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Hemoglobin Koln, is the most common unstable hemoglobin variant worldwide, yet has only rarely been reported in Indians. Herein we report a case of coinheritance of Hb Koln and Hb E, which to the best of our knowledge has not been...
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Hemoglobin Koln, is the most common unstable hemoglobin variant worldwide, yet has only rarely been reported in Indians. Herein we report a case of coinheritance of Hb Koln and Hb E, which to the best of our knowledge has not been reported in the literature so far. The patient presented with mild symptoms of hemolysis with no previous history of blood transfusions.
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Background Accurate measurement of glycated hemoglobin (HbA1c) is crucial for a diabetes diagnosis and subsequent patient management. The detection method and presence of variant Hb can interfere with HbA1c measurements. We evalua...
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Background Accurate measurement of glycated hemoglobin (HbA1c) is crucial for a diabetes diagnosis and subsequent patient management. The detection method and presence of variant Hb can interfere with HbA1c measurements. We evaluated the HbA1c-measuring performance of the DxC 700 AU (Beckman Coulter, Brea, CA, USA) immunoassay-based device in comparison with another immunoassay device and the reference method. Methods A total of 120 normal and 14 variant Hb samples were analyzed using the Cobas c 513 (Roche Diagnostics, Mannheim, Germany) and DxC 700 AU analyzers. Variant Hb samples were also analyzed using the reference method, along with 20 normal samples. The accuracy, precision, linearity, and carryover were determined. Results DxC 700 AU results strongly correlated with those of Cobas c 513 and exhibited accuracy in comparison with the reference method. The within-run, between-run, between-day, and total imprecision (%CV) values for the low- and high-concentration control materials were below 2%. The results of DxC 700 AU were linear over a wide HbA1c range (3.39%–18.30%). Although DxC 700 AU performed well in the presence of variant Hb, the HbA1c concentration was underestimated in the presence of fetal Hb. The possibility of interference from a high HbH proportion could not be ruled out. Conclusions The overall analytical performance of DxC 700 AU was acceptable. The device is accurate, precise, and linear over a wide HbA1c concentration range. Although DxC 700 AU results highly correlated with those of Cobas c 513, caution should be exercised in cases of high HbF and HbH concentrations.
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Summary We describe haematological and DNA characterization of haemoglobinopathies in Thai adolescents caused by compound heterozygosities for Hb E [beta26(B8) Glu-Lys] and two other beta-globin chain variants, Hb Pyrgos [beta83(E...
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Summary We describe haematological and DNA characterization of haemoglobinopathies in Thai adolescents caused by compound heterozygosities for Hb E [beta26(B8) Glu-Lys] and two other beta-globin chain variants, Hb Pyrgos [beta83(EF7) Gly-Asp] and Hb J Bangkok [beta56(D7) Gly-Asp]. Hb analysis demonstrated that although these two beta-chain variants have separated elution profiles on liquid chromatography-based Hb analysis, they have similar alkaline electrophoretic mobilities on cellulose acetate electrophoresis. Haematological data associated with these two previously undescribed conditions were compared with those of pure carriers of the variants found in other unrelated Thai individuals. beta-Globin gene haplotypes linked to these two beta-chain variants and a simple DNA testing based on multiplex allele-specific polymerized chain reaction for differential diagnosis are presented.
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Glycated hemoglobin is widely used in the management of diabetes mellitus. At least 300,000 Americans with diabetes mellitus have the hemoglobin (Hb) C or S trait. The accuracy of HbA1c methods can be adversely affected by the pre...
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Glycated hemoglobin is widely used in the management of diabetes mellitus. At least 300,000 Americans with diabetes mellitus have the hemoglobin (Hb) C or S trait. The accuracy of HbA1c methods can be adversely affected by the presence of these traits. We evaluated the effects of HbC and HbS traits on the results of 14 commercial HbA1c methods that use boronate affinity, enzymatic, immunoassay, and ion exchange methods. Whole blood samples from people homozygous for HbA or heterozygous for HbC or HbS were analyzed for HbA1c. Results for each sample type were compared with those from the CLC 330 comparative method (Primus Diagnostics, Kansas City, MO). After correcting for calibration bias by comparing results from the homozygous HbA group, method bias attributable to the presence of HbC or HbS trait was evaluated with a clinically significant difference being more than 10% (ie, 0.6% at 6% HbA1c). One immunoassay method exhibited clinically significant differences owing to the presence of HbC and HbS traits.
