Author Of 1 Presentation
PS05.02 - Validation of three Secondary Progressive Multiple Sclerosis classification methods in five registries within the SPMS Research Collaboration Network
Abstract
Background
Assigning Secondary Progressive Multiple Sclerosis (SPMS) course consistently is challenging as it is based on a gradual worsening in neurological disability independent of relapses. Clinical SPMS assignment may therefore vary between registries depending on clinical practice. Consequently, a comparison of SPMS between registries would benefit from an objective definition of SPMS.
Objectives
To validate three different methods for classifying patients into Relapsing Remitting Multiple Sclerosis (RRMS) or SPMS, compared to the clinical assignment, in five European Multiple Sclerosis (MS) registries.
Methods
Data from MS registries in Czech Republic (11,336 patients), Denmark (10,255 patients), Germany (23,185 patients), Sweden (11,247 patients), and the United Kingdom (UK) (5,086 patients) were used. Patients with either RRMS or SPMS, age ≥ 18 years at index date (date with the latest Expanded Disability Status Scale (EDSS) observation) were included. Index period was 01/2017 - 12/2019. Three EDSS centric classification methods were applied; method 1: a modified real world EXPAND criteria (Kappos, L. et al., 2018. The Lancet 391(10127), 2018), method 2: the data-derived definition from Melbourne University but without pyramidal Functional Score (Lorscheider, J. et al., 2016. Brain 139(9)), method 3: the decision tree classifier from Karolinska Institutet (Ramanujam, R. et al., 2020. medRxiv, 2020.07.09.20149674). The classifications were compared to the clinical assignment, where sensitivity (SPMS as true positive), specificity (RRMS as true negative) and accuracy were calculated as similarity measurements.
Results
The overall classification performance (sensitivity, specificity, accuracy) among classifiable patients were; method 1: (0.47, 0.85, 0.79), method 2: (0.77, 0.87, 0.85), method 3: (0.84, 0.83, 0.84). The proportions of unclassifiable patients with each method were; method 1: 20.0%, method 2: 32.2%, method 3: 0%. Methods 2 & 3 provided a high sensitivity, specificity and accuracy, while method 1 provided high specificity but low sensitivity. Method 3 was the only method having no unclassifiable patients.
Conclusions
Our findings suggest that these methods can be used to objectively assign SPMS with a fairly high performance in different registries. The method of choice depends on the research question and to what degree unclassifiable patients are tolerable.
Author Of 1 Presentation
P0164 - Smoking is associated with increased plasma neurofilament light levels in multiple sclerosis (ID 1834)
Abstract
Background
Elevated levels of plasma neurofilament light chain (pNfL) is associated with increased disease activity, physical disability and reduced treatment response in persons with multiple sclerosis (MS). However, the association between environmental exposures such as cigarette smoking and pNfL levels is not clear.
Objectives
To investigate the association between cigarette smoking, as one of the most prominent environmental factor associated with MS disease activity, and pNfL-levels in MS.
Methods
This is a retrospective population-based cohort study. Blood samples from incident MS cases were collected at time of diagnosis (from 2001). Concentrations of pNfL were determined using antibodies from UmanDiagnostics and the high-sensitive Single Molecule Array (SimoaTM) NF-light® Advantage kit. We assessed the impact of self-reported cigarette smoking habits at time of sampling on age-stratified pNfL levels above 80th, 95th, and 99th of non-MS controls' percentiles (>C80, >C95, and >C99).
Results
pNfL levels were measured in 2881 MS cases with smoking history of which 320 (11.1%) were current regular smokers and 828 (28.7%) were past regular smokers (median years since quitting 6; IQR 1 to 14). Current smoking was associated with significantly increased odds ratios (OR) of having pNfL-levels >C80, >C95 and >C99 with OR ranging from 1.27 (95% CI: 0.96-1.68) to 1.70 (95% CI: 1.24-2.33) comparing current smokers to never smokers and 1.44 (95% CI: 1.06-1.94) to 1.6 (95% CI: 1.12-2.27) comparing current smokers to past smokers. The OR of having pNfL-levels >C80, >C95 and >C99 in past smokers who quitted 6 to 10 years ago, compared to current smokers, ranged from 0.6 (95% CI: 0.39-0.92) to 0.55 (95% CI: 0.30-0.95), and from 0.62 (95% CI: 0.43-0.89) to 0.53 (95% CI: 0.31-0.87) in those with >10 years since quitting smoking. Although decreased, the ORs were not significant among those quitting smoking 1 to 5 years before sampling (P>0.05).
Conclusions
Current regular smoking is associated with significantly increased risk of displaying high pNfL levels in MS patients, which argue for a negative effect on disease activity. In contrast, there was a beneficial effect of quitting smoking that increased with time since stopping. Our findings support the rational for life style counselling in MS.
Presenter Of 1 Presentation
P0164 - Smoking is associated with increased plasma neurofilament light levels in multiple sclerosis (ID 1834)
Abstract
Background
Elevated levels of plasma neurofilament light chain (pNfL) is associated with increased disease activity, physical disability and reduced treatment response in persons with multiple sclerosis (MS). However, the association between environmental exposures such as cigarette smoking and pNfL levels is not clear.
Objectives
To investigate the association between cigarette smoking, as one of the most prominent environmental factor associated with MS disease activity, and pNfL-levels in MS.
Methods
This is a retrospective population-based cohort study. Blood samples from incident MS cases were collected at time of diagnosis (from 2001). Concentrations of pNfL were determined using antibodies from UmanDiagnostics and the high-sensitive Single Molecule Array (SimoaTM) NF-light® Advantage kit. We assessed the impact of self-reported cigarette smoking habits at time of sampling on age-stratified pNfL levels above 80th, 95th, and 99th of non-MS controls' percentiles (>C80, >C95, and >C99).
Results
pNfL levels were measured in 2881 MS cases with smoking history of which 320 (11.1%) were current regular smokers and 828 (28.7%) were past regular smokers (median years since quitting 6; IQR 1 to 14). Current smoking was associated with significantly increased odds ratios (OR) of having pNfL-levels >C80, >C95 and >C99 with OR ranging from 1.27 (95% CI: 0.96-1.68) to 1.70 (95% CI: 1.24-2.33) comparing current smokers to never smokers and 1.44 (95% CI: 1.06-1.94) to 1.6 (95% CI: 1.12-2.27) comparing current smokers to past smokers. The OR of having pNfL-levels >C80, >C95 and >C99 in past smokers who quitted 6 to 10 years ago, compared to current smokers, ranged from 0.6 (95% CI: 0.39-0.92) to 0.55 (95% CI: 0.30-0.95), and from 0.62 (95% CI: 0.43-0.89) to 0.53 (95% CI: 0.31-0.87) in those with >10 years since quitting smoking. Although decreased, the ORs were not significant among those quitting smoking 1 to 5 years before sampling (P>0.05).
Conclusions
Current regular smoking is associated with significantly increased risk of displaying high pNfL levels in MS patients, which argue for a negative effect on disease activity. In contrast, there was a beneficial effect of quitting smoking that increased with time since stopping. Our findings support the rational for life style counselling in MS.