HemoTypeSC point-of-care testing shows high sensitivity with alkaline cellulose acetate hemoglobin electrophoresis for screening hemoglobin SS and SC genotypes

ABSTRACT Introduction: By providing timely actionable results for prompt management, point-of-care testing (POCT) kits have revolutionised medical care for various diseases, ranging from infectious diseases like malaria to genetic disorders, such as sickle cell disease (SCD). They are, however, underutilised in the diagnosis of SCD in developing countries, where the need is greatest. Objective: The study was aimed at assessing the sensitivity of HemoTypeSC POCT among a cohort of children with SCD, previously diagnosed by Alkaline cellulose acetate hemoglobin electrophoresis (ACAE), with or without high-performance liquid chromatography (HPLC). Methods: In this descriptive cross-sectional study, HemoTypeSC test was conducted on all participants and its sensitivity was determined by comparing results with those obtained using ACAE. Discordance was verified with HPLC. Results: One hundred and forty-five children aged one to 19 years were studied. There were 84 males and 61 females (male: female ratio = 1.4:1). The HemoTypeSC was able to correctly diagnose sickle cell anemia (SCA) and hemoglobin SC in all (100%) of the children tested. Conclusion: The HemoTypeSC shows high sensitivity in detecting SCA and hemoglobin SC. Hence, it is useful for targeted screening of individuals suspected of having SCD, leading to rapid diagnosis of these hemoglobinopathies, even in resource-constrained settings.

Valor diagnóstico de la electroforesis de proteínas y cadenas ligeras libres en suero en el mieloma múltiple / Diagnostic value of serum protein electrophoresis and free light chains in the multiple myeloma's diagnosis

RESUMEN Fundamento: La electroforesis de proteínas y las cadenas ligeras libres en suero son técnicas utilizadas en el diagnóstico del mieloma múltiple. Sin embargo, la utilidad diagnóstica de ambas pruebas puede variar según el método empleado y condiciones reales del medio donde se realicen. Objetivo: Determinar el valor diagnóstico de la electroforesis de proteínas y de las cadenas ligeras libres en suero en el mieloma múltiple. Metodología: Se realizó un estudio retrospectivo de los parámetros electroforesis de proteínas en suero y cadenas ligeras libres en suero a 43 pacientes con diagnóstico de mieloma múltiple por evaluación de la médula ósea. La electroforesis de proteínas se realizó por el método convencional de separación de proteínas sobre papel de acetato de celulosa y para las cadenas ligeras libres se aplicó un ensayo inmunoturbidimétrico en el que se usó un analizador químico (Cobas 311). Se calcularon 7 parámetros que evaluaron la exactitud diagnóstica. Resultados: Todos los parámetros que evaluaron la exactitud diagnóstica estuvieron dentro de los intervalos de confianza en ambas pruebas. Conclusiones: La electroforesis de proteínas y las cadenas ligeras libres en suero son ensayos de gran utilidad en el diagnóstico del mieloma múltiple y se deben utilizar en conjunto para la mayor captación posible de casos.

ABSTRACT Background: Protein electrophoresis and serum free light chains are techniques used in the diagnosis of multiple myeloma. However, the diagnostic utility of both tests may vary according to the method used and the actual conditions of the environment where they are performed. Objective: To determine the diagnostic value of protein electrophoresis and serum free light chains in multiple myeloma. Methodology: A retrospective study of serum protein electrophoresis parameters and serum free light chains was conducted in 43 patients diagnosed with multiple myeloma by bone marrow evaluation. Protein electrophoresis was completed by the conventional method of protein separation on cellulose acetate paper and for free light chains an immunoturbidimetric assay was applied in which a chemical analyzer (Cobas 311) was used. Seven parameters were calculated to evaluate diagnostic accuracy. Results: All parameters assessing diagnostic accuracy were within confidence intervals in both tests. Conclusions: Protein electrophoresis and serum free light chains are very useful assays in the diagnosis of multiple myeloma and should be used in conjunction for the highest possible approval of cases.

