Coccidioides Antibody by CF
Ordering Recommendation

Titers may aid in monitoring coccidioidomycosis (Valley fever) and treatment response. For the initial establishment of diagnosis, refer to Coccidioides Antibodies Panel, Serum by CF, ID, ELISA (0050588), which combines complement fixation and immunodiffusion.

Semi-Quantitative Complement Fixation
1-3 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
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
Unacceptable Conditions
Contaminated or severely lipemic specimens. 
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles) 
Reference Interval
Less than 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.

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.
Component Test Code*Component Chart NameLOINC
0050170Coccidioides Antibody by CF33380-7
* 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.
  • Cocci IgG, IgM CF
  • Coccidioidomycosis IgG/IgM
  • San Joaquin Fever Antibody
  • Valley Fever antibodies