Identificação de potenciais biomarcadores do lúpus eritematoso sistêmico através de abordagem proteômica

Abstract

Systemic Lupus Erythematous (SLE) is an autoimmune disease of connective tissue with large spectrum of clinical manifestations. The immune deregulation leads to autoantibody and immune complexes overproduction, complement activation and persistent tissue inflammation as well. Considering that the current diagnosis depends on the interpretation of complex criteria established by the American College of Rheumatology, and that the disease course is characterized by unpredictable activations and remissions, and that each patient develops different manifestations, the discovery of specific biomarkers becomes urgently necessary. In this context, this study aimed to identify putative biomarkers for active and inactive SLE potentially capable to distinguishing laboratorial SLE from other autoimmune diseases. The 2D-DIGE proteomics technique was used in an unprecedented way, to evaluate the differential abundance of proteins between patients with active SLE, inactive SLE, patients with other autoimmune disease and healthy individuals. One hundred and three differentially abundant proteins were identified. From this amount, 40 with increased abundance in active SLE compared to the other groups, and 6 with increased abundance in active and inactive SLE in relation to the other ones. Other proteins showed increased abundance in SLE compared to the control group, but not in relation to other autoimmune diseases, which demand greater rigor in the validation steps. The following proteins: 1-acid glycoprotein 1 / Orosomucoid 1, Znalpha2-glycoprotein, AMBP preproprotein, alpha-1-acid glycoprotein, apolipoprotein A-IV precursor, immunoglobulin kappa light chain, alpha-2-macroglobulin, chain A, Structure Of Prealbumin e immunoglobulin alpha-2 chain - fragment (Ig2) were selected as promising biomarkers, corroborating data in the literature. On the other hand, proteins like retinol-binding protein 4 isoform X1 e SP-40,40 partial have been proposed for the first time, as potential biomarkers for SLE. It must be stressed that this work is a preliminary study. It is recommended that additional studies must be done to confirm and validate these data.