IL18 and systemic lupus erythematosus: These results were not affected by reducing the HC to those matched by age, gender, and ethnicity (Tables S4 and S5 in Supplementary Material), and the association between increased serum IL-18 concentrations and SLE was further confirmed in multivariable analysis after adjusting for age, gender, and ethnicity (adjusted ratio of GM 1.56; 95% CI 1.19, 2.06; p < 0.01).