Coccidioides Antibody, CF/ID
Label Mnemonic: COCCICSF
Epic code: LAB2893
Downtime form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
Commercial Mail-out Laboratory
5231 RCP
Collection Medium:
CSF collection kit
Preferred Minimum: 2 mL aliquot CSF
Absolute Minimum: 1.2 mL aliquot CSF
Turn Around Time:
3 days upon receipt at reference laboratory
Reference Range:
If positive, results are titered.

Results are reported as positive, negative, or equivocal.
Interpretive Data:
Complement Fixation (CF):
IgG antibody is detected by CF testing. Any CF titer in cerebrospinal fluid (CSF) should be considered significant. A positive complement fixation test in unconcentrated CSF is diagnostic of meningitis.

Immunodiffusion (ID):
IgM and IgG precipitins are rarely found in CSF. However, when present, they are diagnostic of meningitis (100% specific). Since the ID test is 100% specific, it is helpful in interpreting CF results.

Early primary antibody (IgM) found in coccidioidomycosis can be detected by the IgM-specific ID test. IgM precipitins may be detectable within 1 to 4 weeks after the onset of symptoms. The presence of IgG antibody parallels the CF antibody and indicates an active or a recent asymptomatic infection with Coccidioides immitis. Both IgG and IgM antibodies are rarely detected 6 months after infection. However, in some patients having disseminated infection, both IgG and IgM antibodies may be present for several years. IgM and IgG precipitins are not prognostic.

An equivocal result (a band of nonidentity) cannot be interpreted as significant for a specific diagnosis. However, this may be an indication that a patient should be followed serologically.

The sensitivity of serologic testing (CF and ID combined) for coccidioidomycosis is >90% or primary symptomatic cases.
Useful for serologic testing for coccidioidomycosis should be considered when patients exhibit symptoms of meningeal infection and have lived or traveled in areas where Coccidioides immitis is endemic. Any history of exposure to the organism or travel cannot be overemphasized when coccidioidomycosis serologic tests are being considered.

While complement fixation (CF) titers may be present in serum months after the infection has resolved, any CF titer in spinal fluid should be considered significant.
Complement Fixation (CF) Using Coccidioidin: IgG
Immunodiffusion: IgG and IgM
CPT Code:
86635 Coccidioides Antibody, CSF by CF
86635 Coccidioides Antibody, CSF IgG
86635 Coccidioides Antibody, CSF IgM