Candida Antigen Quantitative (Serum/Plasma)
This test measures the presence of antigens from *Candida* fungi in your blood, helping detect active infections such as candidiasis (a fungal infection). It is often used in patients with weakened immune systems or those receiving treatments that increase infection risk.
["Assists in diagnosing fungal infections in bloodstream or organ involvement."]
Key facts at a glance
- LOINC
- 40501-9
- Short code
- CANDAB
- Synonyms
- Candida Ab Titr Ser LA
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum tube (no anticoagulant) or serum separator tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Latex Agglutination
- CPT
- 86628
- SNOMED
- 44558009
- Specimen volume
- 1-2 mL serum (minimum 0.5 mL)
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 2
- Lipemia max
- 3
- Icterus max
- 3
- TAT
- 4–24 hours
- Order
- routine
When Might This Test Be Ordered?
Your healthcare provider may recommend this test if you have symptoms like fever, fatigue, or organ-specific issues (e.g., kidney, liver) that could suggest a fungal infection. It’s also used in patients with conditions like HIV/AIDS, chemotherapy, or long-term use of broad-spectrum antibiotics, which can disrupt gut flora and increase infection risk.
How Is the Test Performed?
A blood sample is drawn from a vein, typically in a clinic or lab. The sample is processed to detect specific fungal antigens using sensitive immunoassay techniques. Results are reported as a concentration level, though exact reference ranges vary by lab.
What Are Common Symptoms to Watch For?
Symptoms of *Candida* infection may include persistent fever, unusual pain or swelling in organs, skin rashes, or digestive issues like diarrhea. If you experience these symptoms alongside risk factors (e.g., recent antibiotics, diabetes, or immune suppression), discuss them with your doctor.
How Does This Test Differ from Other Fungal Tests?
Unlike culture tests (which require growing the fungus) or PCR tests (which detect genetic material), this test identifies antigens directly in blood. It’s faster but may not detect all fungal species or early-stage infections.
Reference range
Negative: <1:4 titer; Positive: ≥1:4 titer suggests prior exposure or active infection. Titers ≥1:8 may indicate active or recent infection, particularly in immunocompromised patients.N/A
No fasting required. Specimen should be collected prior to initiation of antifungal therapy when possible. Avoid hemolysis.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Early detection of *Candida* antigens is critical for prompt treatment, especially in high-risk patients. High levels may indicate active infection requiring antifungal medications, while low or absent levels suggest no current infection. It helps guide decisions about empiric therapy or further diagnostic testing.
Short name
Candida Antigen Level
Frequently asked questions
What does a positive test result mean?
Can this test be used for other fungal infections besides *Candida*?
How soon can I expect results after the test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy