Hematological and genotypic features of 100 patients with hemoglobin E disorders from Yunnan Province / 中华医学遗传学杂志

OBJECTIVE@#To explore hematological and genotypic characteristics of patients with hemoglobin E (Hb E) disorders from Yunnan Province.@*METHODS@#One hundred individuals with Hb E disorders indicated by high performance liquid chromatography (HPLC) were subjected to genetic testing through multiple gap-PCR and reverse dot-blotting analysis.@*RESULTS@#All patients were found to harbor a mutation to the 26th codon of the β -globin chain (HBB: c.79G>A). Ninety patients were heterozygotes, and 10 co-inherited c.79G>A and an α -thalassemia mutation (7 α α /-α, 2 α α /-- and 1 -α /-α). Hematological characteristics of the heterozygotes were: Hb A2 (26.02±3.64)%, Hb F(1.35±1.25)%, MCV(78.83±4.68) fl, MCH(26±1.54) pg, MCHC (329.65±10.73) g/L, HGB (141.08±16.53) g/L, while that of the co-inherited cases was decided by the type of α -thalassemia mutation.@*CONCLUSION@#Hb E can be effectively detected by HPLC. The type of α -thalassemia mutations will determine hematological features of co-inherited cases. Hb E disorders may be missed by relying only on routine blood test upon prenatal screening.

Phenotype Analysis of 78 Cases of Abnormal Hemoglobin E Homozygotes / 中国实验血液学杂志

OBJECTIVE@#To analyze the hematological characteristics of HbE homozygotes.@*METHODS@#Complete blood cells count and hemoglobin electrophoresis were used for phenotypic analysis of 78 cases with HbE homozygotes from Yunnan province, China. The PCR-fluorescence hybridization was used to detect the common gene mutation of thalassemia. The hematological indexes, including MCV, MCH, Hb, HbA2, HbF and HbE were statistically analyzed between groups with different sex, ages and compound α thalassemia status.@*RESULTS@#In HbE homozygotes (HbEE), 89.5% (17/19) children presented mild to moderate microcytic hypochromic anemia, and 10.5% of them presented moderate anemia. 39.6% (19/48) of women with HbEE developed mild anemia ,while 11 cases of male with HbE homozygotes were asymptomatic. The levels of MCV and MCH in HbE homozygotes increased by co-inheritance of α thalassemia mutation.@*CONCLUSION@#The clinical phenotype of HbE homozygote shows highly heterogeneous, which is relates with age, sex and co-inheriting α-globin genotypes. In Hb EE women and children are more likely to develop mild to moderate anemia. The microcytic hypochromic anemia degree is relieved when HbEE combined with α- thalassemia.

Hemoglobin A1c Levels Are Slightly but Significantly Lower in Normoglycemic Subjects With the Hemoglobin E Phenotype

Hb mutations can alter the structure, behavior, stability, or quantity of the globin chain produced. Some Hb variants shorten the erythrocyte life span, resulting in physiologically lower hemoglobin A1c (HbA1c) levels. The hemoglobin E (HbE) phenotype involves a single-nucleotide polymorphism that reduces β-globin chain synthesis. We compared the HbA1c levels of subjects with normal Hb (HbAA; N=131) and HbE (N=148) phenotypes, examining potential hematological and biochemical factors contributing to differences in HbA1c levels. All had normal fasting plasma glucose ( < 5.6 mmol/L), AST, ALT, and creatinine levels. Mean±SD HbA1c levels differed between HbAA and HbE subjects: 5.5±0.3% and 5.3±0.3% (P < 0.001) according to an immunoassay, and 5.5±0.3% and 5.3±0.3% (P < 0.001) according to cation-exchange HPLC, respectively. In multiple logistic regression, only mean corpuscular volume (P < 0.001) contributed to the difference in HbA1c levels between groups. Although a 0.2% difference in HbA1c is relatively small and unlikely to alter clinical decisions, epidemiologically, this can lead to misclassification of a significant proportion of the population, especially since the threshold of non-diabetes HbA1c (≤5.6%) falls very close to the HbA1c median of the general population.

