Type I interferon associated epistasis may contribute to early disease-onset and high disease activity in juvenile-onset lupus.

Pathologic type I interferon (T1IFN) expression is a key feature in systemic lupus erythematosus (SLE) that associates with disease activity. When compared to adult-onset disease, juvenile-onset (j)SLE is characterized by increased disease activity and damage, which likely relates to increased genetic burden. To identify T1IFN-associated gene polymorphisms (TLR7, IRAK1, miR-3142/miR-146a, IRF5, IRF7, IFIH1, IRF8, TYK2, STAT4), identify long-range linkage disequilibrium and gene:gene interrelations, 319 jSLE patients were genotyped using panel sequencing. Coupling phenotypic quantitative trait loci (QTL) analysis identified 10 jSLE QTL that associated with young age at onset (<12 years; IRAK1 [rs1059702], TLR7 [rs3853839], IFIH1 [rs11891191, rs1990760, rs3747517], STAT4 [rs3021866], TYK2 [rs280501], IRF8 [rs1568391, rs6638]), global disease activity (SLEDAI-2 K >10; IFIH1 [rs1990760], STAT4 [rs3021866], IRF8 [rs903202, rs1568391, rs6638]), and mucocutaneous involvement (TLR7 [rs3853839], IFIH1 [rs11891191, rs1990760]). This study suggests T1IFN-associated polymorphisms and gene:gene interrelations in jSLE. Genotyping of jSLE patients may allow for individualized treatment and care.

Development of CARRA/PReS-endorsed consensus Core and Expanded Datasets in childhood-onset systemic lupus erythematosus for international registry-based research.

OBJECTIVES: Childhood-onset systemic lupus erythematosus (cSLE), representing 15%-20% of individuals with SLE, has been difficult to study globally due to differences between registries. This initiative, supported by Childhood Arthritis Rheumatology Research Alliance (CARRA) and Paediatric Rheumatology European Society (PReS), aims to create Core and Expanded cSLE Datasets to standardise and enhance research worldwide. METHODS: 21 international cSLE experts and 4 patients participated in a Delphi process (questionnaires, 2 topic-specific focus groups and 3 virtual consensus meetings) to create 2 standardised cSLE datasets. The Core cSLE Dataset was designed to include data essential to meaningful clinical research across many settings. The Expanded cSLE Dataset was designed for centres able to consistently collect data to address broader research questions. Final data items for the Core and Expanded datasets were determined by consensus defined as >80% agreement) using an adapted nominal group technique and voting. RESULTS: The resulting Core cSLE Dataset contains 46 items, including demographics, clinical features, laboratory results, medications and significant adverse events. The Expanded cSLE Dataset adds 26 additional items and includes patient-reported outcomes. Consensus was also achieved regarding the frequency and time points for data collection: baseline, quarterly follow-up visits, annually and flare visits. CONCLUSION: Standardised Core and Expanded cSLE Datasets for registry-based international cSLE research were defined through the consensus of global experts and patient/caregiver representatives, endorsed by CARRA and PReS. These datasets incorporate disease-specific and patient-specific features, optimised for diverse settings to facilitate international collaborative research for children and adolescents with SLE worldwide.

P2RX7 gene variants associate with altered inflammasome assembly and reduced pyroptosis in chronic nonbacterial osteomyelitis (CNO).

