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Test Code LAB9049 Coccidioides Antibody Reflex, Complement Fixation and Immunodiffusion, Serum

Additional Codes

RSCOC

Specimen Type

Serum


Ordering Guidance


 



Specimen Required


Only orderable as a reflex. For more information see COXIS / Coccidioides Antibody Screen with Reflex, Serum.


Specimen Minimum Volume

1.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

Only orderable as a reflex. For more information see COXIS / Coccidioides Antibody Screen with Reflex, Serum.

 

COMPLEMENT FIXATION:

Negative

If positive, results are titered.

 

IMMUNODIFFUSION:

Negative

Results are reported as positive, negative, or equivocal.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

86635 x 3

LOINC Code Information

Test ID Test Order Name Order LOINC Value
RSCOC Coccidioides Ab, CompF/ImmDiff,S 26625-4

 

Result ID Test Result Name Result LOINC Value
35942 Coccidioides Ab, CompF,S 33379-9
35943 Coccidioides, IgG, ImmDiff,S 46182-2
35944 Coccidioides, IgM, ImmDiff,S 46183-0

Method Name

Only orderable as a reflex. For more information see COXIS / Coccidioides Antibody Screen with Reflex, Serum.

 

Complement Fixation (CF)/Immunodiffusion (ID)

Secondary ID

35928

Useful For

Detection of antibodies to Coccidioides species

Interpretation

Complement Fixation:

Titer results of 1:2 or higher may suggest active disease; however, titers may persist for months after infection has resolved. Increasing complement fixation (CF) titer results in serial specimens are considered diagnostic of active disease.

 

Immunodiffusion:

The presence of IgM antibody may be detectable within 2 weeks after the onset of symptoms; however, antibody may be detected longer than 6 months after infection.

 

The presence of IgG antibody parallels the CF antibody and may suggest an active or a recent asymptomatic infection with Coccidioides immitis/posadasii; however, antibodies may persist after the infection has resolved.

 

An equivocal result (a band of nonidentity) cannot be interpreted as significant for a specific diagnosis. However, this may be an indication that a patient should be followed serologically.

 

Over 90% of primary symptomatic cases will be detected by combined immunodiffusion (ID) and CF testing.

Method Description

Complement Fixation:

Antibody to coccidioidin in the patient's serum is quantitated by complement fixation (CF). The CF test is a 2-stage test based on the ability of antigen-antibody complexes to bind complement (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.(Kaufman L, Kovacs JA, Reiss E: Immunomycology. In: Rose NR, de Macario ED, Folds JD, Lane HC, Nakamura RM, eds. Manual of Clinical Laboratory Immunology. 5th ed. ASM Press; 1997:591-592; Pappagianis D, Zimmer BL: Serology of coccidioidomycosis. Clin Microbiol Rev. 1990;3:247-268; 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)

 

Immunodiffusion:

Immunodiffusion (ID) is a qualitative test employed for the detection of precipitating antibodies present in the serum. Soluble antigens of the fungus are placed in wells of an agarose gel filled Petri dish and the patient's serum and a control (positive) serum are placed in adjoining wells. If present, specific precipitate antibody will form precipitin lines between the wells. Their comparison to the control serum 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 ED, Folds JD, Lane HC, Nakamura RM, eds. Manual of Clinical Laboratory Immunology. 5th ed. ASM Press; 1997:591-593; Pappagianis D, Zimmer BL: Serology of coccidioidomycosis. Clin Microbiol Rev. 1990;3:247-268; 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)

Day(s) Performed

Monday through Friday

Report Available

4 to 7 days

Specimen Retention Time

14 days