The Effect of ABO Blood Groups, Hemoglobinopathy, and Heme Oxygenase-1 Polymorphisms on Malaria Susceptibility and Severity

Malaria is one of the most important public health problems in tropical areas on the globe. Several factors are associated with susceptibility to malaria and disease severity, including innate immunity such as blood group, hemoglobinopathy, and heme oxygenase-1 (HO-1) polymorphisms. This study was carried out to investigate association among ABO blood group, thalassemia types and HO-1 polymorphisms in malaria. The malarial blood samples were collected from patients along the Thai-Myanmar border. Determination of ABO blood group, thalassemia variants, and HO-1 polymorphisms were performed using agglutination test, low pressure liquid chromatography and polymerase chain reaction, respectively. Plasmodium vivax was the major infected malaria species in the study samples. Distribution of ABO blood type in the malaria-infected samples was similar to that in healthy subjects, of which blood type O being most prevalent. Association between blood group A and decreased risk of severe malaria was significant. Six thalassemia types (30%) were detected, i.e., hemoglobin E (HbE), β-thalassemia, α-thalassemia 1, α-thalassemia 2, HbE with α-thalassemia 2, and β-thalassemia with α-thalassemia 2. Malaria infected samples without thalassemia showed significantly higher risk to severe malaria. The prevalence of HO-1 polymorphisms, S/S, S/L and L/L were 25, 62, and 13%, respectively. Further study with larger sample size is required to confirm the impact of these 3 host genetic factors in malaria patients.

A Family With a Hemoglobin E Variant Including a Thai Immigrant Woman in Korea

No abstract available.

Hemoglobin E disorder: Newborn screening program.

Hemoglobin E (Hb E) disorder is an important kind of hemoglobinopathy. It can be seen around the world with the highest prevalence in Southeast Asia. The screening for this disorder becomes the public health policies in many countries. The screening can be performed in several population groups. The newborn screening program for Hb E disorder is an important issue in pediatric genetics. In this brief review, the author discusses on important laboratory tests for screening for Hb E disorder in newborn.

Phenotype and genotype analysis of hemoglobin E / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the genotype and phenotype correlation in the hemoglobin E (HbE) carriers, and to investigate the effect of HbE on hematological parameters.</p><p><b>METHODS</b>The capillary electrophoresis was used to screen total 14 141 samples and blood cell analysis was further processed to the HbE carrying samples. Gap-PCR and reverse dot blot hybridization method were used for the detection of Chinese common mutation of α and β thalassemia.</p><p><b>RESULTS</b>There is a statistical difference in hematological phenotype index (HGB, MCV, MCH, HbE, HbA(2)) between samples of HbE heterozygous (53 samples), HbE homozygous (2 samples), HbE composite α thalassemia (α-thal, 7 samples) and HbE composite β thalassemia (β-thal, 8 samples). Among the four groups, HbE heterozygous \[HGB (122.7 ± 19.99) g/L, MCV (78.65 ± 5.03) fl\] and HbE composite α-thal \[HGB (113.6 ± 22.68) g/L, MCV (73.50 ± 7.73) fl\] had slight effect on hematological parameters, but HbE composite β-thal \[HGB (76.4 ± 12.30) g/L\], MCV (59.23 ± 5.28) fl\] had the heaviest effect on hematological parameters.</p><p><b>CONCLUSION</b>Co-existence of HbE heterozygous and other type thalassemias showed variation in their hematological phenotype, so patients should be informed of genetics in prenatal diagnosis.</p>

Hb E/beta-thalassaemia: a common & clinically diverse disorder.

