Acquired bisalbuminemia: A case report.

Quantitative measurement of serum monoclonal protein (M-protein) is one of the most important tools for monitoring disease activity in monoclonal gammopathies. The aims of this study were to evaluate serum M-protein quantification by capillary zone electrophoresis (CZE) and to compare results with those obtained by densitometric scanning of high-resolution agarose gel electrophoresis (HRE-AGE). The evaluation was carried out on 82 samples from patients with various monoclonal gammopathies. All the suspected M-proteins were confirmed and characterised by immunofixation on agarose gel (IFE). CZE was performed on a Paragon CZE 2000 system (Beckman Coulter). Passing-Bablok regression was: y (CZE)=1.27 x(HRE-AGE)-5.21 g/L. The correlation coefficient was 0.92. Bland-Altman analysis demonstrated a mean difference of -1.83 g/L (95% CI -0.76 to -2.90) with clear evidence of a concentration-related bias. Densitometry gave higher values at low M-spikes (<20 g/L), whereas CZE gave higher values at large M-spikes (>20 g/L). The concentration-related bias was found to be independent of the immunoglobulin isotype. In conclusion, to compare previous results obtained by M-protein densitometric scanning with those obtained by direct measurement of CZE peaks, the calculation of a univocal transforming factor appears to be unreliable.

Capillary zone electrophoresis (CZE) offers the potential for automating serum protein electrophoretic analysis traditionally performed on standard thin-layer agarose gels. The following describes the use of CZE compared to agarose gel electrophoresis (AGE) for the detection of dysproteinemia and paraproteinemia in a clinical study involving 240 patients. The study includes within-run and between-run reproducibility data on the Paragon CZE 2000 Clinical Capillary Electrophoresis System, in addition to concordance data between the two methodologies. Paraprotein quantitation studies comparing AGE versus CZE were also performed. Reproducibility for the automated CZE system was superior to the AGE system. Improved reproducibility for the CZE method is largely due to measuring protein absorbance directly at 214 nm versus the traditional AGE method that measures the amount of dye adsorbed to protein. Reproducibility data as percent coefficient of variance (% CV) for the five classic bands in a normal control serum for between-run precision ranged from 1.2 to 4.5% for CZE compared to AGE, which ranged from 3.8 to 8.0% CV. Concordance studies between AGE and CZE involving dysproteinemias including hypogammaglobulinemia, polyclonal and monoclonal gammopathies, acute and chronic inflammation, nephrosis, hepatodegenerative disease, cirrhosis, and iron deficiency anemia showed 96% agreement. Paraprotein classification, which compared the CZE immunosubtraction method to immunofixation electrophoresis (IFE) on agarose, showed 100% agreement. Certain dysproteinemias involving beta lipoprotein were in partial concordance due to the inability of the CZE procedure to detect this component. Detection limits for monoclonal gammopathies, providing they were not comigrating with other proteins, were IgG 50 mg/dL, IgM 75 mg/dL, and IgA 75 mg/dL. Paraprotein quantitative studies between the two methods showed less than a +/- 0.2 g/dL variation.

The presence of oligoclonal bands in cerebrospinal fluid (CSF) is used as a diagnostic indicator of multiple sclerosis (MS). These bands, gamma-globulins thought to result from a restricted antibody response directed against autoantigens or viral antigens, are consistent with CSF-specific immunoglobulin synthesis when observed in the spinal fluid and not in the serum. Current methodology commonly involves electrophoresing concentrated CSF with high-resolution agarose gel electrophoresis (HRAGE) followed by protein staining in order to visualize the oligoclonal bands. Capillary zone electrophoresis (CZE) was evaluated as an alternative method. Separation of CSF and serum proteins from 54 patients in a bare silica capillary containing a high pH borate buffer allowed for resolution of the five major zones including the gamma-region and showed a 90% concordance with the results from HRAGE banding studies. Since a simple borate buffer did not provide adequate resolution of the oligoclonal bands in the gamma-region, the separation buffer was augmented with polyethylene glycol (PEG) which provided a significant enhancement in resolution of proteins in this region (24 patient study). In addition to obtaining banding information from electropherograms obtained with these separation conditions, it was feasible to calculate a CSF Index which compared favorably with the results from nephelometry. Finally, we show that zwitterionic additives such as O-phosphorylethanolamine may further enhance resolution and that capallary electrophoresis (CE) may allow oligoclonal banding information to be obtained directly from CSF without concentration.

