Ordering Recommendation

Use to monitor coccidioidal antibody titer in serum in response to treatment. For initial diagnosis of coccidioidomycosis, refer to Coccidioides Antibodies Reflexive Panel, Serum (3001982).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube (SST).

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.6 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of acute specimens..

Storage/Transport Temperature


Unacceptable Conditions

Other body fluids. Contaminated, hemolyzed, icteric, or lipemic specimens.


Mark specimens plainly as "acute" or "convalescent."


Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)


Semi-Quantitative Complement Fixation




2-5 days

Reference Interval

Less than 1:2

Interpretive Data

A titer of 1:2 or greater 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; anticoccidioidal CF antibody titers in excess of 1:16 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.

Compliance Category



Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0050170 Coccidioides Antibody by CF 33380-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Coccidioides immitis
  • Coccidioidomycosis
  • Valley Fever
Coccidioides Antibodies by Complement Fixation