The CXCL13 chemokine serves as a potential biomarker to diagnose systemic lupus erythematosus with disease activity.

The aim of our study was to assess the regulatory response of the chemokine CXCL13 in the serum of systemic lupus erythematosus (SLE) patients with disease activity and to evaluate its influence on the inflammatory process in SLE. Serum samples from 97 SLE patients, 49 non-SLE patients (23 patients with other autoimmune diseases and 26 patients with rheumatoid arthritis) and 50 healthy controls were analyzed for the concentration of CXCL13 using ELISA. The results indicated that the serum levels of CXCL13 were significantly higher in SLE patients than in non-SLE patients and healthy controls (p < 0.001). Moreover, the level of CXCL13 decreased as the level of anti-dsDNA IgG decreased after treatment between the anti-dsDNA-positive SLE patients and the anti-dsDNA-negative SLE patients. In addition, serum CXCL13 levels were correlated with SLEDAI in different activities of SLE, renal involvement and active LN. Furthermore, the level of CXCL13 was positively related to the SLEDAI, level of anti-dsDNA IgG, level of ESR and RAI of high-avidity IgG ANAs (HA IgG ANAs). Additionally, statically analysis revealed that CXCL13 would be a best diagnostic value for determining the disease activity of SLE due to its moderate sensitivity (93.5%), specificity (95%), PPV (98.6%), NPV (79.2%) and OR(95%CI,250(30.303-1000)), at a cut-off level of 15.27 pg/mL. First, we indicated that CXCL13 was elevated in SLE patients regardless of the presence or absence of anti-dsDNA IgG ANAs. Furthermore, HA IgG ANAs might affect the circulation of CXCL13. Therefore, the chemokine CXCL13 might be a risk factor influencing the inflammatory process in SLE.