PERIPHERAL BLOOD B CELL SUBSETS IN PATIENTS WITH EARLY AND ESTABLISHED SYSTEMIC LUPUS ERYTHEMATOSUS

PV003 / #307 Poster Topic: AS01 - Adaptive Immunity Background/Purpose To examine B cell subsets in peripheral blood of patients (pts) with early and established systemic lupus erythematosus (SLE), and to analyze the association between the B cell subsets and SLE activity. Methods Peripheral blood of 20 healthy donors, 134 patients (118 women (88%) and 16 men (12%)) with a SLE (SLICC 2012), Me(IQR) age 34 (26-41) years, disease duration 3.0 (0.3-12.0) years; 84 patients had a disease duration of more than 18 months, 50 patients had early SLE (disease duration of less than 18 months), SLEDAI-2K 7 (4-11)) were assessed for B cell subpopulations. CD19+B cells, memory B cells (CD19+CD27+), non-switched memory B cells (CD19+IgD+CD27+), switched memory B cells (CD19+IgD-CD27+), naïve (CD19+IgD+CD27-), double negative (CD19+IgD-CD27-), transitional (CD19+IgD+CD10+CD38++CD27-) B cells and plasmablasts (CD19+CD38+++IgD-CD27+CD20-) were assessed by multicolor flow cytometry. Results In pts with SLE, compared to healthy donors was found the higher percentage of memory B cells, non-switched memory B cells, transitional and plasmablasts; higher absolute level switched memory B cells, transitional and plasmablasts; lower percentage and absolute level naïve B cells. In pts with early SLE, was seen the higher percentage of B cells, higher absolute level of B cells, memory B cells, non-switched and switched memory B cells, naïve, double negative, transitional B cells and lower percentage of plasmablasts (Table 1). In pts with early SLE we found a significant positive correlation between the percentage of double negative B lymphocytes and SLICC (r=0.3), positive correlation between the proteinuria and B lymphocytes (r=0.35), memory B cells (r=0.38), switched memory B cells (r=0.42), double negative lymphocytes (r=0.42); a negative correlation between the percentage of transitional cells and SLICC (r=0.33). Table 1. Conclusions Pts with early SLE have higher levels of B cells, non-switched and switched memory B cells, naïve, double negative, transitional B cells and lower levels of plasmablasts. The level of memory В-cell, switched memory cells, and double negative cells correlates with the level of autoantibodies, the development of nephritis, and the SLICC index.