Cellular miRNA-31 and miRNA-125b as predictors of remission and major disease improvement in patients with early rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that impairs quality of life, highlighting the need for novel biomarkers for early diagnosis and improve disease management. This study explored the cellular microRNAs (miRNAs) profile in early RA to identify potential predictors of therapeutic response. We measured a panel of 768 miRNAs in peripheral blood mononuclear cells (PBMCs) from two early RA cohorts (< 6 months), stratified by sustained SDAI/CDAI remission and non-response to conventional therapy over 12 months. Initial screening identified 13 differentially expressed miRNAs (≥ 1.5-fold change), which were validated in an independent cohort comprising 59 early RA patients and 54 healthy controls. MiRNA levels were quantified by qPCR, and predictive performance was assessed by receiver operating characteristic (ROC) curve. Among the 13 candidates, baseline levels of miRNA-31 and miRNA-125b predicted SDAI/CDAI remission at 6 months. Moreover, changes in their expression after 1 month of therapy predicted Boolean2.0 remission and achievement of major disease improvement (≥ 85% reduction in disease activity) at 6 months. Higher baseline expressions of both miRNAs were consistently observed in patients who achieved remission. These findings suggest that cellular expression of miRNA-31 and miRNA-125b may serve as promising prognostic biomarkers for 6-month remission in early RA.