Cryptococcus antigens

When to request this test

Suspected cryptococcal meningitis, cryptococcal screening in advanced HIV, suspected disseminated cryptococcosis in immunosuppressed patient.

Interferences & limitations

• Cross-reactivity: other fungal infections like Histoplasma and Blastomyces can cause false positives
• Sensitivity: the test is more sensitive in advanced disease stages (e.g., meningitis) and less sensitive in early, localized, or low-burden infections
• False negatives: immunocompromised patients or low antigen levels can result in false-negative results
• Others limitations: the test detects Cryptococcus but does not distinguish between C. neoformans and C. gattii

Elevated immunoglobulin levels and pregnancy may affect results.

Despite these interferences, the Cryptococcus antigen test remains highly valuable, especially for screening and diagnosing cryptococcal meningitis in high-risk populations.

• Sample nature: Serum or CSF
• Recommended volume: 2mL serum & 0.5 mL (CSF)
• Type of container: Serum tube or CSF tube

<2h at room temperature