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Test Code ULFAT Cryptococcus Antigen Titer, Lateral Flow Assay, Urine


Specimen Required


Only orderable as a reflex. For more information see ULFA / Cryptococcus Antigen Screen, Lateral Flow Assay, Random, Urine.


Useful For

Aiding in the diagnosis of infection with Cryptococcus neoformans or Cryptococcus gattii

 

This test should not be used as a test of cure.

Method Name

Only orderable as a reflex. For more information see ULFA / Cryptococcus Antigen Screen, Lateral Flow Assay, Random, Urine.

 

Lateral Flow Assay (LFA)

Reporting Name

Cryptococcus Ag Titer, LFA, U

Specimen Type

Urine

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

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

Reject Due To

Gross hemolysis Reject
Turbid; Colored Reject

Clinical Information

Cryptococcosis is an invasive fungal infection caused by Cryptococcus neoformans or Cryptococcus gattii. The organism has been isolated from several sites in nature, particularly weathered pigeon droppings.

 

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 predilection for infection of healthy individuals.

 

In addition to the lungs, cryptococcal infections frequently involve the central nervous system (CNS), particularly in HIV-infected patients. Mortality associated with CNS cryptococcosis approaches 25% despite antifungal therapy, while untreated CNS cryptococcosis is invariably fatal. Disseminated disease may affect any organ system and usually occurs in immunosuppressed individuals.

Reference Values

Only orderable as a reflex. For more information see ULFA / Cryptococcus Antigen Screen, Lateral Flow Assay, Random, Urine.

Interpretation

The presence of cryptococcal antigen (CrAg) in any body fluid is strongly suggestive of infection with Cryptococcus neoformans or Cryptococcus gattii.

 

Declining titer results are suggestive of clinical response to therapy. However, monitoring CrAg titers should not be used as a test of cure, as low-level titers may persist for extended periods of time following appropriate therapy and disease resolution.

 

In addition to testing for CrAg, patients with presumed disease due to C neoformans or C gattii should have appropriate clinical specimens (eg, blood, bronchoalveolar lavage fluid) submitted for routine smear and fungal culture.

Cautions

A negative result does not preclude the diagnosis of cryptococcosis, particularly if only a single specimen has been tested and the patient shows symptoms consistent with cryptococcal infection.

 

A positive result is suggestive of cryptococcosis; however, all test results should be interpreted in light of other clinical findings.

 

Although rare, extremely high concentrations of cryptococcal antigen (CrAg) can result in weak-positive or false-negative results.

 

Patients with trichosporonosis or Capnocytophaga species infection may yield false-positive results.

 

If followed for clinical purposes, CrAg titers should be followed using the same assay.

Day(s) Performed

Monday through Friday

Report Available

1 to 4 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

87899

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ULFAT Cryptococcus Ag Titer, LFA, U 93766-4

 

Result ID Test Result Name Result LOINC Value
604369 Cryptococcus Ag Titer, LFA, U 93766-4