Measurement of serum albumin by capillary zone electrophoresis, bromocresol green, bromocresol purple, and immunoassay methods

Abstract

Background/Aims: The introduction of capillary zone electrophoresis (CZE) to this laboratory has highlighted discrepancies in albumin measured on an Abbott Aeroset by bromocresol green (BCG) and that calculated by CZE on the basis of total protein measured by Biuret. Methods: This study examined differences in albumin estimation by CZE, Abbott Aeroset BCG, and Aeroset bromocresol purple (BCP), and compared these with albumin estimated by Beckman Array immunoassay. Results: Altman and Bland analysis of results showed a positive bias of BCG with CZE (4.51 g/litre; 95% limits of agreement, 3.77 to 5.26; n = 72) and BCP (3.85 g/litre; 95% limits of agreement, −1.42 to 9.12; n = 72). CZE and BCP agreed closely (0.67 g/litre; 95% limits of agreement, −4.39 to 3.06; n = 72). Analysis of 57 of those samples in which BCG and CZE differed > 5 g/litre showed a positive bias of BCG with immunoassay (8.35 g/litre; 95% limits of agreement, 1.54 to 15.16; n =57), with good agreement between CZE and immunoassay (−0.44 g/litre; 95% limits of agreement, −2.82 to 1.94; n = 57). Conclusions: BCP is superior to BCG for the assay of albumin and has replaced BCG as the routine test for albumin in this laboratory.

The Relationship Between Nontraditional Risk Factors and Outcomes in Individuals With Stage 3 to 4 CKD

“…These may relate to different processing times, non-specific interference from binding to non-albumin proteins, and laboratory calibration differences. 17,18 Therefore, in the same manner as for serum creatinine, we indirectly calibrated both ARIC and CHS serum albumin levels to NHANES values using a regression equation that also accounted for age and sex. This resulted in 0.23 g/dL (2.3 g/L) being added to ARIC values, 0.03 g/dL (0.3 g/L) added to values in the CHS original cohort, and no change to values in the CHS African American cohort.…”

Laboratory reference intervals during pregnancy, delivery and the early postpartum period

“…The two methods rely on dye binding to ALB, but each dye does so by a different mechanism. Discrepancies between results obtained by the two methods have been described (26)(27)(28), probably due to a matrix effect. Fibrinogen increases during pregnancy by a factor of two (8) and this might account for the difference in measurement of ALB by the two methods (29,30).…”

The impact of change in albumin assay on reference intervals, prevalence of ‘hypoalbuminaemia’ and albumin prescriptions

“…6,8 Comparison of patient sample results from both methods, led us to question the validity of applying the consensus Pathology Harmony reference range for serum albumin for our method and local population. We subsequently evaluated the impact of using the new BCP serum albumin assay in conjunction with the Pathology Harmony reference range on the prescription of albumin infusions.…”