Physiologic alterations in cerebrospinal fluid proteins occur inter alia with aging. Agarose gel electrophoresis discriminates many cerebrospinal fluid proteins and in addition quantifies concentration alterations. This study aimed to investigate the time course of these alterations in children and to establish normative values for cerebrospinal fluid protein properties. In 202 children without diseases known to alter cerebrospinal fluid, normative protein properties were quantified using nephelometry, ultrafiltration, high-resolution electrophoresis, and Gaussian curve fit densitometry. Total protein and protein concentrations (albumin and gamma-globulins) decreased from birth until 7 months age, and, from then on, increased slightly (transthyretin, albumin, and alpha2-proteins) or strongly (gamma-globulins). Protein proportions (transthyretin and transferrin) increased until about 3 years of age and decreased from then on. These normative values for children as quantified by high-resolution agarose gel electrophoresis are presented in a significance-structured percentile table. The time courses of these cerebrospinal fluid properties reflect physiologic alterations of the blood-brain barrier function during childhood.

Serum protein electrophoresis is widely used for diagnostic and research purposes. Cellulose acetate (CAE) and agarose gel (AGE) electrophoresis are the most frequently used methods, but capillary zone electrophoresis (CZE) is beginning to be used more in veterinary laboratories. However, reference intervals for CZE in animals and comparison studies with the other electrophoretic techniques are lacking, compromising the diagnostic utility of CZE. The aims of this study were to compare results obtained using CAE, AGE, and CZE; to establish reference intervals for CZE in dogs and cats; and to assess the capacity of CZE to detect abnormalities identified by AGE. Serum samples from 204 dogs, including 104 healthy animals, and 62 cats, including 28 healthy animals, were analyzed using automated systems for CAE, AGE, and CZE. Descriptive statistics and Passing-Bablok and Bland-Altman tests were used to compare results. For each technique, reference intervals were calculated based on results from healthy animals. Concordance between CZE and AGE in detecting pathologic changes was assessed using Cohen's k coefficient. For most protein fractions, values obtained by CAE, AGE, and CZE were significantly different from each other, and constant and proportional errors were often detected. Nevertheless, reference intervals obtained by the 3 techniques overlapped. Moreover, Cohen's k coefficient demonstrated that the capacity of CZE and AGE to detect pathologic changes was comparable. CZE performs comparably to AGE and CAE as long as CZE-specific reference intervals are used for interpretation and distinctive visual patterns for albumin, gaps between fractions, and subpeaks found on CZE tracings are recognized. In addition, CZE offers several technical advantages, such as ease of use and complete automation.

Electrophoresis can be used to aid in the diagnosis of different diseases in avian species. Capillary zone electrophoresis (CZE) is an automated method that is proposed to be superior to the dye methods used in agarose gel electrophoresis (AGE). However, reference intervals (RIs) for CZE in avian species and comparison studies between electrophoretic methods are lacking. The goals of the current study were to compare AGE and CZE methods and determine reference intervals for CZE using plasma from bald eagles (Haliaeetus leucocephalus). Heparinized plasma samples from 44 bald eagles (mean age 18.7 years) under managed care were examined by AGE and CZE. Method comparison analyses were completed, as well as the generation of preliminary RIs using the CZE method and ASVCP guidelines. Passing-Bablok regression and Bland-Altman plots demonstrate that these methods are not equivalent. All fractions were significantly correlated between the methods except for alpha 1 globulin. Inter-assay and intra-assay CVs for CZE were lower or comparable to AGE and ranged from 2.4% to 15.4%, and 0.8% to 8.3%, respectively. CZE resolved more fractions than AGE with two fractions observed in the beta and gamma region vs one for AGE in each region. CZE provided improved resolution and reproducibility for the quantitation of protein fractions in the bald eagle. Although most fraction results correlated with AGE, these methods were judged as not equivalent, necessitating method-specific Rls. Reference intervals generated from a limited number of mostly aged individuals under managed care should be considered preliminary; additional studies will aid in the production of more robust intervals.

