Coccidioides Antibody, Complement Fixation and Immunodiffusion, Serum

Casandra

Casandra Test Code MC41951Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID SCOCCPT Code 86635

Coccidioides Antibody, Complement Fixation and Immunodiffusion, Serum

Clinical Use

Use

The test is used for the diagnosis of coccidioidomycosis, commonly known as Valley Fever, a fungal infection found in the Southwestern US, Central America, and South America. The infection is acquired by inhalation of arthroconidia of Coccidioides immitis/posadasii. It often presents as a mild, self-limiting pulmonary infection, but can progress to more severe forms including chronic pneumonia, resulting in fibronodular or cavitary disease. The test detects IgG antibodies by complement fixation and precipitating antibodies (IgM and IgG) by immunodiffusion, which can suggest active or recent infections, and help in monitoring the serological response of the patient.

Special Instructions

Enzyme immunoassay-positive results should be confirmed using this test. For initial evaluation, the COXIS / Coccidioides Antibody Screen with Reflex, Serum is recommended. When collecting the serum specimen, a Sarstedt Aliquot Tube (5 mL) should be used, and serum should be centrifuged and aliquoted into a plastic vial for submission.

Limitations

Antibodies, both IgM and IgG, may persist in the bloodstream even after the infection has resolved, leading to potential false-positive results for past, resolved infections. The presence of IgG parallels complement fixation antibodies and may suggest an active or recent asymptomatic infection; however, these antibodies can remain even after the infection has cleared. This test cannot distinguish between an active infection and previous exposure alone.

Test Details

FDA Approved