Titers may aid in monitoring coccidioidomycosis (Valley fever) and treatment response. For initial establishment of diagnosis, refer to Coccidioides Antibodies Reflexive Panel (3001982).
Semi-Quantitative Complement Fixation
New York DOH Approval Status
Serum Separator Tube (SST).
Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.4 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of acute specimens.
Hemolyzed, icteric, or lipemic specimens.
Mark specimens plainly as "acute" or "convalescent."
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Less than 1:2
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; anticoccidioidal CF antibody titers in excess if 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.
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 Name||LOINC|
|0050170||Coccidioides Antibody by CF||33380-7|
- Cocci IgG, IgM CF
- Coccidioidomycosis IgG/IgM
- San Joaquin Fever Antibody
- Valley Fever antibodies