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Background: Pulse oximetry is an essential diagnostic method in pediatric emergency medicine and pediatric intensive care. However, if undetected hemoglobin anomalies are the underlying cause measurements of low oxygen saturation ...
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Background: Pulse oximetry is an essential diagnostic method in pediatric emergency medicine and pediatric intensive care. However, if undetected hemoglobin anomalies are the underlying cause measurements of low oxygen saturation can be interpreted incorrectly or may lead to unnecessary examinations. In 2 recently discovered hemoglobin anomalies, Hb Bonn and Hb Venusberg, this resulted in extensive and repeat cardiopulmonary examinations. This review aims to provide an overview of hemoglobin anomalies causing low oxygen saturation. Methods: We describe the methods required for differential diagnosis of hemoglobin anomalies, such as hemoglobin electrophoresis, High Performance Liquid Chromatography, hemoglobin gene sequencing and spectral photometry, and the difficulties with the interpretation of results. Furthermore, with a review of the literature we provide an extensive overview of hemoglobin anomalies which result in low oxygen saturation measurement in pulse oximetry. With the examples of Hb Bonn, a novel hemoglobin mutation of the proximal α1-globin, which results in false low pulse oximetry measurements of oxygen saturation, and Hb Venusberg, a low oxygen-affine hemoglobin mutation of the β-globin, we highlight the difficulties arising from the respective case histories. Conclusion: In pediatric medicine, hemoglobin anomalies must be included in the diagnosis as a possible underlying cause of low oxygen saturation in case of ambiguous or conflicting pulse oximetry findings.
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Study on the phenotypic expression of hemoglobin (Hb) A 2 and Hb E in Hb E disorders has been difficult due to the co-separation of Hb A 2 and Hb E in most Hb analysis assays. Because these two Hbs are separated on capillary elect...
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Study on the phenotypic expression of hemoglobin (Hb) A 2 and Hb E in Hb E disorders has been difficult due to the co-separation of Hb A 2 and Hb E in most Hb analysis assays. Because these two Hbs are separated on capillary electrophoresis, we studied phenotypic expression of Hbs A 2, E and F in various Hb E disorders using this system. This was done on 362 subjects with several Hb E disorders including heterozygous Hb E, homozygous Hb E, β-thalassemia/Hb E, δβ-thalassemia/Hb E, and Hb Lepore/Hb E and those of these disorders with several forms of α-thalassemia. Normal controls showed Hb A 2 of 2.7±0.3%. Heterozygous Hb E and homozygous Hb E had elevated Hb A 2 i.e. 3.8±0.3% and 4.8±0.5%, respectively. Further elevations were observed for β 0-thalassemia/Hb E (6.1±1.9%) and β +-thalassemia/Hb E (7.1±1.2%). Interestingly, no elevation of Hb A 2 was found in the δβ-thalassemia/Hb E, and Hb Lepore/Hb E (2.3±0.3%) but higher Hb F levels were noted which could be useful diagnostic markers. The levels of Hb E were variable. Co-inheritance of these Hb E disorders with α-thalassemia were associated with lower outputs of Hb E and Hb F but the levels of Hb A 2 were not altered. Different phenotypic expression of Hb A 2, Hb E and Hb F could help in differential diagnosis of these Hb E related disorders commonly encountered in the regions where access to molecular techniques is limited.
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Hemoglobin (Hb) Chile [β28(B10) Leu > Met; HBB: c.85 C > A] is a rare hemoglobin variant caused by a missense mutation in the HBB gene. Only one case of Hb Chile has been reported worldwide so far. It is an unstable hemoglobin, c...
