Beta Interferon 1a and Laquinimod Differentially Affect Coagulation-Related Gene Expression in Multiple Sclerosis Patients: Implications for Clinical Efficacy and Side Effects

Laquinimod (LAQ) and interferon-β1a (IFN-β1a, Rebif) are immunomodulatory therapies for relapsing–remitting multiple sclerosis (RRMS) that may also influence vascular and hemostatic pathways. This study investigated transcriptional regulation of coagulation- and fibrinolysis-related genes in peripheral blood mononuclear cells (PBMCs) from LAQ- and IFN-β1a–treated RRMS patients. In the LAQ cohort, within-subject paired analysis revealed significant downregulation of procoagulant and antifibrinolytic transcripts, including F2, F10, SERPINE1 (PAI-1), and TFPI, after six months of treatment (FDR < 0.01, |fold change| ≥ 1.5). These findings suggest that LAQ exerts an anticoagulant and antifibrinolytic transcriptional effect, potentially mediated through aryl hydrocarbon receptor (AhR) signaling. Western blot analysis confirmed decreased PAI-1 protein expression. In contrast, IFN-β1a treatment induced a distinct transcriptional pattern. Genes associated with fibrinolysis and endothelial stabilization (THBD, ANXA2, SERPINA1) were upregulated, while procoagulant mediators (F2R, F13A1, PROS1) were downregulated. Correlation analysis demonstrated significant relationships between interferon-inducible genes and coagulation-related transcripts, suggesting coordinated regulation between type I interferon signaling and vascular pathways. Collectively, these results indicate that LAQ and IFN-β1a exert opposing yet convergent influences on coagulation and fibrinolytic networks in immune cells. Both therapies modulate transcriptional regulators of vascular homeostasis, revealing a potential molecular interface between immune modulation and hemostatic balance in RRMS. These findings are exploratory and hypothesis-generating, warranting further functional and clinical validation.