Detection of miRNA in chronic spontaneous urticaria patients - pilot study
Background Chronic spontaneous urticaria (CSU) is a heterogeneous immune-mediated disorder characterized by recurrent wheals and/or angioedema. Despite advances in understanding its pathogenesis, robust biomarkers for disease stratification remain lacking. MicroRNAs (miRNAs) are key post-transcriptional regulators implicated in immune-mediated diseases and may provide novel insights into CSU. Objective To characterize circulating miRNA expression profiles in CSU and explore their association with clinical phenotypes. Methods Patients were stratified into three groups: urticaria only (n=10), urticaria with angioedema (n=10), and angioedema only (n=10), alongside healthy controls (n=10). Plasma miRNAs were sequenced using the NovaSeq 6000 platform. Data were processed with the nf-core smrnaseq pipeline, followed by multivariate and differential expression analyses in R. Functional enrichment and target prediction analyses were performed using KEGG, Reactome, and WikiPathways. Results Thirty patients (mean age 45.3 years; 76.7% female) were included. Overall, 61 miRNAs were differentially expressed (p < 0.05) across groups, including controls. No miRNAs remained significant after multiple testing correction in pairwise comparisons between clinical subgroups. However, several miRNAs (miR-204-5p, miR-3158-3p, miR-4732-3p, miR-576-5p, and miR-877-5p) showed nominal associations with disease phenotypes. miR-204-5p demonstrated a trend toward reduced expression in patients with urticaria and angioedema (adjusted p = 0.05). Conclusion Circulating miRNA profiles may reflect biological heterogeneity in CSU. Although no subgroup-specific signatures were confirmed after correction for multiple testing, several candidate miRNAs were identified, supporting further investigation of miRNA-based biomarkers in CSU.