Abstract
We tested patients’ urines for albumin, protein, and creatinine by quantitative and dipstick methods. The concentrations of these analytes were established by quantitative, cuvet‐based chemistry methods that we assumed gave the “correct” values. There was good to excellent agreement of the dipstick results with the quantitative methods for the above three analytes. We found many patients who excreted pathological amounts of albumin and/or protein who did not have a diagnosis of kidney disease or other likely causes of proteinuria, suggesting that albuminuria and/or proteinuria were underdiagnosed in our group of patients. Those with cardiovascular disease, kidney disease, or diabetes showed the greatest predictive value of a positive test for albumin or protein by dipstick. Dipstick testing for albumin, protein, and creatinine had good or excellent agreement with quantitative methods. The dipstick tests were easy to use, simple, and low in cost, and can serve well for point‐of‐care testing. J. Clin. Lab. Anal. 15:295–300, 2001. © 2001 Wiley‐Liss, Inc.
Keywords: albumin/creatinine ratio, automated analysis, dye binding, hypertension, immunoassay, microalbuminuria, nephritis, protein/creatinine ratio, proteinuria, urinalysis
REFERENCES
- 1. Mogensen CE, Christensen CK, Vittinghus E. 1983. The stages in diabetic renal disease. Diabetes 32:64–78. [DOI] [PubMed] [Google Scholar]
- 2. Keane W, Eknoyan G. 1999. Proteinuria, albuminuria, risk, assessment, detection, elimination (PARADE): a position paper of the National Kidney Foundation. Am J Kidney Dis 33:1004–1010. [DOI] [PubMed] [Google Scholar]
- 3. Kaplan NM. 1992. Microalbuminuria, a risk factor for vascular and renal complications of hypertension. Am Med 92:8S–12S. [PubMed] [Google Scholar]
- 4. Mogensen CE. 1984. Microalbuminuria predicts clinical proteinuria and early mortality in maturity‐onset diabetes. N Engl J Med 310:356–360. [DOI] [PubMed] [Google Scholar]
- 5. Rachmani R, Levi Z, Lidar M, Slavachevski I, Half‐Onn E, Ravid M. 2000. Considerations about threshold values of microalbuminuria in patients with diabetes mellitus: lessons from an 8‐year follow‐up study of 599 patients. Diabetes Res Clin Pract 49:187–194. [DOI] [PubMed] [Google Scholar]
- 6. Marso SP, Ellis SG, Gurm HS, Lytle BW, Topol E Jr. 2000. Proteinuria is a key determinant of death in patients with diabetes after isolated coronary artery bypass grafting. Am Heart J 139:939–944. [DOI] [PubMed] [Google Scholar]
- 7. Guthrie RM, Lott JA. 1993. Screening for proteinuria in patients with hypertension or diabetes mellitus. J Fam Pract 37:253–255. [PubMed] [Google Scholar]
- 8. Lum G. 2000. How effective are screening tests for microalbuminuria in random urine specimens? Ann Clin Lab Sci 30:406–411. [PubMed] [Google Scholar]
- 9. Hicks JM. 1996. Near patient testing: is it here to stay? J Clin Pathol 49:191–193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10. Pugia MJ, Murakami M, Lott JA, et al. 2000. Screening for proteinuria in Japanese school children: a new approach. Clin Chem Lab Med 38:975–982. [DOI] [PubMed] [Google Scholar]
- 11. Pugia MJ, Lott JA, Profitt JA, Cast TK. 1999. High‐sensitivity dye‐binding assay for albumin in urine. J Clin Lab Anal 13:180–187. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Pugia MJ, Lott JA, Wallace JF, Cast TK, Bierbaum LD. 2000. Assay of creatinine using the peroxidase activity of copper‐creatinine complexes. Clin Biochem 33:63–70. [DOI] [PubMed] [Google Scholar]
- 13. Pugia MJ, Lott JA, Kajima J, et al. 1999. Screening of school children for albuminuria, proteinuria and occult blood with dipsticks. Clin Chem Lab Med 37:149–157. [DOI] [PubMed] [Google Scholar]
- 14. Pugia MJ, Lott JA, Luke KE, Shihabi ZK, Wians FH Jr, Phillips L. 1998. Comparison of instrument‐read dipsticks for albumin and creatinine in urine with visual results and quantitative methods. J Clin Lab Anal 12:280–284. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15. Newman DJ, Pugia MJ, Lott JA, Wallace JF, Hiar AM. 2000. Urinary protein and albumin excretion corrected by creatinine and specific gravity. Clin Chim Acta 29:139–155. [DOI] [PubMed] [Google Scholar]
- 16. Wimsatt DK, Lott JA. 1987. Improved measurement of urinary total protein (including light‐chain proteins) with a Coomassie Brilliant Blue G 250‐sodium dodecyl sulfate reagent. Clin Chem 33:2100–2106. [PubMed] [Google Scholar]
- 17. Price CP, Hicks JC, editors. 1999. Point of care testing. Washington, DC: AACC Press. [Google Scholar]