Global DNA methylation pattern and correlation with complement system proteins in Brazilian patients with systemic lupus erythematosus

Introduction:Nucleic acid methylation may have major effects on gene expres-sion patterns and, by consequence, on the development of autoimmunity, likeSystemic Lupus Erythematosus (SLE).Objective:To investigate the pattern ofglobal DNA methylation in SLE patients and compare this pattern with labora-tory parameters.Methods:Genomic DNA was isolated from SLE patients withnon-active disease (SLEDAI6),and healthy individuals. Global DNA methylation was evaluated by digestion ofgenomic DNA withHpaII andMspI and compared with laboratory parameters.Results and conclusion:A statistical difference in DNA global methylation wasobserved when SLE patients were compared to healthy individuals. A positivecorrelation was observed between the frequency of global methylation and C3and C4 serum levels for SLE patients with SLEDAI