B lymphocytes activity and the expression of toll like receptor 9 on peripheral blood nuclear cells in patients with systemic lupus erythematosus

Objective To study the state of B lymphocytes activation and mRNA expression of toll like receptor 9 on peripheral blood nuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). Methods The percentages of CD19+B lymphocytes and CD19+CD38+B lymphocytes in PBMCs were detected by flow cytometry and mRNA expression level of TLR9 was measured with semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) of patients with SLE. The relationship of the expression level of TLR9 and SLEDAI scores was analyzed. Results The percentages of CD19+ and CD19+CD38+B lymphocytes in SLE were higher than those in healthy controls (P0.01). The mRNA expression level of TLR9 in active SLE was lower than those in both inactive SLE (P0.01) and healthy controls (P0.01), which was negatively related to SLEDAI scores. Conclusion The number of activated B lymphocytes is increased in PBMCs of patients with SLE. The mRNA expression level of TLR9 decreases in active SLE and is negatively related to SLEDAI scores. TLR 9 may be involved in the etiology of SLE.