and complete response rate (odds ratio = 20.4; 95% CI: 6.75-61.64). A statistically significant increase in hemoglobin level and HbF level after treatment, while there was no statistically significant difference in adult hemoglobin (HbA) level, spleen size, and serum ferritin. According to the results of ORR and CRR, transfusion-dependent thalassemia (TDT) patients showed remarkable efficacy of thalidomide, 83 and 52% respectively. So we analyzed 30 transfusion-dependent thalassemia patients from three studies and found that the most frequent ß-globin gene mutations were CD41-42 (-TCTT), while response to thalidomide did not show any statistically significant relationship with XmnI polymorphism or CD41-42 (-TCTT) mutation. About 30% of patients experienced mild adverse effects of thalidomide. Collectively, thalidomide is a relatively safe and effective therapy to reduce the blood transfusion requirements and to increase Hb level in patients with ß-thalassemia.
Project description:Objective:This study focused on the efficacy and safety of thalidomide for patients with ?-thalassemia in a multicenter trial. Methods:Patients with non-transfusion-dependent thalassemia (NTDT) or transfusion-dependent thalassemia (TDT), who were unable to pursue conventional therapy with transfusion and chelation, were recruited over 3 years in three centers in southern China. We evaluated the efficacy and safety of thalidomide in the short-term (three months) and long-term follow-up (12 and 24 months). Response to thalidomide was defined as follows: Main Responder (MaR) showing an increase in hemoglobin (Hb) level of >2.0 g/dl or free from blood transfusion and Minor Responder (MiR) achieving elevated Hb level of 1.0-2.0 g/dl or ?50% reduction in blood transfusion frequency. Results:The overall response rate (ORR) was 93.5%, with MaR and MiR rates accounting for 62.9% and 30.6% in short-term follow-up. For patients with NTDT, the Hb level increased from a baseline mean of 6.8±1.1 g/dl to 9.7±1.9 g/dl (P<0.001). Elevated Hb was mainly attributable to increased fetal hemoglobin (HbF) levels. Among patients with TDT, while an increase in the average Hb concentration was observed, there was a significant drop in yearly transfusions from 20.7±7.7 to 5.8±6.8 blood units per year (P<0.001). The response of patients in both categories was sustained even after an average follow up of 14.6±9.6 months (3-37 months). Minimal side-effects were documented throughout, except peripheral neurotoxicity in one patient. Logistic regression analysis identified the ratio of HbF at baseline (P=0.038, OR=1.111, 95% CI: 1.006-1.226) as an independent risk factor for the primary response to thalidomide. Conclusion:Thalidomide had significant therapeutic effects on patients with ?-thalassemia with a sustained response. Peripheral neuropathy is one of the most feared complications. While these preliminary results support the potential long-term efficacy of thalidomide as a therapeutic agent for ?-thalassemia, several issues need to be addressed before its application in the clinic.
Project description:OBJECTIVE:The aim of the study was to explore genotype distribution thalassemia and G6PD deficiency in Meizhou city, China. METHODS:A total of 16 158 individuals were involved in thalassemia genetic testing. A total of 605 subjects were screened for common Chinese G6PD mutations by gene chip analysis. Genotypes and allele frequencies were analyzed. RESULTS:A total of 5463 cases carried thalassemia mutations were identified, including 3585 cases, 1701 cases, and 177 cases with ?-, ?-, and ? + ?-thalassemia mutations, respectively. --SEA (65.12%), -?3.7 (19.05%), and -?4.2 (8.05%) deletion were the main mutations of ?-thalassemia, while IVS-II-654(C ? T) (40.39%), CD41-42(-TCTT) (32.72%), -28(A ? G) (10.11%), and CD17(A ? T) (9.32%) mutations were the principal mutations of ?-thalassemia in Meizhou. There were significant differences in allele frequencies in some counties. Genetic testing for G6PD deficiency, six mutation sites, and one polymorphism were detected in our study. A total of 198 alleles with the mutation were detected among 805 alleles (24.6%). G6PD Canton (c.1376 G ? T) (45.96%), G6PD Kaiping (c.1388 G ? A) (39.39%), and G6PD Gaohe (c.95 A ? G) (9.09%) account for 94.44% mutations, followed by G6PD Chinese-5 (c.1024 C ? T) (4.04%), G6PD Viangchan (c.871G ? A) (1.01%), and G6PD Maewo (c.1360 C ? T) (0.51%). There were some differences of the distribution of G6PD mutations among eight counties in Meizhou. CONCLUSIONS:The --SEA , -?3.7 , and -?4.2 deletion were the main mutations of ?-thalassemia, while IVS-II-654(C ? T), CD41-42(-TCTT), -28(A ? G), and CD17(A ? T) mutations were the principal mutations of ?-thalassemia in Meizhou. G6PD c.1376 G ? T, c.1388 G ? A, and c.95 A ? G were the main mutations of G6PD deficiency. There were some differences of the distribution of thalassemia and G6PD mutations among eight counties in Meizhou.
