May cause acute glomerulonephritis due to Ag-Ab complexes deposited in glomeruli
Embolic complications: If right-sided, may embolize to lungs & cause abscesses. If left-sided, may embolize to brain, kidneys or other sites & cause abscesses, or may embolize to coronary arteries & cause MI.
May have a long course – weeks to months
Lower virulence organisms; example Strep. viridans
Endocarditis of systemic lupus erythematosus (Libman-Sacks endocarditis)
Marantic endocarditis probably results from a hypercoagulable state such as disseminated intravascular coagulation (DIC) or some forms of cancer (can be part of Trousseau syndrome). The vegetations are sterile, small and do not damage valves, but can embolize. The vegetations form on normal valves. Microscopically there is no inflammation.
SLE vegetations are small and sterile, and frequently form on the undersides of AV valves. They may be seen on the endocardium and chordae too. Microscopically there may be intense inflammation and fibrinoid necrosis involving the leaflet. Scarring of the valves can occur.
Diseases of the Myocardium
Myocarditis (including transplant rejection)
Cardiomyopathy (noninflammatory myocardial dysfunction of unknown [now sometimes known] cause)