BackgroundSystemic lupus erythematous (SLE) shows increased DNA demethylation. An intermediate step to DNA demethylation is the DNA hydroxymethylation, where 5-mC is oxidized into 5-hmC. Hydroxymethylation is not completely understood and it may be related to oxidative stress in SLE patient.ObjectivesTo analyze the association between the hydroxymethylation and demethylation, with the antioxidant response and SLE pathophysiology.MethodsWe analyzed in 142 SLE patients and 34 healthy controls the serum concentration of glutathione (GSH) and glutathione disulphide (GSSG) by UPLC-MS/MS, superoxide dismutase (SOD) and total antioxidant capacity (TAC) by colorimetric methods. 5-mC and 5-hmC levels were measured by colorimetric methods. Complete blood-test was made and clinical data by personal interview was collected. Biostatistical analysis with R (3.3.2.) was performed.ResultsThere is a correlation between the methylation and hydroxymethylation rate (P<0.001), and both were lower in patients than in controls (P=0.024; P<0.001). GSH and GSSG values were lower in patients (P=0.033 y P=0.003), but GSH/GSSG ratio was not statistically different in both groups. SOD levels were higher in patients (P=0.001), but TAC did not show significant differences. Higher demethylation is associated to lower TAC values in patients and healthy controls (P=0.005; P=0.01). In patients, decreased SOD values are associated with higher demethylation and lower hydroxymethylation rates (P<0.001; P=0.007). SOD and TAC levels are increased in SLE patients with higher demethylation and lower hydroxymethylation (P=0.001; P<0.001). We did not observe any association between 5-mC or 5-hmC levels and GSH, GSSG or GSH/GSSG ratio. Higher demethylation is associated to vascular symptoms (defined by RELESSER study) and lupus anticoagulant (AL) positivity (P=0.041; P=0.015), and lower hydroxymethylation to mucocutaneous damage (defined by RELESSER study) and AL positivity (P=0.015; P=0.009). Lower levels of GSH and GSSG were associated to increased accumulated damage assessed by SLICC (P=0.01; P=0.005), and lower SOD values with longer disease duration (P=0.001).ConclusionsWe observed higher demethylation and lower hydroxymethylation in SLE patients than in controls, related to increased SOD activity. Moreover higher demethylation leads to lower TAC levels. These epigenetic disorders are related to antioxidant response disruptions in SLE patients, probably because of the chronic inflammatory condition. Our results suggest that epigenetic processes are involved in SLE physiopathology.AcknowledgementsFinancial support by GVA (GV15/83) is acknowledged.Disclosure of InterestNone declared

ordered at the same time as the ANA, against the Choosing Wisely recommendation of 2013. There were only 22% of ANA that were required for a diagnosis. The 3 specilaties who ordered ANA the most were rheumatology, gastroenterology and the internal medicine (in descending order). The cost for the ANA that were not indicated is more than a thousand dollars. A total of 135 ANCA tests were included. There were 55.6% of ANCA that were ordered in line with the recommandations. However, 50.3% of ANCA were not required for the final diagnosis. Clinical remission of subjects with ANCA was predicted in 100% of cases, even before ordering the ANCA test for follow-up (negative predictive value). Conclusion These results show that the rate of ANA and ANCA tests ordered in line with the recommandations remains low. In the majority of cases, the two antibodies are not required for the final diagnosis. These orders have an important cost for the hospital that can be lowered by providing more education for professionals on avoiding unnecessary tests.

investigate and visualise characteristic marker prevalence and coprevalence patterns. Results Based on the individual marker pattern, patients can often be stratified belonging to different study subgroups. For example, for SLE we show that different reactivity groups exist including patients with different disease activity scores and organ damage patterns. Conclusions We conclude that the approach of a comprehensive prevalence and signature analysis and a vivid data visualisation is useful for any multiplex omics assay.

BackgroundB lymphocyte stimulator factor (BLyS) is produced by wide range of cells of the immune system, and has proven to be a key factor in the selection and survival of B cells. BLyS is an important factor in the pathology of Systemic Lupus Erythematosus; elevated serum levels (≥20ng/mL) of soluble BlyS are at increased risk of flare.ObjectivesAnalyze the association among BLyS levels and clinical manifestations, as well as with SLE clinical activity.MethodsA cross-sectional and observational study was performed in patients diagnosed of SLE according to SLICC 2012 criteria and healthy controls. The study included a complete blood-test and clinical data collected by personal interview. Disease activity assessment was made by SLEDAI index and for the evaluation of chronic damage we used the validated SLICC damage index. Serum concentration of BLyS was analyzed by colorimetric methods. Lupus patients were dichotomized as high and low BLyS levels based on BLyS levels above 2 SD of the mean in healthy controls. Biostatistical analysis with R (3.3.2.) was performed.ResultsTwo hundred forty-two SLE patients were evaluated; 94.4% of them were female. Mean values were as follow: age at diagnosis 33.29±13.53 years, disease duration 15.82±10.56 years, SLEDAI 5.91±5.06, SLICC score 1.06±1.42, BLyS levels 1.811±1.757 ng/mL. The 22.5% of patients displayed increased BLyS levels. The 29.6% of total patients exhibit SLEDAI values up to 6, and only the 7% of them showed SLEDAI values up to 6 and high BLyS levels simultaneously. Higher BLyS levels were significantly correlated to the ANAs positivity (p=0.0006) and lymphopenia (p=0.01) but showed no correlation with hypocomplementemia neither anti-dsDNA. The statistical analysis did not yield differences in the clinical activity or accumulated damage between patients with lower and higher BLyS levels.ConclusionsIn our series we observed a 22.5% of patients with high levels of BLyS, and the 7% of cases had BLyS high levels and SLEDAI>6. BLyS upregulation is related to ANAs positivity and lymphopenia. We have found no statistical evidences on the relationship of BLyS levels and clinical activity in our series of patients.Disclosure of InterestNone declared

based immunocytochemistry assays on SH-SY5Y (human neuroblastoma) cell cultures. The association between serum positivity for AnAb by IHC and a large panel of data (demographic, serologic, SLEDAI, conventional brain MRI, treatment) was investigated by univariate analysis. Multivariate models were fitted with covariates with p<0.05 to identify factors independently associated with serum positivity for AnAb; p<0.05 were considered statistically significant. Results AnAb were detected in 23 (82.1%) NPSLE patients and in 16 (39.0%) SLE patients without NP involvement resulting in 82% specificity (95%CI 71%-90%) and 61% sensitivity (95%CI 48%-72%) in differentiating NPSLE from SLE without NP involvement. None of the sera from MS patients (0%) and healthy subjects (0%) showed AnAb. Serum AnAb by IHC were independently associated with NPSLE (p<0.01) and higher SLEDAI (p<0.01). No association with specific NPSLE syndrome and brain conventional MRI abnormalities was identified. Conclusion AnAb are significantly more frequent in patients with NPSLE than SLE. Further studies are needed to identify the unknown neuronal antigens targeted by AnAb in SLE patients.