RESUMO
OBJECTIVES: Hemoglobinopathies, including thalassemia and hemoglobin (Hb) variants, are common hematological disorders in tropical countries. Accurate and precise separation of hemoglobin types and reliable quantitation are necessary for differential diagnosis of these disorders. METHODS: We have evaluated the analytical performances of premier resolution-high-performance liquid chromatography (PR-HPLC; Trinity Biotech, Co. Wicklow, Ireland) to assist in the presumptive diagnosis of thalassemia and Hb variants commonly found in Southeast Asian countries. HbA0, HbA2, HbE, and HbF levels were separated and quantified in 120 blood samples from unrelated adult subjects and compared with those analyzed by capillary zone electrophoresis (CZE; CAPILLARYS™ 2, Sebia, Norcross, GA, US). The Hb analysis patterns of Hb variants obtained from the PR-HPLC system were also compared to those obtained from HPLC (VARIANT II, ß-thalassemia Short Program, Bio-Rad, Laboratories, Hercules, CA, US) and CZE systems. RESULTS: The PR-HPLC had excellent precision with a coefficient of variation (CV) for HbA2 quantitation of 3.8â¯% within-run and 5.2â¯% between-run. The levels of HbA2/E quantified by the PR-HPLC system correlated well with those of the CZE system (r=0.997). In addition, thalassemia interpretation results obtained from the PR-HPLC and the CZE showed 100â¯% agreement. Moreover, chromatograms of the PR-HPLC were also comparable to those of VII-HPLC and CAP2-CZE electropherograms. CONCLUSIONS: The PR-HPLC system would be applicable to diagnose common forms of thalassemia and Hb variants in Southeast Asia.
Assuntos
Eletroforese Capilar , Humanos , Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Hemoglobinas Anormais/análise , Hemoglobina A2/análise , Hemoglobina E/análise , Hemoglobinopatias/diagnóstico , Hemoglobinopatias/sangue , Hemoglobina Fetal/análise , AdultoRESUMO
The study aimed to identify essential phenotype-modulating factors among the pre-existence of several important ones and clarify their measurable impact on the clinical severity of hemoglobin (Hb) E/ß-thalassemia in a community-recruited population analysis. This prospective study was designed to compare modifiers between community- (less or no symptoms) and hospital-recruited individuals with Hb E/ß-thalassemia. The formerly included couples previously assessed for prenatal thalassemia at-risk status at 42 community and 7 referral hospitals in Thailand through on-site investigations between June 2020 and December 2021. The control included Hb E/ß-thalassemia patients undergoing transfusions. The Mahidol score classified disease severity. Beta-globin, α0-thalassemia (-SEA, -THAI), α+-thalassemia (-α3.7, -α4.2), Hb Constant Spring (αCS) alleles, rs766432 in BCL11A, rs9399137 in HBS1L-MYB, and rs7482144-XmnI were evaluated. Modifiers were compared between 102 community- and 104 hospital-recruited cases. Alleles of ß+, -SEA, -α3.7, αCS, and a minor allele of rs9399137 were prevalent in the community and mild severity groups (p < 0.05). Multiple linear regression analysis associated modulating alleles with -4.299 (-SEA), -3.654 (ß+), -3.065 (rs9399137, C/C), -2.888 (αCS), -2.623 (-α3.7), -2.361 (rs7482144, A/A), -1.258 (rs9399137, C/T), and -1.174 (rs7482144, A/G) severity score reductions (p < 0.05). Certain modifiers must be considered in routine prenatal genetic counseling for Hb E/ß-thalassemia.
