The correlation between the expression of serum intestinal mucosal barrier function markers and the natural killer cell in peripheral blood of patients with systemic lupus erythematosus

Abstract

Abstract Background Dysfunction of the intestinal mucosal barrier may be closely related to the development of autoimmune diseases such as SLE. However, there are fewer studies in this area. This study aimed to analyze the correlation between the expression of serum markers for intestinal mucosal barrier function and the lymphocyte subsets in patients with SLE. Methods 30 SLE patients and 10 healthy individuals were collected in the study. 30 SLE were divided into disease activity group and non-disease activity group according to their SLEDAI score. The levels of serum markers of mucosal barrier function were determined by Enzyme-linked Immunosorbent assay (ELISA). The number of peripheral blood lymphocyte subsets were measured by Flow Cytometry (FCM). The levels of plasma cytokine were detected by Cytometric Bead Array (CBA). Results Compared with the healthy control group, the level of serum zonulin [13.33 (8.69, 28.83) vs5.25 (3.78, 9.25), P < 0.001] and IFABP [2.53 (1.87, 3.38) vs1.68 (1.66, 2.01), P = 0.004] in the SLE patients were increased. Compared with the SLE non-disease active group, the expression level of serum zonulin was significantly higher than that in the SLE disease active group [25.17 (16.78, 33.99) vs 8.74 (6.81, 12.60), P < 0.001]. The expression level of serum zonulin in SLE patients was positively correlated with ESR (r = 0.424, P = 0.020), anti-ds-DNA antibody (r = 0.629, P < 0.001), and negatively correlated with C3 (r=-0.441, P = 0.015); the expression level of IFABP was negatively correlated with C3(r=-0.380, P = 0.038)and C4 (r=-0.432, P = 0.017). There was a negative correlation between the expression level of serum zonulin and the absolute number of total NK cells in peripheral blood in patients with SLE (r=-0.380, P = 0.038). There was a positive correlation between the expression level of serum zonulin and IFN-γ in patients with SLE (r = 0.561, P = 0.015). Conclusion Intestinal mucosal barrier dysfunction is a common occurrence in SLE patients, and it is related to disease activity and antibody production. It can be used as an evaluation indicator of disease progression. The dysfunction is associated with dysregulation of peripheral blood lymphocytes, especially NK cells, in SLE patients. It may be one of the causes of immune homeostasis imbalance in SLE patients.