Factors affecting health-related quality of life in Thai children with thalassemia

<p>Abstract</p> <p>Background</p> <p>Knowledge of the factors associated with health-related quality of life (HRQOL) among patients with thalassemia is essential in developing more suitable clinical, counseling, and social support programs to improve treatment outcomes of these patients. In light of the limited research in this area, this study aims to examine factors associated with HRQOL among children and adolescents with thalassemia in Thailand.</p> <p>Methods</p> <p>A cross-sectional survey was conducted in three selected hospitals in Thailand during June to November 2006. PedsQL™ 4.0 Generic Core Scale (Thai version) was used to assess HRQOL in 315 thalassemia patients between 5 and 18 years of age. Other related clinical characteristics of the patients were collected via medical record review.</p> <p>Results</p> <p>The mean (SD) of the total summary score was 76.67 (11.40), while the means (SD) for the Physical Health Summary score and Psychosocial Health Summary score were 78.24 (14.77) and 75.54 (12.76), respectively. The school functioning subscale scored the lowest, with a mean of 67.89 (SD = 15.92). The following factors significantly affected the HRQOL of the patients: age; age at onset of anemia and age at first transfusion; pre-transfusion hemoglobin (Hb) level; receiving a blood transfusion during the previous three months; and disease severity. In addition, iron chelation therapy had a significant negative effect on HRQOL in the school functioning subscale. In contrast, serum ferritin level, frequency of blood transfusions per year, and gender were not significantly related to HRQOL among these patients. The results from multivariate analysis also confirmed these findings.</p> <p>Conclusions</p> <p>To improve HRQOL of thalassemia patients, suitable programs aimed at providing psychosocial support and a link between the patient, school officials, the family and the physician are important, especially in terms of improving the school functioning score. The findings also confirmed the importance of maintaining a pre-transfusion Hb level of at least 9-10.5 g/dL. In addition, special care and attention should be given to patients with a severe condition, and those who are receiving subcutaneous iron chelation therapy.</p

The molecular basis of beta-thalassemia intermedia in southern China: genotypic heterogeneity and phenotypic diversity

<p>Abstract</p> <p>Background</p> <p>The clinical syndrome of thalassemia intermedia (TI) results from the β-globin genotypes in combination with factors to produce fetal haemoglobin (HbF) and/or co-inheritance of α-thalassemia. However, very little is currently known of the molecular basis of Chinese TI patients.</p> <p>Methods</p> <p>We systematically analyzed and characterized β-globin genotypes, α-thalassemia determinants, and known primary genetic modifiers linked to the production of HbF and the aggravation of α/β imbalance in 117 Chinese TI patients. Genotype-phenotype correlations were analyzed based on retrospective clinical observations.</p> <p>Results</p> <p>A total of 117 TI patients were divided into two major groups, namely heterozygous β-thalassemia (n = 20) in which 14 were characterized as having a mild TI with the Hb levels of 68-95 g/L except for five co-inherited ααα^anti-3.7triplication and one carried a dominant mutation; and β-thalassemia homozygotes or compound heterozygotes for β-thalassemia and other β-globin defects in which the β⁺-thalassemia mutation was the most common (49/97), hemoglobin E (HbE) variants was second (27/97), and deletional hereditary persistence of fetal hemoglobin (HPFH) or δβ-thalassemia was third (11/97). Two novel mutations, Term CD+32(A→C) and Cap+39(C→T), have been detected.</p> <p>Conclusions</p> <p>Chinese TI patients showed considerable heterogeneity, both phenotypically and genotypically. The clinical outcomes of our TI patients were mostly explained by the genotypes linked to the β- and α-globin gene cluster. However, for a group of 14 patients (13 β⁰/β^Nand 1 β⁺/β^N) with known heterozygous mutations of β-thalassemia and three with homozygous β-thalassemia (β⁰/β⁰), the existence of other causative genetic determinants is remaining to be molecularly defined.</p

The Cardiac Transcription Network Modulated by Gata4, Mef2a, Nkx2.5, Srf, Histone Modifications, and MicroRNAs

