Serum Proteins by Capillary Zone Electrophoresis: Approaches to the Definition of Reference Values

Abstract

The Paragon CZE 2000 (Beckman Analytical, Milan, Italy) is an automatic dedicated capillary zone electrophoresis (CZE) system, producing a five-zone serum protein pattern with quantitative estimation of the zones. With the view of substituting this instrument for two previously used serum protein electrophoresis techniques, we planned to produce reference values for the "new" systems leading to compatible interpretation of the results. High resolution cellulose acetate electrophoresis with visual inspection and descriptive reporting (HR-CAE) and five-zone cellulose acetate electrophoresis with densitometry (CAE-D) were the previously used techniques. Serum samples (n = 167) giving "normal pattern" with HR-CAE were assayed with the CZE system, and the results were statistically assessed to yield 0.95 reference intervals. One thousand normal and pathological serum samples were then assayed with the CAE-D and the CZE techniques, and the regression equations of the CAE-D values over the CZE values for the five zones were used to transform the CAE-D reference limits into the CZE reference limits. The two sets of reference values thereby produced were in good agreement with each other and also with reference values previously reported for the CZE system. Thus, reference values for the CZE techniques permit interpretation of results coherent with the previously used techniques and reporting modes.

Establishment of Reference Intervals for Serum Protein Electrophoresis of Apparently Healthy Adults in Addis Ababa, Ethiopia

“…The RIs provided by the reagent manufacturer in France, 15 and other published RIs in Belgium, 14 the USA, 17 Switzerland, 18 Japan, 19 Italy, 20 and France 22 revealed a combined RI for both males and females for all serum protein fractions. But a study conducted by Lim et al 24 recommended the establishment of gender-specific RIs, which would play a crucial role in the interpretation of laboratory results of serum protein fractions.…”

“…The lower percentile is concordant with RIs established by Petrini et al in Italy. 20 In the established RIs, females have a higher upper limit (97.5th percentile) for all globulin fractions (alpha-1 globulin, alpha-2 globulin, beta-1 globulin, beta-2 globulin, and gamma globulin) than males. This study is in agreement with findings of Bossuyt et al in Belgium 13 for alpha and alpha-2, but differs in gamma globulin, which is the same for male and females.…”

“…In recent times, it has been reported as a novel inflammatory indicator for prognosis in various cancers, such as colorectal cancer, lung cancer, esophageal cancer, and breast cancer. 23 This study established RIs for the albumin to globulin ratio, which had not been provided by the manufacturer of reagents in France 15 or in the study conducted by Bossuyt et al in Belgium, 13 or with other published RIs in Belgium, 13,14 the USA, 17 Switzerland, 18 Italy, 20,21 Japan, 19 and France. 22 Except for beta-2 globulin, the RIs established in the current study had a higher upper percentile in all globulin fractions (alpha-1 globulin, alpha-2 globulin, beta-1 globulin, beta-2 globulin, and gamma globulin) compared to the values provided by the reagent manufacturer in France.…”

Miniaturized Electrophoresis: An Evolving Role in Laboratory Medicine

“…Though the CZE method gave higher reference intervals, the results indicate that CE is a reliable, faster, automated alternative to AGE and CAE. Petrini et al (74) furthered these studies, com-paring reference values obtained with the Paragon CZE 2000 and CAE densitometry, analyzing 1000 random normal and pathological serum samples. The two sets of reference values were in good agreement with each other and with reference values previously reported for CZE systems.…”

The multivariate coefficient of variation for comparing serum protein electrophoresis techniques in external quality assessment schemes

“…As for other analytes, the electrophoretic technique is an important factor likely to influence the final results. These techniques essentially depend on the media (agarose gel, cellulose acetate electrophoresis [1]) or on the analytical principle (e.g., the recently developed capillary zone electrophoresis [2][3][4]). In a recent paper [5], we proposed a robust multivariate method to analyse EQA electrophoresis data.…”