Chronic nonbacterial osteomyelitis (CNO), an autoinflammatory bone disease primarily affecting children, can cause pain, hyperostosis and fractures, affecting quality-of-life and psychomotor development. This study investigated CNO-associated variants in P2RX7, encoding for the ATP-dependent trans-membrane K+ channel P2X7, and their effects on NLRP3 inflammasome assembly. Whole exome sequencing in two related transgenerational CNO patients, and target sequencing of P2RX7 in a large CNO cohort (N = 190) were conducted. Results were compared with publicly available datasets and regional controls (N = 1873). Findings were integrated with demographic and clinical data. Patient-derived monocytes and genetically modified THP-1 cells were used to investigate potassium flux, inflammasome assembly, pyroptosis, and cytokine release. Rare presumably damaging P2RX7 variants were identified in two related CNO patients. Targeted P2RX7 sequencing identified 62 CNO patients with rare variants (32.4%), 11 of which (5.8%) carried presumably damaging variants (MAF <1%, SIFT "deleterious", Polyphen "probably damaging", CADD >20). This compared to 83 of 1873 controls (4.4%), 36 with rare and presumably damaging variants (1.9%). Across the CNO cohort, rare variants unique to one (Median: 42 versus 3.7) or more (≤11 patients) participants were over-represented when compared to 190 randomly selected controls. Patients with rare damaging variants more frequently experienced gastrointestinal symptoms and lymphadenopathy while having less spinal, joint and skin involvement (psoriasis). Monocyte-derived macrophages from patients, and genetically modified THP-1-derived macrophages reconstituted with CNO-associated P2RX7 variants exhibited altered potassium flux, inflammasome assembly, IL-1ß and IL-18 release, and pyroptosis. Damaging P2RX7 variants occur in a small subset of CNO patients, and rare P2RX7 variants may represent a CNO risk factor. Observations argue for inflammasome inhibition and/or cytokine blockade and may allow future patient stratification and individualized care.

Contributors to Organ Damage in Childhood Lupus: Corticosteroid Use and Disease Activity.

BACKGROUND: Awareness of paediatric-specific predictors of damage in Childhood-lupus is needed to inform mitigation measures. OBJECTIVES: To ascertain how clinical and demographic variables correlate with damage accrual and identify predictors of damage. METHODS: Analysis included UK JSLE Cohort Study participants. Univariable and multivariable Prentice-Williams-Peterson models investigated how demographic and clinical factors influenced hazards of new damage. Analyses were performed across the entire cohort, in patients with minimal disease activity marked by a time-adjusted average SLEDAI-2K score (AMS)≤2, low activity (AMS ≤ 4), moderate-high activity (AMS > 4) and those with no corticosteroids. RESULTS: Within the entire cohort (n = 430), factors associated with damage included: any methylprednisolone (Hazard Ratio, HR 2.20, [CI 1.33-3.62]), time-adjusted mean Physicians Global Assessment (PGA) (HR 2.87, [CI 1.48-5.56]) and AMS score (HR 1.13, [CI 1.03-1.24], all p< 0.05). Within the low activity subgroup, any methylprednisolone (HR 2.61, [CI 1.04-6.53]) and time-adjusted mean PGA (HR 3.41, [CI 1.52-7.76]) were associated with damage (both p< 0.05). Within the moderate-high activity subgroup, any methylprednisolone (HR 2.29, [CI 1.31-4.00]), time-adjusted mean PGA (HR 2.66, [CI 1.20-5.87]) and AMS score (HR 1.15, [CI 1.03-1.29]), were predictive of damage (all p< 0.05). Baseline organ damage was predictive of subsequent damage accrual in the minimal activity (HR 1.33, CI [1.78-8.08]) and no corticosteroids subgroups (HR 3.64, CI [1.83-7.24], both p< 0.005). CONCLUSION: Disease activity levels (AMS/PGA) and proxy indicators (methylprednisolone exposure, baseline damage) were found to be key predictors of damage accrual. This highlights the importance of practical strategies, to reduce disease activity and long-term treatment toxicity, such as treat-to-target.

Successful stopping of biologic therapy for remission in children and young people with juvenile idiopathic arthritis.

