Protocol - Urinary Microalbumin - Assay
Description
This protocol provides basic instructions for collecting and processing urine according to National Health and Nutrition Examination Survey (NHANES) methods. Albumin concentration is measured according to a fluorescent immunoassay (FIA). The protocol also lists reference ranges for healthy adults.
Specific Instructions
The Diabetes Working Group (WG) recommends that the urine albumin assay be performed on urine collected during a participant’s first morning void but notes that a random sample is also acceptable.
Note from the Diabetes WG: Urine should be stored at -80°C until testing and shipped on dry ice to prevent thawing.
The Sickle Cell Disease Research and Scientific Panel notes that the terms "microalbuminuria" and "macroalbuminuria" have been used clinically to describe different levels of abnormal albumin excretion rate: 30-299 mg/g urine creatinine, and >300 mg/gr urine creatinine, for microalbuminuria and macroalbuminuria, respectively. The Sickle Cell Disease Curative Therapies Working notes that a new terminology has been proposed: "moderately" instead of microalbuminuia, and "markedly increase" for macroalbuminuria. The older terminology could be interpreted as measuring different molecular forms of albumin. Because albuminuria may be affected by non-pathological factors (exercise, menstruation contamination, biological variability, etc.), abnormal values should be confirmed within 1-2 months.
Availability
Protocol
The following is a summary version of the full National Health and Nutrition Examination Survey 2007-2008 protocol.
Urine Collection
Editor’s Note: Please review chapter 5 of the Laboratory Procedures Manual from the National Health and Nutrition Examination Survey 2007-2008 for a full description of urine collection and processing procedures: 2007-2008 NHANES Lab Manual.
The coordinator explains the following instructions to the subject before urine collection:
• Wash hands with soap and water;
• It is important that the cup and cap not touch or come into contact with any parts of the body, clothing, or external surfaces; and
• Close container to minimize exposure to air.
Refrigerate all insufficient urine samples. When additional urine is obtained, pool the urine, mix, and process.
Record the Results of Urine Specimen Collection
Note whether or not urine was collected, and note whether the volume of urine was sufficient or required a second specimen.
Note whether blood is present/visible in the specimen.
Process the Urine for the Urinary Albumin Assay
Pour 3 mL of the specimen for urine albumin into a 5 mL vessel.
Laboratory Procedure for Urinary Albumin
The Diabetes Working Group (WG) recommends that urine albumin concentration be determined according to a fluorescent immunoassay such as the one developed by the University of Minnesota for use in the National Health and Nutrition Examination Survey: Urinary Albumin Lab Assay.
To aid comparability, the Diabetes WG recommends that the investigator record the make and manufacturer of equipment used and the repeatability and coefficients of variation for the assay.
REFERENCE RANGES
(From the NHANES/University of Minnesota laboratory protocol)
| Urinary Albumin in Healthy Subjects | |||||
| Number of Subjects | Author | Method | mg/L μg/mL | μg/min | mg/24 h |
| 100 adults | Chavers et al. (1994) | FIA | 0.2-17.3* | 0.8-14.6 | 1.1-21.0 |
| 20 adults | Mogenson (1976) | RIA | 5-20 | 3.6-23.0 | |
| 11 adults | Howey et al. (1987) | RIA | 8.13+ | 7.1**,+ | 10.2+ |
| 20 children | Fielding et al. (1983) | ELISA | 1.2-15.9** | 1.7-22.9 | |
| NHANES III | Jones et al. (2002) | FIA | < 30 | ||
* obtained from subject data in the published manuscript. ** calculated from published units. + mean values.
Personnel and Training Required
Personnel to collect the urine Laboratory to perform the fluorescent immunoassay
Equipment Needs
Supplies to collect and process urine
Requirements
| Requirement Category | Required |
|---|---|
| Major equipment | No |
| Specialized training | No |
| Specialized requirements for biospecimen collection | No |
| Average time of greater than 15 minutes in an unaffected individual | No |
Mode of Administration
Bioassay
Lifestage
Child, Adolescent, Adult, Senior
Participants
Participants 6 years of age and older
Selection Rationale
The National Health and Nutrition Examination Survey 2007-2008 protocol was selected as the best methodology and one of the most widely used protocols to measure urine creatinine. Additionally, the fluorescent immunoassay (FIA) protocol used by NHANES and developed by the University of Minnesota has been used in other studies, including Atherosclerosis Risk in Communities (ARIC) and Family Investigation of Nephropathy and Diabetes (FIND).
Language
Chinese, English, Other languages available at source
Standards
| Standard | Name | ID | Source |
|---|---|---|---|
| Logical Observation Identifiers Names and Codes (LOINC) | Urinary microalbumin assay proto | 62809-9 | LOINC |
| Human Phenotype Ontology | Abnormal Renal Physiology | HP:0012211 | HPO |
| caDSR Form | PhenX PX141501 - Urinary Microalbumin Assay For Kidney Function | 6170154 | caDSR Form |
Derived Variables
Albuminaria Ratio of urine microalbumin to urine creatinine
| Albuminuria | Ratio of albumin / creatinine (ug/mg) |
| Normal | < 30 |
| Moderately increased | 30-299 |
| Markedly increased | > 300 |
Process and Review
The Expert Review Panel #1 reviewed the measures in the Anthropometrics, Diabetes, Physical Activity and Physical Fitness, and Nutrition and Dietary Supplements domains.