Project description:Pharmacologic induction of fetal hemoglobin (HbF) expression is an effective treatment strategy for sickle cell disease (SCD) and ?-thalassemia. Pomalidomide is a potent structural analog of thalidomide and member of a new class of immunomodulatory drugs. Recent reports demonstrated that pomalidomide reduced or eliminated transfusion requirements in certain hematologic malignancies and induced HbF ex vivo in CD34(+) progenitor cells from healthy and SCD donors. We investigated the effects of pomalidomide on erythropoiesis and hemoglobin synthesis in a transgenic mouse model of SCD. We found that 8 weeks of treatment with pomalidomide induced modest increases of HbF with similar efficacy as hydroxyurea. However, in stark contrast to hydroxyurea's myelosuppressive effects, pomalidomide augmented erythropoiesis and preserved bone marrow function. Surprisingly, combinatory therapy with both drugs failed to mitigate hydroxyurea's myelotoxic effects and caused loss of HbF induction. These findings support further evaluation of pomalidomide as a novel therapy for SCD.
Project description:<h4>Background</h4>Thalassemia is a group of inherited autosomal recessive hemolytic anemia disease caused by reduced or absent synthesis of globin chain/chains of hemoglobin. Only few studies showed the molecular characterization of α- and β-thalassemia in Meizhou city of China.<h4>Methods</h4>A total of 22,401 individuals were collected; hematological and hemoglobin electrophoresis analysis and thalassemia genetic testing were performed.<h4>Results</h4>Eleven thousand and thirty (49.24%) cases with microcytosis (mean corpuscular volume (MCV) < 82 fl), 11,074 (49.44%) cases with hypochromia (mean corpuscular Hb (MCH) < 27 pg) in 22,401 subjects, 11,085 cases with abnormal hemoglobin results were identified in subjects aged ≥6 months. 7,322 (32.69%) subjects harbored thalassemia mutations, including 4,841 (21.61%) subjects with α-thalassemia, 2,237 (9.99%) with β-thalassemia, and 244 (1.09%) with α-thalassemia combined β-thalassemia. 18 genotypes of α-thalassemia mutations and 27 genotypes of β-thalassemia mutations were characterized. The most frequent α gene mutation was --<sup>SEA</sup> (64.69%), followed by -α<sup>3.7</sup> (19.93%), -α<sup>4.2</sup> (7.73%), α<sup>CS</sup> α (3.97%), and α<sup>WS</sup> α (2.83%). The six most common β-thalassemia mutations were IVS-II-654 (C>T) (39.79%), CD41-42 (-TCTT) (33.02%), -28 (A>G) (10.38%), CD17 (A>T) (9.08%), CD27-28 (+C) (2.14%), and CD26 (G>A) (2.02%). In addition, MCV and MCH were sensitive markers for α- and β-thalassemia except for -α<sup>3.7</sup> /αα, -α<sup>4.2</sup> /αα, α<sup>CS</sup> α/αα, α<sup>WS</sup> α/αα, and β<sup>Cap+40-43</sup> /β<sup>N</sup> .<h4>Conclusions</h4>The --<sup>SEA</sup> , -α<sup>3.7</sup> , and -α<sup>4.2</sup> deletions were the main mutations of α-thalassemia, while IVS-II-654 (C>T), CD41-42 (-TCTT), -28 (A>G), and CD17 (A>T) mutations of β-thalassemia in Meizhou. There were some differences in thalassemia mutation frequencies in Meizhou city from other populations in China.