Assuntos
Hemoglobina E , Talassemia alfa , Talassemia beta , Humanos , Talassemia beta/epidemiologia , Talassemia beta/genética , Talassemia beta/terapia , Hemoglobina E/genética , Hemoglobina E/análise , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Aconselhamento Genético , Talassemia alfa/epidemiologia , Talassemia alfa/genética , Talassemia alfa/terapia , GenótipoRESUMO
OBJECTIVE: To detect mutation in cases having haemoglobin A2 level >7% on high performance liquid chromatography. METHODS: The cross-sectional, descriptive study was conducted from July 2017 to December 2018 at the Department of Haematology and Human Genetics and Molecular Biology, University of Health Sciences, Lahore, Pakistan, and comprised patients of either gender with haemoglobin A2 ≥7%. The samples were collected from different cities of Punjab in collaboration with the Punjab Thalassemia Prevention Programme, Lahore. The samples were subjected to complete blood count and high performance liquid chromatography using automated haematology analysers and variant-II beta thalassemia short programme, respectively. To analyse haemoglobin E mutations at the molecular level, polymerase chain reaction-restriction fragment length polymorphism (PCR_RFLP) was performed using a type IIS restriction endonuclease known as Mnl1 (derived from Moraxella nonliquefaciens) to cleave DNA at specific sites and the results were further confirmed on randomly selected samples using Sanger sequencing. Data was analysed using SPSS 25. RESULTS: Of the 39 patients, 15(38.5%) were males and 24(61.5%) were females. The overall median age was 14 (23) years. There were 29 (74.4%) patients with thalassemia family history, and 22(56.4%) had a positive family history of transfusion related to thalassemia, while no patient had a family history of iron therapy. The median haemoglobin A, haemoglobin A2 and haemoglobin F levels were 72.2 (65.2-79.1) %, 26.6 (19.1-34.0) % and 0.9 (-0.8-2.6) %, respectively. After molecular investigation, HbAE mutation was found in 23(59%) patients, while wild type HbAA genotype was found in 16(41%). The heterozygous HbE mutation was present in 23(59%) patients. CONCLUSIONS: Frequently missed/undiagnosed cases of haemoglobin E that co-elute with haemoglobin A2 in the same high performance liquid chromatography window were detected among those with haemoglobin A2 ≥7%.
Assuntos
Hemoglobina E , Talassemia , Talassemia beta , Masculino , Feminino , Humanos , Adolescente , Hemoglobina E/genética , Hemoglobina E/análise , Hemoglobina A2/análise , Hemoglobina A2/genética , Estudos Transversais , Genótipo , Talassemia beta/epidemiologia , Talassemia beta/genética , MutaçãoRESUMO
BACKGROUND: Thalassemia is a common genetic disease in Southeast Asia. Red blood cell (RBC) transfusion is an essential treatment for severe forms of thalassemia. We performed a study to demonstrate RBC alloimmunization and other transfusion-related complications in patients with transfusion-dependent thalassemia (TDT). STUDY DESIGN AND METHODS: A multi-center web-based registry of TDT was conducted in eight medical centers across Thailand. Thalassemia information, transfusion therapy, and transfusion-related complications were collected. Factors associated with each complication were demonstrated using the logistic regression analysis. RESULTS: Of 1000 patients recruited for the study, 449 were males (44.9%). The mean age was 23.9 ± 15.4 years. The majority of patients, 738 (73.8%) had hemoglobin E/beta-thalassemia. In the study, 421 transfusion-related complications were reported from 357 patients (35.7%). Alloimmunization was the most common complication which was found in 156 patients (15.6%) with 284 positive antibody tests. The most frequent antibodies against RBC were anti-E (80/284, 28.2%) followed by anti-Mia (45/284, 15.8%) and anti-c (32/284, 11.3%). Age ≥3 years at initial blood transfusion, splenomegaly, higher frequencies, and volumes of transfusion were significant factors associated with alloimmunization. None of the patients had to terminate blood transfusion due to multiple alloantibodies. Other commonly seen complications were allergic reactions (130, 13.0%), autoimmune hemolytic anemia (70, 7.0%) and febrile non-hemolytic transfusion reaction (54, 5.4%). CONCLUSIONS: Transfusion-related complications, especially alloimmunization, were common among Thai patients with TDT. Extended RBC antigen-matching for the Rh system and Mia should be implemented to prevent the development of alloantibodies in multi-transfused patients.