Haemoglobin E-beta thalassaemia (Hb E/β-thalassaemia) is the genotype responsible for approximately one-half of all severe beta-thalassaemia worldwide. The disorder is characterized by marked clinical variability, ranging from a mild and asymptomatic anaemia to a life-threatening disorder requiring transfusions from infancy. The phenotypic variability of Hb E/β-thalassaemia and the paucity of long-term clinical data, present challenges in providing definitive recommendations for the optimal management of patients. Genetic factors influencing the severity of this disorder include the type of beta-thalassaemia mutation, the co-inheritance of alpha-thalassaemia, and polymorphisms associated with increased production of foetal haemoglobin. Other factors, including a variable increase in serum erythropoietin in response to anaemia, previous or ongoing infection with malaria, previous splenectomy and other environmental influences, may be involved. The remarkable variation, and the instability, of the clinical phenotype of Hb E beta-thalassaemia suggests that careful tailoring of treatment is required for each patient, and that therapeutic approaches should be re-assessed over-time.

Haemoglobinopathies in Southeast Asia.

In Southeast Asia α-thalassaemia, β-thalassaemia, haemoglobin (Hb) E and Hb Constant Spring (CS) are prevalent. The abnormal genes in different combinations lead to over 60 different thalassaemia syndromes, making Southeast Asia the locality with the most complex thalassaemia genotypes. The four major thalassaemic diseases are Hb Bart's hydrops fetalis (homozygous α-thalassaemia 1), homozygous β-thalassaemia, β-thalassaemia/Hb E and Hb H diseases. α-Thalassaemia, most often, occurs from gene deletions whereas point mutations and small deletions or insertions in the β-globin gene sequence are the major molecular defects responsible for most β-thalassaemias. Clinical manifestations of α-thalassaemia range from asymptomatic cases with normal findings to the totally lethal Hb Bart's hydrops fetalis syndrome. Homozygosity of β-thalassaemia results in a severe thalassaemic disease while the patients with compound heterozygosity, β-thalassaemia/Hb E, present variable severity of anaemia, and some can be as severe as homozygous β-thalassaemia. Concomitant inheritance of α-thalassaemia and increased production of Hb F are responsible for mild clinical phenotypes in some patients. However, there are still some unknown factors that can modulate disease severity in both α- and β-thalassaemias. Therefore, it is possible to set a strategy for prevention and control of thalassaemia, which includes population screening for heterozygotes, genetic counselling and foetal diagnosis with selective abortion of affected pregnancies.

Non-haem iron-mediated oxidative stress in haemoglobin E beta-thalassaemia

<p><b>INTRODUCTION</b>Haemoglobin (Hb) E beta-thalassaemia is a common thalassaemic disorder in Southeast Asia and is very common in the eastern and north-eastern parts of India. The disease cause rapid erythrocyte destruction due to the free radical mediated injury but factors for the oxidative injury are not clearly known. We investigated the free reactive iron (non-haem) mediated insult in Hb E beta-thalassaemia.</p><p><b>MATERIALS AND METHODS</b>Thirty Hb E beta-thalassaemic patients (age range, 3 to 15 years) who had undergone blood transfusion at least 1 month prior to sampling and 32 normal healthy individuals (age range, 18 to 30 years) were included in this study. We estimated the ferrozine detected intracellular erythrocytic free reactive iron (nonhaem iron), reduced glutathione (GSH), glutathione reductase activity, cellular damage marker serum thiobarbituric acid reacting substances (TBARS) and also serum ferritin using standard methods.</p><p><b>RESULTS</b>We found that the erythrocytic free reactive iron was significantly higher (P <0.001) in Hb E beta patients and was about 30% more than in controls. The elevated level of erythrocytic non-haem iron was associated with a high level of serum TBARS which was about 86% higher in patients than in controls. The serum ferritin level was also significantly higher (P <0.001) compared to controls. The erythrocytic reduced glutathione level was significantly lower (P <0.001) at about 65% less in the patients' group and the erythrocytic glutathione reductase enzyme was also found to be significantly lower (P <0.001) in Hb E beta-thalassaemia.</p><p><b>CONCLUSIONS</b>We concluded that a significantly elevated level of erythrocytic free reactive iron and lipid peroxidation end product was associated with low erythrocytic GSH level. This reflects non-haem iron mediated cellular damage in Hb E beta-thalassaemia.</p>

Comparison of fast protein liquid chromatography (FPLC) with HPLC, electrophoresis & microcolumn chromatography techniques for the diagnosis of β-thalassaemia.

