Diagnosing ANCA-Associated Vasculitis

Getting a diagnosis of ANCA-associated vasculitis can take time. The early symptoms often look like other, more common illnesses, so doctors usually use a mix of tests to find the cause and rule out other conditions. Knowing what to expect can make the process feel less overwhelming.¹

Why diagnosis can be tricky

Early symptoms can be vague, such as a runny nose that does not get better, fatigue, or a fever with no clear cause. Because these signs are easy to mistake for an infection, your doctor will look at the whole picture: your symptoms, your health history, and the results of several tests.¹

The ANCA blood test

The main blood test for this condition looks for anti-neutrophil cytoplasmic antibodies (ANCA). There are 2 main kinds, called pANCA and cANCA, and each targets a specific protein inside white blood cells. The test helps your doctor find out whether you have autoimmune vasculitis and which type.¹

• A negative result means no ANCA were found, so your symptoms are probably not caused by autoimmune vasculitis.
• A positive result means ANCA were found, which may mean you have autoimmune vasculitis. The result also shows which type of ANCA was found, which helps point to the type of vasculitis.

Blood and urine tests

The ANCA test is usually one of several. Your doctor may order more blood tests and a urine test to check your kidneys. Kidney problems can be silent, so signs like blood in the urine or foamy urine (caused by protein) are important clues that your doctor looks for. A simple blood draw takes only a few minutes.¹

Imaging

Doctors often use a chest X-ray to look for signs of lung involvement. Imaging helps show which organs are affected and how much.²

Biopsy

A biopsy is often needed to confirm the diagnosis. In a biopsy, a doctor removes a small sample of tissue so it can be looked at under a microscope. For this condition, the sample is usually taken from a blood vessel that is swollen, and the kidney is a common site.^1,2

Preparing for the tests

Most of these tests are simple. The ANCA test uses a small needle to take a blood sample from a vein in your arm, and it usually takes less than 5 minutes. You do not normally need to do anything special to prepare, and there is very little risk beyond a slight sting or a small bruise where the needle goes in. If a biopsy is needed, your care team will explain what to expect beforehand.¹

Putting the results together

No single test gives the whole answer. Your doctor will consider your ANCA results along with your symptoms and your other test results. The ANCA test can also be used to help monitor treatment later on, although it is not always an exact way to measure how active the disease is.¹

Talk to your doctor

If you are going through testing, it can help to ask your care team what each test is for and when you will get results. Bring a list of your symptoms and when they started. Getting answers early makes it possible to start a treatment plan that fits your needs.