Capillary zone electrophoresis (CZE) of serum proteins is increasingly gaining impact in clinical laboratories. In this report, we evaluate automated capillary zone electrophoresis by Capillarys (Sebia, France). Within-run and between-run imprecision for the five electrophoretic fractions was <2% and <6%, respectively. Data obtained with Capillarys correlated with results obtained with agarose gel electrophoresis and Paragon CZE 2000 (Beckman Coulter, USA). Analysis of serum obtained from patients with inflammation, nephrotic syndrome, bisalbuminemia, and alpha1-antitrypsin deficiency revealed that Capillarys was able to detect these abnormalities. Two hundred thirty eight samples were analyzed by agarose gel electrophoresis, Capillarys, capillary electrophoresis using Paragon CZE 2000 system, and immunofixation. Sample selection was based on the presence of a disturbed morphology (e.g., spike) of the protein profile or hypogammaglobulinemia on agarose gel electrophoresis and/or Capillarys. Immunofixation revealed the presence of a monoclonal protein, oligoclonal bands, polyclonal pattern, and a normal profile in, respectively, 89, 66, 19, and 64 samples. With Capillarys, Paragon, and agarose gel electrophoresis, a spike and/or disturbed morphology of the profile was found in 222, 182, and 180 samples, respectively. In these samples, immunofixation was negative in 73 (33%), 46 (25%), and 39 (22%) samples, respectively. These data indicate that Capillarys has a lower specificity than agarose gel electrophoresis and Paragon 2000. Of the 89 samples with a monoclonal protein, Capillarys, Paragon, and agarose gel electrophoresis failed to detect, respectively, three, three, and one monoclonal protein(s). Interferences by radio-opaque agents, complement degradation products, fibrinogen, and triglycerides are described. In conclusion, automated capillary zone electrophoresis with Capillarys provides for reproducible, rapid, and reliable serum electrophoresis.

Over the last 5 years, capillary zone electrophoresis (CZE) with the use of fused-silica capillaries has been increasingly introduced in clinical laboratories for routine serum-protein electrophoresis (1). The multichannel, automated Paragon CZE 2000 instrument (seven capillaries in parallel; Beckman Coulter) represented an especially attractive alternative to time-consuming manual techniques. CZE has been documented to perform reliably for the analysis of serum proteins and for the detection of monoclonal components (2)(3). We reported (4) that the sensitivity of the Paragon CZE 2000 system for the detection of monoclonal components (93%) was superior to the sensitivity of cellulose acetate gel electrophoresis (74%) and agarose gel electrophoresis (86%). In a prospective study, Katzman et al. (5) reported sensitivities of 95% and 91% for seven-capillary electrophoresis and agarose gel electrophoresis, respectively. When compared with agarose gel electrophoresis, CZE was able to detect more low-concentration IgA monoclonal components or light chains that were hidden in agarose gel electrophoresis because of comigration with transferrin or C3 (6). Paraproteins that are missed by CZE are typically very low-concentration monoclonal components that are also missed by agarose gel electrophoresis, but not by immunofixation. Problems with the detection of monoclonal components by CZE have been described (7)(8). Using a single-capillary Beckman P/ACE instrument with a capillary and buffer different from the Paragon CZE 2000 system, Jenkins and Guerin (7) performed a prospective study on 5500 specimens in which they compared CZE with agarose gel electrophoresis for the detection of monoclonal components. The authors identified six paraproteins that did not separate correctly on CZE. On agarose gel electrophoresis, all of these proteins migrated in the very slow γ region. The pI …

