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Eosinophilic granulomatosis with polyangiitis (EGPA) (Churg-Strauss)

What is eosinophilic granulomatosis with polyangiitis?

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss) (EGPA), also known as “allergic granulomatosis”, is a rare form of vasculitis which, like Granulomatosis with polyangiitis (Wegener's) (GPA) and microscopic polyangiitis, affects small and medium-sized vessels. Most patients with eosinophilic granulomatosis with polyangiitis (Churg-Strauss) have asthma, nasal and sinus allergies. Patients which EGPA often have unusually high numbers of eosinophils, a type of white blood cell in their blood. Asthma, as well as the presence of eosinophils are common and by themselves are not enough to base the diagnosis of EGPA on. Other problems caused by EGPA include lung infiltrates, rashes, peripheral nervous system disease, abdominal pain, kidney, and cardiac disease.

Who gets eosinophilic granulomatosis with polyangiitis?

EGPA affects people of all ages and both sexes.

What causes eosinophilic granulomatosis with polyangiitis?

The cause of EGPA is not known.

How is eosinophilic granulomatosis with polyangiitis diagnosed?

EGPA is diagnosed on the basis of a combination of symptoms and abnormal laboratory tests including an ANCA test as well as biopsy of affected tissues.

What is the treatment for eosinophilic granulomatosis with polyangiitis?

Treatment of eosinophilic granulomatosis with polyangiitis (Churg-Strauss) usually includes a combination of glucocorticoids and an immunosuppressive drug such as cyclophosphamide, methotrexate, or azathioprine. If diagnosed early, treatment can bring about early remission and prevent organ failure. It is important to understand that the asthma patients with EGPA are treated in the same way as other patients with asthma. Worsening of asthma in patients with EGPA does not necessarily mean that the EGPA is active in other organs. Unfortunately, while remission of symptoms is usually achieved, the relapse rate remains high.

Is asthma part of vasculitis?

Not exactly. Even though asthma is present in almost all patients with eosinophilic granulomatosis with polyangiitis (Churg-Strauss) and corticosteroids represent the cornerstone treatment for both conditions, asthma it is not part of the vasculitis. In eosinophilic granulomatosis with polyangiitis (Churg-Strauss) asthma is more to be considered as an underlying predisposing condition, and it usually persists even after effective treatment for vasculitis.

What are the chances that my newly diagnosed vasculitis will relapse?

It can be hard to determine relapses in eosinophilic granulomatosis with polyangiitis (Churg-Strauss) (EGPA). A return of sinus symptoms and asthma is very common, but these may not represent active vasculitis. These symptoms may require treatment with prednisone and are commonly the rate-limiting features in being able to reduce the prednisone dose in EGPA. Relapses of vasculitis in EGPA are less common and have been reported in ranges from 10-30%.

In Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss) do increases in the eosinophil count predict relapse?

We do not have very good data to tell us what the most reliable markers of disease activity or predictors of relapse in eosinophilic granulomatosis with polyangiitis (Churg-Strauss) (EGPA) are. Eosinophils are one of the subtypes of white blood cells and the level of eosinophils can be measured in the blood. In addition to a careful clinical evaluation, the eosinophil count and other markers of inflammation such as the erythrocyte sedimentation rate (ESR, sed rate) and C-reactive protein (CRP) are usually followed in patients with EGPA. In patients with EGPA who have positive ANCA assays, we also monitor the ANCA level (MPO-ANCA). Some patients with EGPA have elevated IgE levels at the beginning of their disease. In these patients IgE levels can be useful in follow-up to help predict relapse.

Disease activity is absent in most patients with EGPA when eosinophil levels are low. Prednisone suppresses eosinophil counts quickly and effectively. Therefore, eosinophil counts may drop faster than disease activity disappears. On the other hand, when disease activity recurs, this is usually associated with - or preceded by - increases in eosinophil counts. If increasing eosinophil counts are not addressed by changes in therapy, worsening disease activity often follows.