Fungal CSF culture and CAD




Test Mnemonic

FUNCSF

CPT Codes

  • 87102 - QTY (1)
  • 87015 - QTY (1)
  • 87015 - QTY (1)
  • 87118 - QTY (1)
  • 87077 - QTY (1)
  • 87106 - QTY (1)
  • 87107 - QTY (1)
  • 87153 - QTY (1)
  • 87181 - QTY (1)
  • 87184 - QTY (1)
  • 87185 - QTY (1)
  • 87186 - QTY (1)
  • 87186 - QTY (1)
  • 87186 - QTY (1)
  • 87186 - QTY (1)

LOINC ®

11475-1

Aliases

  • Culture, Fungus CSF and Cryptococcus Antigen Detec
  • Cerebrospinal fluid
  • Cryptococcus
  • Cryptococcus Ag Titer
  • Cryptococcus antigen
  • CSF fungal
  • Fungal culture
  • Fungus culture
  • Mold culture
  • Mycology
  • Yeast
  • Yeast culture
  • Cryptococcal antigen detection

Includes

  • Specimens may include some pre-processing steps such as concentration to aid in the recovery of fungal organisms and Cryptococcal antigen detection

Performing Laboratory

n/a


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
1 mLCerebrospinal fluid (CSF)Sterile containerAmbientAmbientSterile technique should be used to collect specimen to decrease contamination issues. Larger volumes of specimen are preferred and concentrated to aid in recovery of fungal organisms. Grossly hemolysed sample may give a false positive result on CAD testing and as such will be rejected for the antigen test but fungal cultures will be set up.

Minimum Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
0.5 mL     

Stability

Environmental Condition Description
Ambient<6 hours is optimal; up to 48 hours acceptable. >48 hours reach out to medical director
Refrigerated24 hours acceptable. >24 hours reach out to medical director
FrozenUnacceptable

Days Performed

Sun - Sat

Turnaround Time

6 weeks

Methodology

Name Description
Culture 

Reference Range

Fungal Culture
Sex Age From Age To Type Range Range Unit
       No fungal growth 

Special Info

Clinical specimens for fungal cultures are processed and plated on selective fungal media to optimize recovery of fungal organisms. Cultures are incubated for 28 days; negative results are auto-updated daily. Any fungal organisms recovered will be isolated and identified by various methods. Additional CPT codes may be applicable for recovery and identification of fungal organisms - 87015 - concentration of specimen, 87102 Fungal culture, 87106 - ID by MALDI-TOF Mass Spec for yeast, 87107 - ID by MALDI-TOF Mass Spec for Mold, 87153 - DNA sequencing. Fungal susceptibility testing for yeast ONLY will be performed (CPT 87186). Yeast susceptibility testing is determined by colorimetric microdilution broth. A standardized inoculation of test organism is incubated with appropriate dilutions of antifungal agents; minimum inhibitory concentration (MIC) are determined by inhibition of growth at the lowest antifungal concentration. MIC are determined and interpreted according to CLSI standards. Filamentous mold susceptibility testing is a send-out test and can be requested by contacting the lab.

Clinical Info

Fungal cultures are not routinely performed on CSF due to the low probability of fungal infections except Cryptococcus species which have a predilection for CNS infections. CSF is the specimen of choice for detection of cryptococcal meningitis in adults and Candida meningitis in children. Cryptococcus antigen test will always be performed on CSF specimens as it is a rapid and sensitive diagnostic method for detection of Cryptococcal meningitis. Declining titers may indicate regression of infection. However, monitoring titers to cryptococcal antigen should not be used as a test of cure or to guide treatment decisions. Low-level titers may persist for extended periods of time following appropriate therapy and resolution of infection

Clinical Limitation

CSF specimens submitted for initial diagnosis that test positive by the lateral flow assay, should also be submitted for routine fungal culture. Culture can aid in differentiating between the 2 common Cryptococcus species causing disease (Cryptococcus neoformans and Cryptococcus gattii) and can be used for antifungal susceptibility testing, if necessary. CAD test should not be used as a screening procedure for the general population. Bloody lumbar puncture and/or contamination of the cerebrospinal fluid (CSF) specimen with serum, other yeast infections such as Trichosporon may lead to a positive Cryptococcus antigen result. CAD titers can be utilised to monitor therapy but titers acquired by different assays are not interchangeable; titers acquired by lateral flow assay may be higher than other antigen assays such as agglutination tests. Extremely high concentrations of cryptococcal antigen can result in negative CAD results. If high burden is suspected, sample may be diluted to resolve false negative. Please call the lab/medical director in such instances.

Clinical Reference

Perfect JR, Dismukes WE, Dromer F, et al: Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America. Clin Infect Dis. 2010 Feb 1;50(3):291-322 Westblade et. al. Larone’s Medically Important Fungi, 7th edition, ASM press, Washington DC., 2024. Leber et al., Clinical Microbiology Procedures Handbook, 5th edition, ASM press, Washington, DC. 2023. Carroll, et al. Manual of Clinical Microbiology, 13th Edition, Volume 3, ASM Press, Washington, DC. 2024.