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

Area of Science:

• Immunology
• Cardiology
• Rheumatology

Background:

• Rheumatic fever (RF) and antiphospholipid syndrome (APS) present distinct cardiac manifestations.
• Shared features include central nervous system and heart involvement, molecular mimicry, and cross-reacting antibodies.
• Endothelial cell activation at the heart valves is a common pathological site.

Purpose of the Study:

• To explore the potential links between heart involvement in RF and APS.
• To highlight common pathogenic mechanisms underlying these two conditions.

Main Methods:

• Review of existing literature on RF and APS heart involvement.
• Analysis of shared immunological phenomena such as molecular mimicry and antibody cross-reactivity.

Main Results:

• Both RF and APS involve the CNS and heart, with endothelial activation in valves.
• Molecular mimicry and cross-reacting antibodies against pathogens and self-molecules are implicated in both.
• Patients with RF may have antiphospholipid antibodies, and APS can be linked to streptococcal infections.
• Cross-reactivity between antibodies to streptococcal M-protein and APS-related antibodies targeting beta-2-glycoprotein-I (beta2GPI) has been observed.

Conclusions:

• Common autoimmune pathways, particularly involving molecular mimicry and cross-reactive antibodies, may link heart involvement in RF and APS.
• Further research into these shared mechanisms could inform diagnostic and therapeutic strategies for both conditions.