Background Systemic lupus erythematous (SLE) is an autoimmune disease characterized by immune system disruption, including T and B cell activation and upregulation of autoantibody and immunocomplexes production that could damage different organs. Sometimes, patients with positives autoantibodies and serological manifestations show low disease activity or clinical remission. There is not enough information about persistent positive autoantibodies in absence of clinical activity neither the role of proinflamatory cytokines in this context.

Objectives To assess the clinical and molecular differences in SLE patients with positives autoantibodies and with low clinical activity or in clinical remission compared to the group with clinical activity.

Methods A cross-sectional, observational study of patients diagnosed of SLE according to SLICC 2012 criteria was performed. In these patients a complete blood-test was made, and clinical data by personal interview was collected. We analyzed the serum concentration of IL10, BLyS and INF1A by colorimetric methods. Biostatistical analysis was performed with R 3.3.2.

Results We selected 130 SLE patients with serological manifestations (defined by RELESSER study) out of 142 SLE patients. 91 cases showed low activity or remission (SLEDAI<6) and 39 presented moderate or high activity (SLEDAI>6). SLE patients with positives autoantibodies without clinical activity showed significantly lower anti-dsDNA levels (P=0.006), lower complement consumption (P=0.003) and lower accumulated damage evaluated by SLICC score (P=0.041). No differences on time of evolution in both groups were observed. In addition, SLE patients with positives autoantibodies without clinical activity exhibit significantly lower levels of IL10 (P<0.001) and INF1A (P=0.019). No differences on BLyS levels in both groups were observed. Finally, SLE patients with positives autoantibodies with clinical activity present more mucocutaneous lesions (P=0.014), musculoskeletal manifestations (P=0.004), neuropsychiatric manifestations (P=0.002), renal manifestations (P<0.001) and lymphopenia (P=0.008) than patients with positives autoantibodies and without clinical activity.

Conclusions In our series of SLE patients with both serological manifestations and low clinical activity have lower levels of IL10 and INF1A, compared to patients with high clinical activity. This result would suggest that differences in the cytokine levels are not related to autoantibodies presence but there are other mechanisms involved in cytokine production that would also be involved in maintenance of clinical remission.

Disclosure of Interest None declared