Lab Test

Coccidioides immitis Antibodies by Immunodiffusion

Valley Fever, San Joaquin Fever

Test Codes

EPIC: LAB7040, Beaker: XCOCG, ARUP: 50183

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Let serum specimens clot 30-60 minutes then centrifuge to separate serum from cells within. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 2.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 1.2 mL)

Rejection Criteria

  • Hemolyzed specimens.
  • Specimens not collected and processed as indicated.

In-Lab Processing

  • Let serum specimens clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 2.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 1.2 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 48 hours
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 1 year

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to ARUP Laboratories, Salt Lake City, UT.

Performed

Sunday – Saturday.
Results available in 3-6 days.

Reference Range

None detected.

Test Methodology

Qualitative Immunodiffusion.

Interpretation

  • Coccidioides infection is demonstrated by the detection of IgM antibody to the Immunodiffusion Tube Precipitin (IDTP) antigen. IgM antibody may be detected 1 to 3 weeks after the onset of primary infection and may suggest active or recent infection. IgM antibody is rarely detected 6 months after infection but may reappear with relapse and may persist in disseminated cases.
  • IgG antibody may also be demonstrated in response to the Immunodiffusion Complement Fixation (IDCF) antigen may represent active or past infection. Negative fungal serology does not rule out current infection.

CPT Codes

86635

Contacts

Last Updated

11/2/2023

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