Navigating the Challenge: Selecting the Optimal Assay for Serum Albumin Measurement

Photometric techniques are the most common methods for measuring serum albumin, where albumin binds with an organic dye to form a complex. These methods are popular due to their simplicity, automation potential, speed, and cost-effectiveness, with bromocresol green (BCG) and bromocresol purple (BCP) being the most frequently used dyes.

A 2-year-old boy presented with facial swelling, starting around the eyes in the morning and gradually spreading to the face, improving by evening, and accompanied by reduced urine output. He was diagnosed with nephrotic syndrome and treated with a high-calorie, high-protein diet, oral prednisolone, furosemide, and intravenous albumin. Despite treatment, his local laboratory's serum albumin level remained consistently low. However, tests from a private lab showed levels higher than the state lab. The nephrology team was informed of this discrepancy and chose to rely on the private lab's results.

A comparison study between BCP and BCG methods found a good correlation overall, but Bland-Altman analysis revealed that BCG had a significant positive bias compared to BCP, explaining the lab discrepancies. The study underscored the importance of clinician awareness of different serum albumin measurement methods, noting that BCP is more specific and does not overestimate albumin in kidney disease patients like BCG does.