Background: Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are systemic and heterogeneous autoimmune pathologies with a worldwide distribution that affects mainly women. The abnormal biological activity of cytokines and their imbalance are implicated in the development of Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). The Colombian population has high levels of ethnic admixture between African, Native American, and European ancestral populations. Therefore, it is important to characterize the cytokine profile in this admixed population in the search for disease biomarkers.

Objectives: This study aimed to evaluate the plasma cytokine levels in a group of Colombian women with RA and SLE and to explore the cytokine correlation network with blood and clinical parameters.

Methods: A cytokine/chemokine magnetic bead-based panel was used to quantify in plasma samples the concentration of 17 cytokines. Kruskal-Wallis along with Dunn’s test allowed us to compare the cytokine levels between the groups. We assessed their predictive value through receiver operating characteristic (ROC) analysis and 10-fold cross-validation of a partial least squares (PLS) model. We calculated the correlation between the levels of the cytokines and the blood and clinical parameters with Spearman’s correlation.

Results: We quantified the cytokine concentrations of 77 Colombian women, including 24 SLE patients, 24 RA patients, and 29 age- and BMI-matched healthy controls. We found two correlation clusters in RA: GM-CSF, CX3CL1 and IL-12p70, and the leukocytes including lymphocytes and neutrophils, and the other one with IL-12p70, IL-17A, IL-2, TNF-α and VEGF correlated with CRP (Figure 2a). All these cytokines were statistically significant, and GM-CSF, CX3CL1 and TNF-α also had the greatest AUC (area under the ROC curve) (Figure 1a). In SLE there were no correlation clusters, but we found that the PLS model with the 10-cross fold validation had an accuracy of 81,8% and that MCP-1 is significantly increased in these patients but also is correlated with ESR and CRP (Figure 2b).

Conclusion: The cytokines significantly increased in RA and SLE and showing a correlation with blood parameters of inflammation and activation of the immune response currently used in the clinical setting, can be more reliable markers of both RA and SLE.

REFERENCES: NIL.

Acknowledgements: Our sincere gratitude is extended to the RA and SLE patients and to the healthy controls subjects who agreed to participate in this study.

Disclosure of Interests: None declared.