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Study Type: Longitudinal cohort study (HR-pQCT imaging)

Key Question: How do disease activity, diagnosis, and seropositivity influence longitudinal changes in bone density, microarchitecture, and strength in RA and PsA?

Key Findings:

• Seropositive RA (RA+) had significantly lower trabecular vBMD than PsA (−14.71 mg HA/cm³, 95% CI 2.85–26.58) and seronegative RA (RA−) (−16.92 mg HA/cm³, 95% CI 0.97–32.86) at baseline.
• Over 5 years, total vBMD declined most in RA+ (−16.2 mg HA/cm³, 95% CI −20.9 to −11.4), with smaller losses in RA− and PsA.
• PsA showed relative cortical preservation; sustained remission was associated with preserved bone structure, while high disease activity predicted deterioration across all groups.

Clinical Relevance: Supports serostatus-stratified bone risk assessment and reinforces the value of achieving sustained remission to prevent structural bone loss in RA/PsA patients managed in NHS rheumatology services.

Limitations: Observational design with variable follow-up duration limits causal inference regarding disease activity and bone outcomes.

Study Type: Genetic association study with functional/mechanistic validation (targeted sequencing cohort plus in vitro and molecular modelling studies)

Key Question: Does a novel truncating TLR7 variant contribute to juvenile-onset SLE pathogenesis via a distinct molecular mechanism?

Key Findings:

• A private heterozygous TLR7 p.Glu834* variant was identified in one of 319 UK jSLE patients, presenting with severe multisystem/neuropsychiatric disease and a family history of lupus-like autoimmunity.
• The truncated protein forms an unconventional TLR7:TLR8 heterodimer (favoured over native TLR8:TLR8 dimerisation per structural modelling), driving enhanced proinflammatory cytokine output and an elevated peripheral blood IFN signature.
• Findings implicate a novel non-canonical TLR7/8 signalling mechanism distinct from previously described gain-of-function TLR7 variants.

Clinical Relevance: This supports incorporating TLR7 genetic screening into severe/refractory jSLE work-up within NHS paediatric rheumatology genomics pathways and strengthens rationale for TLR7/8- or IFN-pathway-targeted therapies (e.g., anifrolumab) in genetically stratified patients.

Limitations: Findings derive from a single patient/family, limiting generalisability until replicated in independent cohorts.

Study Type: Phase 2 trial substudy (pharmacodynamic/biomarker analysis), PAISLEY SLE trial

Key Question: Does TYK2 inhibition with deucravacitinib produce measurable changes in interferon and B-cell pathway biomarkers in patients with active SLE?

Key Findings:

• At baseline, 42 genes and 75 proteins were differentially expressed between SLE patients (n=363) and healthy volunteers.
• Deucravacitinib produced rapid, sustained reductions in IFN-responsive gene/protein expression, B-cell pathway markers, and serological biomarkers, with increased complement C3/C4, versus placebo.
• IFN signature score fell in both IFN-high and IFN-low subgroups; anti-dsDNA titres decreased specifically in the IFN-high subgroup.

Clinical Relevance: These mechanistic data support deucravacitinib's biological rationale in SLE and underpin ongoing UK-relevant phase 3 POETYK SLE-1/SLE-2 trials, offering a potential oral alternative to biologics for IFN-driven disease.

Limitations: All analyses were descriptive/exploratory without formal statistical comparison, limiting definitive efficacy conclusions.

Study Type: Retrospective cohort study (Canadian Early Arthritis Cohort, 2007–2023)

Key Question: In early rheumatoid arthritis, does the route of glucocorticoid administration (oral vs parenteral) affect the likelihood of remaining on steroids or escalating to advanced therapy at 12 months?

Key Findings:

• Persistent GC use at 12 months: 63% (both routes), 47% (oral), 26% (parenteral), 8% (no GC).
• Adjusted odds of ongoing GC use at 1 year were higher with oral (OR 9.8) than parenteral GC (OR 4.1), versus no GC.
• Advanced therapy escalation was similar across groups (14–16%), regardless of GC route.

Clinical Relevance: Favouring intra-articular/intramuscular GC over oral courses in newly diagnosed RA may reduce cumulative steroid exposure without compromising disease control, supporting steroid-sparing strategies relevant to NHS treat-to-target pathways.

Limitations: Observational design with treatment allocation by clinician choice risks confounding by indication (e.g., disease pattern influencing route selection).

