/ β mRNA expression is upregulated and positively correlated with the expression of / in peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

CCAAT/enhancer-binding protein β (C/EBP β) has important roles in numerous signaling pathways. The expression of the majority of regulators and target gene products of C/EBP β, including tumor necrosis factor α-induced protein 3 () and TNFAIP3-interacting protein 1 (), are upregulated in patients with systemic lupus erythematosus (SLE). The aim of the present study was to investigate whether / β expression is associated with SLE pathogenesis and correlates with and expression. Quantitative reverse transcription-polymerase chain reaction analysis was used to assess the expression of / β, , and mRNA in peripheral blood mononuclear cells (PBMC) from 20 patients with SLE and 20 healthy controls. Spearman's rank test was used to determine the correlation between / β expression and SLE disease activity, and that between / β expression and / expression in PBMCs from patients with SLE. / β mRNA expression was markedly increased in patients with SLE compared with healthy controls. The expression of / β was positively correlated with the SLE disease activity index and negatively correlated with the serum level of complement components C3 and C4. In addition, β mRNA expression was increased in PBMCs from SLE patients that were positive for antinuclear, anti-Smith and anti-nRNP antibodies, compared with the antibody negative SLE patients. Furthermore, the mRNA expression levels of / β in patients with SLE was positively correlated with and expression. The results of the current study suggest that the increased expression of / β in PBMCs and the interaction between / β and / may be involved in the pathogenesis of SLE.