Assuntos
Anemia Hemolítica Autoimune , Hemoglobina E , Talassemia , Reação Transfusional , Adolescente , Adulto , Criança , Pré-Escolar , Eritrócitos , Feminino , Hemoglobina E/análise , Humanos , Isoanticorpos , Masculino , Tailândia/epidemiologia , Talassemia/complicações , Talassemia/terapia , Adulto JovemRESUMO
INTRODUCTION: Hemoglobin (Hb)-F inducers are known to improve Hb level and transfusion dependence in thalassemia. This pilot study was conducted to assess the efficacy and safety of Hb-F inducer thalidomide compared to hydroxyurea (HU) in Hb E-ß thalassemia patients. METHODS: This was a prospective interventional single-centre study with 45 Hb E-beta thalassemia patients equally divided into group-I (thalidomide+folic acid), group-II (HU + folic acid) and group-III (folic acid). Response was assessed at various time intervals with 12-months follow up period. Primary end points were increment in Hb, Hb-F level and improvement in transfusion requirement; secondary end point were tolerability and safety. RESULTS: There was 100% responder (R: Hb-increment ≥1 g/dl) in group-I with 66.67% major responder (MaR: Hb-increment ≥2 g/dl), while there were 40% and 0% responder in group-II and III respectively. Hb-increment was significantly (p-value <0.0001) better in thalidomide arm compared to HU. The Hb-increment was attributable to both increase in Hb-F levels and reduction in ineffective erythropoiesis in thalidomide arm. Transfusion reduction was significantly better in group-I compared to group-II (100% vs 34%). No severe adverse effects was reported by patients of any group. CONCLUSION: Thalidomide showed a persistent significant Hb-increment and transfusion independence in Hb E-ß thalassemia patients compared to HU.
Assuntos
Antidrepanocíticos/uso terapêutico , Hidroxiureia/uso terapêutico , Imunossupressores/uso terapêutico , Talidomida/uso terapêutico , Talassemia beta/tratamento farmacológico , Adolescente , Adulto , Antidrepanocíticos/efeitos adversos , Criança , Feminino , Hemoglobina E/análise , Hemoglobinas/análise , Humanos , Hidroxiureia/efeitos adversos , Imunossupressores/efeitos adversos , Índia/epidemiologia , Masculino , Projetos Piloto , Estudos Prospectivos , Centros de Atenção Terciária , Talidomida/efeitos adversos , Adulto Jovem , Talassemia beta/sangue , Talassemia beta/epidemiologiaRESUMO
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.
Assuntos
Eritroblastos/metabolismo , Hemoglobina E/análise , Talassemia beta/patologia , Receptores de Activinas Tipo II/genética , Receptores de Activinas Tipo II/metabolismo , Adolescente , Adulto , Apoptose , Estudos de Casos e Controles , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Eritroblastos/citologia , Eritropoese , Feminino , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Hemoglobina E/genética , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Adulto Jovem , Talassemia beta/genéticaRESUMO
INTRODUCTION: Knowledge on frequency of carrier status of thalassaemia in a country is very important to form a plan of reducing the disease burden. In Sri Lanka, the amount of research done regarding the topic is insufficient considering the amount of thalassaemia carriers who are being detected island wide, which is increasing in numbers annually. Kurunegala is one of the districts in Sri Lanka where thalassaemia is prevalent. OBJECTIVES: To determine the prevalence of and factors associated with ß - thalassaemia trait and Hb E thalassaemia among school children aged 14-17 years in Kurunegala district. METHODOLOGY: Descriptive cross sectional study. Using probability proportional to size sampling technique, 55 clusters of 30 students in the age range 14-17 years each, were selected from all the schools in Kurunegala district. Within each school, the required number of children was selected randomly. RESULTS: Out of the participants (n=1821), 5.7% (104) were ß thalassaemia carriers and 1.2% (21) were Hb E carriers. CONCLUSION: The results of this study provided the true burden of ß thalassaemia trait and Hb E thalassemia in Kurunegala district. The study also revealed the distribution of ß thalassaemia trait and Hb E disorders within the district is not even. The frequency of thalassaemia showed a significant difference across ethnic groups in the district.