Background & objectives: β-thalassaemia is a genetic disorder and an important health problem around the world. Quantitative haemoglobin A2 (HbA2) levels are used for the diagnosis of β-thalassaemia. The conventional methods are high performance liquid chromatography (HPLC), electrophoresis, and microcolumn chromatography techniques. We established a fast protein liquid chromatography (FPLC) method, to measure quantitatively of HbA2 levels, and compared its efficacy with conventional methods. Methods: The FPLC method, using a DEAE Sepharose, Hi Trap anion-exchange column chromatography technique was set up for HbA2 measurement. In this study, 220 blood samples were screened for haemoglobin type by FPLC technique and also using HPLC, microcolumn chromatography and electrophoresis. Results: The FPLC results were highly correlated (r = 0.985, P<0.001) with those of HPLC for quantification of HbA2 as well as cellulose acetate electrophoresis (r = 0.977) and microcolumn chromatography (r = 0.980). The FPLC method showed 100 per cent sensitivity and specificity, positive and negative predictive value for β-thalassaemia diagnosis. In addition, the FPLC method was simple, rapid, low cost and reproducible. The HbA2/E range of FPLC for β-thalassaemia was 6-10 per cent, HbE trait was 10-40 per cent, β-thalassaemia/HbE was 40-60 per cent and homozygous HbE was more than 60 per cent. Interpretation & conclusions: Our findings suggested that FPLC method could be used as a cost-effective method for routine β-thalassaemia diagnosis.

Hemoglobin E disorders in Eastern Uttar Pradesh.

The distribution of hemoglobin E (alpha2beta2 26Glu (R)Lys ) is mostly restricted to Northeastern India. While evaluating the patients of jaundice, we came across two cases of hemoglobin E (Hb E) disorders. The first case is in a 22-year-old Bengali male and the second case of Hb E/beta thalassemia in a 5-year-old Hindu boy. The family study revealed Hb E trait in both the parents of Case 1, whereas in Case 2, the father was found to have Hb E trait and the mother had beta -thalassemia minor, thus confirming the diagnosis. Herein, we present the laboratory diagnosis and comparative data of the spectrum of Hb E disorders (i.e., heterozygous Hb E trait, homozygous Hb E disease and compound heterozygous Hb E/beta -thalassemia) that was found in our index cases and their parents.

Hemoglobin E detection using PCR with confronting two-pair primers.

OBJECTIVES: To develop and apply the polymerase chain reaction with confronting two-pair primers (PCR-CTPP) for detection and identification of hemoglobin E (Hb E). MATERIAL AND METHOD: Fifty unrelated northern Thais were included in the present study. DNA was extracted from peripheral blood mononuclear cells and targeted to amplify by PCR-CTPP. The amplified product was analyzed and compared with the reference hemoglobin electrophoresis and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: The results validated a completely concordant among these three methods consisting of 74%, 24%, and 2% identified as normal, heterozygous, and homozygous Hb E type, respectively. CONCLUSION: Successful Hb E genotyping by PCR-CTPP was introduced. It allows for confirming and simultaneously detection with other thalassemia mutations.

Low cost combination of DCIP and MCV was better than that of DCIP and OF in the screening for hemoglobin E.

