A fluorescence immunochromatographic assay for rapid and sensitive detection of human prealbumin in serum

Abstract

Protein-energy malnutrition is a significant problem among hospitalized patients. Prealbumin, a plasma protein, is commonly used in clinical practice to assess nutritional status. Prealbumin is also a powerful predictor of mortality risk in dialysis patients. Variation in prealbumin concentration provides valuable information regarding malnutrition and diagnostic applications. Fluorescent microspheres, which combine with anti-human prealbumin monoclonal antibodies, were introduced into an immunochromatographic assay for quantitative detection of human prealbumin in serum. A sandwich immunoassay was developed and the fluorescence intensity of the test line in the test strip was proportional to the prealbumin content in the specimens. The fluorescence intensities of the test and control lines were recorded using a commercial fluorescence strip reader. The results showed that the limit of detection of prealbumin reached 1.0 ng mL⁻¹ within 20 min with a good linear range of 8.0 ng mL⁻¹ to 110.0 ng mL⁻¹. Serum specimens can be diluted 5000 times to avoid matrix interference. The average intra- and inter-assay recoveries ranged from 95.7% to 102.8% and 95.3% to 105.6% respectively, with corresponding variation coefficients of 3.3% to 4.3% and 4.1% to 9.9%. The test strip showed no cross-reaction with hemoglobin and albumin. A significantly good agreement was observed between the test strip and immunoturbidimetric assay. The developed novel assay in this study is a sensitive, specific, reproducible, time-saving, inexpensive, and quantitative method for detection of human prealbumin in serum.