Aspergillus Antigen (Serum) – Quantitative

What Is This Test Measuring?

The test detects specific antigens produced by *Aspergillus* fungi, which can appear in your blood during an active infection. These antigens are not the same as antibodies (which your immune system makes to fight the fungus). The presence of these antigens suggests the fungus is actively growing in your body.

Why Might You Need This Test?

Your healthcare provider may order this test if you have symptoms like persistent cough, fever, or lung issues (e.g., pneumonia-like symptoms) and risk factors for *Aspergillus* infection, such as weakened immune systems (e.g., from HIV, chemotherapy, or lung disease). It’s also used in monitoring patients with known fungal infections.

How Is the Test Performed?

A small blood sample is drawn from your arm. The sample is sent to a lab where it’s analyzed using a sensitive immunoassay method to detect fungal antigens. Results are typically available within 24–48 hours.

What Do the Results Mean?

Positive results indicate active *Aspergillus* infection, which requires prompt medical treatment (e.g., antifungal drugs). Negative results mean no detectable antigens were found in this sample, but infection could still be present in other parts of your body or may require further testing.