OBJECTIVES: Clinicians concerned about long-term safety of biologics in JIA may consider tapering or stopping treatment once remission is achieved despite uncertainty in maintaining drug-free remission. This analysis aims to (i) calculate how many patients with JIA stop biologics for remission, (ii) calculate how many later re-start therapy and after how long, and (iii) identify factors associated with re-starting biologics. METHODS: Patients starting biologics between 1 January 2010 and 7 September 2021 in the UK JIA Biologics Register were included. Patients stopping biologics for physician-reported remission, those re-starting biologics and factors associated with re-starting, were identified. Multiple imputation accounted for missing data. RESULTS: Of 1451 patients with median follow-up of 2.7 years (IQR 1.4, 4.0), 269 (19%) stopped biologics for remission after a median of 2.2 years (IQR 1.7, 3.0). Of those with follow-up data (N = 220), 118 (54%) later re-started therapy after a median of 4.7 months, with 84% re-starting the same biologic. Patients on any-line tocilizumab (prior to stopping) were less likely to re-start biologics (vs etanercept; odds ratio [OR] 0.3; 95% CI: 0.2, 0.7), while those with a longer disease duration prior to biologics (OR 1.1 per year increase; 95% CI: 1.0, 1.2) or prior uveitis were more likely to re-start biologics (OR 2.5; 95% CI: 1.3, 4.9). CONCLUSIONS: This analysis identified factors associated with successful cessation of biologics for remission in JIA as absence of uveitis, prior treatment with tocilizumab and starting biologics earlier in the disease course. Further research is needed to guide clinical recommendations.

Panel sequencing links rare, likely damaging gene variants with distinct clinical phenotypes and outcomes in juvenile-onset SLE.

OBJECTIVES: Juvenile-onset systemic lupus erythematosus (jSLE) affects 15-20% of lupus patients. Clinical heterogeneity between racial groups, age groups and individual patients suggests variable pathophysiology. This study aimed to identify highly penetrant damaging mutations in genes associated with SLE/SLE-like disease in a large national cohort (UK JSLE Cohort Study) and compare demographic, clinical and laboratory features in patient sub-cohorts with 'genetic' SLE vs remaining SLE patients. METHODS: Based on a sequencing panel designed in 2018, target enrichment and next-generation sequencing were performed in 348 patients to identify damaging gene variants. Findings were integrated with demographic, clinical and treatment related datasets. RESULTS: Damaging gene variants were identified in ∼3.5% of jSLE patients. When compared with the remaining cohort, 'genetic' SLE affected younger children and more Black African/Caribbean patients. 'Genetic' SLE patients exhibited less organ involvement and damage, and neuropsychiatric involvement developed over time. Less aggressive first line treatment was chosen in 'genetic' SLE patients, but more second and third line agents were used. 'Genetic' SLE associated with anti-dsDNA antibody positivity at diagnosis and reduced ANA, anti-LA and anti-Sm antibody positivity at last visit. CONCLUSION: Approximately 3.5% of jSLE patients present damaging gene variants associated with younger age at onset, and distinct clinical features. As less commonly observed after treatment induction, in 'genetic' SLE, autoantibody positivity may be the result of tissue damage and explain reduced immune complex-mediated renal and haematological involvement. Routine sequencing could allow for patient stratification, risk assessment and target-directed treatment, thereby increasing efficacy and reducing toxicity.

Pulmonary hypertension in juvenile-onset systemic lupus erythematosus: a case series.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a rare multisystem autoimmune disorder with a variable clinical phenotype. Pulmonary hypertension (PHTN) is a recognised (and not uncommonly asymptomatic) complication of the condition with an associated poor prognosis in adults. It is relatively rare in juvenile-onset SLE (JSLE). METHODS: We present a retrospective descriptive case series of four female children aged 4 to 15 years at presentation of JSLE and aged 8 to 27 years at time of diagnosis of PHTN from the United Kingdom. All cases were identified through the UK JSLE Cohort Study. RESULTS: Of 665 children with JSLE in the UK cohort study to date (data from 2006-2020), four (0.6%) were identified as having PHTN. 3/4 of the PHTN cases presented with cardiovascular symptoms and / or signs at presentation.3/4 were treated with Rituximab and had a good long-term outcome. Shared clinical features include high baseline disease activity scores. CONCLUSIONS: JSLE has a high associated cardiovascular morbidity and mortality and early identification of treatable complications such as PHTN is vital. We suggest that children with high baseline disease activity scores and those presenting with cardiovascular symptoms and signs are most likely to have concurrent PHTN. Routine echocardiography is an effective screening tool and should be used as part of a standard diagnostic work-up.

Urinary complement proteins are increased in children with IgA vasculitis (Henoch-Schönlein purpura) nephritis.

