Binding of bromocresol green and bromocresol purple to albumin in hemodialysis patients

作者：Delanghe Sigurd; Van Biesen Wim; Van de Velde Nadeige; Eloot Sunny; Pletinck Anneleen; Schepers Eva; Glorieux Griet; Delanghe Joris R^*; Speeckaert Marijn M

来源：Clinical Chemistry and Laboratory Medicine, 2018, 56(3): 436-440.

DOI：10.1515/cclm-2017-0444

• albumin
• bromocresol green
• bromocresol purple
• carbamylation
• para-cresyl sulfate
• uremic toxins

Background: Colorimetric albumin assays based on binding to bromocresol purple (BCP) and bromocresol green (BCG) yield different results in chronic kidney disease. Altered dye binding of carbamylated albumin has been suggested as a cause. In the present study, a detailed analysis was carried out in which uremic toxins, acute phase proteins and Kt/V, a parameter describing hemodialysis efficiency, were compared with colorimetrically assayed (BCP and BCG) serum albumin.
Methods: Albumin was assayed using immunonephelometry on a BN II nephelometer and colorimetrically based on, respectively, BCP and BCG on a Modular P analyzer. Uremic toxins were assessed using high-performance liquid chromatography. Acute phase proteins (C-reactive protein and alpha(1)-acid glycoprotein) and plasma protein alpha(2) macroglobulin were assayed nephelometrically. In parallel, Kt/V was calculated.
Results: Sixty-two serum specimens originating from hemodialysis patients were analyzed. Among the uremic toxins investigated, total para-cresyl sulfate (PCS) showed a significant positive correlation with the BCP/BCG ratio. The serum alpha(1)-acid glycoprotein concentration correlated negatively with the BCP/BCG ratio. The BCP/BCG ratio showed also a negative correlation with Kt/V.
Conclusions: In renal insufficiency, the BCP/BCG ratio of serum albumin is affected by multiple factors: next to carbamylation, uremic toxins (total PCS) and alpha(1)-acid glycoprotein also play a role.

• 出版日期2018-3