Understanding IgE Levels in ABPA: What They Mean, How They Change, and What to Expect

If you’ve been diagnosed with Allergic Bronchopulmonary Aspergillosis (ABPA) or are being assessed for it, you may have heard that your IgE level is high. This can feel alarming, especially if treatment hasn’t yet been started. You might be wondering: What does a high IgE actually mean? How do treatments affect it? And what happens if treatment is stopped?

This article aims to explain what IgE levels tell us in ABPA, how they change over time, and how they’re used to guide treatment.

🧪 What is IgE and Why Is It Important in ABPA?

IgE (Immunoglobulin E) is a type of antibody made by your immune system when it overreacts to allergens. In ABPA, the immune system has an allergic-type response to the fungus Aspergillus fumigatus, which is commonly found in the environment. This immune overreaction leads to inflammation in the lungs, mucus buildup, and potential long-term lung damage.

A raised total IgE level:

• Helps support a diagnosis of ABPA.

• Is used by doctors to track how active the disease is.

• Can help monitor how well treatment is working, and whether the disease is flaring up again.

While a high IgE level alone doesn’t always mean you feel worse, it often reflects that the allergic inflammation is active and needs managing.

💊 How Is IgE Reduced in ABPA?

Treatments for ABPA aim to bring down inflammation in the lungs, and when that happens, IgE levels often fall as well. There are three main types of treatment:

1. Steroids (e.g. prednisolone)

• These are often used as the first treatment for ABPA.

• They can bring down IgE levels within a few weeks, and help improve breathing and reduce mucus.

• However, when steroids are stopped, IgE levels often rise again unless other treatments are also used.

2. Biologic therapies (e.g. omalizumab, mepolizumab, dupilumab)

• These newer treatments target specific parts of the immune system that drive allergic inflammation.

• They may help keep IgE levels lower over the long term and reduce the need for steroids.

• In some cases, IgE may remain stable for months or years while on biologics, though responses vary from person to person.

3. Antifungal medication (e.g. itraconazole, voriconazole)

• These drugs reduce the amount of Aspergillus in the lungs, which may reduce the allergic reaction.

• They may help stabilise IgE levels but are usually not enough on their own for active ABPA.

⏱️ What Happens When Treatment Stops?

One of the most common concerns among patients is how long IgE stays low once treatment is stopped.

• After stopping steroids, IgE levels often begin to rise again within a few weeks to a few months, especially if no other treatment is in place.

• After stopping biologics, the return of symptoms and rise in IgE may happen more slowly — over several months — but varies from person to person.

• If fungal exposure continues (e.g. in a damp or mouldy home), or the underlying immune reaction stays active, IgE is more likely to increase again.

It’s important to remember that monitoring IgE over time helps your doctor decide whether ABPA is active again and whether a change in treatment is needed.

🧠 Why Might Treatment Be Delayed?

Not everyone with a high IgE level is started on treatment right away. Your doctor may be:

• Waiting for more information, such as CT scan results or lung function tests.

• Being cautious about starting long-term steroids, especially if you’ve had side effects before.

• Considering alternative treatment options like antifungals or biologics.

• Monitoring to see if symptoms improve on their own or remain stable.

If you’re not receiving treatment and you’re unsure why, it’s completely reasonable to ask for clarification — or to seek a second opinion.

👥 What Do Other Patients Say?

Many people with ABPA share similar experiences:

• “Steroids helped quickly, but the effect didn’t last after I stopped.”

• “I’ve been stable on a biologic and haven’t needed steroids in months.”

• “It took a long time to get diagnosed — I had to ask lots of questions and push for answers.”

• “My IgE rose again when I was exposed to damp or dusty environments.”

Your experience might be different, but it can be helpful to hear from others and learn what has worked for them.

✅ Key Points to Remember

• A raised IgE level is a common and important feature of ABPA.

• IgE usually falls during treatment and rises again when treatment stops — especially if nothing else is done to control the inflammation.

• Steroids work quickly, but effects often wear off without long-term planning.

• Biologics and antifungals may help maintain lower IgE and reduce flares.

• If you feel uncertain about your care, seeking a second opinion is perfectly appropriate.

Tip: Keep a personal record of your IgE levels, symptoms, and any treatments you’re on. This can help you and your doctor spot patterns and make informed decisions together.