S100A8 and systemic lupus erythematosus: Figures 1B, C show elevated urine and saliva concentrations of S100A8 in patients with SLE compared with those in HCs (2,029.4 ± 2,251.4 vs. 1,096.7 ± 1,422.8 pg/ml, p = 0.001; and 290,496.3 ± 513,156.5 vs. 47,742.1 ± 60,875.7 pg/ml; p < 0.001, respectively).