Influence of age on disease progression

Patients with paediatric-onset MS (POMS) have initially slower disability progression rates [1], but higher relapse rates compared with adult-onset patients [2,3]. An important outstanding question is: What is the impact of age at DMT start on time to first relapse and time to first confirmed EDSS progression across the full age spectrum?

Factors that need to be taken into account are gender, year of DMT start, type of DMT, pre-DMT relapses, EDSS, time since first MS symptom, and MS severity score [4]. Dr Viktor von Wyl (University of Zurich, Switzerland) tried to answer this question using the Swiss Association for Common Tasks of Health Insurers database which contains data from 14,718 MS patients who initiated their first DMT between 1995 and 2017 (69% women; 85% relapsing-remitting MS; mean age 39±11.5 years; disease duration 6±8 years; 80% IFN-beta or glatiramer acetate) [5].

Data from 9,705 MS patients were eligible for this analysis. The association between age at disease onset and EDSS progression had a sigmoidal shape: EDSS progression hazard remained stable in patients with disease onset from early childhood to about 32 years; then increased sharply around the age of 45 years; and afterwards remained stable at a relatively high level [6]. In contrast, the association between age at disease onset and relapse risk was almost linear: the risk for relapse was highest at younger ages and decreased continuously from childhood to around 35 years of age. For example, a 20-year old patient with first symptoms of MS had a 1.5-fold higher risk for relapse on DMT than a 38-year old patient, after adjustment for other factors (gender, relapse-activity before DMT initiation, EDSS, pyramidal functional system score, and MS severity score). Risk of relapse remained constant for a decade and then continuously decreased from age 45 years onwards.

So, age at DMT start is an important factor affecting relapse and confirmed disability progression, independent of other characteristics and possibly type of DMT. Age at first symptom onset and disease duration are also relevant and correlated with age at DMT start. The age between 37 and 40 years seems critical with regard to the compensation of damage in the central nervous system caused by MS. Patients older than 40 years who start with a DMT have a higher risk of disability progression, when controlling for important clinical disease characteristics [6].

1. Renoux C, et al. N Engl J Med. 2007;356:2603-13.
2. Benson LA, et al. Mult Scler Relat Disord. 2014;3:186-93.
3. Gorman MP, et al. Arch Neurol. 2009;66:54-9.
4. Roxburgh RH, et al. Neurology. 2005;64:1144-51.
5. Lorscheider J, et al. Mult Scler. 2018;24:777-785.
6. von Wyl V, et al. ECTRIMS 2019, abstract 302.

Posted on 8 November 201922 March 2021