Cytokine profiles and their correlation with clinical and blood parameters in rheumatoid arthritis and systemic lupus erythematosus

Abstract The abnormal biological activity of cytokines and their imbalance are implicated in developing rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Cytokine levels were measured in RA and SLE patients and compared to healthy controls using the Wilcoxon rank sum test and Kruskal–Wallis test. The relationship between cytokine levels and blood and clinical parameters was assessed using Spearman's correlation test. Compared to healthy controls, both RA and SLE patients exhibited elevated levels of GM-CSF, CX3CL1, IFN-α2, IL-12p70, IL-17A, TNF-α, IL-1β, and IFN-γ, which is evidence of their shared inflammatory signature. IL-2 levels were elevated exclusively in RA patients, while MCP-1 and IL-10 were uniquely increased in SLE patients. Notably, TNF-α showed the most significant increase in SLE patients. IL-4 was elevated in SLE patients with nephritis, correlating with IL-6, IL-10, sCD40L, and IL-8, suggesting B cell involvement in lupus nephritis. The negative correlation between CX3CL1 and TNF-α with HDL in RA and SLE respectively, highlights the potential association of these inflammatory markers with cardiovascular risk. These findings underscore the complex cytokine interplay in RA and SLE. CX3CL1 emerges as a potential therapeutic target for RA, while TNF-α and IL-4 show promise as therapeutic targets for SLE.