Vasculitis

What is vasculitis?
Vasculitis is an inflammation of the wall of a blood vessel, a tube that carries blood. Blood vessels are the arteries, veins and capillaries in the body. Vasculitis can affect a blood vessel of any size. This inflammation may result in narrowing or occlusion (blocking) of the vessel; weakening of the vessel wall which could lead to an aneurysm and/or to hemorrhage or bleeding. When vessel narrowing or occlusion occurs, the organ supplied by that blood vessel suffers from ischemia (lack of oxygen), which can cause damage with a loss of organ function or even patient death if a critical organ is involved.

There are many types of vasculitis. They comprise a group of rare and complex diseases. They are classified as primary when there is no known cause and classified as secondary when a cause can be identified. Examples of secondary vasculitis are those caused by infections, medication toxicity (drug reaction), cancer and other diseases such as lupus and rheumatoid arthritis. Examples of primary vasculitis include Wegener's granulomatosis, Churg-Strauss syndrome, polyarteritis nodosa, Takayasu's arteritis and giant cell arteritis.

What are the symptoms?
Symptoms vary greatly depending on the organ(s) involved and the extent of the inflammation and/or ischemia. The lungs, skin, kidneys and peripheral nervous system are frequently involved in systemic vasculitis. If the lung is affected, the patient may have shortness of breath, coughing and/or chest pain. Different skin rashes or lesions may be caused by vasculitis affecting the skin. Symptoms from peripheral nerve disease include numbness or complete loss of sensation, pain and abnormal sensations such as burning or tingling. Virtually any organ system may be involved by different types of vasculitis.

What are the risk factors for vasculitis?
Studies have looked at genetic factors and have noted an association of certain vasculitides (plural form of vasculitis) with the presence of some genes. However, there are no known specific genes that are linked with a greater risk of developing vasculitis. Infectious agents, medications and certain connective tissue diseases may be associated with vasculitis, but other factors are yet to be identified and proven.

How is vasculitis diagnosed?
Establishing the diagnosis of vasculitis is not easy as the signs and symptoms may vary greatly. The diagnosis is a result of a combination of symptoms, laboratory tests, biopsy and/or angiography. There is no laboratory test that alone confirms the diagnosis of vasculitis, but certain tests may be helpful.

A biopsy is performed in most cases, as it is considered the gold standard test for vasculitis. However, it is not always feasible. Medium and large vessels are not accessible to biopsy unless the patient undergoes a surgical procedure. The biopsy results may also be affected by several factors including what organ is subject to biopsy, the sampling method used and the operator's skills and experience.

What is the treatment?
Treatment is not the same for all vasculitides as these diseases have unique clinical manifestations and prognosis. Sometimes vasculitis may be treated with corticosteroid alone whereas in other cases it may require a second immunosupressive medication (e.g. Wegener's granulomatosis). Many factors affect the choice of treatment including the organ-systems involved and the severity and extent of disease. Cyclophosphamide is used in combination with steroids in severe cases, when critical organ function is affected or in life-threatening situations. In less severe cases, a less toxic agent such as methotrexate (MTX) may be used. Some cases require staged therapy with two steps: initial therapy to control the disease and the second step therapy for maintenance to reduce the risk of relapse. Methotrexate or azathioprine are commonly used agents for maintenance treatment. Most patients with vasculitis are treated by rheumatologists but other physicians may also be experienced in treating this problem.

How can vasculitis be prevented?
Many patients with a history of vasculitis must be monitored closely for relapses. Certain diseases may require monitoring of laboratory tests monthly. Immediate medical evaluation is important if recurrent or new symptoms appear that may indicate a relapse. Most patients with vasculitis require long-term follow-up for monitoring of disease activity, medication toxicity and damage from other diseases associated with vasculitis.

Resources: www.vasculitisfoundation.org

About the Author: Alexandra Villa-Forte, MD, MPH is a clinical rheumatologist in the Center for Vasculitis Care and Research, Department of Rheumatic and Immunologic Diseases at the Cleveland Clinic Foundation. Most of her time is devoted to patient care and teaching of residents and rheumatology fellows.