Immune complex deposition and coronary vasculitis in systemic lupus erythematosus. Report of two cases.

Extramural coronary arteries were examined in two patients with systemic lupus erythematosus (SLE). Coronary vasculitis was found in both patients. One patient with clinically and serologically inactive SLE had died suddenly and was found to have a myocardial infarction secondary to the coronary vasculitis. Immunopathologic studies demonstrated immune reactants in the walls of inflamed and noninflamed arterial segments in a pattern consistent with immune complex aggregates. Immunologic injury secondary to immune complex deposition may be responsible for the development of coronary disease in patients with SLE. This has been demonstrated in experimental animals but not in humans. Although this is an uncommon complication of SLE, it represents a cause of sudden death and a potentially treatable lesion in this patient population. Its occurrence may be related to the deposition of immune aggregates in the walls of coronary vessels.