Cryptococcus Antigen Titer, Lateral Flow Assay, Spinal Fluid

Casandra

Casandra Test Code MC92826Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID CLFATCPT Code 87899

Cryptococcus Antigen Titer, Lateral Flow Assay, Spinal Fluid

Clinical Use

Use

This test is useful for monitoring Cryptococcus antigen titers in cerebrospinal fluid and aiding in the diagnosis of cryptococcosis. Cryptococcosis is an invasive fungal infection caused by Cryptococcus neoformans or Cryptococcus gattii. The presence of cryptococcal antigen in any body fluid is indicative of cryptococcosis. Disseminated infection is usually accompanied by a positive serum test, and declining titers may indicate regression of infection. However, this test should not be used as a test of cure or to guide treatment decisions.

Special Instructions

For non-electronic orders, complete and send the Infectious Disease Serology Test Request (T916) with the specimen. CSF specimens submitted for initial diagnosis that test positive by the lateral flow assay should also be submitted for routine fungal culture to aid in differentiating between the two common Cryptococcus species causing disease and for antifungal susceptibility testing, if necessary.

Limitations

A traumatic lumbar puncture and contamination of the cerebrospinal fluid (CSF) specimen with serum may lead to a false positive result. Cryptococcus antigen titers acquired by different assay methods are not interchangeable, and titers should be monitored using the same method on serially collected samples. 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. Testing should not be performed as a screening procedure for the general population and should only be performed when clinical evidence suggests the diagnosis of cryptococcal disease.

Test Details

FDA Approved