Role of Inflammasome Activation in Systemic Lupus Erythematosus: Are Innate Immune Cells Activated?

Abstract Background Systemic lupus erythematosus (SLE) is characterized by a wide spectrum of clinical and immunological abnormalities. New data have emerged about the role of inflammasomes in autoimmune diseases. We aimed to investigate whether basal inflammasome activation occurs in SLE patients, and whether a relationship between inflammasome-related-cytokines and disease activity exists. Methods Fourteen (14) consecutive SLE patients and 13 healthy individuals, matched by sex, age and ethnicity, were included. Demographics, laboratory and clinical data were recorded. Peripheral blood mononuclear cells (PBMCs) from patients and controls were obtained and monocytes were isolated by negative selection. Purified monocytes were stimulated with LPS in the presence or absence of Caspase-1 inhibitor. CD14 and Caspase-1 expression were analyzed by flow cytometry. Cytokine levels were determined in plasma and culture supernatants by ELISA. Student's t test and Mann–Whitney tests were used for statistical analysis. Results The percentage of CD14+/Caspase-1+ was significantly higher in monocytes from SLE patients compared to normal controls (p  Conclusions Monocytes from SLE patients exhibited increased inflammasome activation, characterized by high expression of Caspase-1, IL-1β and IL-18. Caspase-1 specific inhibitor decreased inflammasome activation (in vitro) by suppressing the production of IL-18.