ARUP's Laboratory Test Directory

Coccidioides Antibody by CF : 0050170

Mnemonic: COCCI

Methodology: Semi-Quantitative Complement Fixation
Performed: Sun-Sat
Reported: 1-3 days
Specimen Required: Collect: Serum separator tube OR CSF.

Specimen Preparation: Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum OR CSF to an ARUP Standard Transport Tube. (Min: 0.15 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of acute specimens. Mark specimens plainly as acute or convalescent.

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Contaminated or severely lipemic specimens.

Stability (collection to initiation of testing): After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference Interval:
< 1:2
Interpretive Data: Any titer suggests past or current infection. However, greater than 30 percent of cases with chronic residual pulmonary disease have negative Complement Fixation (CF) tests. Titers of less than 1:32 (even as low as 1:2) may indicate past infection or self-limited disease; titers greater than or equal to 1:32 may indicate disseminated infection. CF serology may be used to follow therapy. Antibody in CSF is considered diagnostic for coccidioidal meningitis, although 10 percent of patients with coccidioidal meningitis will not have antibody in CSF.
Note: CF measures both IgM and IgG. As single antibody titers are generally not diagnostic, paired specimens are preferred. Acute and convalescent specimens (drawn at least 21 days apart), showing at least a fourfold rise in titer, are diagnostic.

Negative fungal serology does not rule out the possibility of current infection.
CPT Code(s): 86635
Cross References: Coccidioidomycosis IgG/IgM (Coccidioides Antibody by CF) , San Joaquin Fever Antibody (Coccidioides Antibody by CF) , Valley Fever (Coccidioides Antibody by CF)