What Is ANCA-Associated Vasculitis?

ANCA-associated vasculitis is a group of rare autoimmune diseases. In these conditions, the immune system attacks the body's own small blood vessels by mistake.^1,2

The 2 main types are granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). If you or a loved one was just diagnosed, learning the basics can help you feel more prepared for what comes next.^2,3

What is ANCA-associated vasculitis?

Vasculitis means inflammation of the blood vessels. The inflammation limits the flow of blood to important organs, which can cause damage. ANCA stands for anti-neutrophil cytoplasmic antibody. Antibodies are proteins that the immune system normally makes to fight germs. In ANCA-associated vasculitis, these antibodies attack healthy white blood cells called neutrophils instead, which leads to swelling in the blood vessels.^1,4

What causes ANCA-associated vasculitis?

In most cases, the exact cause is not known. It is an autoimmune condition, which means the immune system attacks the body's own tissues by mistake. Researchers are still working to understand why this happens. Because the cause is not fully known, there is no proven way to prevent it.⁴

The 2 main types: GPA and MPA

Both types are forms of small-vessel vasculitis, but they tend to affect the body in slightly different ways:^1-4

• Granulomatosis with polyangiitis (GPA) – This type was once called Wegener's granulomatosis. It most often affects the sinuses, nose, lungs, and kidneys, but it can involve other organs too.
• Microscopic polyangiitis (MPA) – This type most often affects the kidneys, lungs, nerves, skin, and joints.

Which parts of the body can it affect?

Because blood vessels run throughout the body, ANCA-associated vasculitis can affect more than one area at the same time. The sinuses, nose, lungs, and kidneys are among the most commonly affected. This is why one disease can cause a mix of symptoms that may seem unrelated at first.⁴

Common signs and symptoms

Symptoms depend on which organs are involved, and they can come on slowly or quickly. Early signs are easy to mistake for other illnesses, so it helps to know what to watch for:⁴

• Cold-like symptoms – A runny or stuffy nose that does not get better
• Joint pain – Aches in the joints
• Fatigue and weakness – Feeling unusually tired or run down

If signs like these do not go away or get worse, talk with your doctor.

Who gets it and how common is it?

ANCA-associated vasculitis is rare. It affects about 200 people in every million. It can affect people at any age. Men and women are affected equally, and it is more common in white people.^4,5

Why early diagnosis and treatment matter

ANCA-associated vasculitis can worsen quickly, so finding it early is important to help prevent lasting organ damage. The good news is that most people improve with medicines that slow or stop the inflammation. Treatment works differently for each person, so your care team will tailor a plan to you.^2,4

Talk to your doctor

If you have questions about ANCA-associated vasculitis, write them down and bring them to your next doctor’s appointment. You do not have to manage this alone. Learning how the condition is diagnosed and treated is a helpful next step, and your care team is there to guide you.