Project description:BACKGROUND Higher fetal hemoglobin (HbF) levels can ameliorate the clinical severity of ß-thalassemia. The use of integrative strategies to combine results from gene microarray expression profiling, experimental evidence, and bioinformatics helps reveal functional long noncoding RNAs (lncRNAs) in ß-thalassemia and HbF induction. MATERIAL AND METHODS In a previous study, a microarray profiling was performed of 7 individuals with high HbF levels and 7 normal individuals. Thirteen paired samples were used for validation. lncRNA NR_001589 and uc002fcj.1 were chosen for further research. The quantitative reverse transcription-PCR was used to detect the expression levels of 2 lncRNAs. The Spearman correlation test was employed. The nuclear and cytoplasmic distribution experiment in K562 cells was used to verify the subcellular localization of 2 lncRNAs. Potential relationships among lncRNAs, predicted microRNAs (miRNAs), and target gene HBG1/2 were based on competitive endogenous RNA theory and bioinformatics analysis. RESULTS Average expression levels of NR_001589 and uc002fcj.1 were significantly higher in the high-HbF group than in the control group. A positive correlation existed between NR_001589, uc002fcj.1, and HbF. The expression of NR_001589 was in both the cytoplasm and the nucleus, mostly (77%) in the cytoplasm. The expression of uc002fcj.1 was in both the cytoplasm and the nucleus; the cytoplasmic proportion was 43% of the total amount. A triple lncRNA-miRNA-mRNA network was established. CONCLUSIONS Novel candidate genetic factors associated with the HBG1/2 expression were identified. Further functional investigation of NR_001589 and uc002fcj.1 can help deepen the understanding of molecular mechanisms in ß-thalassemia.
Project description:Background and Objectives. ?-Thalassemia and sickle cell disease are genetic disorders characterized by reduced and abnormal ?-globin chain production, respectively. The elevation of fetal hemoglobin (HbF) can ameliorate the severity of these disorders. In sickle cell disease patients, the HbF level elevation is associated with three quantitative trait loci (QTLs), BCL11A, HBG2 promoter, and HBS1L-MYB intergenic region. This study elucidates the existence of the variants in these three QTLs to determine their association with HbF levels of transfusion-dependent Saudi ?-thalassemia patients. Materials and Methods. A total of 174 transfusion-dependent ?-thalassemia patients and 164 healthy controls from Eastern Province of Saudi Arabia were genotyped for fourteen single nucleotide polymorphisms (SNPs) from the three QTL regions using TaqMan assay on real-time PCR. Results. Genotype analysis revealed that six alleles of HBS1L-MYB QTL (rs9376090C p = 0.0009, rs9399137C p = 0.008, rs4895441G p = 0.004, rs9389269C p = 0.008, rs9402686A p = 0.008, and rs9494142C p = 0.002) were predominantly associated with ?-thalassemia. In addition, haplotype analysis revealed that haplotypes of HBS1L-MYB (GCCGCAC p = 0.022) and HBG2 (GTT p = 0.009) were also predominantly associated with ?-thalassemia. Furthermore, the HBS1L-MYB region also exhibited association with the high HbF cohort. Conclusion. The stimulation of HbF gene expression may provide alternative therapies for the amelioration of the disease severity of ?-thalassemia.
Project description:BACKGROUND:ß-thalassemia is one of the most common inherited blood disorders in the world and a major deterrent to the public health of Bangladesh. The management of thalassemia patients requires lifelong frequent blood transfusion and the available treatment options are unsatisfactory. A national policy on thalassemia prevention is mandatory in Bangladesh. However, precise and up-to-date information on the frequency of ß-thalassemia carriers are missing due to lack of accurate diagnostic approaches, limited access to information and absence of national screening program. This study aims to determine the nationwide carrier frequency of hemoglobin E (HbE) and ?- thalassemia and mutation spectrum among the carriers using molecular, hematological and biochemical methods. METHODS:The study enrolled a total of 1877 individuals (60.1% male and 39.9% female) aged between 18 and 35?years. Total sample size and its division-wise breakdown were calculated in proportion to national and division-wise population. Venous blood was collected and subjected to CBC analysis and Hb-electrophoresis for each participant. Serum ferritin was measured to detect coexistence of iron deficiency anemia with thalassemia carrier. DNA-based High Resolution Melting (HRM) curve analysis was performed for confirmation of carrier status by mutation detection. RESULTS:Of 11.89% (95% CI, 10.43-13.35) carriers of ?-globin gene mutations, 8.68% (95% CI, 7.41-9.95) had HbE trait (ETT) and 2.24% (95% CI, 1.57-2.91) had beta-thalassemia trait (BTT). Among eight divisions, Rangpur had the highest carrier frequency of 27.1% (ETT-25%, BTT-2.1%), whereas Khulna had the lowest frequency of 4.2% (ETT-4.2% only). Moreover, ?- thalassemia, HbD trait, HbE disease, hereditary persistence of HbF were detected in 0.11, 0.16, 0.43 and 0.16% participants, respectively. HRM could identify two individuals with reported pathogenic mutations in both alleles who were erroneously interpreted as carriers by hematological indices. Finally, a total of nine different mutations including a novel mutation (c.151A?>?G) were detected in the ?-globin gene. CONCLUSIONS:Since carrier frequency for both HbE and ?-thalassemia is alarmingly high in Bangladesh, a nationwide awareness and prevention program should be made mandatory to halt the current deteriorating situations. Mutation-based confirmation is highly recommended for the inconclusive cases with conventional carrier screening methods to avoid any faulty detection of thalassemia carriers.