Protein Electrophoresis of Serum and Heparinized Plasma in the Common Mynah (Acridotheres tristis).

Although serum protein electrophoresis is a diagnostic tool available through many veterinary laboratories, there currently are no reference intervals for protein fractions in healthy common mynahs (Acridotheres tristis). Therefore, electrophoretic patterns of proteins in serum and heparinized plasma of the common mynah were evaluated. Blood specimens were collected from 55 healthy adult common mynahs of unknown age (26 males and 29 females). The serum total protein and protein fractions were measured using the biuret method followed by cellulose acetate electrophoresis (CAE). The serum level of albumin was compared with bromocresol green (BCG) dye-binding and CAE methods. Four protein fractions, including albumin and α, ß, and γ globulins, were recorded in the electrophoretogram of serum specimens. Sex appeared to have no significant effect on the measured parameters. The serum BCG albumin fraction was significantly higher than the CAE albumin fraction (P = .01). Also, the comparison of total protein and protein fractions in serum and plasma specimens of 25 of the 55 birds sampled showed that total protein (Cohen index d = 0.66, P = .03), gamma globulin (d = 1.13, P = .00), and total globulin (d = 0.67, P = .00) in plasma samples were significantly higher than those in serum samples. The results of this study provide the specific reference intervals for total protein and protein fractions in common mynahs, which are essential for proper interpretation of laboratory results and also revealed that the albumin measurement by the BCG method yields unreliable results in common mynahs.

Production of sialic acid rich glycopeptide from bovine κ-casein glycomacropeptide by hydrolyzing with papain.

Bovine κ-casein glycomacropeptide (GMP) is a sialic acid containing glycopeptide having many biological activities. The study described in this research communication was undertaken to determine whether sialic acid rich glycopeptide can be produced from GMP by proteinase treatment. A sample of GMP was hydrolyzed with papain, and the obtained hydrolysate was chromatographed on a column of diethylaminoethyl-Sephacel to obtain a glycopeptide fraction (GPF). This product accounted for average 48.1% dry weight of GMP or 81.1% total recovered sialic acid from GMP. The content of sialic acid (expressed as % dry weight) was 1.7 times higher in GPF (22.6) than in unhydrolyzed GMP (13.4). Major differences in amino acid composition between GPF and GMP were found in the contents (mol%) of: lysine (<1 and 4.5, respectively), serine (20.3 and 10.3, approximately twice higher in GPF), asparagine/aspartic acid and isoleucine. The contents of the last two amino acids were approximately twice lower in GPF. On gel filtration chromatography with Sephacryl S-100, GMP was eluted as a single peak with elution volume similar to that of dimeric ß-lactoglobulin (36.6 kDa) whereas GPF was eluted in two peaks both with elution volumes greater than that of α-lactalbumin (14.2 kDa). These peak fractions containing high (fraction I) and low (fraction II) molecular size glycopeptides gave different sialic acid to peptide ratio, which was 1.7 times higher in fraction I than in fraction II. Results of size exclusion HPLC on Superdex-75 were consistent with those of gel filtlation chromatography. On cellulose acetate electrophoresis, the mobility of GPF relative to that of GMP as 1.0 was found to average 1.2, suggesting a higher negative charge density in GPF than in GMP. It was concluded that papain digestion of GMP is an efficient method to produce glycopeptide with high sialic acid content.

Chondroitin/dermatan sulfate purified from corb (Sciaena umbra) skin and bone: In vivo assessment of anticoagulant activity.

The present work deals with the extraction and purification of chondroitin sulfate/dermatan sulfate from skin (CSG) and bone (CBG) of corb (Sciaena umbra). Electrophoresis of these polymers in barium acetate buffer on cellulose acetate revealed two fractions similar to dermatan sulfate and chondroitin sulfate. The in vivo anticoagulant activity of both chondroitin sulfate/dermatan sulfate (CS/DS) were evaluated, at 25 and 75 mg kg-1 of body weight (b.w), using activated partial thromboplastin time (aPTT), prothrombine time (TT) and thrombin time (PT) tests. Results showed that aPTT of CSG and CBG at 75 mg kg-1 of b.w were prolonged by 1.59 and 1.48-fold respectively, compared with the control. Further, toxicity studies on liver performed by the catalytic activity of transaminases in plasma, oxidative stress markers and hepatic morphological changes demonstrated that CSG and CBG at both doses are not toxics. In summary, the higher activity and lower toxicity of both CS/DS, especially at 25 mg kg-1 of b.w, recommended these compounds as a better drug candidate.

