Galactomannan (Aspergillus Antigen) Test: Booking, Price, and Results
About Galactomannan (Aspergillus Antigen) Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | GM Test, Aspergillus Antigen Test, Galactomannan Antigen Test, Aspergillus GM Test |
| Sample Type | Bronchoalveolar lavage fluid (BAL) |
| Fasting Required | No fasting required |
| Report Time | 2 days |
| Recommended For | Adults and children of any gender with a weakened immune system or suspected fungal infection |
| Price | Starting at ₹5,300 |
What Is a Galactomannan (Aspergillus Antigen) Test?
The galactomannan (Aspergillus antigen) test is a specialised diagnostic test that detects a specific sugar-like substance released by Aspergillus fungi during infection. It is primarily used to identify invasive aspergillosis, a serious fungal infection that mainly affects people with weakened immune systems. The test analyses a sample of bronchoalveolar lavage (BAL) fluid collected from the lungs. It is also known as the GM test, Aspergillus antigen test, galactomannan antigen test, or Aspergillus GM test.
What Does a Galactomannan (Aspergillus Antigen) Test Measure?
The galactomannan (Aspergillus antigen) test detects a polysaccharide (a complex sugar) found in the outer wall of Aspergillus fungi. When Aspergillus fungi grow inside the body, they release this substance into body fluids, where it can be detected. The amount of galactomannan present is broadly proportional to the amount of fungus in the tissues.
The result is expressed as an optical density index (ODI), calculated by comparing the light absorption of the patient's sample against a standard control. The table below summarises what is measured and its significance:
| Parameter | What It Tells Us |
|---|---|
| Galactomannan Index (BAL fluid) | Indicates the presence and approximate level of Aspergillus fungal matter in lung fluid |
Why Is a Galactomannan (Aspergillus Antigen) Test Done?
Doctors order this test when a patient shows signs of a possible Aspergillus fungal infection, particularly those who cannot fight infection well. It helps confirm or rule out invasive aspergillosis early, often before other tests become conclusive.
Common Symptoms That May Require This Test
The following symptoms are common reasons a doctor may request a galactomannan (Aspergillus antigen) test:
- Persistent cough or coughing up blood (haemoptysis)
- Unexplained fever and chills
- Shortness of breath or wheezing
- Chest pain
- Crackling sounds in the lungs (rales)
- Bloody sputum (mucus)
- Unexplained joint pain
Conditions This Test Can Help Detect
This test supports the identification of several conditions. Here are the main ones:
- Invasive aspergillosis (IA), a serious fungal infection in immunocompromised patients
- Aspergillosis affecting the lungs, sinuses, or brain
- Distinguishing fungal infections from bacterial or viral illnesses with overlapping symptoms
Galactomannan (Aspergillus Antigen) Test for Chronic Disease Monitoring
For patients at risk of invasive aspergillosis, such as those undergoing chemotherapy or bone marrow transplantation, galactomannan levels can be monitored regularly to detect early infection and track the response to antifungal treatment. Antigen levels typically decline when therapy is working. For maximum sensitivity, testing is recommended at least twice weekly during periods of neutropenia (very low white blood cell counts).
How to Prepare and What to Expect
Preparation for this test is straightforward, but a few steps will help ensure the most accurate result.
Do You Need to Fast?
No fasting is required before the galactomannan (Aspergillus antigen) test. However, it is advisable to avoid foods containing galactomannan, such as rice, pasta and fenugreek seeds before the test, as these may affect results.
Practical Tips Before Your Test
The following steps will help you prepare for your visit:
- Avoid rice, pasta, fenugreek seeds and other galactomannan-containing foods before the test
- Inform your doctor about any antibiotics you are taking, especially amoxicillin or piperacillin, as these can interfere with results
- Bring a detailed clinical history, including your symptoms, previous test results, and any recent infections, transplants, or chemotherapy, as this is required for the test
- Wear comfortable clothing that allows easy access to the chest or arm area
- Inform your doctor about any ongoing antifungal medication, as this may affect result sensitivity
Step-by-Step Procedure
The sample for this test is BAL (bronchoalveolar lavage) fluid, collected from the lungs by a trained medical professional in a clinical setting. The procedure follows these steps:
- You will be asked to provide your clinical history before the procedure begins.
- A bronchoscope (a thin, flexible tube) is passed through the nose or mouth and into the lungs.
- A small amount of sterile saline is introduced into the lung passages and then gently withdrawn, collecting fluid from the airways.
