Background Systemic lupus erythematous (SLE) is a systemic autoimmune/inflammatory condition. Approximately 15–20% of patients develop symptoms before their 18th birthday and are diagnosed with juvenile-onset SLE (JSLE). Gender distribution, clinical presentation, disease courses and outcomes vary significantly between JSLE patients and individuals with adult-onset SLE. This study aimed to identify age-specific clinical and/or serological patterns in JSLE patients enrolled to the UK JSLE Cohort Study. Methods Patient records were accessed and grouped based on age at disease-onset: pre-pubertal (≤7 years), peri-pubertal (8–13 years) and adolescent (14–18 years). The presence of American College of Rheumatology (ACR) classification criteria, laboratory results, disease activity [British Isles Lupus Assessment Group (BILAG) and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K) scores] and damage [Systemic Lupus International Collaborating Clinics (SLICC) damage index] were evaluated at diagnosis and last follow up. Results A total of 418 JSLE patients were included in this study: 43 (10.3%) with pre-pubertal disease onset; 240 (57.4%) with peri-pubertal onset and 135 (32.3%) were diagnosed during adolescence. At diagnosis, adolescent JSLE patients presented with a higher number of ACR criteria when compared with pre-pubertal and peri-pubertal patients [pBILAG2004 scores: 9(4–20] vs. 7(3–13] vs. 7(3–14], respectively, p = 0.015] with increased activity in the following BILAG domains: mucocutaneous ( p = 0.025), musculoskeletal ( p = 0.029), renal ( p = 0.027) and cardiorespiratory ( p = 0.001). Furthermore, adolescent JSLE patients were more frequently ANA-positive ( p = 0.034) and exhibited higher anti-dsDNA titres ( p = 0.001). Pre-pubertal individuals less frequently presented with leukopenia ( p = 0.002), thrombocytopenia ( p = 0.004) or low complement ( p = 0.002) when compared with other age groups. No differences were identified in disease activity (pBILAG2004 score), damage (SLICC damage index) and the number of ACR criteria fulfilled at last follow up. Conclusions Disease presentations and laboratory findings vary significantly between age groups within a national cohort of JSLE patients. Patients diagnosed during adolescence exhibit greater disease activity and “classic” autoantibody, immune cell and complement patterns when compared with younger patients. This supports the hypothesis that pathomechanisms may vary between patient age groups.

Large-scale analysis of the genetic basis of pediatric systemic lupus erythematosus Abstract Background Systemic lupus erythematosus (SLE) is a rare immunological disorder where genetic factors are important in causation. Mendelian forms of lupus have been described in the context of almost 30 genotypes in humans, and more than 60 in mice. Murine susceptibility models and genome-wide association studies (GWAS) also highlight the role of genetic variants in pathogenesis. The overall genetic contribution to pediatric SLE is unknown. Methods We designed a next-generation sequencing panel comprising 147 genes, including all known Mendelian lupus causing (KLC) genes in humans, and lupus associated genes identified through GWAS and animal models (potentially lupus causing, PLC, genes). Using this panel we screened 117 probands fulfilling American College of Rheumatology criteria for SLE, ascertained through two cohorts of pediatric SLE in the UK and France, and 791 ethnically matched controls from the 1000 Genomes Project. Results Mendelian genotypes were present in 6.8% of probands. Beyond these cases, rare, predicted damaging variants were significantly enriched in the SLE cohort compared to controls, with an odds ratio of 14.09 and 3.99 in KLC and PLC genes respectively. Overall, 27% of SLE probands versus 4.6% of controls were identified with at least one rare, predicted damaging variant amongst our selected gene panel (p = 4.14×10 −15). Conclusion Rare and predicted damaging variants in KLC and PLC genes were highly enriched in a population of pediatric onset lupus, with 1 in 15 probands demonstrating clear Mendelian causation. Germline defects of innate immunity represent the main genetic contribution to SLE in children.

