Abstract:Objective To study the expressions of CD19+ CD5+ B cells and interleukin 10 (IL-10) and their clinical significance in patients with systemic lupus erythematosus (SLE). Methods In this study 65 SLE-stable patients, 65 SLE-active patients and 70 healthy control people were included. CD19+ CD5+ B cell subsets were detected with flow cytometry. IL-10 level in serum was detected with enzyme linked immunosorbent assay (ELISA). The correlations of CD19+ CD5+ B cell count and serum IL-10 level with SLE disease activity index (SLEDAI) score and complement were analyzed. Results The CD19+ CD5+ B cell count, albumin, C3 and C4 in the SLE-active group and SLE-stable group were significantly lower than those in the control group (P < 0.05). The IL-10 and ESR in the SLE-active and stable groups were higher than those in the control group, the differences were statistically significant (P < 0.05). The CD19+ CD5+ B cell count, albumin, C3 and C4 in the SLE-active group were significantly lower than those in the SLE-stable group (P < 0.05). The SLEDAI score, IL-10 and ESR in the SLE-active group were higher than those in the SLE-stable group, the differences were statistically significant (P < 0.05). The CD19+ CD5+ B cell count was negatively related with the SLEDAI score, but IL-10 was positively related with the SLEDAI score (P < 0.05). As the SLEDAI score increased, CD19+ CD5+ B cell count showed a lowering trend, and IL-10 showed an uptrend.Conclusions CD19+ CD5+ B cells and IL-10 may participate in the occurrence and development of SLE. The changes of CD19+ CD5+ B cells and IL-10 in the peripheral blood might contribute to the pathogenesis and correlate with the disease activity of SLE, which can be used as evaluation indexes of SLE activity.