Test Code ALU Aluminum, 24 Hour, Urine
Reporting Name
Aluminum, 24 Hr, UUseful For
Monitoring aluminum exposure
Preferred matrix for assessment of exposure in patients with normal kidney function since rapidly filtered by kidneys
Monitoring metallic prosthetic implant wear
This test is not an acceptable substitute for serum aluminum measurements and is not recommended for routine aluminum screening.
Method Name
Dynamic Reaction Cell Inductively Coupled Plasma Mass Spectrometry (DRC-ICP-MS)
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
UrineOrdering Guidance
The recommended test for routine aluminum screening is AL / Aluminum, Serum.
Necessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic urine container with no metal cap or glued insert
Submission Container/Tube: Plastic urine tube or clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 10 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
3. See Metals Analysis Specimen Collection and Transport for complete instructions.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 28 days | |
Ambient | 28 days | ||
Frozen | 28 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Special Instructions
Reference Values
0-17 years: Not established
≥18 years: <13 mcg/24 hours
Day(s) Performed
Tuesday
CPT Code Information
82108
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
ALU | Aluminum, 24 Hr, U | 26707-0 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
8828 | Aluminum, 24 Hr, U | 26707-0 |
TM15 | Collection Duration | 13362-9 |
VL13 | Urine Volume | 3167-4 |
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.Clinical Information
Under normal physiologic conditions, the usual daily dietary intake of aluminum (5-10 mg) is eliminated completely. Excretion is accomplished by avid filtration of aluminum from the blood by the glomeruli of the kidney. Patients in kidney failure lose the ability to clear aluminum and are candidates for aluminum toxicity.
Many factors increase the incidence of aluminum toxicity in patients with kidney failure:
-Aluminum-laden dialysis water can expose dialysis patients to aluminum.
-Aluminum-laden albumin can expose patients to an aluminum burden they cannot eliminate.
-The dialysis process is not highly effective at eliminating aluminum.
-Aluminum-based phosphate binder gels are administered orally to minimize phosphate accumulation; a small fraction of this aluminum may be absorbed and accumulated.
If it is not removed by kidney filtration, aluminum accumulates in the blood where it binds to proteins such as albumin and is rapidly distributed through the body. Aluminum overload leads to accumulation of aluminum at two sites: brain and bone. Brain deposition has been implicated as a cause of dialysis dementia. In bone, aluminum replaces calcium at the mineralization front, disrupting normal osteoid formation.
Urine aluminum concentrations are likely to be increased above the reference range in patients with metallic joint prosthesis. Prosthetic devices produced by Zimmer Company and Johnson and Johnson typically are made of aluminum, vanadium, and titanium. This list of products is incomplete, and these products change occasionally; see prosthesis product information for each device for composition details.
Interpretation
Daily excretion greater than 10 mcg/24 hours indicates exposure to excessive amounts of aluminum. In kidney failure, the ability of the kidney to excrete aluminum decreases, while the exposure to aluminum increases (aluminum-laden dialysis water, aluminum-laden albumin, and aluminum-laden phosphate binders).
Patients receiving chelation therapy with desferrioxamine (for iron- or aluminum-overload states) also excrete considerably more aluminum in their urine than normal.
Prosthesis wear is known to result in increased circulating concentration of metal ions.(1) Modest increase (10-20 mcg/24 hours) in urine aluminum concentration is likely to be associated with a prosthetic device in good condition. Urine concentrations above 50 mcg/ 24 hours in a patient with an aluminum-based implant and not undergoing dialysis, suggests significant prosthesis wear. Increased urine trace element concentrations in the absence of corroborating clinical information do not independently predict prosthesis wear or failure.
Cautions
Falsely increased results may be obtained if the specimen is collected in nonacid-washed polypropylene collection vessels or if metal caps are used to seal the container. Preanalytical steps (specimen collection and transport) are the most likely processes that can affect the quality of trace metals analysis in clinical samples. Specimens must be collected and processed following these instructions: Metals Analysis Specimen Collection and Transport.
Method Description
The metal of interest is analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)