Study Type: Meta-analysis of population-based registry data (CDC National Lupus Registry network)

Key Question: How does SLE incidence in the US vary by age, sex, race, and ethnicity, including under-recognised groups such as men and older adults?

Key Findings:

• Peak SLE incidence occurred in women aged 30–39 (12.7/100,000 person-years, 95%CI 9.5–16.8), versus men aged 60–69 (2.1, 95%CI 1.3–3.4).
• Black women aged 20–39 had the highest overall incidence (23.6, 95%CI 20.7–26.8); Asian women had highest paediatric-onset rates (<20 years: 6.5) and American Indian/Alaska Native women highest late-onset rates (>60 years: 9.4).
• 10.0% of cases were diagnosed before age 20 and 15.1% after age 60.

Clinical Relevance: UK rheumatologists should maintain a high index of suspicion for SLE outside typical young-female presentations, particularly in older men and specific ethnic subgroups, to reduce diagnostic delay.

Limitations: US registry-derived racial/ethnic categories and case ascertainment may not generalise directly to UK demographic or healthcare contexts.

Study Type: Retrospective cohort study (national registry analysis)

Key Question: What is the real-world incidence of hepatotoxicity, including confirmed drug-induced liver injury (DILI), among US patients with ANCA-associated vasculitis treated with avacopan?

Key Findings:

• Among 238 avacopan-treated patients, hepatic enzyme elevations were infrequent: AST elevation incidence 4.24/100 person-years (95% CI 1.77–10.19); ALT 2.67 (0.86–8.27); ALP 3.56 (1.34–9.49); bilirubin 1.80 (0.45–7.19).
• Two confirmed DILI cases (0.8%), both RUCAM score 9 (highly probable causality), including one with biopsy-confirmed severe hepatocellular injury.
• Early liver monitoring was inconsistent (median first test at 32 days; average testing interval 125 days).

Clinical Relevance: Despite low overall incidence, severe confirmed DILI occurred, reinforcing the need for rigorous, early liver function monitoring in UK patients prescribed avacopan for AAV amid ongoing regulatory scrutiny.

Limitations: Small sample size and incomplete/irregular liver enzyme monitoring likely underestimate true DILI incidence.

Study Type: Translational research (human sample analysis combined with in vitro and murine mechanistic studies)

Key Question: Does IL-12 signalling drive podocyte injury and senescence in lupus nephritis, and could this pathway be therapeutically targeted?

Key Findings:

• Serum IL-12 was elevated in LN patients (p=0.006) and lupus-prone mice (p=0.041), with increased podocyte IL-12 receptor expression in both species.
• IL-12 activated CaMK4/STAT4 signalling, causing mitochondrial dysfunction, oxidative stress, and podocyte senescence with cytoskeletal disruption.
• Podocyte-specific deletion of Il12rb1 reduced senescence, glomerular injury, and proteinuria in both lupus-prone and nephrotoxic nephritis models.

Clinical Relevance: This identifies the IL-12–IL-12R axis as a novel podocyte-protective therapeutic target in LN, relevant given growing UK interest in biologics (e.g., ustekinumab) for refractory lupus nephritis.

Limitations: Human data were correlative and based on a small cohort (n=39), with causal mechanistic evidence derived solely from murine and in vitro models.

Study Type: Translational/mechanistic study (transcriptomic, proteomic, and in vitro analyses)

Key Question: Is complement activation a feature of Still disease pathogenesis, and how does it relate to interferon signalling?

Key Findings:

• Monocyte transcriptomics showed marked complement pathway enrichment at SD onset vs remission (Padj=3.7×10⁻³⁶), with C1QB/C1QC among the top upregulated genes.
• Active SD patients had elevated C1q, C3a, C5a, and terminal complement complex levels, plus increased functional classical complement activity versus inactive disease and JIA.
• C1QB/C1QC expression correlated with IFN-γ-related markers (IL-18, CXCL9, CXCL10); IFN-γ induced monocytic C1q production, and C1q in turn amplified IFN-γ release from CD8+ T cells, indicating a feed-forward loop.

Clinical Relevance: These findings identify complement (particularly C1q) as a novel biomarker and potential therapeutic target in Still disease, relevant to UK paediatric and adult rheumatology services managing this rare but high-morbidity autoinflammatory condition, including MAS risk stratification.

Limitations: Small subgroup sizes (e.g., MAS n=2) and cross-sectional design limit causal inference and generalisability.