Diagnosing coccidioidomycosis in spinal fluid
Complement Fixation (CF) Using Coccidioidin: IgG
Immunodiffusion: IgG and IgM
Coccidioides, Spinal Fluid
San Joaquin Valley Fever
COCCI CF and ID, CSF
Container/Tube: Sterile vial
Specimen Volume: 2 mL
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.
|Specimen Type||Temperature||Time||Special Container|
|CSF||Refrigerated (preferred)||14 days|
Diagnosing coccidioidomycosis in spinal fluid
Coccidioidomycosis (Valley fever, San Joaquin Valley fever) is a fungal infection found in the southwestern United States, Central America, and South America. It is acquired by inhalation of arthroconidia of Coccidioides immitis/posadasii. Usually, it is a mild, self-limiting pulmonary infection. Less commonly, chronic pneumonia may occur, progressing to fibronodular cavitary disease. A rash often develops within 1 to 2 days, followed by erythema nodosum or multiforme and accompanying arthralgias. About 2 weeks after exposure, symptomatic patients develop fever, cough, malaise, and anorexia; chest pain is often severe. Coccidioidomycosis may disseminate beyond the lungs to involve multiple organs, including the meninges.
Serologic testing for coccidioidomycosis should be considered when patients exhibit symptoms of meningeal infection and have lived in or traveled to areas where Coccidioides immitis/posadasii is endemic. Any history of exposure to the organism or travel cannot be overemphasized when coccidioidomycosis serologic tests are being considered.
If positive, results are titered.
Results are reported as positive, negative, or equivocal.
IgG antibody is detected by complement fixation (CF) testing. Any CF titer in cerebrospinal fluid (CSF) should be considered significant. A positive complement fixation test in un-concentrated CSF is diagnostic of meningitis.
IgM and IgG precipitins are rarely found in CSF. However, when present, they are diagnostic of meningitis (100% specific). Since the immunodiffusion test is 100% specific, it is helpful in interpreting CF results.
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.
1. Larone D, Mitchell T, Walsh T: Histoplasma, blastomyces, coccidioides, and other dimorphic fungi causing systemic mycoses. In: Murray PR, Baron EJ, Pfaller MA, et al, eds. Manual of Clinical Microbiology. 7th ed. ASM Press, 1999:1260-1261
2. Ramanan P, Wengenack NL, Theel ES: Laboratory diagnosis for fungal infections. A review of current and future diagnostic assays. Clin Chest Med. 2017 Sep;38(3):535-554. doi: 10.1016/j.ccm.2017.04.013
The immune response of a person to an infection frequently begins with the formation of specific antibody that is capable of combining in vitro with homologous antigen and complement (C'). The complement fixation (CF) test is a 2-stage test based on the ability of antigen-antibody complexes to bind C'. In the first stage, antigen and antibody combine and fix C'. The second stage is an indicator system in which sheep erythrocytes, sensitized by rabbit anti-sheep red cell antibody (hemolysin), are used to demonstrate the presence of unfixed C'. If the patient's serum contains C'-fixing antibody that reacts with the specific antigen (a positive reaction), C' will be fixed and excess C' will not be available to react with and lyse the sensitized sheep erythrocytes. If no antigen-antibody reaction occurs (a negative reaction), C' will be available to lyse the sheep erythrocytes. The CF titer is determined by the greatest dilution of serum (antibody) in which the sheep erythrocytes are not lysed.
Immunodiffusion (ID) is a qualitative test employed for the detection of precipitating antibodies present in the CSF. Soluble antigens of the fungus are placed in wells of an agarose gel filled Petri dish and the patient's CSF and a control (positive) CSF are placed in adjoining wells. If present, specific precipitate antibody will form precipitin lines between the wells. Their comparison to the control CSF establishes the results. When performing the ID test, only precipitin bands of identity with the reference bands are significant.(Kaufman L, Kovacs JA, Reiss E: Immunomycology. In: Rose NR, de Macario EC, Folds JD, et al, eds. Manual of Clinical Laboratory Immunology. 5th ed. ASM Press, 1997:591-593; Ramanan P, Wengenack NL, Theel ES: Laboratory diagnosis for fungal infections. A review of current and future diagnostic assays. Clin Chest Med. 2017 Sep;38:535-554)
Monday through Friday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
86635 x 3
|Test Id||Test Order Name||Order LOINC Value|
|CCOC||Coccidioides Ab, CompF/ImmDiff, CSF||88745-5|
|Result Id||Test Result Name||
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|81542||Coccidioides Ab, CompF, CSF||13917-0|
|21002||Coccidioides, IgG, ImmDiff, CSF||94662-4|
|21001||Coccidioides, IgM, ImmDiff, CSF||94663-2|