Vasculitis is a term used to describe inflammation of blood vessels, which can develop as a result of infection or from one of several other causes. In anti-neutrophil cytoplasmic autoantibody (ANCA) vasculitis, the inflammation is caused by the body’s own immune system. A disease of this kind is called an autoimmune disease. ANCA vasculitis can be treated with certain types of medication and medical procedures, but sometimes organs can become severely damaged to the point of failure. In such cases, the only treatment is an organ transplant.
A normal healthy immune system attacks viruses, bacteria and parasites, killing these invaders and preventing or destroying infection. This reaction is mediated by white blood cells, which produce a variety of proteins, such as antibodies and other molecules, that help fight infection. Autoimmune vasculitis develops because the body’s immune system becomes sensitized to attack proteins that are present on the surface of blood vessel cells. In ANCA vasculitis, white blood cells called B lymphocytes produce antibodies that attack another type of white blood cell called the neutrophil.
When ANCAs attack neutrophils, they cause the neutrophils to make holes in the walls of small blood vessels in a wide variety of tissue and organ types. The abnormal neutrophils potentially could attack blood vessels anywhere in the body, so the range of symptoms that ANCA vasculitis can cause is very broad. In the skin, this disease causes red spots called purpura to develop. In the lungs and nose, uncontrolled bleeding can occur. Kidney failure eventually can result if the kidneys come under attack, and nerve damage is another possible consequence if blood vessels near nerves are affected.
One of the most serious forms of this disease is called ANCA glomerulonephritis. In this type of ANCA disease, neutrophils attack tiny blood vessels in the glomeruli of the kidneys. The glomeruli are the part of the kidney responsible for filtering urine so that waste substances are excreted and proteins that the body requires are retained. When the glomeruli are under attack, proteins and blood are present in the urine, sometimes in large amounts. Eventually, as the glomeruli do more and more damage, the kidneys fail altogether.
ANCA vasculitis can be a short-term disease or a chronic disease that cannot be cured. In most cases, a person with this type of vasculitis can live a healthy life if he or she receives the right treatment. Depending on the symptoms, a patient might receive steroids or other immune system-suppressing drugs to stop the immune system's attacks on blood vessel walls, and the patient might receive antibiotics when infection develops.
People who have severe or chronic symptoms might have a treatment called plasmaphoresis, in which ANCAs are removed from the blood. When someone has ANCA glomerulonephritis that leads to kidney failure, the only possible treatment is a transplant. Even so, a small proportion of patients can experience further kidney-related vasculitis symptoms even after a kidney transplant.
