EGPA generally more severe in patients with GI involvement
Study finds more severe disease, mortality risk when gastrointestinal tract affected
Rates of relapse, and mortality, are higher in people with eosinophilic granulomatosis with polyangiitis (EGPA) that affects the gastrointestinal (GI) tract — and periods of remission less likely — relative to EGPA patients without GI involvement, according to a study in China.
Those with GI involvement also presented with worse disease markers and were more likely to show weight loss, which was identified as a potential risk factor for the GI tract being affected.
These findings indicate that “maintenance treatment and management strategies should be carefully chosen for this subgroup of patients,” the researchers wrote.
GI tract involvement can be common in EGPA, a rare form of AAV
The study, “Clinical characteristics and long-term outcome of patients with gastrointestinal involvement in eosinophilic granulomatosis with polyangiitis,” was published in the journal Frontiers in Immunology.
EGPA is the rarest form of ANCA-associated vasculitis (AAV), a group of autoimmune disorders characterized by blood vessel damage and inflammation. EGPA is marked by the accumulation of eosinophils, a type of immune cell, into masses in small blood vessels.
A complex and multisystem disease, EGPA can have a wide array of manifestations involving several organs, but most commonly the lungs and gastrointestinal tract.
While “severe GI involvement could be life-threatening and was acknowledged as a poor prognostic factor in EGPA patients,” few large studies have investigated the clinical characteristics of EGPA patients with GI involvement.
A research team at institutes in Beijing retrospectively assessed the characteristics and outcomes of 94 EGPA patients (60 men and 34 women) hospitalized at a center there from December 2001 to August 2021.
Their mean age at disease onset was 47.2, and they had been living with the disease for a median of 42 months, or about 3.5 years.
At their first hospitalization, used as a baseline measure, 40 patients (42.6%) were not receiving treatment for their EGPA, while 31 (33%) were using anti-inflammatory glucocorticoids and immunosuppressants and, 23 others (24.5%) were on glucocorticoids alone.
Most patients (77.7%) had no sign of GI involvement and were classified as a non-GI group, while 21 others (22.3%) did and were placed in the GI group. Six of the 21 patients with GI involvement (28.6%) “had GI manifestations as their initial symptoms at EGPA onset,” the researchers wrote.
Abdominal pain (90.5%) was the most common GI symptom, followed by diarrhea (42.9%) and nausea/vomiting (23.8%), consistent with previous reports. However, some patients presented with unusually mild GI symptoms, such as poor appetite, heartburn, and acid regurgitation, with GI involvement confirmed in subsequent exams.
“Therefore, clinicians should also pay attention to mild GI symptoms in the evaluation of EGPA patients,” the team wrote.
Weight loss a strong indicator of GI involvement in EGPA patients
Compared with non-GI patients, the GI group at baseline had significantly higher levels of C-reactive protein (CRP; an inflammation marker) and higher results on the Birmingham vasculitis activity score (BVAS) and Five Factor Score (FFS) — two measures that assess disease activity and prognosis.
Weight loss also was significantly more likely in people with GI involvement than among the non-GI group. Further analyses, adjusted for baseline glucocorticoid treatment, identified only weight loss as a potential risk factor for GI involvement in EGPA patients.
No significant differences between these patient groups were found for age, other organ involvement, treatment, eosinophil counts, erythrocyte sedimentation rate (ESR), and blood levels of immunoglobulin E, a type of antibody involved in allergic reactions.
ESR measures how quickly red blood cells settle in a test tube, and it is often used as an inflammatory marker.
Treatment approaches to achieve disease remission in hospitalized patients were generally comparable regardless of GI involvement.
However, over a median follow-up of 38 months (about three years), cumulative relapse rates were significantly higher among patients with GI involvement than those in the non-GI group at one year (19.2% vs. 3.8%) and three years (54.6% vs. 13.1%). GI group patients also showed significantly lower long-term remission rates that those without involvement (33.3% vs. 86.3%).
These poor outcomes also influenced survival, with patients with GI involvement having significantly lower cumulative one-year (75.2%) and three-year (67.7%) survival rates than those without GI involvement (100% for both time periods).
In particular, all patients with GI bleeding (14.3%) or perforation (14.3%) had a poor prognosis. As such, “clinicians need to pay full attention to this condition and give sufficient intervention at early stage,” the researchers wrote.
“EGPA patients with GI involvement had distinct features from those without GI involvement, including higher [CRP] level, higher BVAS and FFS scores,” the scientists concluded.
These patients also had a “lower cumulative survival rate, lower long-term remission rate and higher cumulative relapse rate compared with those without GI involvement,” they added.
One study limitation was its retrospective nature and the fact that all data came from patients at a single hospital. Future studies involving patients at various centers and following them over time are needed to confirm these findings, the researchers noted.