BACKGROUND: Children with immunoglobulin A vasculitis (IgAV Henoch-Schönlein purpura) frequently encounter nephritis (IgAV-N) with 1-2% risk of kidney failure. The pathophysiology of IgAV-N is not fully understood with speculation that complement may contribute. The aim of this study was to identify whether urinary complement proteins are increased in children with IgAV-N. METHODS: A cross-sectional prospective cohort of children with IgAV were recruited together with controls including healthy children and children with systemic lupus erythematosus (SLE). Patients were subdivided according to the presence of nephritis. Urinary C3, C4, C5, and C5a were measured by enzyme-linked immunosorbent assay (ELISA) and corrected for urinary creatinine. RESULTS: The study included 103 children; 47 with IgAV (37 IgAV without nephritis, IgAVwoN; 10 IgAV-N), 30 SLE and 26 healthy children. Urinary complement C3, C4, and C5 were all statistically significantly increased in all children with IgAV compared to SLE patients (all p < 0.05). In patients with IgAV-N, urinary complement C3, C4, C5, C5a were all statistically significantly increased compared to IgAVwoN (C3 14.65 µg/mmol [2.26-20.21] vs. 2.26 µg/mmol [0.15-3.14], p = 0.007; C4 6.52 µg/mmol [1.30-9.72] vs. 1.37 µg/mmol [0.38-2.43], p = 0.04; C5 1.36 µg/mmol [0.65-2.85] vs. 0.38 µg/mmol [0.03-0.72], p = 0.005; C5a 101.9 ng/mmol [15.36-230.0] vs. 18.33 ng/mmol [4.27-33.30], p = 0.01). Using logistic regression, the urinary complement components produced an outstanding ability to discriminate between patients with and without nephritis in IgAV (AUC 0.92, p < 0.001). CONCLUSIONS: Children with IgAV-N have evidence of increased complement proteins present in their urine that may indicate a pathological role and may allow treatment stratification. A higher resolution version of the Graphical abstract is available as Supplementary information.

Mesenchymal Stem Cells in the Pathogenesis and Therapy of Autoimmune and Autoinflammatory Diseases.

Mesenchymal stem cells (MSCs) modulate immune responses and maintain self-tolerance. Their trophic activities and regenerative properties make them potential immunosuppressants for treating autoimmune and autoinflammatory diseases. MSCs are drawn to sites of injury and inflammation where they can both reduce inflammation and contribute to tissue regeneration. An increased understanding of the role of MSCs in the development and progression of autoimmune disorders has revealed that MSCs are passive targets in the inflammatory process, becoming impaired by it and exhibiting loss of immunomodulatory activity. MSCs have been considered as potential novel cell therapies for severe autoimmune and autoinflammatory diseases, which at present have only disease modifying rather than curative treatment options. MSCs are emerging as potential therapies for severe autoimmune and autoinflammatory diseases. Clinical application of MSCs in rare cases of severe disease in which other existing treatment modalities have failed, have demonstrated potential use in treating multiple diseases, including rheumatoid arthritis, systemic lupus erythematosus, myocardial infarction, liver cirrhosis, spinal cord injury, multiple sclerosis, and COVID-19 pneumonia. This review explores the biological mechanisms behind the role of MSCs in autoimmune and autoinflammatory diseases. It also covers their immunomodulatory capabilities, potential therapeutic applications, and the challenges and risks associated with MSC therapy.

Longitudinal analysis of urinary proteins in lupus nephritis - A pilot study.

Approximately 30% of adult-onset systemic lupus erythematosus (SLE) patients develop lupus nephritis (LN). The gold standard for LN detection involves renal biopsies, invasive procedures not suitable for routine disease monitoring. A urinary biomarker panel comprised of lipocalin-like prostaglandin D synthase (LPGDS), transferrin, alpha-1-acid glycoprotein (AGP-1), ceruloplasmin, monocyte chemoattractant protein 1 (MCP-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) has shown promise to predict LN and response to rituximab at baseline. Whether these proteins predict LN during longitudinal sampling, however, remained unknown. Here, we quantified aforementioned urinary proteins at baseline (N = 25), six and twelve months (N = 17 each) after rituximab treatment. Urine MCP-1 (at six and twelve months) and AGP-1 (at twelve months) levels varied between patients with active vs mildly active/inactive LN. Findings support the use of urinary proteins to detect active LN in ongoing disease monitoring in adult-onset SLE patients, but need to be validated in larger cohorts.

