(a) Comparison of plasma levels of HMGB1 between pAPS, APA+SLE, APS+SLE patients and HCs. (b) Comparison of plasma levels of HMGB1 between SLE patients with and without disease flares. (c) Comparison of plasma levels of sRAGE between pAPS, APA+SLE, APS+SLE patients and HCs. (d) Comparison of plasma levels of sRAGE between SLE patients with and without disease flares. P values of < 0.008 were regarded as statistically significant for multiple comparisons. APA, antiphospholipid antibody; HC, healthy control; HMGB1, high-mobility group box 1; pAPS, primary antiphospholipid syndrome; SLE, systemic lupus erythematosus; sRAGE, soluble receptor for advanced glycation end products.