Inborn errors of metabolism comprise a clinically diverse group of conditions that arise from the decreased activity of an enzyme or metabolite transporter and subsequent blockade in a metabolic pathway. These disorders are typically considered in the differential diagnosis of critically ill neonates or young children presenting with hypoglycaemia, metabolic acidosis or hyperammonaemia. However, beyond these classic presentations, a broader group of inborn errors of metabolism can manifest more subtly, with progressive articular and multi-systemic involvement that mimics or overlaps with typical features of rheumatological disease. Consequently, these conditions might be misdiagnosed for years as rheumatological diseases, including juvenile idiopathic arthritis, systemic sclerosis, idiopathic inflammatory myopathies and systemic lupus erythematosus. Moreover, these disorders provide unique opportunities to understand the complex interplay between metabolism and immune function. With the growing availability of disease-modifying therapies for inborn errors of metabolism, rheumatologists must be able to recognize these disorders, particularly in patients with atypical features or treatment-refractory disease.

WNT5A is a noncanonical WNT ligand that is overexpressed in autoimmune systemic sclerosis (SSc). While the pathogenic effects of WNT5A have been established in SSc fibroblasts, its contribution to profibrotic SSc macrophage activation is unknown. The goal of this study was to determine the effects of WNT5A on fibrotic macrophage activation.

In SLE, expanded B cell subtypes like double-negative 2 (DN2) may harbour autoreactivity, which may be linked to impaired checkpoint regulation. We investigated checkpoint molecule CD72 on B cells, its clinical associations, and dynamic changes upon rituximab (RTX) treatment.

Assessing quality of life in patients with axial spondyloarthritis (axSpA) is essential for capturing the full burden of the disease beyond clinical and imaging findings. Quality of life measures support clinicians in identifying unmet patient needs and informing treatment decisions. The aim of this study was to develop and validate the first Bulgarian version of the Ankylosing Spondylitis Quality of Life (ASQoL) questionnaire.

Lupus nephritis (LN) is a major cause of morbidity in childhood-onset systemic lupus erythematosus (cSLE). Cyclophosphamide (CYC) and mycophenolate mofetil (MMF) are recommended first-line induction therapies, yet comparative pediatric real-world data, particularly from Asian populations, remain limited. This study compared the effectiveness of CYC and MMF for induction of renal remission and evaluated patterns and predictors of treatment switching among Filipino children with LN.

Mycophenolate mofetil (MMF) is routinely used in early diffuse cutaneous systemic sclerosis (dcSSc) but not in limited cutaneous (lc)SSc. This may miss an opportunity to slow disease progression. MINIMISE-Pilot tested the feasibility of an open-label event-driven randomised trial of MMF vs no immunosuppression in lcSSc.

Neurological involvement in Sjögren's disease (neuro-SjD), reported by up to 20% of patients, represents a highly relevant extra-glandular manifestation. Owing to the clinical complexity, frequent diagnostic delay and the poor response to treatment, neuro-SjD remains a major unmet need. This study aimed to better understand the burden of neuro-SjD from the patient perspective, focusing on the overall care journey.

Subglottic stenosis (SGS) is a challenging manifestation of granulomatosis with polyangiitis (GPA), often relapsing and poorly responsive to immunosuppressive treatment. Current guidelines lack specific recommendations for SGS management and evidence is limited. This study aimed to identify features of SGS associated with a more aggressive course and to assess the efficacy of available treatments in preventing relapses.

Early-onset primary Sjögren's disease (pSjD) represents a specific clinical phenotype with poorer prognosis. We aim to compare early- and late-onset pSjD immunophenotypes to identify key distinct immunological features.

To examine contemporary trends in mortality due to granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) in Europe.

Sjogren's disease (SjD) shows a strong female predominance, but the contribution of age-related hormone changes to this sex bias remains uncertain. We investigated whether natural hormonal transitions across the lifespan align with variation in male and female prevalence of SjD.

SSc-associated interstitial lung disease (SSc-ILD) is the leading cause of death amongst SSc patients. However, profibrotic factors in SSc-ILD have not been systematically assessed and their working mechanisms remain unclear.

Refractory manifestations of Behçet's disease (BD) are commonly treated with TNF-α inhibitors; however, a subset of patients do not respond or are intolerant, prompting the need for alternative therapies. This study aimed to assess the real-life use, efficacy, and safety of non-TNF targeted biologic agents in BD.