Immunopathology of rheumatic pericarditis

Immunologic mechanisms have been implicated in the endocarditis, myocarditis, and arthritis of acute rheumatic fever. However, pericarditis, a major manifestation of acute rheumatic fever with a clinical incidence of 5-10%, has not been studied. We have evaluated a patient who had this febrile disease with arthritis and pericarditis. Pericardial tissue showed extensive deposition of IgG, IgM, and C3 both on the pericardial surface and within the walls of pericardial blood vessels. Our findings of immunoglobulins and complement within the inflamed pericardium suggest an immune-mediated mechanism for the pericarditis of acute rheumatic fever.