Abstract: Background & Aims: Growing evidence suggests an increased prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) in the context of immune-mediated inflammatory diseases (IMIDs). We aimed to clinically and mechanistically characterize steatotic liver disease (SLD) in a prospective cohort of patients with IMID compared to controls.
Methods: Cross-sectional, case-control study including a subset of patients with IMID. Controls from the general population were age-, sex-, type 2 diabetes-, and BMI-matched at a 1:2 ratio. SLD was established using controlled attenuation parameter. Liver biopsies were obtained when significant liver fibrosis was suspected. Total RNA was extracted from freshly frozen cases and analyzed by RNA-seq. Differential gene expression was performed with ?limma-voom?. Gene set-enrichment analysis was performed using the fgsea R package with a preranked ?limma t-statistic? gene list.
Results: A total of 1,456 patients with IMID and 2,945 controls were included. Advanced SLD (liver stiffness measurement >?9.7 kPa) (13.46% vs. 3.79%; p <0.001) and advanced MASLD (12.8% vs. 2.8%; p <0.001) prevalence were significantly higher among patients with IMID than controls. In multivariate analysis, concomitant IMID was an independent, and the strongest, predictor of advanced SLD (adjusted odds ratio 3.318; 95% CI 2.225-4.947; p <0.001). Transcriptomic data was obtained in 109 patients and showed 87 significant genes differentially expressed between IMID-MASLD and control-MASLD. IMID-MASLD cases
displayed an enriched expression of genes implicated in pro-tumoral activities or the control of the cell cycle concomitant with a negative expression of genes related to metabolism.
Conclusions: The prevalence of advanced SLD and MASLD is disproportionately elevated in IMID cohorts. Our findings suggest that IMIDs may catalyze a distinct MASLD pathway, divergent from classical metabolic routes, highlighting the need for tailored clinical management strategies