Real world treatment of juvenile-onset systemic lupus erythematosus: Data from the UK JSLE cohort study.

BACKGROUND: In the absence of clinical trials evidence, Juvenile-onset Systemic Lupus Erythematosus (JSLE) treatment plans vary. AIM: To explore 'real world' treatment utilising longitudinal UK JSLE Cohort Study data. METHODS: Data collected between 07/2009-05/2020 was used to explore the choice/sequence of immunomodulating drugs from diagnosis. Multivariate logistic regression determined how organ-domain involvement (pBILAG-2004) impacted treatment choice. RESULT: 349 patients met inclusion criteria, median follow-up 4-years (IQR:2,6). Mycophenolate mofetil (MMF) was most commonly used for the majority of organ-domains, and significantly associated with renal involvement (OR:1.99, 95% CI:1.65-2.41, pc < 0.01). Analyses assessing the sequence of immunomodulators focused on 197/349 patients (meeting relevant inclusion/exclusion criteria). 10/197 (5%) solely recieved hydroxychloroquine/prednisolone, 62/197 (31%) received a single-immunomodulator, 69/197 (36%) received two, and 36/197 patients (28%) received ≥three immunomodulators. The most common first and second line immunomodulator was MMF. Rituximab was the most common third-line immunomodulator. CONCLUSIONS: Most UK JSLE patients required ≥two immunomodulators, with MMF used most commonly.

Prospective epidemiological study of juvenile-onset systemic lupus erythematosus in the UK and Republic of Ireland.

OBJECTIVES: The primary objective was to define the incidence of JSLE in children <16 years of age in the UK and Republic of Ireland (ROI). The secondary objective was to describe presenting features, classification criteria, initial management and disease damage in newly presenting JSLE patients. METHODS: A prospective JSLE epidemiological study was undertaken between September 2017 and September 2019 with support of the British Paediatric Surveillance Unit and other professional groups involved in diagnosis and management of JSLE patients. Treating consultants reported all cases of JSLE seen. A follow-up study at 1 year examined management and progression of disease and treatment. RESULTS: There were 124 incident cases included in the final analysis. Incidence was estimated using ACR-1997 classification criteria (0.36/100 000), SLICC-2012 classification criteria (0.41/100 000) and clinician expert opinion (0.46/100 000). A high disease burden was seen, with 71.0% of patients requiring ongoing systemic CS treatment at 1 year; 98.2% receiving immunomodulatory treatment; and 20.4% accruing damage in the year following diagnosis (predominantly neuropsychiatric-related), with substantial involvement from multiple speciality teams. CONCLUSIONS: The minimum UK and ROI incidence of JSLE is between 0.36 and 0.46/100 000, depending on the case definition used. Challenges in classification of patients with JSLE are highlighted, but overall this study supports the use of SLICC-2012 classification criteria. The high levels of disease damage and ongoing CS use 1 year after diagnosis is concerning, highlighting the need for further interventions to improve outcomes in JSLE.

Attainment of low disease activity and remission targets reduces the risk of severe flare and new damage in childhood lupus.

OBJECTIVES: To assess the achievability and effect of attaining low disease activity (LDA) or remission in childhood-onset SLE (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.

Serum protein signatures differentiate paediatric autoimmune/inflammatory disorders.

