Granulomatosis with polyangiitis (GPA) is a rare disease that inflames and damages small blood vessels in many organs, including the kidneys, lungs, and sinuses. The inflammation limits blood flow and prevents enough oxygen from getting to your organs and tissues. This affects how well they work.
Inflamed lumps of tissue, called granulomas, form around the blood vessels. Granulomas can damage organs.
GPA is one of several types of vasculitis, a disorder that causes inflammation in the blood vessels.
GPA was previously known as Wegener’s granulomatosis.
GPA sometimes doesn’t cause symptoms early in the disease. The nose, sinuses, and lungs are usually the first areas affected.
The symptoms you develop depend on the organs involved:
- Nose. Symptoms can include nosebleeds and crusting.
- Sinuses. Sinus infections or a stuffed or runny nose may develop.
- Lungs. May include coughing, bloody phlegm, shortness of breath, or wheezing.
- Ears. Ear infections, pain, and hearing loss may be experienced.
- Eyes. Symptoms can include redness, pain, or vision changes.
- Skin. Sores, bruises, or rashes may develop.
- Kidneys. You may have blood in the urine.
- Joints. Swelling and pain in the joints may be experienced.
- Nerves. May include numbness, tingling, or shooting pains in the arms, legs, hands, or feet.
More general, body-wide symptoms include:
- general ill feeling, called malaise
- night sweats
- aches and pains
- weight loss
GPA is an autoimmune disease. This means the body’s immune system mistakenly attacks its own healthy tissues. In the case of GPA, the immune system attacks blood vessels.
Doctors don’t know what causes the autoimmune attack. Genes don’t seem to be involved and GPA rarely runs in families.
Infections might be involved in triggering the disease. When viruses or bacteria get into your body, your immune system responds by sending out cells that produce inflammation. The immune response could damage healthy tissues.
In the case of GPA, blood vessels are damaged. However, no one type of bacteria, virus, or fungus has been definitively linked to the disease.
You can get this disease at any age, but it’s most common in people ages 40 to 65.
GPA is a very rare disease. According to the U.S. National Library of Medicine, only 3 out of every 100,000 people in the United States will get it.
Your doctor will first ask about your symptoms and medical history. Then you’ll have an exam.
There are several types of tests your doctor might use to help them make a diagnosis.
Blood and urine tests
Your doctor may use any of the following blood and urine tests:
- Antineutrophil cytoplasmic antibody (ANCA) test. This blood test looks for proteins called antibodies that most people with GPA have. However, it can’t confirm definitely that you have GPA. About 20 percent of people with GPA have a negative ANCA test result.
- C-reactive protein and erythrocyte sedimentation rate (sed rate). These blood tests can be used to identify inflammation in your body.
- Complete blood count (CBC). A CBC is common test that measures your blood cell counts. A low red blood cell count is a sign of anemia, which is common in people with GPA whose kidneys are affected.
- Urine or blood creatinine. These tests measure levels of the waste product creatinine in your urine or blood. A high creatinine level is a sign that your kidneys aren’t working well enough to filter wastes from your blood.
These tests take pictures from inside your body to look for organ damage:
- X-rays. A chest X-ray uses small amounts of radiation to take pictures of the affected area, such as of the lungs and blood vessels.
- CT scan. This test uses computers and rotating X-ray machines to take more detailed pictures of the affected area.
- MRI scan. An MRI uses magnets and radio waves to produce detailed, cross-sectional images of the area in question without bones obstructing the view of tissues and organs.
The only way to confirm that you have GPA is with a biopsy. During this surgical procedure, your doctor removes a small sample of tissue from an affected organ, such as your lung or kidney, and sends it to a lab. A lab technician looks at the sample under a microscope to see if it looks like GPA.
A biopsy is an invasive procedure. Your doctor may recommend a biopsy if blood, urine, or imaging test results are abnormal and they suspect GPA.
GPA can permanently damage organs, but it’s treatable. You may need to keep taking medicine in the long term to prevent the disease from coming back.
Drugs your doctor can prescribe include:
- anti-inflammatory drugs, such as corticosteroids (prednisone)
- immune-suppressing drugs, such as cyclophosphamide, azathioprine (Azasan, Imuran), and methotrexate
- the chemotherapy drug rituximab (Rituxan)
Your doctor might combine drugs like cyclophosphamide and prednisone to more effectively bring down inflammation. More than 90 percent of people improve with this treatment.
If your GPA isn’t severe, your doctor may recommend treating it with prednisone and methotrexate. These medications have fewer side effects than cyclophosphamide and prednisone.
The drugs used to treat GPA can cause side effects. Some side effects are serious. For example, they can lower your body’s ability to fight infection or weaken your bones. Your doctor should monitor you for side effects like these.
If the disease is affecting your lungs, your doctor may prescribe a combination antibiotic, such as sulfamethoxazole-trimpethoprim (Bactrim, Septra), to prevent infection.
GPA can be very serious if it isn’t treated, and it can get worse quickly. Possible complications include:
- kidney failure
- lung failure
- hearing loss
- heart disease
- skin scars
- damage to the nose
- deep vein thrombosis (DVT), a blood clot in the deep vein of the leg
You’ll need to keep taking your medication to prevent a relapse. GPA comes back in about half of people within two years after they stop treatment.
The outlook for people with GPA depends on how severe your disease is and which organs are involved. Medication can effectively treat this condition. However, relapses are common. You’ll need to keep seeing your doctor for follow-up tests to make sure GPA doesn’t return and to prevent complications.