LUPUS FACT OF THE DAY: What Causes Vasculitis? Vasculitis can be caused by: • Infection of the blood vessel walls. This is rare. When it occurs, bacteria, viruses, or fungi infect the blood vessel. White blood cells move in to destroy the infectious agents and damage the blood vessel in the process. This is a serious condition and requires prompt antibiotic treatment. • Antibodies that react against cells in vessel walls. In some cases of vasculitis, an antibody against the cytoplasm of neutrophils (anti-neutrophil cytoplasm antibodies, or ANCA) is the probable cause of the inflammation and damage. • An immune or "allergic" reaction in the vessel walls. This cause of vasculitis is more common. Substances that cause allergic reactions are called antigens (abbreviated from anti-genetic, meaning “against genetic material”). Antigens cause the body to make proteins called antibodies which attach (bind) to the antigen for the purpose of getting rid of it. Antigens and antibodies that bind together are called immune complexes. Two primary ways in which immune complexes destroy antigens are: o by attracting white blood cells to digest the antigen o by activating other body substances to help destroy the antigens Unfortunately, some immune complexes do not serve their purpose of destroying antigens. Instead, they remain too long in the body and circulate in the blood and deposit in tissues. They commonly accumulate in blood vessel walls, where they cause inflammation. It is likely that some white blood cells (cytotoxic cells) which kill infectious agents can also accidentally damage blood vessels and cause vasculitis. ANCA probably react against white blood cells in vessel walls and increase the injury to vessels
Posted on: Wed, 18 Sep 2013 18:19:22 +0000