Open AccessMethodological evaluation and comparison of five urinary albumin measurements
Author(s) -
Liu Rui,
Li Gang,
Cui XiaoFan,
Zhang DongLing,
Yang QingHong,
Mu XiaoYan,
Pan WenJie
Publication year - 2011
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.20477
Subject(s) - nephelometry , turbidimetry , microalbuminuria , radioimmunoassay , urine , albumin , chromatography , immunoassay , chemistry , coefficient of variation , albuminuria , urinary system , medicine , urology , kidney disease , immunology , renal function , antibody
Background : Microalbuminuria is an indicator of kidney damage and a risk factor for the progression kidney disease, cardiovascular disease, and so on. Therefore, accurate and precise measurement of urinary albumin is critical. However, there are no reference measurement procedures and reference materials for urinary albumin. Methods : Nephelometry, turbidimetry, colloidal gold method, radioimmunoassay, and chemiluminescence immunoassay were performed for methodological evaluation, based on imprecision test, recovery rate, linearity, haemoglobin interference rate, and verified reference interval. Then we tested 40 urine samples from diabetic patients by each method, and compared the result between assays. Results : The results indicate that nephelometry is the method with best analytical performance among the five methods, with an average intraassay coefficient of variation (CV) of 2.6%, an average interassay CV of 1.7%, a mean recovery of 99.6%, a linearity of R =1.00 from 2 to 250 mg/l, and an interference rate of <10% at haemoglobin concentrations of <1.82 g/l. The correlation ( r ) between assays was from 0.701 to 0.982, and the Bland–Altman plots indicated each assay provided significantly different results from each other. Conclusion : Nephelometry is the clinical urinary albumin method with best analytical performance in our study. J. Clin. Lab. Anal. 25:324–329, 2011. © 2011 Wiley‐Liss, Inc.