Vasculitis: Understanding Autoimmune Inflammation of Blood Vessels

When your immune system turns on your own blood vessels, things go wrong fast. Vasculitis isn’t just one disease-it’s a group of rare but serious conditions where your body’s defense system attacks the walls of your arteries and veins. This inflammation can narrow, weaken, or even block blood flow to vital organs. Left untreated, it can lead to kidney failure, stroke, heart attack, or tissue death. The good news? With early diagnosis and the right treatment, most people can regain control of their health.

What Happens Inside Your Blood Vessels?

Your blood vessels-arteries, veins, and capillaries-are the highways of your body. They carry oxygen, nutrients, and immune cells to every organ. In vasculitis, the immune system mistakes the vessel walls for invaders. White blood cells swarm the area, causing swelling, damage, and scarring. Over time, the vessel wall thickens, the lumen narrows, or worse, an aneurysm forms. In severe cases, the vessel ruptures or clots off completely.

This damage doesn’t happen evenly. Different types of vasculitis target different vessel sizes:

• Large-vessel vasculitis affects the aorta and its major branches. Giant cell arteritis (GCA) is the most common, usually hitting people over 50. It often attacks the temples, causing headaches, jaw pain when chewing, and sometimes sudden vision loss.
• Medium-vessel vasculitis targets arteries like those feeding the kidneys, intestines, or skin. Polyarteritis nodosa (PAN) falls here, and Kawasaki disease-which mostly affects children under 5-can cause coronary artery aneurysms if not treated quickly.
• Small-vessel vasculitis is the most dangerous because it hits capillaries in the kidneys, lungs, and nerves. Conditions like granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA) are all ANCA-associated. That means a specific antibody, called ANCA, is often found in the blood.

Each type has its own pattern. But the result is always the same: less blood flow means less oxygen. Organs start to fail.

How Do You Know If You Have It?

Vasculitis is sneaky. Its symptoms look like the flu, arthritis, or even aging. That’s why most people wait 6 to 12 months before getting a correct diagnosis.

Common signs include:

• Red or purple spots, bumps, or bruises on the skin-especially on the lower legs
• Joint pain or swelling
• Constant fatigue and fever with no clear cause
• Numbness or tingling in hands or feet
• Coughing up blood or shortness of breath
• Stomach pain, nausea, or bloody stools
• Headaches, scalp tenderness, or jaw pain when eating
• Loss of appetite or unexplained weight loss

Some people feel fine until their kidneys start failing. That’s why doctors always check urine for blood or protein, even if you don’t feel sick. Blood tests often show high levels of inflammation: ESR over 50 mm/hr or CRP above 5 mg/dL. But the real clue? ANCA antibodies.

For GPA, c-ANCA targeting proteinase-3 shows up in 80-90% of cases. For MPA and EGPA, p-ANCA targeting myeloperoxidase is more common. But no single test confirms vasculitis. You need the full picture: symptoms, blood work, imaging, and often a biopsy.

How Is It Diagnosed?

There’s no single test for vasculitis. Doctors piece it together like a puzzle.

• Blood tests check for inflammation markers and ANCA antibodies. But remember: ANCA can be positive in other conditions, and some people with vasculitis test negative.
• Imaging shows vessel damage. A CT or MRI can reveal inflamed arteries in the head, chest, or abdomen. An ultrasound might show thickened walls in the temporal artery for giant cell arteritis.
• Tissue biopsy is still the gold standard. A small sample from the skin, kidney, lung, or nerve can show the telltale signs: immune cells tearing through vessel walls, fibrinoid necrosis, or leukocytoclastic debris. A skin biopsy in someone with purple spots can confirm small-vessel vasculitis.
• Urine tests are non-negotiable. Even if you feel fine, protein or red blood cells in your urine mean your kidneys are under attack.

The Five Factor Score helps doctors judge how serious it is. It looks at five high-risk features: kidney involvement, heart issues, gastrointestinal bleeding, nerve damage, or lung bleeding. The more you have, the higher your risk of death without aggressive treatment.