Assuntos
Hemoglobina E , Hemoglobinopatias , Talassemia beta , Adolescente , Estudos Transversais , Hemoglobina E/análise , Hemoglobina E/genética , Hemoglobinopatias/epidemiologia , Humanos , Prevalência , Sri Lanka/epidemiologia , Estudantes , Talassemia beta/epidemiologiaRESUMO
BACKGROUND: There is no external quality assessment (EQA) program for hemoglobin analysis that uses lyophilized hemoglobin control materials with HbA2/E in levels as high as those found in people with the ß-thalassemia trait, HbE trait, ß-thalassemia/HbE disease or homozygous HbE; these are all found frequently in the southeast Asian population. The aim of this study was to evaluate the efficiency of the control materials used in the established proficiency testing (PT) program at the Associated Medical Sciences-Clinical Service Center (AMC-CSC), Chiang Mai University, Chiang Mai, Thailand. METHODS: The PT program for Hb analysis and the thalassemia interpretation was established in compliance with ISO/IEC17043:2010. Three cycles per year were performed in 2015 and 2016. In each cycle, three different types of control material were provided to the participants. Each participant analyzed the control materials in the same manner as in their routine practices. Hb analysis results and their thalassemia interpretation codes were entered into the report form and sent back to AMC-CSC. RESULTS: The number of participants increased from 63 in 2015 to 76 in 2016. In addition, the number of participants who took part in all three cycles increased from 95.2% (60/63) in 2015 to 100% (76/76) in 2016. All participants reported the correct Hb measurement and type; however, misinterpretations in thalassemia diagnosis were noted. CONCLUSIONS: The lyophilized hemoglobin control materials prepared at AMC-CSC were used successfully in our PT program. However, the study results indicate the need for further improvement in thalassemia interpretation skills for laboratory staff.
Assuntos
Hemoglobina Fetal/análise , Hemoglobina A2/análise , Hemoglobina E/análise , Ensaio de Proficiência Laboratorial , Talassemia/diagnóstico , Humanos , TailândiaRESUMO
BACKGROUND: The objective of the study was to describe a formula based on hemoglobin (Hb)A2 and HbF levels for differentiation of homozygous HbE and HbE-ß-thalassemia. METHODS: A total of 1256 subjects suspected for homozygous HbE or HbE-ß0-thalassemia were recruited at the ongoing thalassemia screening program at Khon Kaen University, Thailand. Hb analysis was done using capillary electrophoresis. Genotyping was based on DNA analysis. An arbitrary formula based on HbA2 and HbF was developed statistically for differentiation of the two conditions. Validation was carried out prospectively on another 139 subjects encountered at routine laboratory. RESULTS: Among 1256 subjects, Hb and DNA analyses identified cases with homozygous HbE (n=1076, 85.7%), HbE-ß0-thalassemia (n=140, 11.1%), HbE-δß0-thalassemia (n=30, 2.4%) and unknown HbE-related disorder (n=10, 0.8%). An inverse correlation between the amounts of HbA2 and HbF in HbE-ß0-thalassemia was observed. With differences in the amounts of HbA2 and HbF between the groups, an arbitrary score (7.3 HbA2+HbF) was developed where score above 60 indicated HbE-ß0-thalassemia. Application of this score on another 139 subjects showed accurate prediction of HbE-ß0-thalassemia with 100% sensitivity, 96.5% specificity, 85.7% positive predictive value and 100% negative predictive value. Successful application onto couples at risk was demonstrated. CONCLUSIONS: An established score should prove useful in the differentiation of homozygous HbE and HbE-ß0-thalassemia in routine setting and lead to a significant reduction in number of referring cases for molecular testing.
Assuntos
Hemoglobina E/análise , Talassemia beta/diagnóstico , Área Sob a Curva , Análise Mutacional de DNA , Diagnóstico Diferencial , Eletroforese Capilar , Hemoglobina Fetal/análise , Genótipo , Hemoglobina A2/análise , Hemoglobina E/genética , Homozigoto , Humanos , Curva ROC , Sensibilidade e Especificidade , Talassemia beta/genéticaRESUMO
Variation of fetal hemoglobin (Hb F) expression in heterozygous Hb E (HBB: c.79G>A) individuals is associated with several genetic modifiers and not well understood. This study was undertaken in order to determine the effect of single nucleotide polymorphisms (SNPs), including XmnI Gγ (rs7482144), rs766432 on the BCL11A gene and rs9376074 on the HBS1L gene, on Hb F levels in Southern Thai heterozygous Hb E individuals. A total of 97 Southern Thai subjects carrying heterozygous Hb E were selected for the hematological study. After excluding the samples with α-thalassemia (α-thal) interaction or moderate anemia, because both conditions can affect the hematological parameters, the remaining 74 samples were submitted to SNP analysis. Hematological parameters were measured using an automated hematology analyzer and high performance liquid chromatography (HPLC). The results show that rs766432 was strongly associated with increased Hb F levels and rs7482144 was associated with Hb F levels in each subgroup (genotype) of rs766432. This study suggested that the BCL11A locus has a major effect on Hb F levels compared with the XmnI polymorphism in Hb E heterozygotes. This association of Hb F levels with SNPs is useful for the interpretation of hemoglobin (Hb) typing in heterozygous Hb E samples with high Hb F levels. Future research will need to address the better understanding of the mechanisms of the SNPs that regulate Hb F production without stress erythropoiesis in Hb E heterozygotes.
