The Aspergillus IgG Antibody test is a blood test that is used to diagnose Aspergillosis, a fungal infection caused by the Aspergillus fungus. Aspergillosis can affect various organs in the body, such as the lungs, sinuses, and central nervous system. The test measures the levels of IgG antibodies produced by the immune system in response to the Aspergillus fungus. An elevated level of Aspergillus IgG antibodies in the blood can indicate a current or previous Aspergillus infection. However, a positive result alone does not necessarily mean an active infection as these antibodies can persist in the body for years after the infection. The Aspergillus IgG Antibody test is usually performed alongside other diagnostic tests, such as a chest X-ray, CT scan, or biopsy, to confirm the diagnosis of Aspergillosis. The test is a safe and minimally invasive procedure, involving the collection of a small blood sample from the patient, which is then sent to a laboratory for analysis.