Because of their rarity, limited awareness among non-specialists, and significant overlaps in their clinical presentation, childhood autoimmune/inflammatory conditions represent a diagnostic and therapeutic challenge. Juvenile idiopathic arthritis (JIA), with its 7 sub-forms, is the most common paediatric "rheumatic" disease. Juvenile-onset systemic lupus erythematosus (jSLE) is a severe autoimmune/inflammatory disease that can affect any organ system and shares clinical features with JIA. To overcome issues around diagnostic approaches in the context of clinical overlap, we aimed at the definition of disease sub-form specific cytokine and chemokine profiles. Serum samples from patients with JIA (n = 77) and jSLE (n = 48), as well as healthy controls (n = 30), were collected. Samples were analysed using the Meso Scale Discovery (MSD) U-PLEX Biomarker Group 1 (hu) panel. Distinct serum protein signatures associate with JIA vs jSLE disease groups. Proteins with high discriminatory ability include IL-23, MIP-1ß, MCP-1, M-CSF and MDC. Furthermore, serum IL-18, MIF, MIP-5 and YKL-40 discriminate between systemic JIA and other JIA subtypes. Thus, simultaneous quantification of serum proteins in a panel format may provide an avenue for the diagnosis and monitoring of childhood autoimmune/inflammatory conditions.

A panel of urinary proteins predicts active lupus nephritis and response to rituximab treatment.

OBJECTIVES: ∼30% of patients with SLE develop LN. Presence and/or severity of LN are currently assessed by renal biopsy, but biomarkers in serum or urine samples may provide an avenue for non-invasive routine testing. We aimed to validate a urinary protein panel for its ability to predict active renal involvement in SLE. METHODS: A total of 197 SLE patients and 48 healthy controls were recruited, and urine samples collected. Seventy-five of the SLE patients had active LN and 104 had no or inactive renal disease. Concentrations of lipocalin-like prostaglandin D synthase (LPGDS), transferrin, alpha-1-acid glycoprotein (AGP-1), ceruloplasmin, monocyte chemoattractant protein 1 (MCP-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were quantified by MILLIPLEX® Assays using the MAGPIX Luminex platform. Binary logistic regression was conducted to examine whether proteins levels associate with active renal involvement and/or response to rituximab treatment. RESULTS: Urine levels of transferrin (P <0.005), AGP-1 (P <0.0001), MCP-1 (P <0.001) and sVCAM-1 (P <0.005) were significantly higher in SLE patients when compared with healthy controls. Furthermore, levels of transferrin, AGP-1, ceruloplasmin, MCP-1 and sVCAM-1 (all P <0.0001) were higher in SLE patients with active LN when compared with patients without active LN. A combination of five urine proteins, namely LPGDS, transferrin, ceruloplasmin, MCP-1 and sVCAM-1 was a good predictor of active LN (AUC 0.898). A combined model of LPGDS, transferrin, AGP-1, ceruloplasmin, MCP-1 and sVCAM-1 predicted response to rituximab treatment at 12 months (AUC 0.818). CONCLUSIONS: Findings support the use of a urinary protein panel to identify active LN and potentially predict response to treatment with rituximab in adult SLE patients. Prospective studies are required to confirm findings.

'It is good to have a target in mind': qualitative views of patients and parents informing a treat to target clinical trial in juvenile-onset systemic lupus erythematosus.

OBJECTIVE: We sought to explore patient and parental views on treatment targets, outcome measures and study designs being considered for a future JSLE treat-to-target (T2T) study. METHODS: We conducted topic-guided, semistructured interviews with JSLE patients and parents and analysed the 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 ongoing 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, help structure treatment and 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 and parents on T2T targets and study designs. Complementary quantitative studies assessing the achievability and impact of different targets (e.g. lupus low disease activity state or remission) are now warranted to inform an international consensus process to develop treatment targets.

Behçet's syndrome in children and young people in the United Kingdom and the Republic of Ireland: a prospective epidemiological study.

OBJECTIVES: To define the incidence and prevalence of Behçet's syndrome (BS) in children and young people (CYP) up to the age of 16 years in the United Kingdom (UK) and Republic of Ireland (ROI). METHODS: A prospective epidemiological study was undertaken with the support of the British Paediatric Surveillance Unit (BPSU) and the British Society of Paediatric Dermatologists (BSPD). Consultants reported anonymised cases of BS seen. A follow-up study at one year examined progression of disease and treatment. RESULTS: Over a two-year period, 56 cases met the International Criteria for Behçet's Disease. For children under 16 years of age, the two-year period prevalence estimate was 4.2 per million (95% CI: 3.2, 5.4) and the incidence was 0.96 per million person years (95% CI: 0.66, 1.41). Mucocutaneous disease was the most common phenotype (56/100%), with ocular (10/56; 17.9%), neurological (2/56; 3.6%) and vascular involvement (3/56; 5.4%) being less common. Median age at onset was 6.34 years and at diagnosis was 11.72 years. There were slightly more female than male children reported (32/56; 55.6%). The majority of cases (85.7%) were white Caucasian. Apart from genital ulcers, which were more common in females, there were no significant differences in frequency of manifestations between male or females, nor between ethnicities. Over 83% of cases had three or more non-primary care healthcare professionals involved in their care. CONCLUSION: BS is extremely rare in CYP in the UK and ROI and most have mucocutaneous disease. Healthcare needs are complex, and coordinated care is key.

