Post-Translational Modifications of Lipoproteins: Emerging Players Linking Inflammation and Cardiovascular Disease in Rheumatoid Arthritis-A Narrative Review.

Patients with rheumatoid arthritis (RA) have an increased risk of cardiovascular disease (CVD) that cannot be fully explained by traditional cardiometabolic risk factors. The observed 'lipid paradox', where RA patients with lower total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels exhibit higher CVD risk, may be attributed to post-translational modifications (PTMs). These lipoprotein PTMs likely arise from inflammatory pathways. While PTMs like citrullination and carbamylation are well recognized in RA joint pathology, their occurrence in other protein compartments and their role in CVD have been less well explored. This scoping review summarizes the current literature on PTMs of lipoproteins, including oxidation, nitration, carbamylation, and citrullination, and their impacts on CVD in RA. We also discuss immune responses to these PTMs, their interactions with scavenger receptors, and the effects of disease-modifying antirheumatic drugs. Further research on PTMs may uncover new pathways linking autoimmunity, inflammation, and vascular damage, offering novel diagnostic and therapeutic opportunities for RA-associated CVD.