Proteomic analysis of human plasma and peripheral blood mononuclear cells in Systemic Lupus Erythematosus patients

Systemic Lupus Erythematosus (SLE) is characterized by alterations both innate and adaptive immune systems, that lead to the loss of immunologic tolerance. Plasma and PBMCs proteome and cytokines analyses can help to better understand the cellular mechanisms of this disease. The aim of this study was to observe the changes in the proteome and in cytokines expression in SLE patients, in order to increase our knowledge about pathogenesis and to find possible biomarkers or therapeutic targets.We used 2-DE and MS analyses to identify the protein of interest, and Western blot and ELISA to validate. MAG-PIX instrument was used to quantify plasma cytokines.Several proteins were differentially expressed in the PBMCs from SLE patients. Among these, Peroxiredoxin 2 could be used as target protein for further investigations. In plasma, we found that clusterin levels increased, but it is not statistically significant. These proteomic results provide suggestions for understanding the molecular mechanisms of SLE.Cytokines analysis showed that plasma concentrations were significantly higher in SLE patients than in healthy subjects. ROC curves analyses showed that MCP-1, MIP-1 and sCD40L have high diagnostic power. These results suggest the potential usefulness of these cytokines in SLE as potential biomarkers.Further studies are required to confirm our results. It would be interesting to analyse data both from treated subjects and from subjects in different phases of the disease.