Interferon-β-1a induces increases in vascular cell adhesion molecule : implications for its mode of action in multiple sclerosis

Abstract We investigated soluble vascular cell adhesion molecule-1 (sVCAM) levels and MRI lesions over 24 weeks in 15 Relapsing Remitting MS (RRMS) patients randomized prospectively to receive once-weekly (qw) IFN-β-1a 30 μg intramuscularly (IM) (Group I, 8 patients) or three-times-weekly (tiw) IFN-β-1a 44 μg subcutaneously (SC) (Group II, 7 patients). Both groups demonstrated a significant increase in sVCAM during treatment when compared to pre-treatment levels. Patients on IFN-β-1a 44 μg SC tiw had a significant ( p p p =0.009). We postulate that the mode of action of IFN-β therapy in MS may involve the induction of an increase in sVCAM. sVCAM could bind VLA-4 on T-cells and intercept their adhesion to the blood brain barrier (BBB). This mechanism is consistent with the observed clinical effect of IFN-β in reducing MRI contrast enhancing lesions.