Observation of Granulocyte Adsorption in Adacolumn Cellulose Acetate Beads after Granulocytapheresis.

Adacolumn is a therapeutic mode for ulcerative colitis that achieves therapeutic efficacy through the adhesion of leukocytes to cellulose acetate beads. We used scanning electron microscopy and observed leukocyte adsorption on Adacolumn beads after granulocytapheresis/granulocyte and monocyte adsorption apheresis. We then compared results between two patients with a low and high C-reactive protein (CRP) levels to determine whether adhesion is affected by a difference in leukocyte activity depending on the level of inflammation. We found that the surface layers of the beads from both patients were covered by a clay-like layer, and spherical granulocytes were adsorbed here and there on top of it. In cross-section the adsorbed granulocytes were visible in the clay-like layer and the surface layer alike. The clay-like layer had a maximum thickness of approximately 12 µm in the low CRP patient and approximately 50 µm in the high CRP patient, so in the high CRP patient the clay-like adsorption layer was thicker. Taken together, adsorption onto beads is considered to involve an immunological mechanism. Our findings suggest that granulocytes contact and adhere to each other at the surface layer after adsorption, and that granulocyte-granulocyte adhesion is enhanced by a higher inflammatory response.

Cellulose Acetate Electrophoresis of Hemoglobin.

The electrophoresis on cellulose acetate membrane is most widely used because of its simplicity, and is without the use of any sophisticated instrument other than electrophoresis apparatus and the cellulose acetate strip. Here we describe a modified version of cellulose acetate membrane electrophoresis for hemoglobin separation from blood sample. Sharp, clear bands without tailing effects can be obtained with this method. The method and apparatus described here would be appropriate to separate protein fractions under 1 h at voltages up to 60 V/cm measured between the electrodes.

Human albumin purification: a modified and concise method.

BACKGROUND: Among different proteins of blood, albumin is considered a unique protein due to having special properties. Now, various protocols are used for the albumin purification worldwide, each of them has its own advantages and disadvantages. Meanwhile, a common method which is often used for the production of albumin is a combination of Cohn along with different types of chromatography. The aim of the present study was to create a concise and cost-effective albumin purification method by employing a conventional method with some modifications. METHODS: In this research, the albumin was purified from human serum using chilled ethanol, followed by chromatographic methods. The purity of harvested albumin was evaluated by cellulose acetate membrane electrophoresis (CAME) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Western blotting (WB) analysis and thermostability were used for functional and stability measurement assessment, respectively. RESULTS: SDS-PAGE and CAME showed that the purity of purified human albumin was about 99%. Purified human albumin showed a single band with a molecular weight of 66 kDa. The results were validated by WB analysis .Also, the thermostability of purified albumin was same as the commercial albumin. CONCLUSION: This method can be a robust technique for purification of albumin in order to use clinical and research approaches.

One-pot analysis of sulfated glycosaminoglycans.

