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HelpTest Code CRS Chromium, Serum
Reporting Name
Chromium, SUseful For
Screening for occupational exposure
Monitoring metallic prosthetic implant wear
Method Name
Inductively Coupled Plasma-Mass Spectometry (DRC-ICP-MS)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumOrdering Guidance
The US Food and Drug Administration recommended test for monitoring chromium in patients with metal-on-metal implants is CRWB / Chromium, Blood.
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: Metal Free Specimen Vial (T173)
Collection Container/Tube: Plain, royal blue-top Vacutainer plastic trace element blood collection tube
Submission Container/Tube: 7-mL Mayo metal-free, screw-capped, polypropylene vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Allow the specimen to clot for 30 minutes; then centrifuge the specimen to separate serum from the cellular fraction.
2. Remove the stopper. Carefully pour specimen into a Mayo metal-free, polypropylene vial, avoiding transfer of the cellular components of blood. Do not insert a pipet into the serum to accomplish transfer, and do not ream the specimen with a wooden stick to assist with serum transfer.
3. See Metals Analysis Specimen Collection and Transport for complete instructions.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | METAL FREE |
| Ambient | 28 days | METAL FREE | |
| Frozen | 28 days | METAL FREE |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Special Instructions
Reference Values
<0.3 ng/mL
When collected by a phlebotomist experienced in ultra-clean collection technique and handled according to the instructions in Metals Analysis Specimen Collection and Transport, we have observed the concentration of chromium in serum to be below 0.3 ng/mL. However, the majority of specimens submitted for analysis from unexposed individuals contain 0.3 ng/mL to 0.9 ng/mL of chromium. Commercial evacuated blood collection tubes not designed for trace-metal specimen collection yield serum containing 2.0 ng/mL to 5.0 ng/mL chromium derived from the collection tube.
Day(s) Performed
Tuesday, Wednesday, Friday
CPT Code Information
82495
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CRS | Chromium, S | 5622-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8638 | Chromium, S | 5622-6 |
Clinical Information
Chromium (Cr) exists in valence states. Hexavalent chromium (Cr[+6]) and trivalent chromium (Cr[+3]) are the 2 most prevalent forms. Cr(+6) is used in industry to make chromium alloys including stainless steel, pigments, and electroplated coatings. Cr(+6), a known carcinogen, is immediately converted to Cr(+3) upon exposure to biological tissues. Cr(+3) is the only chromium species found in biological specimens.
Serum Cr concentrations are likely to be increased above the reference range in patients with metallic joint prosthesis. Prosthetic devices produced by DePuy Company, Dow Corning, Howmedica, LCS, PCA, Osteonics, Richards Company, Tricon, and Whiteside typically are made of chromium, cobalt, and molybdenum. This list of products is incomplete, and these products change occasionally; see prosthesis product information for each device for composition details.
Interpretation
Results greater than the flagged value indicate clinically significant exposure to chromium (Cr) (see Cautions about specimen collection). The reported units of measurement for chromium of ng/mL is equivalent to mcg/L.
Prosthesis wear is known to result in an increased circulating concentration of metal ions. A modest increase (0.3-0.6 ng/mL) in serum Cr concentration is likely to be associated with a prosthetic device in good condition. Serum concentrations above 1 ng/mL in a patient with a Cr-based implant suggest significant prosthesis wear. Increased serum trace element concentrations in the absence of corroborating clinical information do not independently predict prosthesis wear or failure. However, the US Food and Drug Administration recommends testing chromium in EDTA anticoagulated whole blood in symptomatic patients with metal-on-metal implants.
Cautions
Specimens from unexposed individuals collected using metal-free collection procedures typically have chromium above 0.3 ng/mL. Chromium is present in our environment at 100-fold to 1000-fold higher concentration than found in biological tissues. Reports of increased serum chromium could be due to external contamination. Metal-free serum collection procedures must be followed, and centrifuged serum must be aliquoted into a Mayo Clinic Laboratories metal-free vial to avoid external contamination. Specimens collected using an anticoagulant are unacceptable; trace amounts of chromium are present in anticoagulants used in evacuated collection tubes.
Method Description
The metal of interest is analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)