Which of the following statements about immune complex-mediated diseases is NOT true?

Question

A. Immune complexes may contain antibodies bound to either self or foreign antigens.
B. Immune complex-mediated diseases generally show systemic manifestations.
C. Pathologic features of immune complex diseases are determined by the cellular source of the antigen.
D. Small complexes are deposited in vessels more than large complexes, which are usually efficiently phagocytosed.
E. Complexes containing cationic antigens are more likely to produce severe, long-lasting injury by depositing in blood vessels and renal glomeruli.

Answer 1

ANS: C. A hallmark of immune complex-mediated disease is that pathologic features reflect the site of immune complex deposition and are not determined by the cellular source of the antigen. As such, immune complex-mediated diseases tend to be systemic, with little or no specificity for particular tissues. Immune complexes that cause disease may be composed of either self antigens or foreign antigens with bound antibodies. These complexes are produced during normal immune responses, but they cause disease only when they are produced in excessive amounts or are not efficiently cleared so that they become deposited in tissues. Small complexes are often not phagocytosed and tend to be deposited in vessels more readily than large complexes, which are usually cleared by phagocytes. Complexes containing cationic antigens bind tightly to negatively charged components of basement membranes of blood vessels and kidney glomeruli, typically producing long-lasting injury.