Routine isolation, estimation, and characterization of glycosaminoglycans (GAGs) is quite challenging. This is compounded by the fact that the analysis is technique-intensive and more often there will be a limitation on the quantity of GAGs available for various structural, functional and biological studies. In such a scenario, the sample which can be made available for estimation and elucidation of disaccharide composition and species composition as well remains a challenge. In the present study, we have determined the feasibility where isolated sulfated GAGs (sGAG) that is estimated by metachromasia is recovered for further analysis. sGAG-DMMB complex formed after estimation of sGAG by DMMB dye-binding assay was decomplexed and sGAGs were recovered. Recovered sGAGs were analysed by cellulose acetate membrane electrophoresis and taken up for disaccharide composition analysis by HPLC after fluorescent labelling. Good recovery of sGAGs after metachromasia was observed in all samples of varying levels of purity by this protocol. Further analysis using cellulose acetate membrane electrophoresis showed good separation between species of sGAGs namely chondroitin/dermatan sulfate and heparan sulfate, with comparatively lesser interference from hyaluronic acid, a non-sulfated GAG. Analysis of recovered sGAGs, specifically heparan sulfate by HPLC showed characteristic disaccharide composition akin to that of GAG obtained by the conventional protocol. Thus, in the present paper, we show that sGAG can be recovered in comparatively purer form after routine estimation and can be used for further analysis thus saving up on the precious sample.

Evaluation of usefulness of a commercial agarose gel electrophoresis kit (QuickGel SP) for bovine serum protein electrophoresis.

The aim of this study was to show the usefulness of a commercial agarose gel electrophoresis (AGE) kit (QuickGel SP) for separating bovine serum protein fractions in comparison with conventional cellulose acetate electrophoresis (CAE). Serum protein bands were verified using five reference reagents corresponding to albumin and α1-, ß1-, ß2-, and γ-globulins. AGE clearly revealed six separated fractions of albumin and α1-, α2-, ß1-, ß2-, and γ-globulin fractions in 100% and 77.8% in serum samples of dairy cows from the healthy (n=27) and diseased groups (n=27), respectively. The α1- and α2-globulins were not separated by CAE in 14.8% and 96.3% of the samples from the healthy and diseased groups, respectively, whereas ß2- and γ-globulin were not separated by CAE in 96.3% and 100% of the samples from the healthy and diseased groups, respectively. More than 94% of the points for the α-globulin fractions (α1- and α2-globulins), the ß-γ-globulin fractions (ß1-, ß2-, and γ-globulins), and the albumin/globulin ratio between AGE and CAE were within agreement on the Bland-Altman plots. However, the mean biases were not near zero in the albumin and ß-γ-globulin fractions. These results suggest that the high-resolution commercial AGE kit can be utilized to separate bovine serum protein fractions.

Misleading presentation of haemoglobin electrophoresis data.

Haemoglobinopathies are common in sub-Saharan Africa. As such haemoglobin electrophoresis are required to inform clinical decision making. However, haemoglobin electrophoresis is an assay that detects protein at either alkaline or acidic pH. Such assays do not interrogate gene sequences but rather the product of a gene. As many post-transcriptional and post-translational modifications impact the final output of the gene (i.e. protein), presentation of such protein-based assay must accurately reflect the technique employed. It is grossly misleading and scientifically inaccurate to report cellulose acetate and/or citrate agar haemoglobin electrophoresis results as 'haemoglobin genotype'. We propose a new paradigm in which haemoglobin electrophoresis data would be presented as 'haemoglobin phenotype' at a specified pH. FUNDING: None declared.

Preliminary Evaluation of a Point-of-Care Testing Device (SickleSCAN™) in Screening for Sickle Cell Disease.

Sickle cell disease affects about 150,000 births annually in Nigeria. Early diagnosis is hampered by factors such as centralized and urban localization of laboratories, high cost of diagnostic equipment and inadequate skilled manpower to operate them. The need for a low-cost, portable, easy-to-use diagnostic test for sickle cell disease is critical, especially in resource-poor countries. In this study, we evaluated the performance characteristics of a novel point-of-care testing device (SickleSCAN™), and its acceptability and feasibility, as a possible screening tool for sickle cell disease. In the first phase, we assessed the performance characteristics of SickleSCAN™ by evaluating 57 subjects comprising both children and adults attending a primary health center, for Hb SS (ßS/ßS; HBB: c.20A>T), Hb SC (ßS/ßC; HBB: c.19G>A) and Hb AS (ßA/ßS) using SickleSCAN™, cellulose acetate electrophoresis (CAE) and high performance liquid chromatography (HPLC). Performance characteristics such as diagnostic sensitivity and specificity were compared to HPLC as a standard method. We subsequently undertook a second phase wherein the acceptability and feasibility of the device for sickle cell disease screening, was evaluated using semi-structured and structured questionnaires among 197 healthcare personnel and 221 subjects, respectively. Sickle cell disease was carried by 3.4% of the subjects. The diagnostic sensitivity, specificity and test efficiency of SickleSCAN™ for sickle cell disease (Hb SS and Hb SC), were 100.0, 98.2 and 98.2%, respectively. Findings from this study showed SickleSCAN™ to be a viable screening tool that can easily be applied in community-based screening for early diagnosis of sickle cell disease with little expertise and low cost.