Treatment: Stopping the Attack

Treatment depends on the type, severity, and organs involved. But the goal is always the same: shut down the immune attack and protect your organs.

For severe cases, doctors start with high-dose steroids like prednisone-often 0.5 to 1 mg per kg of body weight daily. That’s a lot. But it’s necessary to calm the inflammation fast.

Then comes the immune-suppressing drug:

• Cyclophosphamide has been the go-to for decades. It’s powerful but comes with risks like bladder damage and infertility.
• Rituximab targets B-cells-the immune cells that make ANCA. It’s now preferred for many cases because it’s just as effective and safer long-term.
• Avacopan is the newest player. Approved in 2021, it blocks a protein called C5a that drives inflammation. In clinical trials, patients on avacopan plus low-dose steroids had the same remission rates as those on high-dose steroids-but with 2,000 mg less steroid exposure over a year. That means fewer side effects: less weight gain, fewer broken bones, lower diabetes risk.

Once remission is reached, maintenance therapy begins. This lasts 18 to 24 months or longer. Options include:

• Methotrexate
• Azathioprine
• Rituximab (given every 6 months)

For giant cell arteritis, steroids are still first-line. But now, tocilizumab-an IL-6 blocker-is approved to help reduce steroid doses. For Kawasaki disease, high-dose IV immunoglobulin and aspirin are standard. And for Buerger’s disease? Quitting tobacco isn’t optional. If you keep smoking, nothing else works.

What’s the Long-Term Outlook?

The good news: most people go into remission. About 80-90% of those with ANCA-associated vasculitis do. But relapse is common-nearly half within five years.

Survival rates vary. For polyarteritis nodosa, someone with no major organ damage has a 95% chance of living five years. If they have two or more major organ issues? That drops to 50%. That’s why early treatment matters so much.

People with giant cell arteritis often need steroids for years. Long-term steroid use brings risks: osteoporosis, cataracts, diabetes, high blood pressure. That’s why newer drugs like tocilizumab and avacopan are game-changers-they help you get off steroids faster.

Children with Kawasaki disease need lifelong heart monitoring. About 1 in 5 untreated kids develop coronary artery aneurysms. Even with treatment, some need regular echocardiograms for years.

What’s New in Research?

Science is moving fast. Researchers are looking for better ways to predict flares before they happen. Blood tests for B-cell activating factor (BAFF) and urinary MCP-1 are showing promise as early warning signs.

Clinical trials are testing new drugs:

• Mepolizumab for EGPA: Early results show it cuts relapse rates by half.
• Abatacept for giant cell arteritis: Aiming to reduce steroid dependence.
• Belimumab: Already used in lupus, now being tested for vasculitis.

The Vasculitis Clinical Research Consortium is building a national database to track outcomes and find patterns. The goal? Personalized treatment. Not one-size-fits-all, but the right drug for your type, your antibodies, your risk profile.

Living With Vasculitis

It’s not just about medicine. It’s about lifestyle, monitoring, and support.

• Get vaccinated. Steroids weaken your immune system. Stay up to date on flu, pneumonia, and shingles shots.
• Protect your bones. Take calcium and vitamin D. Ask about bone density scans.
• Watch for infection. A fever that won’t go away? Call your doctor. It could be a flare-or something else.
• Stay active. Gentle exercise helps with fatigue and joint pain. Walking, swimming, yoga.
• Find your community. Support groups, online forums, patient advocacy groups-they help you feel less alone.

Vasculitis isn’t curable. But it’s manageable. Many people live full lives-work, travel, raise families. The key is staying ahead of it. Regular check-ups. Blood tests. Listening to your body.

If you’ve been told your symptoms are ‘just stress’ or ‘old age’-get a second opinion. Vasculitis is rare, but it’s real. And if you’re feeling off, don’t wait six months to find out why.

When to Seek Help Immediately

Call your doctor or go to the ER if you have:

• Sudden vision loss or double vision
• Coughing up blood
• Severe chest or abdominal pain
• Weakness or numbness on one side of the body
• Dark urine or no urine for 12+ hours

These could mean your blood vessels are blocking critical blood flow. Minutes matter.