Correlation of the expression levels of BLyS and its receptors mRNA in patients with systemic lupus erythematosus

Objectives: To measure the levels of B-lymphocyte stimulator (BLyS) and its receptors mRNA expression in peripheral blood mononuclear cells (PBMCs) using quantitative real-time polymerase chain reaction (PCR) method and to investigate the relationship between BLyS and its receptors mRNA expression and systemic lupus erythematosus (SLE). Design and methods: Specific primers and TaqMan probe were designed, and real-time PCR was performed. According to the standard curve of plasmids DNA, the levels of BLyS and its receptors mRNA expression in 37 patients with SLE and 30 healthy subjects were determined. The ratio of the expression levels of BLyS mRNA to that of β2-microglobulin (β2M) mRNA and the ratio of the expression levels of BLyS receptors mRNA to that of β2M mRNA were regarded as indicator for the levels of BLyS and its receptors mRNA expression. Results: The expression of BLyS, TACI and BAFF-R mRNA in PBMCs from patients with SLE was significantly elevated compared to healthy controls (P < 0.001 for each), and active patients with SLE group had higher mRNA expression than patients with SLE inactive group (P < 0.001 for each). The patients with elevated anti-double-stranded DNA (anti-dsDNA) antibody titers had enhanced BLyS, TACI and BAFF-R mRNA expression (P < 0.05 for BLyS; and P < 0.01 for TACI and BAFF-R). Conclusion: The BLyS, TACI and BAFF-R mRNA expression levels were significantly elevated in patients with SLE, which suggests that BLyS, TACI and BAFF-R might be involved in the pathogenesis, and that mRNA expression levels might serve as a biomarker of disease activity.