GALACTOMANNAN (ASPERGILLUS ANTIGEN) TEST
(Flat ₹801 OFF - Sanovra Lab)
Report Time: 2nd Working Day | Sample: Blood (Serum) | Test Code: BC107
The Galactomannan Antigen Test is a specialized blood test used to detect Invasive Aspergillosis (IA), a serious fungal infection caused by the mold Aspergillus. While this mold is everywhere in the environment, it typically only attacks people with weakened immune systems.
What is Galactomannan?
Galactomannan is a polysaccharide (complex sugar) that forms a major part of the cell wall of Aspergillus molds.
When the fungus invades the body and grows (hyphal growth), it sheds this molecule into the bloodstream or lung fluids. By testing for Galactomannan, we are effectively looking for the fingerprint of the growing fungus inside the body.
Who Needs This Test? (High Risk Patients)
This test is not for healthy people with a mild cough. It is specifically critical for High-Risk Immunocompromised Patients, including:
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✔Stem Cell/Bone Marrow Transplant Recipients: Especially those with Graft-vs-Host Disease (GVHD).
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✔Organ Transplant Recipients: Lung or Kidney transplant patients on immunosuppressive drugs.
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✔Chemotherapy Patients: Particularly those with Leukemia (AML/ALL) suffering from severe neutropenia (low white blood cells).
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✔Severe COVID-19 / Influenza: Patients in ICU on ventilators are increasingly prone to CAPA (COVID-19 Associated Pulmonary Aspergillosis).
Interpreting Your Results: The Index Value
Unlike simple positive/negative tests, Galactomannan is reported as an Optical Density Index (ODI). This is a ratio.
| Index Value (Serum) | Interpretation |
|---|---|
| < 0.5 | Negative: No evidence of Invasive Aspergillosis. |
| ≥ 0.5 | Positive: Indicates probable Invasive Aspergillosis. Doctors will usually correlate this with a CT scan of the chest. |
Why is this Test Better than a Culture?
Growing a fungus in a lab dish (Culture) takes days or weeks, and often comes back negative even if the patient is sick. The Galactomannan test is:
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➤Faster: Results in 48 hours.
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➤More Sensitive: Can detect infection 7-14 days before clinical symptoms or X-ray changes appear.
Preparation & Sample Type
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✔Sample: Usually Serum (Blood). In cases of lung infection, doctors may collect BAL Fluid (Bronchoalveolar Lavage) via bronchoscopy, which is even more accurate.
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✔Fasting: No fasting is required.
Frequently Asked Questions (FAQs)
If you have a healthy immune system, it is extremely unlikely. We breathe in Aspergillus spores every day without issue. Infection only happens when the immune system is severely weakened.
No. Patients on antifungal prophylaxis (preventative medicine like Posaconazole) may test negative even if they have the infection because the drug suppresses the fungal growth just enough to lower antigen levels.
In high-risk transplant units, doctors often perform "Serial Screening"—testing the patient twice a week to catch the infection the moment it starts.
They are similar but different. Beta-D-Glucan detects many types of fungi (Candida, Pneumocystis, Aspergillus). Galactomannan is specific to Aspergillus.
Early Detection Saves Lives
For high-risk patients, timely diagnosis of fungal infections is critical. Trust the Galactomannan Test at Sanovra Lab.
Disclaimer: The information provided here is for educational purposes only and does not constitute medical advice. Laboratory results should always be interpreted by a qualified Infectious Disease Specialist or Hematologist.