Objective We sought to explore patient and parental views on treatment targets, outcome measures and study designs being considered for a future juvenile-onset systemic lupus erythematosus (JSLE) treat to target (T2T) study. Methods Topic guided, semi-structured interviews with JSLE patients/parents. Analysis of audio recorded interviews using thematic approaches. Results Patients and parents differed regarding symptoms they felt would be tolerable, representing ‘low disease activity’. Patients often classed symptoms that they had previously experienced, were ‘invisible’ or had minimal disruption on their life as signs of low disease activity. Parents were more accepting of visible signs, but were concerned about potential organ involvement and symptom severity. Overall, patients and parents preferred that children were entirely asymptomatic, with no on-going treatment side-effects. They regarded fatigue as particularly challenging, requiring proper monitoring using a fatigue patient reported outcome measure. Most families felt that reducing corticosteroids would also be a good treatment target. Overall, families liked the concept of T2T, commenting that it could help to improve disease control, structure treatment, improve communication with clinicians and treatment compliance. They were concerned that T2T might increase the frequency of hospital visits, thus impacting upon schooling, parental employment, and finances. Families made suggestions on how to modify the future trial design to mitigate such effects. Conclusion This study provides guidance from patients/parents on T2T targets and study designs. Complementary quantitative studies assessing the achievability and impact of different targets (e.g. LLDAS or remission) are now warranted, to inform an international consensus process to agree treatment targets.

Objectives To assess the achievability and effect of attaining low disease activity (LDA) or remission in childhood (cSLE). Methods Attainment of three adult-SLE derived definitions of LDA (LLDAS, LA, Toronto-LDA), and four definitions of remission (clinical-SLEDAI-defined remission on/off treatment, pBILAG-defined remission on/off treatment) was assessed in UK JSLE Cohort Study patients longitudinally. Prentice-Williams-Petersen-GAP recurrent event models assessed the impact of LDA/remission attainment on severe flare/new damage. Results LLDAS, LA and Toronto-LDA targets were reached in 67%, 73% and 32% of patients, after a median of 18, 15 or 17 months, respectively. Cumulatively, LLDAS, LA and Toronto-LDA was attained for a median of 23%, 31% and 19% of total follow-up-time, respectively. Remission on-treatment was more common (61% cSLEDAI-defined, 42% pBILAG-defined) than remission off-treatment (31% cSLEDAI-defined, 21% pBILAG-defined). Attainment of all target states, and disease duration (>1 year), significantly reduced the hazard of severe flare (p< 0.001). As cumulative time in each target increased, hazard of severe flare progressively reduced. LLDAS attainment reduced the hazard of severe flare more than LA or Toronto-LDA (p< 0.001). Attainment of LLDAS and all remission definitions led to a statistically comparable reduction in the hazards of severe flare (p> 0.05). Attainment of all targets reduced the hazards of new damage (p< 0.05). Conclusions This is the first study demonstrating that adult-SLE-derived definitions of LDA/remission are achievable in cSLE, significantly reducing risk of severe flare/new damage. Of the LDA definitions, LLDAS performed best, leading to a statistically comparable reduction in the hazards of severe flare to attainment of clinical-remission.

Systemic lupus erythematosus (SLE) is a systemic autoimmune/inflammatory disease. Patients diagnosed with juvenile-onset SLE (jSLE), when compared to individuals with adult-onset SLE, develop more severe organ involvement, increased disease activity and greater tissue and organ damage. In adult-onset SLE, clinical characteristics, pathomechanisms, disease progression and outcomes do not only vary between individuals and age groups, but also ethnicities. However, in children and young people, the influence of ethnicity on disease onset, phenotype and outcome has not been investigated in detail. In this study, we investigated clinical and laboratory characteristics in pediatric SLE patients from different ethnic backgrounds (White Caucasian, Asian, Black African/Caribbean) accessing data from a national cohort of jSLE patients (the UK JSLE Cohort Study). Among jSLE patients in the UK, ethnicity affects both the disease’s clinical course and outcomes. At diagnosis, Black African/Caribbean jSLE patients show more “classical” laboratory and clinical features when compared to White Caucasian or Asian patients. Black African/Caribbean jSLE patients exhibit more renal involvement and more frequently receive cyclophosphamide and rituximab. Studies targeting ethnicity-specific contributors to disease expression and phenotypes are necessary to improve our pathophysiological understanding, diagnosis and treatment of jSLE.