Objectives To detect the mRNA expression of B lymphocyte induced maturation protein-1 (Blimp-1) in CD19+ B cells in peripheral blood of patients with systemic lupus erythromatosus (SLE) and healthy controls, and explore its clinical significance.
Methods Expression level of Blimp-1 mRNA in CD19 +B cells in peripheral blood was determined by real-time PCR in 40 SLE patients and 20 healthy controls. The ratio of CD19–CD138+ plasma cells to CD19+ B cells and the ratio of CD19+CD27+ memory B cells to CD19+ B cells were studied by flow cytometry in peripheral blood of two groups.
Results 1. The expression level of Blimp-1 mRNA in CD19+ B cells in peripheral blood od SLE patients was higher than that in healthy controls (P<0.05), and the expression level of Blimp-1 in active SLE patients was higher than that in inactive SLE patients (P<0.05). 2. The CD19–CD138+ plasma cells/CD19+ B cells ratio was increased in SLE patients compared to healthy controls (P<0.01), and the CD19–CD138+ plasma cells/CD19+ B cells ratio in active SLE patients group was higher than that in inactive SLE patients (P<0.05). However, the CD19+CD27+ memory B cells/CD19+ B cells ratio showed no significantly different between SLE patients and healthy controls (P>0.05). 3. The expression level of Blimp-1 was positive correlated with the CD19–CD138+ plasma cells/CD19+ B cells ratio (rs=0.336, P=0.034), positive correlated with anti-dsDNA antibody and immunoglobulin G (rs=0.493, P=0.006; rs=0.527, P=0.004), positive correlated with anti-nucleosome antibody and anti-C1q antibody (rs=0.452, P=0.040; rs=0.522, P=0.015), negative related with white blood cell count and platelet count (rs= -0.367, P=0.046; rs= -0.386, P=0.035).
Conclusions The expression of Blimp-1 was up-regulated in SLE patients and significantly correlated with plasma cells, which suggests that Blimp-1 may be involved in the pathogenesis of SLE by promoting plasma cells differentiation.
Acknowledgement This work was funded by a grant from the National Nature Science Foundation of China (No. 81373187) and the Clinical Research Special Foundation of Chinese Medical Association (12040730373).
Disclosure of Interest None declared