Test Catalog

Test ID: COWB    
Cobalt, Blood

Useful For Suggests clinical disorders or settings where the test may be helpful

Monitor exposure to cobalt

 

Monitoring metallic prosthetic implant wear

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Cobalt is a naturally occurring, hard, grey element widely distributed in the environment. It is used to produce alloys in the manufacturing of aircraft engines, cutting tools, and some artificial hip and knee joint prosthesis devices. Cobalt salts are also used in the glass and pigment industry. Previously, cobalt salts were sometimes used as foam stabilizers in the brewing industry; this practice was banned due to the cardiovascular diseases it induced. One of the radioactive isotopes of cobalt, (60)Co, is used to sterilize medical equipment, in radiation therapy for cancer patients, and to irradiate food.

 

Cobalt is an essential cofactor in vitamin B12, which is necessary for neurological function, brain function, and the formation of blood.  For most people, food is the largest source of cobalt intake. However, more than a million workers are potentially exposed to cobalt and its compounds, with the greatest exposure in mining processes, cemented tungsten-carbide industry, cobalt powder industry, and alloy production industry.

 

Cobalt is not highly toxic, but large doses will produce adverse clinical manifestations. Acute symptoms include pulmonary edema, allergy, nausea, vomiting, hemorrhage, and renal failure. Chronic exposure to cobalt-containing hard metal (dust or fume) can result in a serious lung disease called "hard metal lung disease," which is a type of pneumoconiosis (lung fibrosis). Furthermore, inhalation of cobalt particles can cause respiratory sensitization, asthma, shortness of breath, and decreased pulmonary function. Even though the primary route of occupational exposure to cobalt is the respiratory tract, skin contact is also important because dermal exposures to hard metal and cobalt salts can result in significant systemic uptake. Sustained exposures can cause skin sensitization, which may result in eruptions of contact dermatitis.

 

Per FDA recommendations, orthopedic surgeons should consider measuring and following serial cobalt concentrations in EDTA anti-coagulated whole blood in symptomatic patients with metal-on-metal hip implants as part of their overall clinical evaluation. Blood cobalt concentrations are likely to be increased above the reference range in patients with joint prosthesis containing cobalt. Prosthetic devices produced by Depuy Company, Dow Corning, Howmedica, LCS, PCA, Osteonics, Richards Company, Tricon, and Whiteside are typically 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.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

0-17 years: not established

> or =18 years: <1.0 ng/mL

Interpretation Provides information to assist in interpretation of the test results

Concentrations greater or equal to 1.0 ng/mL indicate possible environmental or occupational exposure.

Cobalt concentrations associated with toxicity must be interpreted in the context of the source of exposure. In the context of failed metal-on-metal prosthetics, elevated cobalt in serum or blood is rarely the initial finding and is often preceded by physical symptoms including: reduced range of motion, swelling, inflammation around the joints, and general discomfort or pain.

 

The ACGIH Biological Exposure Index (BEI) for cobalt in blood is 1 mcg/L (1 ng/mL), which should be collected at the end of shift at the end of the work week.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test should not be ordered to assess vitamin B12 activity.

 

Because this test uses mass spectrometry detection, the radioactive form of cobalt, (60)Co, is not quantified.

 

Specimen collection procedures for cobalt require special specimen collection tubes, rigorous attention to ultraclean specimen collection and handling procedures, and analysis in an ultraclean facility. Unless all of these precautions are taken, elevated blood cobalt results may be an incidental and misleading finding.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Tower SS: Arthroprosthetic cobaltism: neurological and cardiac manifestations in two patients with metal-on-metal arthroplasty: A case report. J Bone Joint Surg Am 2010;92:1-5

2. Keegan GM, Learmonth ID, Case CP: A systematic comparison of the actual, potential, and theoretical health effects of cobalt and chromium exposures from industry and surgical implants. Crit Rev Toxicol 2008;38:645-674

3. De Smet K, De Hann R, Calistri A, et al: Metal ion measurement as a diagnostic tool to identify problems with metal-on-metal hip resurfacing. J Bone Joint Surg Am 2008;90:202-208

4. Lison D, De Boeck M, Verougstraete V, Kirsch-Volders M: Update on the genotoxicity and carcinogenicity of cobalt compounds. Occup Environ Med 2001;58:619-625

5. US Food and Drug Administration: Information about Soft Tissue Imaging and Metal Ion Testing. Accessed 7/5/17. Available at: www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/MetalonMetalHipImplants/ucm331971.htm

6. US Department of Health and Human Services: Toxicological profile for cobalt. Atlanta, GA. Accessed 4/2004. Available at. www.atsdr.cdc.gov/toxprofiles/tp33.pdf

7. Nader R, Horwath AR, Wittwer CT: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Sixth Edition. St. Louis: Elsevier 2017

Special Instructions Library of PDFs including pertinent information and forms related to the test