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HelpTest ID LFACX Cryptococcus Antigen with Reflex, Spinal Fluid
Specimen Required
Container/Tube: Sterile vial
Specimen Volume: 1 mL
Forms
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.
Useful For
Aiding in the diagnosis of cryptococcosis
This test should not be used as a test of cure or to guide treatment decisions.
This test should not be performed as a screening procedure for the general population.
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CLFA | Cryptococcus Ag Screen w/Titer, CSF | Yes | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CLFAT | Cryptococcus Ag Titer, LFA, CSF | Yes | No |
| FGENC | Fungal Culture, CSF | Yes, (Order FGEN) | No |
Testing Algorithm
If result is positive, Cryptococcus antigen titer will be performed at an additional charge.
If Cryptococcus antigen titer is positive, then fungal culture will be performed at an additional charge.
Method Name
Lateral Flow Assay (LFA)
Reporting Name
Cryptococcus Ag w/Reflex, LFA, CSFSpecimen Type
CSFSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| CSF | Refrigerated (preferred) | 14 days |
| Frozen | 14 days |
Clinical Information
Cryptococcosis is an invasive fungal infection caused by Cryptococcus neoformans or Cryptococcus gattii. C neoformans has been isolated from several sites in nature, particularly weathered pigeon droppings. C gattii was previously only associated with tropical and subtropical regions. More recently, however, this organism has been found to be endemic in British Columbia and the Pacific Northwestern United States and is associated with several different tree species.
Infection is usually acquired via the pulmonary route. Patients are often unaware of any exposure history. Approximately half of the patients with symptomatic disease have a predisposing immunosuppressive condition such as AIDS, steroid therapy, lymphoma, or sarcoidosis. Symptoms may include fever, headache, dizziness, ataxia, somnolence, and cough. While the majority of C neoformans infections occur in immunocompromised patient populations, C gattii has a higher predilection for infection of healthy individuals.(1,2)
In addition to the lungs, cryptococcal infections frequently involve the central nervous system (CNS), particularly in patients infected with HIV. Mortality among patients with CNS cryptococcosis may approach 25% despite antibiotic therapy. Untreated CNS cryptococcosis is invariably fatal. Disseminated disease may affect any organ system and usually occurs in immunosuppressed individuals.
Reference Values
CRYPTOCOCCUS ANTIGEN SCREEN WITH TITER
Negative
Reference values apply to all ages.
CRYPTOCOCCUS ANTIGEN TITER, LFA
Negative
Reference values apply to all ages.
FUNGAL CULTURE
Negative
If positive, fungus will be identified.
Reference values apply to all ages.
Cautions
A traumatic lumbar puncture and contamination of the cerebrospinal fluid (CSF) specimen with plasma may lead to a positive Cryptococcus antigen result from CSF in patients without neuroinvasive cryptococcosis.
A negative result does not preclude diagnosis of cryptococcosis, particularly if only a single specimen has been tested and the patient shows symptoms consistent with cryptococcosis.
A positive result is indicative of cryptococcosis; however, all test results should be reviewed in light of other clinical findings.
Testing should not be performed as a screening procedure for the general populations and should only be performed when clinical evidence suggests the diagnosis of cryptococcal disease.
Although rare, extremely high concentrations of cryptococcal antigen can result in weak test lines and, in extreme instances, yield false-negative test results.
This assay has not been evaluated for cross-reactivity in patients with trichosporonosis.
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 35 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
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.CPT Code Information
87899-Cryptococcus Ag Screen w/Titer, CSF
87899-Cryptococcus Ag Titer, LFA, CSF (as appropriate)
87102-Fungal Culture, CSF (as appropriate)