Assuntos
Hemoglobina Fetal/análise , Hemoglobina E/análise , Locos de Características Quantitativas , Genótipo , Heterozigoto , Humanos , Polimorfismo de Nucleotídeo Único , Tailândia/epidemiologiaRESUMO
Available and flexible choice of methods for screening and detecting ß-thalassemia (ß-thal) can promote control of thalassemia in developing countries. In this study, two methods, the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and reverse dot-blot hybridization assays were developed to detect common ß-thal mutations in 244 thalassemia patients and 152 healthy people in North Vietnam. The most common mutation was codon 26 (G>A), also known as Hb E (HBB: c.79G>A), accounting for 26.4% of the total studied chromosomes, followed by codons 41/42 (-TCTT) (HBB: c.126_129delCTTT) and codon 17 (A>T) (HBB: c.c.52A>T), accounting for 19.4 and 16.4%, respectively. In addition, codon 95 (+A) (HBB: c.c.287_288insA) that is known as the Vietnamese mutation, accounted for 0.6%. Moreover, the heterozygous state of the four mutations was also found in healthy people, of which Hb E was again the most common mutation with a frequency 3.0%. The results of this study provide available methods and indicative data for preventive and control strategies concerning the genetic diagnosis of thalassemia.
Assuntos
Mutação , Talassemia beta/genética , Códon , Feminino , Frequência do Gene , Hemoglobina E/análise , Heterozigoto , Humanos , Masculino , Vietnã/epidemiologia , Talassemia beta/diagnóstico , Talassemia beta/epidemiologiaRESUMO
This community-based study investigated anemia prevalence and certain hematologic features and their possible relationships to thalassemia and iron deficiency (ID) in a population of older people in Northeastern Thailand. Participants included 319 apparently healthy individuals ranging in age from 60 to 98 years, whose current health status was assessed by means of personal interviews. Blood samples were also collected to determine the following parameters: red blood cell indices, serum ferritin, C-reactive protein, hemoglobin profiles, and the α0-thalassemia gene. Based upon established WHO criteria, the overall prevalence of anemia was found to be 47.7%, increasing from 39% within the age group of 60-70 years to 68% in those >80 years. Factors considered to be significant contributors to anemia were classified as ID (3.6%), thalassemia (56.2%), and "unknown" (40.1%). Overall, only 2.4% of participants exhibited any ID. Hematologic changes appear to correlate with age. Our findings provide not only baseline information, potentially useful for implementing appropriate control measures, but also an enhanced awareness and understanding of the factors contributing to anemia among the elderly in the region.