The role of topically applied l-ascorbic acid in ex-vivo examination of burn-injured human skin.

Wound treatment and healing is complex and is comprised of an elaborate set of processes including cellular, spectroscopic and biochemical ones as well as the "reaction" of local tissue to thermal injury. Vitamin C as l-ascorbic acid (LA) prevents injurious effects of oxidants because it reduces reactive oxygen species to stable molecules, it becomes oxidized to the short-lived ascorbyl radical. As a result, antioxidant treatment may contribute to minimizing injury in burn patients. The aim of this study is to assess changes in molecular structure of collagen extracted from human epidermis burn wound scab during incubation of the epidermis in l-ascorbic acid solution. The study will be performed using FTIR and FT Raman spectroscopies. During this research it was observed that the intensity of Raman peaks increased where healing was being modified by LA. The intensity of the amide III band at 1247cm-1 relative to the intensity at 1326cm-1 was used to test tissue repair degree at the incision site. FTIR spectra were recorded from frozen specimens of serum modified by LA; an analysis of shifts in the amide I band position was conducted. The appearance of a new band for frozen samples modified by LA was observed around 1149-1220cm-1. The above conclusions confirmed the creation of hydrogen bonds between NH stretch and CO. Samples being incubated in solutions of l-ascorbic acid demonstrated the absence of electrophoretic bands of albumin. Alterations in the surface of the skin incubated in l-ascorbic acid were investigated with the use of Scanning Electron Microscopy (SEM). A decrease in external symptoms of burn injury was noted in the damaged epidermis incubated in l-ascorbic acid.

Ion-imprinted silica adsorbent modified diffusive gradients in thin films technique: Tool for speciation analysis of free lead species.

A new diffusive gradients in thin films (DGT) device, using Pb(II) ion-imprinted silica (IIS) as the binding agents and commercial cellulose acetate dialysis (CAD) membrane as the diffusion layer (CAD/IIS-DGT), has been developed and evaluated for sampling and measurement of free Pb(II) species. The CAD/IIS-DGT devices were successfully applied to the measurement of free Pb(II) species in synthetic solutions, in natural freshwaters and in industrial wastewaters. The CAD/IIS-DGT provides reliable results over pH range of 4.5-6.5 and a wide range of ionic strength from 1.0×10(-3) to 0.7 mol L(-1). The concentrations of the free Pb(II) species in synthetic solution containing different concentrations of ligands measured by CAD/IIS-DGT showed a good agreement with the value measured by Pb-ion selective electrode. Field deployments of the CAD/IIS-DGT devices allowed accurate measurements of the concentrations of free Pb(II) species.

Succinylation-Alcian Blue Staining of Mucins on Polyvinylidene Difluoride Membranes.

Alcian blue staining has been widely used to visualize acidic mucins and mucopolysaccharides in supported molecular matrix electrophoresis (SMME) and on membrane transferred from electrophoresis gels. Mucins with low acidic glycan content, however, cannot be stained with Alcian blue, which is one of the major drawbacks of this staining method. On the other hand, periodic acid-Schiff staining can selectively visualize glycoproteins, including mucins, regardless of the acidic residue content; however, periodic acid-Schiff staining decomposes glycans. Here, we introduce succinylation-Alcian blue staining as an alternative staining method to visualize mucins, regardless of the acidic residue content, and without glycan decomposition.