Project description:Mutations in human Krüppel-like factor 1 (KLF1) have recently been reported to be responsible for increased fetal hemoglobin (HbF) and hemoglobin A2 (HbA2). Because increased HbF and HbA2 levels are important features of ?-thalassemia, we examined whether there is any relationship between KLF1 mutation and ?-thalassemia in China. To do this, we first studied the incidence of KLF1 mutations in 2 Chinese populations: 3839 individuals from a thalassemia endemic region in south China and 1190 individuals from a non-thalassemia endemic region in north China. Interestingly, we found that the prevalence of KLF1 mutations is significantly higher in the thalassemia endemic region than that in non-thalassemia endemic region (1.25% vs 0.08%). Furthermore, we identified 7 functional variants including 4 previously reported (p.Gly176AlafsX179, p.Ala298Pro, p.Thr334Arg, and c.913+1G>A) and 3 novel variants (p.His299Asp, p.Cys341Tyr, and p.Glu5Lys) in southern China. The 2 most common mutations, p.Gly176AlafsX179 and p.His299Asp, accounted for 90.6% of the total. We found that zinc-finger mutations in KLF1 were selectively represented in 12 ?-thalassemia intermedia patients and resulted in significantly different transfusion-free survival curves. Our findings suggest that KLF1 mutations occur selectively in the presence of ?-thalassemia to increase the production of HbF, which in turn ameliorates the clinical severity of ?-thalassemia.
Project description:Increase of the expression of ?-globin gene and high production of fetal hemoglobin (HbF) in ?-thalassemia patients is widely accepted as associated with a milder or even asymptomatic disease. The search for HbF-associated polymorphisms (such as the XmnI, BCL11A and MYB polymorphisms) has recently gained great attention, in order to stratify ?-thalassemia patients with respect to expectancy of the first transfusion, need for annual intake of blood, response to HbF inducers (the most studied of which is hydroxyurea).A?-globin gene sequencing was performed on genomic DNA isolated from a total of 75 ?-thalassemia patients, including 31 ?039/?039, 33 ?039/?+IVSI-110, 9 ?+IVSI-110/?+IVSI-110, one ?0IVSI-1/?+IVSI-6 and one ?039/?+IVSI-6.The results show that the rs368698783 polymorphism is present in ?-thalassemia patients in the 5'UTR sequence (+25) of the A?-globin gene, known to affect the LYAR (human homologue of mouse Ly-1 antibody reactive clone) binding site 5'-GGTTAT-3'. This A?(+25 G->A) polymorphism is associated with the G?-globin-XmnI polymorphism and both are linked with the ?039-globin gene, but not with the ?+IVSI-110-globin gene. In agreement with the expectation that this mutation alters the LYAR binding activity, we found that the A?(+25 G->A) and G?-globin-XmnI polymorphisms are associated with high HbF in erythroid precursor cells isolated from ?039/?039 thalassemia patients.As a potential explanation of our findings, we hypothesize that in ?-thalassemia the G?-globin-XmnI/A?-globin-(G->A) genotype is frequently under genetic linkage with ?0-thalassemia mutations, but not with the ?+-thalassemia mutation here studied (i.e. ?+IVSI-110) and that this genetic combination has been selected within the population of ?0-thalassemia patients, due to functional association with high HbF. Here we describe the characterization of the rs368698783 (+25 G->A) polymorphism of the A?-globin gene associated in ?039 thalassemia patients with high HbF in erythroid precursor cells.
Project description:The introduction of regular red cell transfusions 60 years ago transformed ?-thalassemia major from a fatal childhood illness into a chronic disorder. Further advances in the prevention of transfusion-transmitted infections and management of iron overload have allowed survival and quality of life to approach normal. However, transfusion therapy for some other thalassemia syndromes continues to challenge clinical decision-making. Nearly one-half of the patients with E ß thalassemia are transfusion-dependent, yet the criteria for initiating transfusions or hemoglobin targets are not well defined. Patients with thalassemia intermedia who begin transfusions as adults are at very high risk for developing red cell alloimmunization and serious hemolytic transfusion reactions. In the growing number of survivors of Bart hydrops fetalis, the approach to transfusion therapy and iron chelation is rapidly evolving. A collaboration between hematology and transfusion medicine specialists will be essential to improving patient care and developing evidence-based guidelines.