Assuntos
Anemia Ferropriva/epidemiologia , Talassemia/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Proteína C-Reativa/análise , Feminino , Hemoglobina E/análise , Hemoglobinas/análise , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Prevalência , Tailândia/epidemiologiaRESUMO
INTRODUCTION: Haemoglobin Bart's (Hb Bart's) level is associated with α-thalassaemia traits in neonates, enabling early diagnosis of α-thalassaemia. The study aimed to detect and quantify the Hb Bart's using Cord Blood (CB) and CE Neonat Fast Hb (NF) progammes on fresh and dried blood spot (DBS) specimen respectively by capillary electrophoresis (CE). METHODS: Capillarys Hemoglobin (E) Kit (for CB) and Capillarys Neonat Hb Kit (for NF) were used to detect and quantify Hb Bart's by CE in fresh cord blood and dried blood spot (DBS) specimens respectively. High performance liquid chromatography (HPLC) using the ß-Thal Short Programme was also performed concurrently with CE analysis. Confirmation was obtained by multiplex ARMS Gap PCR. RESULTS: This study was performed on 600 neonates. 32/600 (5.3%) samples showed presence of Hb Bart's peak using the NF programme while 33/600 (5.5%) were positive with CB programme and HPLC methods. The range of Hb Bart's using NF programme and CB programme were (0.5-4.1%) and (0.5-7.1%), respectively. Molecular analysis confirmed all positive samples possessed α-thalassaemia genetic mutations, with 23/33 cases being αα/--SEA, four -α3.7/-α3.7, two αα/-α3.7 and three αα/ααCS. Fifty Hb Bart's negative samples were randomly tested for α-genotypes, three were also found to be positive for α-globin gene mutations. Thus, resulting in sensitivity of 91.7% and 88.9% and specificity of 100% for the Capillarys Cord Blood programme and Capillarys Neonat Fast programme respectively. CONCLUSION: Both CE programmes using fresh or dried cord blood were useful as a screening tool for α-thalassaemia in newborns. All methods show the same specificity (100%) with variable, but acceptable sensitivities in the detection of Hb Bart.
Assuntos
Eletroforese Capilar , Sangue Fetal/citologia , Hemoglobinas Anormais/metabolismo , Talassemia alfa/diagnóstico , Cordocentese , Eletroforese Capilar/métodos , Hemoglobina E/análise , Hemoglobina E/biossíntese , Humanos , Recém-Nascido , Talassemia beta/diagnósticoRESUMO
Hb E [ß26(B8)GluâLys; HBB: c.79G > A]-ß-thalassemia (ß-thal) has an extremely variable clinical presentation. We report the clinical features of these patients from five Indian states together with their hematological and molecular characteristics. Seventy-eight Hb E-ß-thal patients from different regions [West Bengal (30), Maharashtra (21), Uttar Pradesh (13), Bihar (11), Orissa (3)] were clinically evaluated along with hematological profiles and molecular characteristics (ß-thal mutations, XmnI polymorphisms, α genotypes). Twenty-nine of the 78 patients had a mild clinical presentation (clinical score 2.2 ± 1.1), while 15 had moderate severity (clinical score 6.1 ± 1.2) with occasional transfusion needs, and 34 patients were severely affected (clinical score 8.2 ± 0.5) requiring regular blood transfusions. The age at clinical presentation in the severely affected patients was lower (6 months-10 years) as compared to those with milder symptoms (2 years-34 years). Thirty-four patients showed splenomegaly (spleen ≥3 cm below the costal margin) and five patients were splenectomized. The severe ß+ IVS1-5 (G > C) (HBB: c.92 + 5G > C) was the most common ß-thal mutation, while seven other mutations were also seen. The XmnI [+/+] and [-/-] polymorphisms were seen in 24.1 and 10.3% of mildly affected patients and 14.7 and 17.6% of severely affected patients respectively. A single α gene deletion (-α3.7/αα) was found in 20.7% of mildly affected and 5.9% of severely affected patients, respectively. No specific differences in the clinical, hematological or molecular characteristics were observed in the Hb E-ß-thal patients from various geographic regions or different ethnic groups.