Guidance from the ERP includes:
• Changed the name of measure
• Revised descriptions of measure
Back-compatible: no changes to Data Dictionary
Previous version in Toolkit archive (link)
Protocol Name from Source
National Health and Nutrition Examination Survey (NHANES), Laboratory Procedures Manual, 2007
Source
Centers for Disease Control and Prevention (CDC), National Center for Health Statistics (NCHS). (2007). National Health and Nutrition Examination Survey Questionnaire. Laboratory Procedures Manual. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention.
Centers for Disease Control and Prevention (CDC), National Center for Health Statistics (NCHS). (2007). National Health and Nutrition Examination Survey Questionnaire. University of Minnesota Laboratory Procedures Manual for Urinary Albumin by Sequoia-Turner Digital Fluorometer, Model 450. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention.
General References
References for Reference Values from the lab protocol:
Allon, M., Lawson, L., Eckman, J.R., Delaney, V., & Bourke, E. (1988). Effects of nonsteroidal antiinflammatory drugs on renal function in sickle cell anemia. Kidney International, 34, 500-506.
American Diabetes Association (ADA). (2014a). Diagnosis and classification of diabetes mellitus. Diabetes Care, 37(Suppl. 1), S81-S90.
American Diabetes Association (ADA). (2014b). Standards of Medical Care in Diabetes-2014. Diabetes Care, 37(Suppl. 1), S14-S80.
Chapter 1: Definition and classification of CKD. (2013). Kidney international supplements, 3(1), 19-62.
Chavers, B. M., Mauer, S. M., Ramsay, R. C., & Steffes, M. W. (1994). Relationship between retinal and glomerular lesions in IDDM patients. Diabetes, 43, 441-446.
de Jong, P.E., de Jong-Van Den Berg, T.W., Sewrajsingh, G.S., Schouten, H., Donker, A.J.M., & Statius van Eps, L.W. (1980). The influence of indomethacin on renal hemodynamics in sickle cell anemia. Clinical Science, 59, 245-250.
Guasch, A., Cua, M., & Mitch, W.E. (1996). Early detection and the course of glomerular injury in patients with sickle cell anemia. Kidney International, 49, 786-791.
Guasch, A., Navarrete, J., Zayas, C.F., Nass, K., & Eckman, J.R. (2006). Glomerular involvement in adults with sickle hemoglobinopathies: prevalence and clinical correlates of progressive renal failure. Journal of the American Society of Nephrology, 17, 2228-2235.
Fielding, B. A., Price, D. A., & Houlton, C. A. (1983). Enzyme immunoassay for urinary albumin. Clinical Chemistry, 29, 355-357.
Howey, J. E. A., Browning, M. C. K., & Fraser, C. G. (1987). Selecting the optimum specimen for assessing slight albuminuria, and a strategy for clinical investigation: novel uses of data on biological variation. Clinical Chemistry, 33, 2032-2038.
Jones, C. A, Francis, M. E., Eberhardt, M. S., Chavers, B. Coresh, J., Engelgau, M., . . . Agodoa, L. Y. (2002). Microalbuminuria in the US population: Third National Health and Nutrition Examination Survey. American Journal of Kidney Diseases, 39, 445-459.
Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. (2013). KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International Supplement, 3, 1-150.
Mogenson, C. E. (1976). Renal function changes in diabetes. Diabetes, 25, 872-879.
Stevens, P. E., Levin, A., & Kidney Disease: Improving Global Outcomes Chronic Kidney Disease Guideline Development Work Group Members (2013). Evaluation and management of chronic kidney disease: synopsis of the kidney disease: improving global outcomes 2012 clinical practice guideline. Annals of internal medicine, 158(11), 825-830. https://doi.org/10.7326/0003-4819-158-11-201306040-00007
Protocol ID
141501
Variables
Export Variables| Variable Name | Variable ID | Variable Description | dbGaP Mapping | |
|---|---|---|---|---|
| PX141501_Assay_Repeatability | ||||
| PX141501040000 | Repeatability of the assay | N/A | ||
| PX141501_Coefficient_Of_Variation | ||||
| PX141501050000 | Coefficient of variation for the assay | N/A | ||
| PX141501_Equipment_Make | ||||
| PX141501030100 | Make of the equipment used to determine the more | N/A | ||
| PX141501_Equipment_Manufacturer | ||||
| PX141501030200 | Manufacturer of the equipment used to more | N/A | ||
| PX141501_Sample_Comments | ||||
| PX141501020000 | Record any comments about the urine during more | Variable Mapping | ||
| PX141501_Urinary_Microalbumin_Concentration | ||||
| PX141501060000 | Concentration of urinary microalbumin | N/A | ||
| PX141501_Urine_Collection_Comments | ||||
| PX141501010000 | Record any comments about the urine more | N/A | ||
Measure Name
Urinary Microalbumin Assay
Release Date
May 10, 2010
Definition
A bioassay to measure urine concentration of albumin, which is produced by the liver and is the most abundant protein in the blood
Purpose
Albumin is only filtered out of blood by the kidneys when there is damage to the glomeruli, as in diabetes. The earliest measure of this damage is the appearance of small (micro-) amounts of albumin in the urine. Additionally, the ratio of urine albumin to urine creatinine, called microalbuminuria, is used to predict the risk of nephropathy (National Health and Nutrition Examination Survey and University of Minnesota Laboratory Procedure Manual for Urinary Creatinine, 2008).
Keywords
diabetes, nephropathy, kidney, kidney disease, kidney failure, microalbuminuria, macroalbuminuria, NHANES, sickle cell, sickle cell disease, SCD
Measure Protocols
| Protocol ID | Protocol Name |
|---|---|
| 141501 | Urinary Microalbumin - Assay |
Publications
There are no publications listed for this protocol.