Comparative 1H NMR Lipoprotein Profiling of Rheumatoid Arthritis and Systemic Lupus Erythematosus Patients Highlights Disease-Specific Lipoprotein Dysregulation

Rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are systemic autoimmune diseases associated with increased cardiovascular risk and metabolic alterations. We applied 1H NMR spectroscopy to profile lipoproteins and metabolites in women with RA, SLE, and healthy controls. Both RA and SLE showed shared alterations in HDL metabolism, including reduced HDL particle size and lower concentrations of small HDL particles compared with controls. RA exhibited additional changes, notably a significant reduction in small LDL particle concentration. Metabolite profiling further differentiated RA, revealing significantly lower circulating levels of glutamine, alanine, and GlycB. Correlation analyses demonstrated that in RA, LDL particle concentrations were positively associated with disease activity (DAS28-ESR), and large LDL particles correlated positively with IFN-γ and VEGF. In SLE, HDL particle measures were associated with complement components, with small HDL particles positively correlated with C3 and HDL particle size inversely correlated with C3, while large LDL particles correlated positively with IL-6 and negatively with MDC. Together, these results indicate that RA and SLE share common lipoprotein alterations, while RA displays additional metabolic changes. NMR-derived lipoprotein and metabolite profiles may provide complementary information for assessing inflammation and cardiovascular risk in autoimmune diseases.