Eosinophilic Granulomatosis with Polyangiitis (EGPA) is a rare immune disorder that can impact various parts of the body, particularly the respiratory system and blood vessels. While there is currently no cure for EGPA, a range of treatments are available to help manage symptoms and achieve periods of remission, where disease activity is significantly reduced. These treatments often involve medications, including certain types delivered through injections.
What EGPA Is
Eosinophilic Granulomatosis with Polyangiitis, previously known as Churg-Strauss syndrome, is a rare autoimmune condition. It involves inflammation of small and medium-sized blood vessels, a condition called vasculitis, and an unusually high number of eosinophils, a specific type of white blood cell. This disease affects an estimated 5,000 individuals in the United States and typically presents in adults, with a peak age of incidence between 35 and 50 years.
EGPA is frequently associated with a history of allergies or asthma, with adult-onset asthma often being an early symptom that can precede other manifestations by years. The condition can affect multiple organs, including the lungs, skin, sinuses, heart, kidneys, nervous system, and gastrointestinal tract. The disease often progresses through phases, typically starting with allergic symptoms, followed by an increase in eosinophils, and then vasculitis.
How Injections Treat EGPA
Injectable biologics play an important role in managing EGPA by targeting eosinophils, which contribute to inflammation. Mepolizumab (Nucala) and benralizumab (Fasenra) are examples of such biologics. Mepolizumab is a monoclonal antibody that works by binding to interleukin-5 (IL-5), a cytokine that regulates eosinophil activity. By neutralizing IL-5, mepolizumab reduces eosinophil levels and inflammation.
Benralizumab is another monoclonal antibody that targets the interleukin-5 receptor on eosinophils. This blocks IL-5 interaction, reducing eosinophil production and survival. Benralizumab also promotes the programmed cell death of eosinophils and basophils, enhancing their removal from the body. These injectable treatments are often used to reduce the reliance on corticosteroids, which are commonly prescribed but can have significant long-term side effects.
Other Treatments for EGPA
Beyond injectable biologics, other medications are commonly used to manage EGPA. Corticosteroids, such as prednisone, are frequently the initial treatment to reduce inflammation and eosinophil levels, often starting with a high dose to achieve remission. Once remission is achieved, the corticosteroid dose is gradually reduced, though many individuals may continue on a low maintenance dose. Long-term use of corticosteroids can lead to side effects like weight gain, high blood sugar, and bone thinning.
Immunosuppressants are also used, either when corticosteroids alone are not effective or to minimize corticosteroid use due to side effects. These medications, including azathioprine, methotrexate, and cyclophosphamide, work by suppressing the immune system’s activity to reduce inflammation. Cyclophosphamide is often used for severe cases, sometimes followed by other immunosuppressants for maintenance. Rituximab, another immunosuppressant, has also shown benefit in treating steroid-resistant or relapsing EGPA.
Receiving EGPA Injections
Injectable medications for EGPA, such as mepolizumab and benralizumab, are typically administered as subcutaneous injections. Mepolizumab is typically given as a subcutaneous injection every four weeks. Benralizumab is also administered subcutaneously every four weeks. These injections can be given at home by the patient or a caregiver after proper training, or in a healthcare clinic setting.
Common side effects associated with these injections can include injection site reactions, such as pain, redness, or itching. Other common side effects include headache, back pain, fatigue, and sore throat. Patients should discuss any new or concerning symptoms with their healthcare provider, as some reactions, though rare, can be more serious and may occur hours or even days after the injection.
Living with EGPA
Living with EGPA requires ongoing management and a collaborative approach with a healthcare team. While a cure for EGPA does not exist, effective treatment can lead to remission and improve quality of life. Regular monitoring by healthcare providers is important to assess disease activity, eosinophil levels, and potential side effects from medications. This often involves routine blood tests and imaging studies.
Adherence to the prescribed treatment plan is important for controlling symptoms and preventing disease flares. Individuals with EGPA may also benefit from lifestyle considerations, such as maintaining good nutrition, staying hydrated, getting regular sleep, and engaging in appropriate exercise. Given that medications can affect the immune system, staying up-to-date with recommended vaccinations is also a consideration to help prevent infections. A multidisciplinary care team, which may include rheumatologists, pulmonologists, and other specialists, along with patient support resources, can provide comprehensive support for managing this chronic condition.