Electrophoretic separation of alginic sodium diester and sodium hexametaphosphate in chondroitin sulfate that interfere with the cetylpyridinium chloride titration assay.

The most commonly used chondroitin sulfate (CS) assay method is cetylpyridinium chloride (CPC) titration. Cellulose acetate membrane electrophoresis (CAME) is the technique used for detection of impurities in the U.S. Pharmacopeia's CS monograph. Because CPC titration is a relatively nonspecific quantitative technique, the apparent amount of CS as determined by CPC titration alone may not reflect the true amount of CS due to possible interference with the CPC assay by impurities that contain CPC titratable functional groups. When CAME is used in conjunction with CPC titration, certain non-CS and adulterants can be visualized and estimated, and a true value for CS can be assigned once the presence of these non-CS impurities has been ruled out. This study examines conjunct application of CPC and CAME in ascertaining CS assay and purity in the presence of certain adulterants. These include propylene glycol alginate sulfate sodium, known in commerce as alginic sodium diester (ASD), and Zero One (Z1), a water-soluble agent newly reported in the CS marketplace and subsequently identified as sodium hexametaphosphate. ASD, Z1, and CS are similar in physical appearance and solubility in water and ethanol. They are also titratable anions and form ionic pairs with CPC, therefore interfering with the CPC titration assay for CS CAME separates these adulterants from each other and from CS by differences in their electrophoretic mobility. CAME is able to detect these impurities in CS at levels as low as 0.66% by weight. Although it is recommended that a method for detecting impurities (e.g., CAME) be used in cormbination with relatively nonspecific assay methods such as CPC titration, this is seldom done in practice. Assay results for CS derived fromn CPC titration may, therefore, be misleading, leaving the CS supply chain vulnerable to adulteration. In this study, the authors investigated ASD and Z1 adulteration of CS and developed an electrophoretic separation of these adulterants in CS and procedures to isolate ASD from CS matrixes containing these adulterants. The authors describe in this paper utilization of an orthogonal approach to establish the identity of Z1 as sodium hexametaphosphate and to confirm the identity of ASD, including ethanol fractionation, FTIR spectroscopy, differential scanning calorimetry, and NMR spectroscopy. The authors suggest that CAME is a cost-effective and easy to use methodfor detecting certain impurities in CS raw ingredients and recommend that CPC and CAME be used in combination by QC laboratories as a means of effectively deterring the practice of adulterating CS raw materials with the known adulterants ASD and Z1 and/or other non-chondroitin substances that can be separated from CSby CAME and that exhibit CPC titration behavior similar to CS.

Polimorfismo genético da glicose-6-fosfato desidrogenase na população da região de Araraquara, Estado de São Paulo / Genetic polymorphism of glucose-6-phosphate dehydrogenase in the population of Araraquara, State of São Paulo

The most important role played by the enzyme Glucose-6-Phosphate Dehydrogenase (G6PD) in erythrocyte metabolism is in generating energy and reducing power used to protect the cell against oxidative attack. G6PD deficiency is the erythroenzymopathy that most frequently causes hemolytic anemia, and more than 130 molecular variants have already been identified. The aim of this study was to analyze the genetic mutations in the G6PD-deficient adult males in the population of the region of Araraquara, São Paulo State. Out of 5087 male blood donors, 89 were deficient for G6PD, as confirmed by assaying the enzyme activity and electrophoresis on cellulose acetate. Thus, a frequency of 1.75% of G6PD-deficient patients was found, this value being similar to other investigations in São Paulo state. Molecular analysis was performed by amplification of genomic DNA with specific primers and digestion with restriction enzymes. In 96.6% of the patients, the G6PD A¯ variant was observed, with mutations at residues 376(A-G) and 202(G-A). Mean G6PD specific activity among the patients was 1.31 IU.g Hb-1.min-1 at 37ºC, that is 10.8% of the normal activity of the G6PD B enzyme. The variant forms G6PD A¯680(G-T) and 968(T-C) were not found. In 3.4% of the deficient individuals, the G6PD Mediterranean variant was found, with a mutation at 563(C-T). In these cases,mean enzymatic activity was 0.25 IU.g Hb-1.min-1 at 37ºC, or 2.1% of the enzymatic activity of G6PD B. Theuse of traditional techniques, allied to the identification of the different molecular variants, is important for the understanding of the structural and functional properties and hemolytic behavior of the red blood cells of the patient...