A selected group of 308 sera were analyzed by capillary electrophoresis (CE), agarose gel electrophoresis (AGE), and cellulose acetate electrophoresis (CAE) and evaluated for abnormalities that would suggest the presence of a monoclonal protein. The sensitivity (an electrophoretic abnormality in sera that contained a monoclonal protein) and specificity (a normal electrophoretic pattern in sera that did not contain a monoclonal protein) was determined for each electrophoretic procedure. CAE was the most specific procedure and CE was the most sensitive. The increase in sensitivity of CE was primarily due to increased detection of cryoglobulins and free light chains. The quantitation of the gamma region and/or monoclonal antibody peaks by CE was similar to results obtained by AGE. Quantitation of very large monoclonal protein peaks (> 3.0 g/dL) by on-line absorption detection (CE) yielded higher results than quantitation by dye-binding (AGE).

Abnormal protein patterns in blood serum and cerebrospinal fluid detected by capillary electrophoresis

Determination of poorly separated monoclonal serum proteins by capillary zone electrophoresis

Three methods of capillary electrophoresis compared with high-resolution agarose gel electrophoresis for serum protein electrophoresis

Evaluation of serum protein separation by capillary electrophoresis: prospective analysis of 1000 specimens

Capillary zone electrophoresis and immune adsorption were evaluated for identification of serum protein abnormalities and immunotyping of monoclonal proteins. A 7-capillary, electrophoresis instrument and solid phase immunosubtraction reagents were used in a prospective study of 1,518 patients. Serum protein electrophoresis was performed by agarose gel electrophoresis and capillary electrophoresis and interpreted with regard to identification of abnormalities consistent with monoclonal gammopathies. The agarose gel electrophoresis had a sensitivity and specificity of 91% and 99%, respectively, whereas capillary electrophoresis gave results of 95% and 99%. Immunotyping of the monoclonal proteins was performed by immunofixation and immunosubtraction. Capillary electrophoresis was more sensitive than agarose gel electrophoresis for the identification of monoclonal proteins in serum. In addition, the immunosubtraction method seems technically simpler and more automated than immunofixation and represents a useful additional approach for immunotyping monoclonal proteins.

Serum protein electrophoresis (SPE) is the first-line test for the diagnosis of monoclonal gammopathies. While agarose gel electrophoresis (AGE) has been the traditional gold standard, capillary zone electrophoresis (CZE) offers potential advantages in terms of resolution and sensitivity. This study aimed to compare the diagnostic accuracy of these two techniques in detecting monoclonal gammopathies. A retrospective study was conducted on 10,909 adult patients without a prior diagnosis of monoclonal gammopathy who underwent SPE between 2017 and 2019. All patients received both AGE using the HYDRASIS 2 SCAN (Sebia, Issy-les-Moulineaux, France) and CZE using the CAPILLARYS 2 instrument (Sebia). Additional laboratory tests, including immunofixation electrophoresis and free light chain quantification in serum and urine, were performed. The final diagnosis was established one year after the initial diagnostic workup. The sensitivity of AGE was 87.6% (95% confidence interval (CI: 86.9 - 88.2), with a specificity of 99.5%. In contrast, CZE demonstrated a sensitivity of 94.2% (CI: 93.8 - 94.6) and a specificity of 98.9%. CZE is a valuable tool for the diagnosis of monoclonal gammopathies, offering improved sensitivity over AGE. However, CZE may struggle to detect certain monoclonal immunoglobulins due to their insolubility in the CZE buffer, leading to precipitation and undetected results on electrophoretic tracings, even at high serum levels. SPE should be used in conjunction with complementary tests to ensure comprehensive detection of monoclonal immunoglobulins.