Ask the Doctors May 2014 Issue

Ask The Doctors: May 2014

Vasculitis and its treatment ...... The real meaning behind testing positive for the HLA-B27 gene

Q. I’ve recently been diagnosed with vasculitis in addition to rheumatoid arthritis. What is vasculitis and what is the best way to treat it?
A. Vasculitis refers to inflammation of the blood vessels, including arteries and veins. There are many types of vasculitis, and one type can occur in the setting of rheumatoid arthritis (RA). Vasculitis can cause a wide range of signs and symptoms depending on which organs are involved. With lung involvement, you experience shortness of breath and cough. With muscles and nerves, you may get numbness or weakness in the hands or feet, while with skin involvement, red spots (purpura), lumps (nodules) or sores (ulcers) can develop.

Vasculitis can range from mild forms to those that are life threatening, and can affect both sexes and all ages. For instance, a few types of vasculitis affect certain groups of people, such as Kawasaki disease and Henoch-Schonlein purpura occurring predominately in children, and giant cell arteritis, which occurs only in adults over 50 years old. The most common diagnostic test for vasculitis is a biopsy of the affected tissue, when possible.

Although vasculitis can be mild with patients experiencing only one episode, certain types of the condition can be chronic and disabling. The condition is typically first treated with glucocorticoids (prednisone).

More serious cases may require the use of immunosuppressive drugs, such as cyclophosphamide (Cytoxan®). Methotrexate (Rheumatrex®, Trexall®) or azathioprine (Imuran®) are used for less serious forms of vasculitis.

Some patients with RA may develop vasculitis and require steroids and immunosuppressive drugs. Patients with more severe RA are at greater risk, including those with high levels of rheumatoid factor, smoking and rheumatoid nodules. Newer drugs may also help treat the symptoms of vasculitis. A study published in Arthritis Care and Research (March 2012) showed that the immunotherapy drug rituximab (Rituxan®) effectively treats some forms of vasculitis, including vasculitis associated with RA. The research demonstrated complete remission in systemic rheumatoid vasculitis in nearly three-fourths of patients receiving rituximab.

Q. I’ve tested positive for the HLA-B27 gene. Does this mean that I’ll definitely develop ankylosing spondylitis?
A. The HLA-B27 gene is a perfectly normal gene found in about six to eight percent of the general population, and no more than two percent of people born with this gene will eventually have ankylosing spondylitis (AS). The interaction of other genes with HLA-B27 is responsible for increasing or decreasing the risk of developing AS, according to Cleveland Clinic rheumatologist Chad Deal, MD.

For example, if a family member has spondylitis and you test positive for the HLA-B27 gene, your chance of getting the disease increases. “The risk of developing AS is 20 percent if a parent has AS, so about 80 percent of children who inherit HLA-B27 from a parent with ankylosing spondylitis do not develop the disorder,” says Dr. Deal. “In those with the HLA-B27 gene, but no family history of AS, the risk is much less than 20 percent. In addition to other genes that interact with HLA-B27 to increase or decrease the risk, the environment has a modifying influence.”

Interestingly, while over 95 percent of Caucasians with AS are positive for the HLA-B27 gene, only 50 percent of African-Americans with AS test positively for the gene. The gene has also been associated with more than 100 diseases, including reactive arthritis, inflammatory bowel disease and psoriatic arthritis.