Assuntos
Hemoglobina E/análise , Mutação , Talassemia beta/genética , Adolescente , Adulto , Criança , Pré-Escolar , Deleção de Genes , Humanos , Índia/epidemiologia , Lactente , Epidemiologia Molecular , Índice de Gravidade de Doença , Esplenomegalia/etiologia , Esplenomegalia/cirurgia , Talassemia beta/complicações , Talassemia beta/epidemiologiaRESUMO
Clinical severity assessment and molecular analysis of ß-, α-globin genes and the -158 (C > T) XmnI polymorphism of the (G)γ-globin gene were performed in 80 pediatric patients with Hb E (HBB: c.79G > A)/ß-thalassemia (ß-thal) to investigate the effects of coinheritance of α-thalassemia (α-thal) and other molecular determinants on their clinical severity. The mean age was 9.4 ± 5.1 years. By using clinical severity score, 35 (43.8%), 27 (33.8%) and 18 cases (22.5%) had moderate, mild and severe disease, respectively. Nine ß-thal mutations were identified. All were ß° or severe ß⺠mutations. Five patients (6.3%) had coinherited α°-thal. All five patients had mild disease with baseline hemoglobin (Hb) values of 7.9 ± 1.5 g/dL, mild hepatosplenomegaly and close-to-normal growth. Only one required a red blood cell transfusion. The disease severity was significantly different among the groups with and without α-thal (p = 0.025), but was not different among the groups with or without the XmnI polymorphism (p = 0.071). This study demonstrates that coinheritance of α°-thal alleviates the degree of disease severity in Hb E/ß-thal. All our patients with coinherited α°-thal have mild disease.
Assuntos
Hemoglobina E/genética , Mutação , Polimorfismo Genético , alfa-Globinas/genética , Talassemia alfa/genética , Talassemia beta/genética , gama-Globinas/genética , Adolescente , Criança , Pré-Escolar , Códon , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Feminino , Estudos de Associação Genética , Hemoglobina E/análise , Hemoglobina E/metabolismo , Humanos , Lactente , Íntrons , Masculino , Mutação Puntual , Polimorfismo de Fragmento de Restrição , Estudos Retrospectivos , Deleção de Sequência , Índice de Gravidade de Doença , Tailândia , alfa-Globinas/análise , alfa-Globinas/metabolismo , Talassemia alfa/sangue , Talassemia alfa/complicações , Talassemia beta/sangue , Talassemia beta/complicações , Talassemia beta/fisiopatologia , gama-Globinas/análise , gama-Globinas/metabolismoRESUMO
We present 3 cases of discordant results from screening hemoglobin A1c (HbA1c) measured by ion-exchange high-performance liquid chromatography (HPLC) all due to various forms of interference and flagged by the instrument as "suspected hemoglobin E (HbE)." The first case was due to a rare hemoglobin variant, later confirmed to be hemoglobin Hoshida, the second due to "true" heterozygous HbE, and the third a result of analytical artifact causing splitting of the HbA1c peak without an underlying variant hemoglobin. We examine the similarities in these cases along with the laboratory work-up to classify each cause of interference to demonstrate the wide array of potential causes for the suspected HbE flag and why it warrants proper work-up. Because there is no standardized method of reporting out hemoglobin variant interference in HbA1c measurement, we discuss our laboratory's process of investigating discordant HbA1c measurements and reporting results in cases with variant interference as 1 possible model to follow, along with discussing the associated laboratory, ethical, and clinical considerations. We also examine the structure of hemoglobin Hoshida, HbE, and conduct a brief literature review of previous reports.
Assuntos
Hemoglobinas Glicadas , Hemoglobina E , Humanos , Hemoglobinas Glicadas/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Hemoglobina E/análise , Hemoglobina E/genética , Masculino , Feminino , Pessoa de Meia-Idade , AdultoRESUMO
BACKGROUND: The present study was conducted to evaluate the analytical performance and the organizational aspects of Capillarys 2 Flex Piercing system (CFP) respect to agarose electrophoresis and HPLC methods in hemoglobinopathies screening. METHODS: The measurement of imprecision in HbA 2 and HbF quantification was verified on HbA 2 CFP control and on three samples; 74 whole blood samples were used to evaluate migration time imprecision of hemoglobin variants S, C and E (HbS, HbC, and HbE); to compare methods, 451 samples were tested on CFP and HPLC; reference values were verified as value distribution in 160 blood donors and at ROC curve analysis on 449 samples from routine analysis. RESULTS: Imprecision: the analytical CV % s ranged from 1.25 to 3.9 at HbA 2 quantification, the CV % was 3.78 at HbF quantification; the running time imprecision for HbS and HbC and HbE ranged from 0.20 to 0.69 % . Method comparison: at regression analysis findings were HbA 2: CFP=1.21×HPLC0.64, HbF: CFP=1.31×HPLC−0.75, HbS: CFP=1.10×HPLC−3.24. Reference values: the HbA 2 95th percentile range was 2.52.8; HbF was undetectable in 154 out 160 samples tested; at ROC curve analysis the best combination of sensitivity and diagnostic efficiency was obtained using 2.2 and 3.0, as reference values, for HbA 2 and 1.1 as the upper reference limit for HbF. Organizational aspects: with respect to the procedures currently implemented in our laboratory CFP requires 2 h less time and obviates the need for some manual steps. CONCLUSIONS: The quantification, reproducibility and diagnostic efficiency provided by CFP in identification and quantification of hemoglobins appear accurate. In addition, the use of primary tubes allows improved safety, and the avoidance of some manual steps, that prolong working time and are a source of possible errors.
