Aspergillus fumigatus IgG

This blood test measures IgG antibodies that your immune system makes against Aspergillus fumigatus, a common mold found in soil, dust, and indoor environments. IgG antibodies reflect past or ongoing exposure and tend to persist, which helps clinicians assess longer-term interactions between you and this mold.

Clinicians use this test alongside your symptoms, chest imaging, and other laboratory studies to evaluate conditions such as chronic lung colonization or infection and certain allergic lung diseases related to Aspergillus. The result on its own does not diagnose or rule out disease, so it is interpreted in context.

Results can support the diagnosis of chronic pulmonary aspergillosis, aspergilloma, or hypersensitivity-related conditions when your clinical picture and imaging fit. Tracking antibody levels over time, ideally using the same method, may help monitor response to treatment and stability of disease.

Your clinician may order this test if you have a long-lasting cough, breathlessness, fatigue, coughing up blood, or lung cavities or nodules on scans, especially if you have underlying lung disease. It is often paired with tests such as Aspergillus IgE, galactomannan, fungal cultures, and high-resolution CT to provide a clearer picture.

A higher antibody level suggests your immune system has recognized Aspergillus fumigatus and may support a diagnosis when combined with your symptoms, examination, and imaging. Some people with frequent environmental exposure can have detectable antibodies without active illness, so results are weighed against other findings.

If you take medicines that suppress the immune system or have conditions that weaken immunity, you might not produce typical amounts of antibody. In that case, a low result does not fully exclude disease. When results are unexpected, your clinician may repeat the test, use the same laboratory for follow-up, or add other tests and imaging before deciding on next steps.