Olfactory threshold as a biomarker of long-term relapse activity in multiple sclerosis
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Published on: August 25, 2014
Klaus Berek1, Harald Hegen1, Michael Auer1
1Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
Background:
Olfactory threshold (OT) is a marker of short-term inflammatory activity in multiple sclerosis (MS).
Objective:
To investigate whether OT predicts long-term MS clinical disease course.
Methods:
This was a 6-year prospective longitudinal study on MS patients at the MS clinic Innsbruck. Clinical visits assessing the occurrence of relapses, Expanded Disability Status Scale (EDSS) scores, and disease-modifying treatment (DMT), were conducted biannually. OT testing was performed at baseline (BL), year 1 (Y1), year 2 (Y2) and year 6 (Y6), using the threshold subscore of the "Sniffin' Sticks" test. Cognitive function was assessed by the Symbol Digit Modalities Test.
Results:
Of 139 MS patients, 92 were eligible for Y6 follow-up. 68% experienced relapses, 53% EDSS worsening, 29% progression independent of relapse activity (PIRA) and 41% cognitive deterioration. OT scores were lower at BL, Y1 and Y2 in patients requiring DMT escalation. In multivariable analysis, higher OT scores at BL, Y1, Y2 and Y6 were associated with lower risk of relapse (hazard ratio, HR: 0.65-0.92) and EDSS worsening (HR: 0.86-0.89), while no associations were found for PIRA and cognitive deterioration.
Conclusions:
OT is a potential surrogate marker for long-term inflammatory disease activity and DMT failure in MS.
Insights
Olfactory threshold (OT) can predict long-term multiple sclerosis (MS) disease course. Higher OT scores indicate a lower risk of relapses and disability worsening, suggesting OT as a marker for inflammatory activity.
Area of Science:
- Neurology
- Immunology
- Biomarker Research
Background:
- Olfactory threshold (OT) is recognized as a marker for short-term inflammatory activity in multiple sclerosis (MS).
- The predictive value of OT for the long-term clinical disease course in MS remains to be fully elucidated.
Purpose of the Study:
- To investigate the potential of olfactory threshold (OT) as a predictor of the long-term clinical disease course in multiple sclerosis (MS).
- To determine if OT can forecast disease progression, relapse rates, and treatment responses over a six-year period.
Main Methods:
- A prospective longitudinal study followed 139 MS patients for 6 years, with biannual clinical assessments.
- Olfactory threshold (OT) testing using the
- Sniffin' Sticks
- test was conducted at baseline and years 1, 2, and 6.
- Expanded Disability Status Scale (EDSS) scores, relapse occurrence, and cognitive function (Symbol Digit Modalities Test) were evaluated.
Main Results:
- Higher olfactory threshold (OT) scores at baseline and follow-up were associated with a reduced risk of relapses (HR: 0.65-0.92) and EDSS worsening (HR: 0.86-0.89).
- Lower OT scores were observed in patients requiring escalation of disease-modifying treatment (DMT).
- No significant association was found between OT and progression independent of relapse activity (PIRA) or cognitive deterioration.
Conclusions:
- Olfactory threshold (OT) shows potential as a surrogate marker for predicting long-term inflammatory disease activity in multiple sclerosis (MS).
- OT may also serve as an indicator of disease-modifying treatment (DMT) failure in MS patients.
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