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Diseases

Genetic and Rare Diseases Information Center (GARD)

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Granulomatosis with polyangiitis (Wegener's)


Other Names for this Disease
  • Midline granulomatosis
  • Wegener granulomatosis
  • WG
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Your Question

My aunt has Wegener's. When she was out camping she got bitten by a spider and was never the same. It took a few years for them to diagnose her. They had tested her for Wegener's and it came back negative. How is that possible that it came back negative and suddenly now it's positive? How much longer will I be able to be with her?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

How is Wegener's granulomatosis diagnosed?

Wegener's granulomatosis (WG) has a wide variety of ways that it may present itself. Affected individuals may first report some chronic, nonspecific complaints including fevers, night sweats, fatigue, lethargy, loss of appetite and weight loss; this may make the diagnosis difficult at first.[1] However, to treat people with WG most effectively, healthcare professionals must diagnose the disease early.[2]

There are no specific blood tests that can be used to diagnose WG, but blood tests are important to rule out other causes of illness and to determine which organ may be affected. Most blood tests can only suggest that a person has inflammation somewhere in the body. Anemia (low red blood cell count), elevated white blood cell count and platelet count, and an elevated sedimentation rate are commonly found in people with Wegener's granulomatosis. If the kidneys are involved, a healthcare professional can see red blood cells and structures called red blood cell casts in the urine when viewed under a microscope, and the blood tests measuring kidney function may show abnormalities. X-ray results can also be very helpful in diagnosing WG. People with lung problems will have abnormal chest X-rays. CT (computed tomography) scans in people with sinus problems may show thickening of the sinus lining. Many people with active WG have a blood test that shows the presence of a specific type of antibody, a disease-fighting protein, called antineutrophil cytoplasmic antibodies (ANCA). Although a positive ANCA test is useful to support a suspected diagnosis of WG, in most instances healthcare professionals do not use it by itself to diagnose this disorder. Furthermore, The ANCA test may be negative in some people with active Wegener's granulomatosis.[2]

Currently, the only clear-cut way to diagnose Wegener's granulomatosis is by performing a biopsy (removing a tiny piece of tissue) of an involved organ (usually the sinuses, lung, or kidney). A healthcare professional will examine tissue from the organ under the microscope to confirm the presence of vasculitis and granulomas (a specific type of inflammation), which together are features of Wegener's granulomatosis. A biopsy is very important both to confirm the presence of the disorder and also to make sure other disorders that may have similar signs and symptoms are not present.[2]
Last updated: 7/27/2011

Is it possible for someone who actually has Wegener's granulomatosis to "test negative" for the condition?

There may be several reasons that a healthcare provider may believe that an individual does not have Wegener's granulomatosis (WG) when the individual actually has the condition. Because there is not one specific test used to diagnose WG, obtaining the correct diagnosis may involve needing several different tests over a period of time. When an affected individual is undergoing the process of testing, sometimes more common or more likely conditions are first considered. Conditions that share some of the signs and symptoms of WG need to be ruled out before the diagnosis of WG can be made.

Although some tests are helpful in suggesting a diagnosis of WG, not all affected individuals will have a positive result for these tests at the time the tests are done (or they may never have a positive result for some of the tests). For example, individuals may have an abnormal kidney function test if the kidneys are affected by WG,[2] but the kidney function test may be normal if the kidneys are not affected at the time of testing. A normal kidney function test might lead a healthcare provider to believe a diagnosis of WG is unlikely. Another example is an affected individual receiving a negative result on the ANCA test. Although receiving a positive result on this test is useful to support a diagnosis of WG, this test may be negative in some people with active WG.[2]

To obtain a correct diagnosis of WG, it is important to work with a healthcare provider who is familiar with diagnosing this condition. An experienced provider can choose the right combination of tests and interpret the results correctly. It is important to remember that no test is 100% reliable because some potential (however small) for human or mechanical error is always involved.
Last updated: 7/28/2011

What is the prognosis for individuals with Wegener's granulomatosis?

The prognosis (the likely "course") for individuals with Wegener's granulomatosis (WG) depends on many factors that are unique to each affected individual. Factors that may affect an individual's prognosis may include how early an individual is diagnosed; when treatment is begun; the response to treatment; and how severely the individual is affected. With the appropriate treatment, the outlook is generally good for people with WG.[2]

Untreated, severe WG is associated with a very high risk of death. However, more people survive when they receive aggressive treatment. The most common causes of death in WG include infection, respiratory failure (when not enough oxygen passes from your lungs to your blood), kidney failure, cancer, and damage to the heart.[1]

Approximately half of people with the condition may experience a return of their disease. This usually occurs within 2 years of stopping medicine, but it can occur at any point during treatment or after stopping treatment. Therefore, it is extremely important that people continue to see their healthcare professionals regularly, both while they are on these medicines as well as after they have stopped taking the medicines.[2]
Last updated: 7/28/2011

References