EOSINOPHILIC GRANULOMATOSIS WITH POLYANGITIIS (EGPA, CHURG-STRAUSS SYNDROME)
EGPA can be associated with pulmonary, ear-nose-throat, cutaneous, cardiac, intestinal, renal and neurological manifestations.
The symptoms of EGPA can range from mild to life-threatening, and may vary among individuals, however almost all patients have asthma and/or sinus polyps, and hypereosinophylia (i.e., an increased level of white blood cells called eosinophils).
Other symptoms include:
- Rapid and sudden weight loss
- Muscle and joint pain
- Skin rashes
- Numbness or tingling of the hands or feet
- Sudden loss of strength in the hands or feet
- Chest pain or palpitations
- Increasing shortness of breath or coughing
- Abdominal pain
- Presence of blood in the stools
- Kidney disease
As a vasculitis, it is classified among autoimmune diseases; indeed, EGPA is known as an ANCA-associated vasculitis, as auto-antibodies attacking the body’s own blood protein (anti-neutrophil cytoplasmic antibody) can be detected in some patients.
However, infectious and environmental risk factors have been described, and they could play a role as triggers of EGPA onset or relapse, particularly on subjects with a genetic susceptibility.
Among the most useful tests to diagnose EGPA are:
- Urinalysis: Excessive protein or presence of red blood cells may indicate inflammation of the kidneys.
- Blood tests: The ANCA test (i.e., the search for autoantibodies against anti-neutrophil cytoplasmic proteins), when positive, can be helpful in confirming diagnosis. However, a positive ANCA test is not a specific marker for EGPA diagnosis: indeed, only around 30-50 percent of individuals with EGPA are ANCA positive, and ANCA-test can be positive also in case of other ANCA-associated vasculitis (different from EGPA). Other common tests include blood inflammatory parameters, such as the erythrocyte sedimentation rate (ESR) and the C-reactive protein (CRP) test. All of these tests may support a diagnosis of EGPA, but are not conclusive on their own. A tissue biopsy is typically needed.
- Tissue biopsy: This surgical procedure removes a small tissue sample from an affected vessel or organ, which is examined under a microscope for signs of inflammation or tissue damage.
- Imaging studies: X-rays and computed tomography (CT) scans may reveal pulmonary or ear-nose-throat involvement.
- Heart echocardiogram: All patients with EGPA should be screened for heart involvement.
To date, novel therapeutic strategies (including the biologic agents rituximab and mepolizumab) have been developed, to reduce the need of steroids, the possible adverse events related to the long-term use of immune-modulating/immunosuppressants medications, as well as to guarantee a better control of the disease.
Even with effective treatment, EGPA is a chronic illness with cycles of relapse and remission. For this reason, regular doctor visits and ongoing monitoring of lab and imaging tests are important to guarantee the disease control and to avoid serious complications.
Most relevant scientific publications and insights
C. Marvisi et al.
New perspectives in eosinophilic granulomatosis with polyangiitis (EGPA): report of the first meeting of the European EGPA Study Group
P.A. Lyons et al.
Genome-wide association study of eosinophilic granulomatosis with polyangiitis reveals genomic loci stratified by ANCA status
S. Moiseev et al.
International Consensus on ANCA Testing in Eosinophilic Granulomatosis with Polyangiitis
A. Canzian et al.
Use of Biologics to Treat Relapsing and/or Refractory Eosinophilic Granulomatosis With Polyangiitis: Data From a European Collaborative Study
M. Papo et al.
Significance of PR3-ANCA positivity in eosinophilic granulomatosis with polyangiitis (Churg-Strauss)
M. Zampieri et al.
Cardiac involvement in eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome): Prospective evaluation at a tertiary referral centre
F. Maritati et al.
Occupational exposures and smoking in eosinophilic granulomatosis with Polyangiitis (Churg-strauss syndrome)
A. Bettiol et al.