Cryptococcus Antigen – Blood and CSF

*Uncontrolled print copy. Valid only on day of print: 28 May 2023.

Testing Indications

Cryptococcal antigen can be detected in serum in patients with cryptococcal pneumonia or meningitis or other extra-pulmonary site infection, especially in patients with HIV/AIDS.

Patients on treatment with rising antigen titers in CSF or serum should be assessed for persistence or recurrence of infection.

Specimen Collection and Handling

Specimen Requirements

Test Requested	Required Requisition(s)	Specimen Type	Minimum Volume	Collection Kit
Cryptococcus Antigen	General Test Requisition	Serum or Blood	1.0 ml (serum) or 5.0 ml (blood)	Blood, clotted - vacutainer tubes (SST)
Cryptococcus Antigen	General Test Requisition	CSF	1.0 ml	Sterile container

Submission and Collection Notes

Both blood and spinal fluid are tested for cryptococcal antigen – not antibody.

Include symptoms and date of onset on the General Test Requisition Form.

Limitations

Haemolysed, icteric, lipemic or microbially contaminated sera or plasma are not recommended for testing.

Storage and Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

Special Instructions

Centrifuge if using SST. Place specimen in biohazard bag and seal. Store specimen at room temperature and ship ASAP after collection.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Cryptococcus antigen Testing is performed 3 times per week. Note: testing is not available on weekends.

Turnaround time is up to 3 days from receipt by PHO Laboratory.

Test Methods

Cryptococcal Antigen Latex Agglutination System (CALAS^®) is a qualitative and semi-quantitative test system for the detection of capsular polysaccharide antigens of Cryptococcus neoformans in serum and CSF.

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.

References

LAB-SD-008, Blood Collection using Serum Separator Tubes