- Approximately 5 ml of this BAL fluid is collected in a sterile container.
- The sample is labelled and stored at a refrigerated temperature of 2 to 8°C for safe transport.
- The sample is sent to the laboratory, where it is analysed using Enzyme Immunoassay (EIA) to measure galactomannan levels.
Factors That Can Affect Accuracy
Several factors can influence the reliability of your result:
- Antibiotics such as piperacillin/tazobactam or amoxicillin/clavulanic acid (may cause false-positive results)
- Recent consumption of galactomannan-rich foods such as rice, pasta, or fenugreek seeds
- Ongoing antifungal therapy (may reduce the sensitivity of the test)
- Cross-reactivity with other moulds, including penicillium and alternaria
- Damage to the stomach lining due to cytotoxic therapy, radiation, or graft-versus-host disease
- Patients receiving total parenteral nutrition (TPN) or certain intravenous fluids
Understanding Your Galactomannan (Aspergillus Antigen) Test Results
Your doctor will review your result in the context of your symptoms, medical history, and other diagnostic findings. A single result is rarely used in isolation. The table below provides general reference values:
| Parameter | Result | Interpretation |
|---|---|---|
| Galactomannan Index | Less than 0.5 ODI | Negative: Active Aspergillus infection is less likely, though not fully ruled out |
| Galactomannan Index | 0.5 ODI or above | Positive: May indicate active infection; further testing is needed to confirm |
These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Certain circumstances can affect how your result should be read:
A negative result does not completely rule out invasive aspergillosis. If infection is still suspected clinically, repeat testing is recommended. Two or more consecutive positive results from separate samples are generally needed before a positive diagnosis is considered confirmed.
The false-positive rate is higher in children than in adults. Patients receiving intravenous nutrition, those with conditions such as chronic granulomatous disease, or those with gut wall damage from cytotoxic treatment may show false-positive results even without active Aspergillus infection.
How to Maintain Healthy Levels
While there is no guaranteed way to prevent Aspergillus infection, the following general steps may reduce risk, particularly for those with a weakened immune system:
- Maintain good personal hygiene and avoid touching dusty or mould-prone surfaces without protection
- Stay away from environments with high mould exposure, such as construction sites, compost heaps, and poorly ventilated spaces
- Follow your doctor's guidance on immunosuppressive medications and any preventive antifungal therapy that may have been prescribed
Lupin Diagnostics Galactomannan (Aspergillus Antigen) Test Price
The galactomannan test cost starts at ₹5,300 at Lupin Diagnostics. This test requires a visit to a hospital as directed by the doctor; home collection is not available for this test. Indicative prices across cities are listed below:
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 5300 |
| CHENNAI | 5300 |
| HYDERABAD | 5300 |
| KOLKATA | 5300 |
| NAVI MUMBAI | 5300 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Follow these steps for galactomannan test online booking:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time for sample collection.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
The galactomannan (Aspergillus antigen) test is used to detect invasive aspergillosis in people with weakened immune systems, such as those who have had stem cell or organ transplants or who are undergoing cancer treatment. It helps doctors confirm a fungal diagnosis and differentiate it from bacterial or viral infections with similar symptoms.
No fasting is required. However, it is a good idea to avoid foods rich in galactomannan, such as rice, pasta and fenugreek seeds, before the test, as these may lead to a false-positive result.
At Lupin Diagnostics, your report is typically ready within 2 days of sample collection. You will receive it digitally via email or WhatsApp.
Yes, certain antibiotics, particularly piperacillin/tazobactam and amoxicillin/clavulanate, are known to cause false-positive results. Always inform your doctor about any medications you are currently taking before the test.
A positive result suggests the presence of Aspergillus fungal activity and supports a diagnosis of invasive aspergillosis. However, a positive finding should always be reviewed alongside other tests, such as cultures, imaging, and clinical assessment, before a final diagnosis is made.
This test is recommended for patients with prolonged neutropenia, those who have received an allogeneic haematopoietic stem cell or solid-organ transplant, those on corticosteroids or other immune-suppressing treatments, and anyone with other significant risk factors for invasive fungal infection. Your doctor will advise whether this test is appropriate for you.
Yes. Galactomannan can often be detected in the blood several days, sometimes 7 to 14 days, before other signs of infection become apparent. This early detection window allows doctors to begin antifungal treatment sooner, which can improve outcomes.
Galactomannan (Aspergillus Antigen) Test: Booking, Price, and Results