The transcriptome, as the pool of all transcribed elements in a given cell, is regulated by the interaction between different molecular levels, involving epigenetic, transcriptional, and post-transcriptional mechanisms. However, many previous studies investigated each of these levels individually, and little is known about their interdependency. We present a systems biology study integrating mRNA profiles with DNA–binding events of key cardiac transcription factors (Gata4, Mef2a, Nkx2.5, and Srf), activating histone modifications (H3ac, H4ac, H3K4me2, and H3K4me3), and microRNA profiles obtained in wild-type and RNAi–mediated knockdown. Finally, we confirmed conclusions primarily obtained in cardiomyocyte cell culture in a time-course of cardiac maturation in mouse around birth. We provide insights into the combinatorial regulation by cardiac transcription factors and show that they can partially compensate each other's function. Genes regulated by multiple transcription factors are less likely differentially expressed in RNAi knockdown of one respective factor. In addition to the analysis of the individual transcription factors, we found that histone 3 acetylation correlates with Srf- and Gata4-dependent gene expression and is complementarily reduced in cardiac Srf knockdown. Further, we found that altered microRNA expression in Srf knockdown potentially explains up to 45% of indirect mRNA targets. Considering all three levels of regulation, we present an Srf-centered transcription network providing on a single-gene level insights into the regulatory circuits establishing respective mRNA profiles. In summary, we show the combinatorial contribution of four DNA–binding transcription factors in regulating the cardiac transcriptome and provide evidence that histone modifications and microRNAs modulate their functional consequence. This opens a new perspective to understand heart development and the complexity cardiovascular disorders

Genetic modifiers of Hb E/β⁰thalassemia identified by a two-stage genome-wide association study

<p>Abstract</p> <p>Background</p> <p>Patients with Hb E/β⁰thalassemia display remarkable variability in disease severity. To identify genetic modifiers influencing disease severity, we conducted a two-stage genome scan in groups of 207 mild and 305 severe unrelated patients from Thailand with Hb E/β⁰thalassemia and normal α-globin genes.</p> <p>Methods</p> <p>First, we estimated and compared the allele frequencies of approximately 110,000 gene-based single nucleotide polymorphisms (SNPs) in pooled DNAs from different severity groups. The 756 SNPs that showed reproducible allelic differences at <it>P </it>< 0.02 by pooling were selected for individual genotyping.</p> <p>Results</p> <p>After adjustment for age, gender and geographic region, logistic regression models showed 50 SNPs significantly associated with disease severity (<it>P </it>< 0.05) after Bonferroni adjustment for multiple testing. Forty-one SNPs in a large LD block within the β-globin gene cluster had major alleles associated with severe disease. The most significant was bthal_bg200 (odds ratio (OR) = 5.56, <it>P </it>= 2.6 × 10^-13). Seven SNPs in two distinct LD blocks within a region centromeric to the β-globin gene cluster that contains many olfactory receptor genes were also associated with disease severity; rs3886223 had the strongest association (OR = 3.03, <it>P </it>= 3.7 × 10^-11). Several previously unreported SNPs were also significantly associated with disease severity.</p> <p>Conclusions</p> <p>These results suggest that there may be an additional regulatory region centromeric to the β-globin gene cluster that affects disease severity by modulating fetal hemoglobin expression.</p

Integrative proteome and transcriptome analysis of extramedullary erythropoiesis and its reversal by transferrin treatment in a mouse model of Beta-thalassemia

Beta-thalassemia results from mutations of the β-hemoglobin (Hbb) gene and reduced functional Hbb synthesis. Excess α-Hb causes globin chain aggregation, oxidation, cytoskeletal damage, and increased red blood cell clearance. These events result in anemia, altered iron homeostasis, and expansion of extramedullary erythropoiesis. Serum transferrin (Tf) is suggested to be an important regulator of erythropoiesis in murine models of thalassemia. The present study was conducted to establish a quantitative proteomic and transcriptomic analysis of transferrin-modulated extramedullary erythropoiesis in the spleen of wild type and thalassemic Hbb(th3/+) mice. Our LC-MS/MS protein analysis and mRNA sequencing data provide quantitative expression estimates of 1590 proteins and 24 581 transcripts of the murine spleen and characterize key processes of erythropoiesis and RBC homeostasis such as the whole heme synthesis pathway as well as critical components of the red blood cell antioxidant systems and the proliferative cell cycling pathway. The data confirm that Tf treatment of nontransfused Hbb(th3/+) mice induces a systematic correction of these processes at a molecular level. Tf treatment of Hbb(th3/+) mice for 60 days leads to a complete molecular restoration of the normal murine spleen phenotype. These findings support further investigation of plasma-derived Tf as a treatment for thalassemia