P9 Increase of IL10 and INFA2 are associated to clinical activity in systemic lupus erythematous patients

Objective We aimed to analyze the association between inflammatory cytokine levels (IFN-a2, IFN-b, IFN-g, IL10 and BLyS) and disease activity for a 12 months of follow-up in SLE patients. Methods A longitudinal, observational prospective study with evaluations at baseline and follow-up visits every 3 months in SLE patients (SLICC 2012 criteria) and 65 healthy controls was performed. In SLE patients complete laboratory test, clinical evaluation and SLEDAI score was carried out. We analyzed inflammatory cytokines serum levels by colorimetric methods in all cases. Results 45 SLE patients (86.7% female) participated in the study, with a mean age at diagnosis of 32.8 (16.2) years and a mean time of disease evolution of 17.9 (11.4) years. The 28.9% of patients showed SLEDAI>6 at the basal visit. The 66.7% were under glucocorticoid treatment, 44.4% under immunosupressants (methotrexate, azatioprine, belimumab or mycophenolate) and 66.7% under antimalarials. SLEDAI and inflammatory cytokine levels during follow-up is shown in table 1. Statistical analysis showed significant association between SLEDAI score and IL-10 (P=0.014) and IFNa2 (0.009), as well as a tendency with IFN-beta (P=0.057), independently of the time of follow-up. Regarding to clinical activity biomarkers, we observed an association between high levels of antidsDNA and elevated IFN-beta (P=0.005) and IFN-gamma (P=0.038), and low levels of C3 and an increment in IL-10 (P=0.006). Patients under antimalarials treatment during follow-up exhibit low levels of IL-10 (P=0.012) and those under belimumab treatment showed high levels of BLyS (P<0.001). No influence of age at diagnosis, time of evolution, vitamin D levels, corticoids and tobacco use in cytokine levels was observed. SLE patients were categorized by normal or high level of the five cytokines, based on the cytokine level above 2 SD of the mean in healthy controls. Despite the fact that no specific cytokine profile associated with clinical activity was observed, those patients with high SLEDAI score had increased levels of IL10. Conclusion We observed an association between IL-10, IFN-alpha2, IFN-beta and IFN-gamma levels with clinical activity, independently of the time of follow-up. IL-10 levels may be influenced by antimalarial treatment and BLyS levels by belimumab treatment.