Objective Systemic lupus erythematosus (SLE) is a clinically heterogeneous disease with limited reliable diagnostic biomarkers. We investigated whether gene methylation could meet sensitivity and specificity criteria for a robust biomarker. Methods IFI44L promoter methylation was examined using DNA samples from a discovery set including 377 patients with SLE, 358 healthy controls (HCs) and 353 patients with rheumatoid arthritis (RA). Two independent sets including 1144 patients with SLE, 1350 HCs, 429 patients with RA and 199 patients with primary Sjögren’s syndrome (pSS) were used for validation. Results Significant hypomethylation of two CpG sites within IFI44L promoter, Site1 (Chr1: 79 085 222) and Site2 (Chr1: 79 085 250; cg06872964), was identified in patients with SLE compared with HCs, patients with RA and patients with pSS. In a comparison between patients with SLE and HCs included in the first validation cohort, Site1 methylation had a sensitivity of 93.6% and a specificity of 96.8% at a cut-off methylation level of 75.5% and Site2 methylation had a sensitivity of 94.1% and a specificity of 98.2% at a cut-off methylation level of 25.5%. The IFI44L promoter methylation marker was also validated in an European-derived cohort. In addition, the methylation levels of Site1 and Site2 within IFI44L promoter were significantly lower in patients with SLE with renal damage than those without renal damage. Patients with SLE showed significantly increased methylation levels of Site1 and Site2 during remission compared with active stage. Conclusions The methylation level of IFI44L promoter can distinguish patients with SLE from healthy persons and other autoimmune diseases, and is a highly sensitive and specific diagnostic marker for SLE.

In conclusion, we have identified a new risk locus shared between RA and SLE through a meta-analysis including GWAS datasets of both diseases. This study represents the first comprehensive large-scale analysis on the genetic overlap between these two complex disorders.

IntroductionThe purpose of this observational study was to analyze the rates, characteristics and associated risk factors of severe infections in patients with systemic autoimmune diseases (SAD) who were treated off-label with biological agents in daily practice.MethodsThe BIOGEAS registry is an ongoing Spanish prospective cohort study investigating the long-term safety and efficacy of the off-label use of biological agents in adult patients with severe, refractory SAD. Severe infections were defined according to previous studies as those that required intravenous treatment or that led to hospitalization or death. Patients contributed person-years of follow-up for the period in which they were treated with biological agents.ResultsA total of 344 patients with SAD treated with biological agents off-label were included in the Registry until July 2010. The first biological therapies included rituximab in 264 (77%) patients, infliximab in 37 (11%), etanercept in 21 (6%), adalimumab in 19 (5%), and 'other' agents in 3 (1%). Forty-five severe infections occurred in 37 patients after a mean follow-up of 26.76 months. These infections resulted in four deaths. The crude rate of severe infections was 90.9 events/1000 person-years (112.5 for rituximab, 76.9 for infliximab, 66.9 for adalimumab and 30.5 for etanercept respectively). In patients treated with more than two courses of rituximab, the crude rate of severe infection was 226.4 events/1000 person-years. A pathogen was identified in 24 (53%) severe infections. The most common sites of severe infection were the lower respiratory tract (39%), bacteremia/sepsis (20%) and the urinary tract (16%). There were no significant differences relating to gender, SAD, agent, other previous therapies, number of previous immunosuppressive agents received or other therapies administered concomitantly. Cox regression analysis showed that age (P = 0.015) was independently associated with an increased risk of severe infection. Survival curves showed a lower survival rate in patients with severe infections (log-rank and Breslow tests < 0.001).ConclusionsThe rates of severe infections in SAD patients with severe, refractory disease treated depended on the biological agent used, with the highest rates being observed for rituximab and the lowest for etanercept. The rate of infection was especially high in patients receiving three or more courses of rituximab. In patients with severe infections, survival was significantly reduced. Older age was the only significant predictive factor of severe infection.

(1) Objectives: To describe the clinical characteristics and clinical course of hospitalized patients with COVID-19 and autoimmune diseases (ADs) compared to the general population. (2) Methods: We used information available in the nationwide Spanish SEMI-COVID-19 Registry, which retrospectively compiles data from the first admission of adult patients with COVID-19. We selected all patients with ADs included in the registry and compared them to the remaining patients. The primary outcome was all-cause mortality during admission, readmission, and subsequent admissions, and secondary outcomes were a composite outcome including the need for intensive care unit (ICU) admission, invasive and non-invasive mechanical ventilation (MV), or death, as well as in-hospital complications. (3) Results: A total of 13,940 patients diagnosed with COVID-19 were included, of which 362 (2.6%) had an AD. Patients with ADs were older, more likely to be female, and had greater comorbidity. On the multivariate logistic regression analysis, which involved the inverse propensity score weighting method, AD as a whole was not associated with an increased risk of any of the outcome variables. Habitual treatment with corticosteroids (CSs), age, Barthel Index score, and comorbidity were associated with poor outcomes. Biological disease-modifying anti-rheumatic drugs (bDMARDs) were associated with a decrease in mortality in patients with AD. (4) Conclusions: The analysis of the SEMI-COVID-19 Registry shows that ADs do not lead to a different prognosis, measured by mortality, complications, or the composite outcome. Considered individually, it seems that some diseases entail a different prognosis than that of the general population. Immunosuppressive/immunoregulatory treatments (IST) prior to admission had variable effects.