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CSF coccidioides complement fixation is a test that check for infection due to the fungus Coccidioides immitis in the cerebrospinal (CSF) fluid. This is the fluid surrounding the brain and spine.
Coccidioides antibody test - spinal fluid
A sample of spinal fluid is needed for this test. The sample is usually obtained by lumbar puncture (spinal tap).
The sample is sent to a laboratory where it is examined for Coccidiodes antibodies using a laboratory method called complement fixation. This technique checks if your body has produced substances called antibodies to a specific foreign substance (antigen), in this case Coccidioides immitis. Antibodies defend your body against bacteria, viruses, and fungi. If the antibodies are present, they stick, or "fix" themselves, to the antigen. This is why the test is called "fixation."
A consent form must be signed. Expect to remain in the hospital for several hours afterward.
There are different ways to get a sample of CSF. Lumbar puncture (spinal tap) is the most common method. During the test:
Complement fixation is one of several tests for the fungus Coccidioides immitis.
The absence of fungus (a negative test) is normal.
If the test is positive for fungus, there may be an active infection in the central nervous system.
Risks of lumbar puncture include:
In some cases, this test may be done as a blood test.
During the early stage of an illness, few antibodies may be detected. Antibody production increases during the course of an infection. For this reason, this test may be repeated several weeks after the first test.
An abnormal spinal fluid test means that the central nervous system is infected. But an abnormal blood test does not pinpoint the exact area of infection. It only means that there is a coccidioides infection somewhere in the body.
Galgiani JN. Coccidioidomycosis. In: Goldman L, Schafer Al, eds. Goldman's Cecil Medicine. 23rd ed. Philadelphia, Pa: Elsevier Saunders; 2011: chap 341.