Assuntos
Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Ágar , Eletroforese Capilar , Hemoglobinas/análise , Cromatografia Líquida de Alta Pressão/normas , Eletroforese em Gel de Ágar/normas , Eletroforese Capilar/normas , Hemoglobina Fetal/análise , Hemoglobina Fetal/normas , Hemoglobina A2/análise , Hemoglobina A2/normas , Hemoglobina C/análise , Hemoglobina E/análise , Hemoglobina Falciforme/análise , Hemoglobinas/normas , Humanos , Curva ROC , Valores de Referência , Análise de RegressãoRESUMO
OBJECTIVE: To compare red blood cell indices among normal, beta-thalassemia trait or hemoglobin (Hb) E trait, and beta-thalassemia/Hb E diseases mid-gestational fetuses. METHODS: One hundred seventy-five fetuses at risk of beta-thalassemia/Hb E disease undergoing cordocentesis with determination of Hb levels and red blood cell indices at mid-pregnancy were recruited. The fetal diagnoses were based on fetal Hb typing and DNA analysis. The fetuses were divided into three groups: normal, beta-thalassemia trait or Hb E trait, and beta-thalassemia/Hb E disease. RESULTS: The prevalence of beta-thalassemia/Hb E disease, beta-thalassemia trait or Hb E trait, and normal fetuses was 32.6% (57 cases), 28.6% (50 cases) and 36.6% (64 cases), respectively. Mean Hb levels and red blood cell indices were not significantly different among the three groups of fetuses. However, almost 10% of beta-thalassemia/Hb E fetuses had some degree of anemia. The most anemic fetuses had a ß(0) mutation. CONCLUSION: There is no significant difference in Hb level and red blood cell indices among fetuses at risk of beta-thalassemia/Hb E disease.
Assuntos
Índices de Eritrócitos , Hemoglobina Fetal/análise , Hemoglobina E/análise , Segundo Trimestre da Gravidez/sangue , Talassemia beta/sangue , Estudos de Casos e Controles , Cordocentese , Feminino , Idade Gestacional , Hemoglobina E/genética , Humanos , Mutação , Gravidez , Diagnóstico Pré-Natal/estatística & dados numéricos , Talassemia beta/diagnóstico , Talassemia beta/epidemiologia , Talassemia beta/genéticaRESUMO
ß -thalassemia/Hb E is known to cause oxidative stress induced by iron overload. The glutathione system is the major endogenous antioxidant that protects animal cells from oxidative damage. This study aimed to determine the effect of disease state and splenectomy on redox status expressed by whole blood glutathione (GSH)/glutathione disulfide (GSSG) and also to evaluate glutathione-related responses to oxidation in ß -thalassemia/Hb E patients. Twenty-seven normal subjects and 25 ß -thalassemia/Hb E patients were recruited and blood was collected. The GSH/GSSG ratio, activities of glutathione-related enzymes, hematological parameters, and serum ferritin levels were determined in individuals. Patients had high iron-induced oxidative stress, shown as significantly increased serum ferritin, a decreased GSH/GSSG ratio, and increased activities of glutathione-related enzymes. Splenectomy increased serum ferritin levels and decreased GSH levels concomitant with unchanged glutathione-related enzyme activities. The redox ratio had a positive correlation with hemoglobin levels and negative correlation with levels of serum ferritin. The glutathione system may be the body's first-line defense used against oxidative stress and to maintain redox homeostasis in thalassemic patients based on the significant correlations between the GSH/GSSH ratio and degree of anemia or body iron stores.