Eosinophilic asthma diagnosis
There are three ways that eos asthma may be diagnosed. Clinical symptoms and treatment response guide continued management.
Eosinophilic asthma blood test
The number of eosinophils in a patient’s blood are measured. The blood draw (venipuncture) is a simple, minimally-invasive procedure. It may be performed in a doctor’s office. People with eosinophilic asthma will have a high eosinophil count (at least 150 cells/ul but generally over 300 cells/ul). High eosinophils with asthma does not always mean that a person has eosinophilic asthma. Other types of eosinophil-associated disease can cause too many eosinophils in the blood as well. Therefore, a doctor will interpret the results in context with a patient’s history, symptoms, and clinical exam.
Sputum sample examination
A patient’s sputum sample is examined under a microscope. To get the sample of sputum for testing, a patient coughs up a mucus sample. This procedure is non-invasive and may be performed in a doctor’s office. Having more than 2-3% of cells being eosinophilic in the sputum suggests eosinophilic asthma.
Bronchial biopsy or bronchial fluid examination
A patient’s bronchial biopsy or bronchial fluid from the lung is examined under a microscope. This procedure is more involved and invasive. A doctor who specializes in lung disease (pulmonologist) performs a bronchoscopy. They insert a thin tube (bronchoscope) through the nose or mouth. Small samples of tissue or fluid are collected (biopsy) and are then analyzed to determine the infiltration of eosinophils. This procedure is performed under local or general anesthesia but usually does not require a hospital stay.
Eosinophilic asthma treatment
When treating eos asthma, the goal is to reduce the eosinophils in the airways and control a person’s breathing. Many patients who have eos asthma respond to common asthma therapies, including inhaled medicines and/or oral corticosteroids. Other patients may not respond to these therapies and subsequently use of other agents should be considered.
Common types of asthma medications
There are four basic types of asthma medications that each treat a different part of your asthma. Currently used drugs for eosinophilic asthma include:
- bronchodilators relax and open the airways to relieve asthma symptoms such as coughing, wheezing, chest tightness and shortness of breath
- anti-inflammatory medications (inhaled corticosteroids) reduce and prevent lung inflammation
- combination medications combine a bronchodilator and anti-inflammatory in one device
- leukotriene modifiers block the action of leukotrienes, chemicals involved in immune system responses
- biologics are medications that target the specific cells and pathways that cause inflammation related to severe asthma; these are sometimes referred to as “targeted therapies”
Biologic therapies that target eosinophils may also be prescribed to treat eos asthma. Biologics that are currently approved for use in the U.S. include the following:
- Benralizumab binds to the interleukin-5 receptor and prevents this cytokine from activating eosinophils. It works with your body to attract immune cells that reduce eosinophils. It is administered as a shot and is approved for use in the U.S. for the add-on maintenance treatment of patients with severe asthma aged 12 years and older with eos asthma. It is used in combination with other asthma medications.
- Mepolizumab binds to interleukin-5 and decreases the number of eosinophils in your blood to reduce inflammation in the lungs. It is administered as a shot and is approved for use in the U.S. to treat patients aged 6 years or older who have eos asthma. It is used in combination with other asthma medications.
- Reslizumab also binds to interleukin-5 and decreases eosinophils in your blood to reduce inflammation in the lungs. It is administered intravenously and is approved for use in the U.S. as an add-on treatment for patients aged 18 years or older who have eos asthma.
- Dupilumab binds the interleukin-4 receptor and reduces inflammation in the lungs. It is administered as a shot and is approved as an add-on maintenance therapy in patients with moderate-to-severe asthma aged 12 years and older, such as eos asthma, or with oral corticosteroid-dependent asthma. It is also approved to treat severe eczema (atopic dermatitis) and chronic sinusitis with nasal polyposis.
Rules of TWO®
When you experience asthma symptoms on a regular basis or asthma limits what you can do in a day, it’s important to speak up, work with your team and get the care you need and deserve. Your asthma may not be in control. Use the Rules of Two® (see graphic below) to find out more about your asthma control, then take the results to your doctor. You can use these results to discuss asthma control and your Asthma Action Plan with your doctor.
Rules of TWO®
When is quick relief for asthma NOT ENOUGH?
- Take your quick relief inhaler more than TWO TIMES A WEEK?
- Awaken at night with asthma more than TWO TIMES A MONTH?
- Do you refill you quick relief inhaler more than TWO TIMES A YEAR?
- Use prednisone TWO or more times a year for flares of asthma?
- Measure changes in peak flow with asthma symptoms of more than TWO TIMES 10 (20%)?
If you answer “YES” to any of the questions, current guidelines suggest you talk with your physician about adding an inhaled anti-inflammatory to improve your asthma control.