The Siemens DCA Systems microalbumin/creatinine assay is a quantitative test that measures low concentrations of albumin and creatinine in urine and generates an albumin-to-creatinine ratio. This test is important for early detection of kidney disease in diabetic patients. The reported range of albumin for this assay is 5 to 300 mg/L. To more accurately identify samples with albumin levels of greater than 300 mg/L on the DCA point-of-care systems, several antibody sources were screened and qualified using the Siemens ADVIA 1200 (545 nm) and the Roche COBAS MIRA (500 nm) systems. A research study was conducted on 3 full cartridge lots, and the results are described. Precision testing showed within-run coefficient of variation (%) was 5.8%, 4.7%, and 3.5%, and total coefficient of variation (%) was 6.6%, 5.2%, and 4.3% for the 3 controls tested.Using the ADVIA 1200 as the comparative method, a correlation study was performed on 40 natural human urine samples, ranging from 11 to 275 mg/L of albumin. The combined regression analysis for the 3 lots had a slope of 1.02, an R 2 of 0.98, and an intercept of 1.1 mg/L. Forty natural human urine samples ranging from 2063 to 5987 mg/L of albumin were used to demonstrate high-dose-hook mitigation with the 3 lots. Every result reported was greater than 300 mg/L. Conclusions:The data show that all lots demonstrated excellent precision and correlation with another commercial method. Samples of up to nearly 6000 mg/L of albumin were tested successfully with all 3 lots, and 100% of results were reported as greater than 300 mg/L.

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