January 1, 2010
Dear Mayo Clinic:
I have read that vasculitis is a rare disease, but I am beginning to wonder if it is rare or if doctors just don't understand it. My husband has this condition, but the routine blood tests performed come back negative. How can we know for sure if vasculitis is the correct diagnosis? If it is vasculitis, what are his treatment options?
Vasculitis, an inflammation of blood vessel walls, is fairly rare, but it isn't just one disease. Rather, the term describes a group of diseases that comprise many forms of vasculitis. Accurate diagnosis and appropriate treatment need to be based on the type of vasculitis your husband has.
Vasculitis is an autoimmune disease; the immune system damages its own tissue, in this case the blood vessel walls. Because blood vessels are present throughout the body, vasculitis can affect any organ. Usually, vasculitis is a systemic disease and multiple organs are affected simultaneously. The size of the blood vessel affected — that is, large-vessel vasculitis, medium-size vessel vasculitis, and small-vessel vasculitis — determines how vasculitis is categorized. Many specific forms of the disease fall under each of those categories.
Vasculitis is a serious condition because damage to the blood vessel wall can cause narrowing or blockage of the vessel. The result is a lack of blood to the organ that the blood vessel supplies, which can lead to organ damage. The type of damage depends on the organ affected. For example, if the blood vessels of the lungs are affected, a patient may have bleeding into the lungs and shortness of breath. If vasculitis is damaging the kidneys, a person might experience kidney failure. Occasionally, blood vessel wall damage can weaken the wall itself, which may lead to formation of an aneurysm (outward bulging of the vessel wall).
Diagnosing vasculitis can be a challenge. Blood tests can help in diagnosing some forms but, in others, blood tests may not be sufficient. Because the condition involves inflammation, blood tests for most people with vasculitis show high levels of markers of inflammation. But blood work usually isn't enough, because the blood tests available are generally not specific to inflammation caused by vasculitis. For some forms of vasculitis, such as Wegener's granulomatosis, a more specific blood test called antineutrophil cytoplasmic antibodies (ANCA) serologies may help identify the disease.
In addition to blood work, many physicians who suspect vasculitis recommend imaging studies of the blood vessels and internal organs. If there's concern that a patient has a form of medium-size or large-vessel vasculitis that's affecting the aorta or the major branches of the aorta, then computerized tomography (CT) or magnetic resonance (MR) angiography can be used to look for signs of vasculitis. Those signs can include thickening or swelling in the blood vessel wall. CT and MR imaging can also reveal vasculitis-caused damage to a patient's internal organs. Occasionally, conventional angiography may also be required to obtain detailed images of blood vessels.
However, a tissue biopsy is often the definitive procedure in diagnosing vasculitis. A small piece of the affected blood vessel or the affected organ is surgically removed and closely examined for signs of vasculitis.
Once vasculitis has been diagnosed, treatment options depend on the type of vasculitis and its severity. A few types may resolve without treatment, but that's uncommon. In some rare situations, the disease is limited to a single organ, and a patient may be cured.
Most forms of vasculitis are serious and potentially even life-threatening and require aggressive treatment with immune-suppressant medicines to reduce the blood vessel inflammation and prevent further damage. Corticosteroids — typically prednisone — are commonly prescribed for vasculitis because they are very effective at suppressing inflammation. Most forms of vasculitis improve with prednisone, but corticosteroids can cause bothersome side effects. To limit the amount of corticosteroids necessary, a number of other immunosuppressive drugs can be used as well.
Because vasculitis usually is a chronic condition, treatment typically lasts years. Most patients require long-term immunosuppressive therapy. Given his situation, I'd recommend your husband be evaluated by a rheumatologist. If the diagnosis remains inconclusive, evaluation in a specialized vasculitis center may be necessary.
— Kenneth Warrington, M.D., Rheumatology, Mayo Clinic, Rochester, Minn.