Limited sensitivity and specificity of the ACR/EULAR-2019 classification criteria for SLE in JSLE?-observations from the UK JSLE Cohort Study.

OBJECTIVES: This study aimed to test the performance of the new ACR and EULAR criteria, that include ANA positivity as entry criterion, in JSLE. METHODS: Performance of the ACR/EULAR-2019 criteria were compared with Systemic Lupus International Collaborating Clinics (SLICC-2012), using data from children and young people (CYP) in the UK JSLE Cohort Study (n = 482), with the ACR-1997 criteria used as reference standard. An unselected cohort of CYP positive for ANA (n = 129) was used to calculate positive/negative predictive values of the criteria. RESULTS: At both first and last visits, the number of patients fulfilling the different classification criteria varied significantly (P < 0.001). The sensitivity of the SLICC-2012 criteria was higher when compared with that of the ACR/EULAR-2019 criteria at first and last visits (98% vs 94% for first visit, and 98% vs 96% for last visit; P < 0.001), when all available CYP were considered. The ACR/EULAR-2019 criteria were more specific when compared with the SLICC-2012 criteria (77% vs 67% for first visit, and 81% vs 71% for last visit; P < 0.001). Significant differences between the classification criteria were mainly caused by the variation in ANA positivity across ages. In the unselected cohort of ANA-positive CYP, the ACR/EULAR-2019 criteria produced the highest false-positive classification (6/129, 5%). CONCLUSION: In CYP, the ACR/EULAR-2019 criteria are not superior to those of the SLICC-2012 or ACR-1997 criteria. If classification criteria are designed to include CYP and adult populations, paediatric rheumatologists should be included in the consensus and evaluation process, as seemingly minor changes can significantly affect outcomes.

Neuropsychiatric involvement in juvenile-onset systemic lupus erythematosus: Data from the UK Juvenile-onset systemic lupus erythematosus cohort study.

INTRODUCTION: Juvenile-onset systemic lupus erythematosus (JSLE) is a rare autoimmune/inflammatory disease with significant morbidity and mortality. Neuropsychiatric (NP) involvement is a severe complication, encompassing a heterogeneous range of neurological and psychiatric manifestations. METHODS: Demographic, clinical, and laboratory features of NP-SLE were assessed in participants of the UK JSLE Cohort Study, and compared to patients in the same cohort without NP manifestations. RESULTS: A total of 428 JSLE patients were included in this study, 25% of which exhibited NP features, half of them at first visit. Most common neurological symptoms among NP-JSLE patients included headaches (78.5%), mood disorders (48.6%), cognitive impairment (42%), anxiety (23.3%), seizures (19.6%), movement disorders (17.7%), and cerebrovascular disease (14.9%). Peripheral nervous system involvement was recorded in 7% of NP-SLE patients. NP-JSLE patients more frequently exhibited thrombocytopenia (<100 × 109/L) (p = 0.04), higher C-reactive protein levels (p = 0.01), higher global pBILAG score at first visit (p < 0.001), and higher SLICC damage index score at first (p = 0.02) and last (p < 0.001) visit when compared to JSLE patients without NP involvement. CONCLUSIONS: A significant proportion of JSLE patients experience NP involvement (25%). Juvenile-onset NP-SLE most commonly affects the CNS and is associated with increased overall disease activity and damage.

Clinical and laboratory phenotypes in juvenile-onset Systemic Lupus Erythematosus across ethnicities in the UK.

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.