OBJECTIVE: To evaluate hemoglobin E screening tests in a large scale of cases. MATERIAL AND METHOD: A cross-sectional descriptive study was conducted Whole blood obtained from subjects was evaluated for CBC, OF, DCIP, and hemoglobin typing. RESULTS: Five hundred twenty seven hemoglobin E and 280 reference subjects participated. DCIP's sensitivity, specificity, positive predictive value, and negative predictive value were 97.16%, 98.93%, 99.42%, and 95.19%, respectively. These values of OF were 69.12%, 80.00%, 86.67%, and 57.88%, respectively. In the combination of DCIP and OF gave rise to these values of 99.43%, 79.29%, 90.03%, and 96.67%, respectively. Finally the combination of DCIP and MCV < 80 fL resulted in these values to be 99.43%, 98.93%, 99.43%, and 98.93%, respectively. False positive and false negative rate were 1.07% and 0.57%, respectively. CONCLUSION: Combination of DCIP and MCVwas better than that of DCIP and OF in hemoglobin E screening.

Role of interleukin-3 and signaling pathways on beta-thalassemia/HbE erythroid progenitor cell in culture.

In order to study the role of the cytokine interleukin-3 (IL-3) and its signaling pathways in erythropoiesis of beta-thalassemia/HbE erythroid progenitor cells, CD34 positive cells were isolated from peripheral blood of patients and healthy subjects. After culturing the cells in the presence or absence of IL-3, cell viability was measured by trypan blue staining and apoptotic cells were analyzed by flow cytometry. After 7 days of culture the highest percent erythroid progenitor cell viability was obtained with cells from healthy subjects, while the lowest percentage was found in those from splenectomized beta-thalassemia/HbE. Viability of beta-thalassemia/HbE erythroid progenitor cells in the presence of IL-3 was higher than that of nonsupplemented cells. In addition, specific inhibitors of protein kinase C (Ro-318220), phospholipase C (U-73122) and Janus kinase 2 (AG-490) were used to investigate the involvement of signaling pathways in erythropoiesis. Percent apoptosis of erythroid progenitor cells from splenectomized beta-thalassemia/HbE subjects treated with RO-318220 was higher than those of nonsplenectomized beta-thalassemia/HbE and healthy subjects. Treatment with U-73122 resulted in enhanced percent apoptotic cells from normal and beta-thalassemia/HbE subjects. All these effects were independent of IL-3 treatment.

Preliminary study of the effect of vitamin E supplementation on the antioxidant status of hemoglobin-E carriers.

The antioxidant status of hemoglobin-E carriers was studied pre- and post-treatment with vitamin E for 3 months. Fourteen hemoglobin-E carriers (age = 21.36 +/- 1.08 years, BMI = 18.32 +/- 1.22 kg/m2) were treated with vitamin E 200 I.U. daily for 3 months. Fasting blood samples were collected and analyzed for erythrocyte superoxide dismutase activity, total antioxidant activity, hemoglobin concentration, hematocrit, MCV, Heinz body formation and osmotic fragility test. The blood parameters before and after vitamin E treatment were compared. The results showed that superoxide dismutase activity in the erythrocytes was significantly decreased, while total antioxidant activity in plasma, and the osmotic fragility of the erythrocytes, was significantly increased after vitamin E supplementation. However, hematocrit, MCV, and Heinz body formation did not change significantly. This demonstrated that vitamin E 200 IU could be used as a lipophilic antioxidant in red blood cells and could help increase the level of antioxidant in hemoglobin-E carriers.

Antioxidant in plasma of hemoglobin-E trait.

A study of antioxidant levels among Thai subjects with a hemoglobin E trait was undertaken. The objective of this study was to determine whether the antioxidant level would be disturbed in the HbE condition. All 185 volunteer subjects, 171 normal healthy subjects and 14 HbE carriers were recruited. For each case, an antioxidant determination was performed using the Trolox equivalent antioxidant capacity (TEAC) method. According to this study, the average antioxidant level in the healthy group was 3.439 +/- 0.220 mM Trolox equivalent, and in HbE trait group was 3.276 +/- 0.209 mM Trolox equivalent. There was a significant decrease of the antioxidant level in the HbE trait group (p = 0.008).