A importância da enzima Glicose-6-fosfato desidrogenase (G6PD) no metabolismo eritrocitário está na obtenção de energia calórica e redutora para a proteção celular contra agressões oxidativas. A deficiência de G6PD é a eritroenzimopatia que causa mais frequentemente anemia hemolítica, com mais de 130 variantes moleculares identificadas. O objetivo deste estudo foi realizar a análise molecular da deficiência de G6PD em uma população masculina adulta da região de Araraquara, SP, para a identificação das mutações genéticas. Nos 5087 doadores de sangue do sexo masculino pesquisados, foram encontrados 89 deficientes de G6PD, confirmados pela determinação da atividade enzimática e eletroforese em acetato de celulose, com frequência de 1,75%, valores semelhantes aos encontrados por outros pesquisadores no Estado de São Paulo. A análise molecular realizada pela amplificação do DNA genômico com iniciadores específicos e digestão com enzimas de restrição, demonstrou que 96,6% dos deficientes apresentaram a variante G6PD A¯, com as mutações 376(A-G) e 202(G-A) e atividade enzimática média de 1,31 UI.g de Hb-1.min-1 a 37ºC, correspondendo a 10,8% da atividade enzimática da enzima normal G6PD B. Não foram encontradas as formas variantes G6PD A¯ 680(G-T) e 968(T-C). Em 3,4% dos indivíduos deficientes, foi encontrada a variante G6PD Mediterrânea, mutação 563(C-T) e atividade enzimática média de 0,25 UI.g de Hb-1.min-1 a 37ºC, correspondendo a 2,1% da atividade enzimática da G6PD B. A utilização das técnicas tradicionais, aliadas à identificação da variante molecular, são importantes na compreensão das propriedades estruturais, funcionais e comportamento hemolítico dos glóbulos vermelhos do paciente...

ß-Globin gene sequencing of hemoglobin Austin revises the historically reported electrophoretic migration pattern.

CONTEXT: Hemoglobin (Hb) Austin was defined in 1977, using amino acid sequencing of samples from 3 unrelated Mexican-Americans, as a substitution of serine for arginine at position 40 of the ß-globin chain (Arg40Ser). Its electrophoretic migration on both cellulose acetate (pH 8.4) and citrate agar (pH 6.2) was reported between Hb F and Hb A, and this description persists in reference literature. OBJECTIVES.-To review the clinical features and redefine the diagnostic characteristics of Hb Austin. DESIGN: Eight samples from 6 unrelated individuals and 2 siblings, all with Hispanic surnames, were submitted for abnormal Hb identification between June 2010 and September 2011. High-performance liquid chromatography, isoelectric focusing (IEF), citrate agar electrophoresis, and bidirectional DNA sequencing of the entire ß-globin gene were performed. RESULTS: DNA sequencing confirmed all 8 individuals to be heterozygous for Hb Austin (Arg40Ser). Retention time on high-performance liquid chromatography and migration on citrate agar electrophoresis were consistent with that identification. Migration on IEF, however, was not between Hb F and Hb A, as predicted from the report of cellulose acetate electrophoresis. By IEF, Hb Austin migrated anodal to ("faster than") Hb A. CONCLUSIONS: Hemoglobin Austin (Arg40Ser) appears on IEF as a "fast," anodally migrating, Hb variant, just as would be expected from its amino acid substitution. The cited historic report is, at best, not applicable to IEF and is probably erroneous. Our observation of 8 cases in 16 months suggests that this variant may be relatively common in some Hispanic populations, making its recognition important. Furthermore, gene sequencing is proving itself a powerful and reliable tool for definitive identification of Hb variants.