Which of the following types of hepatitis is associated with an immune-mediated vasculitis characterized by p-ANCA antibodies?
High-Yield Explanation
Hepatitis B is associated with polyaeritis nodosa (PAN), a necrotizing vasculitis of small- and medium-sized muscular aeries involving all organ systems. A significant percentage of patients with PAN have hepatitis B antigenemia. They also have circulating immune complexes containing hepatitis B antigen. Hepatitis B antigen, IgM, and complement can be demonstrated in blood vessel walls. P-ANCA (perinuclear-anti nuclear cytoplasmic antibody) is a marker for polyaeritis nodosa. Hepatitis A is not associated with a vasculitis. Hepatitis C accounts for 50-70% of chronic hepatitis. Chronic hepatitis C can be associated with immune-complex mediated extrahepatic complications, but is less common than hepatitis B. Hepatitis C does have a significant association with essential mixed cryoglobulinemia, which presents with glomerulonephritis, ahralgias, hepatosplenomegaly, and lymphadenopathy, in addition to a vasculitis. However, there is no association with p-ANCA. Hepatitis D requires that the patient be co-infected with hepatitis B. As such, it does not independently cause disease, but it can produce a worsening of the liver disease.