How Is GPA Diagnosed?

GPA has symptoms similar to a number of other disorders, which may make it difficult to diagnose. However, for the most effective and successful treatment, early diagnosis is critical.

Once the diagnosis of GPA is suspected, a biopsy (tissue sample) of an affected area is often performed to try to confirm the presence of vasculitis. Biopsies are only recommended for organ sites in which there are abnormal findings present by examination, laboratory tests, or imaging.

It is the combination of symptoms, results of physical examinations, laboratory tests, X-rays, and sometimes a biopsy (sample) of affected tissue (skin, nasal membranes, sinus, lung, kidney or other sites) that together prove the diagnosis of GPA. Following treatment, these factors are also critical in judging whether the disease is active or in remission.

A positive blood test for antineutrophil cytoplasmic antibodies (ANCA) can support a suspected diagnosis of the disease. However, this blood test does not by itself prove the diagnosis of GPA or determine disease activity.

Sometimes the lungs may be abnormal even though there are no symptoms such as cough or shortness of breath. If symptoms of GPA are apparent, but not from the lungs, one quarter to one third of patients may still have unexpected lung abnormalities detected on imaging tests (conventional X-rays or a CT scan). Therefore, it is important to have lung images performed if active GPA is suspected — even if you don’t have any symptoms of lung disease.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.