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Hemoglobin (Hb) Chile [β28(B10) Leu > Met; HBB: c.85 C > A] is a rare hemoglobin variant caused by a missense mutation in the HBB gene. Only one case of Hb Chile has been reported worldwide so far. It is an unstable hemoglobin, characterized by cyanosis associated with chronic methemoglobinemia and hemolytic anemia induced by sulfonamides or methylene blue.A 9-year-3-month-old girl had mild anemia of unknown etiology for more than 6 years. She had a slight pallor without other symptoms or signs. The complete blood count revealed normocytic normochromic anemia with a sometimes-elevated reticulocyte count, and the bone marrow cytology showed marked erythroid hyperplasia, but the tests related to hemolysis were normal. Therefore, the whole exome sequencing was performed and showed a heterozygous mutation for HBB: c.85 C > A. With asymptomatic methemoglobinemia confirmed later, she was eventually diagnosed with Hb Chile.This is the first report of Hb Chile in China and the second worldwide. This case shows that Hb Chile is clinically heterogeneous and difficult to diagnose and expands our understanding on the clinical and hematological traits of the disease.
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The presence of HbC is a rare event in Europe and Mediterranean region where thalassemia and HbS are more frequently encountered. The rarely diagnosed cases are linked with the migration from West-Central Africa. Albania is one of...
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The presence of HbC is a rare event in Europe and Mediterranean region where thalassemia and HbS are more frequently encountered. The rarely diagnosed cases are linked with the migration from West-Central Africa. Albania is one of the Mediterranean countries where inherited haemoglobin disorders are considerably widespread. Studies have shown the presence of thalassemia, sickle cell disease and sporadic cases of Hb O-Arab, Hb Lepore especially in the areas where malaria has been endemic. In 2006 we identified the first case with HbSC disease and until 2020 we have found 15 cases with HbC variant. In this study we have collected and analyzed the laboratory and clinical data of HbC cases. Our data support reports that HbC combinations with HbS and beta thalassemia are clinically important. Our data confirm the presence of the HbC variant in ex-malaric areas where thalassemia and HbS are quite widespread.
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Our study evaluates a fast and easy way to perform point-of-care testing (POCT) measurements of glycated hemoglobin HbA1c in comparison with an immunoassay on an automated biochemistry analyzer and cation exchange chromatography, ...
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Our study evaluates a fast and easy way to perform point-of-care testing (POCT) measurements of glycated hemoglobin HbA1c in comparison with an immunoassay on an automated biochemistry analyzer and cation exchange chromatography, the two methods routinely used in clinical laboratories for the measurement of HbA1c. A significant finding of our study is that although the POCT instrument insert claims that the method is not affected by the presence of HbS in the heterozygous state or in combination with beta-thalassemia, discrepant results were found in some cases with such hemoglobinopathies. In these cases, the two POCT and laboratory immunoassay methods showed clinically significant positive interferences with samples containing the HbS trait. We conclude that samples with the HbS trait should be interpreted with caution when tested using the POCT instrument.
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The effect of pH, ADP and the soluble components of the muscle on the extractability of cod hemoglobin was studied. A marked decrease in hemoglobin extractability from washed and unwashed mince was observed at pH 6.0. This coincid...
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The effect of pH, ADP and the soluble components of the muscle on the extractability of cod hemoglobin was studied. A marked decrease in hemoglobin extractability from washed and unwashed mince was observed at pH 6.0. This coincided with the binding of the hemoglobin to cod sarcoplasmic reticulum at pH 6.0. After 10 min of incubation at pH 6.0, most non-extractable hemoglobin could be extracted at pH 7.0 or higher. The soluble fraction of cod muscle increased hemoglobin extractability and decreased the hemoglobin bound to the sarcoplasmic reticulum. A decrease in hemoglobin extractability in unwashed mince with added ADP at pH 7.0 occurred with an increased amount of deoxyhemoglobin. The results suggested that medium pH and deoxygenation of hemoglobin were related to the decrease in hemoglobin extractability at pH 6.0.
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