Olfactory threshold (OT), which is associated with short-term inflammatory activity in relapsing MS, serves as an independent predictor of freedom from disease activity after starting disease modifying therapy (DMT), according to findings published in Multiple Sclerosis Journal. Harald Hegen, MD, PhD, and colleagues examined whether OT could predict treatment response in relapsing MS in a 5-year prospective study of 123 patients. After examining OT at the start of DMT (M0), 3 months (M3), and 12 months (M12), they found that higher OT scores at each timepoint were independently linked with reduced relapse probability, with the greatest risk reduction at M3 (HR, 0.44; P<0.001). Improvement of OT scores from M0 to M3 was also tied to decreased relapse risk (HR, 0.12; P<0.001). OT score of greater than6.5 at M3 was the greatest predictor of relapse freedom (HR,0.10; P<0.001) with high diagnostic accuracy (positive predictive value, 87%).