From rheumatic fever to Libman-Sacks endocarditis: is there any possible pathogenetic link?

The heart lesions of rheumatic fever and the heart involvement in antiphospholipid syndrome (APS), have different clinical pictures. Yet, there are several common characteristics linking both diseases: 1) central nervous system (CNS) and heart involvement; 2) molecular mimicry between the a pathogen and the origin of the disease; 3) cross reacting antibodies between the pathogen and self molecules; 4) endothelial cell activation in the 'crime-area' i.e., the valves; 5) some of the patients with RF have circulating antiphospholipid antibodies, while APS may be associated with streptococcal infection; and 6) recently, a cross-reactivity between antibodies directed to the streptococcal M-protein and its synthetic derivative in rheumatic fever (RF) and antibodies derived from APS patients targeting the beta-2-glycoprotein-I (beta 2GPI) and a beta 2GPI related synthetic peptide. In the current paper, we summarize the possible links between the heart involvement in RF and APS.