The Secondary Progressive Risk Score (SP-RiSc) may assist in identifying patients at an increased risk of converting from relapsing-remitting to secondary phase multiple sclerosis (MS), according to study results published in European Journal of Neurology.
As limited data exist on the value of various features in predicting the risk of transition from relapsing-remitting MS to secondary progressive phase, the objective of the current study was to determine the role of SP-RiSc, which integrates demographic, clinical and MRI data collected during the first 2 years after disease diagnosis, in predicting the risk for secondary progressive phase.
The study sample included 262 patients with relapsing-remitting MS from the MS Specialist Centre of the University of Verona, Italy, between 2005 and 2010 and followed-up to 2018. Study researchers evaluated the probability of developing secondary progressive course using clinical and imaging data at diagnosis and after the first 2 years of disease course. They combined the most predictive factors associated with the risk of secondary progressive conversion to develop the SP-RiSc tool.
The participants were randomly split into training set (219 participants) and a testing set (43 participants). During the 10 years of follow-up, 69 (26%) patients converted to secondary progressive MS.
Using Random Survival Forest, a machine learning approach, study researchers identified 7 variables that were highly predictive of the risk for converting to secondary progressive MS, including global cortical thinning (minimal depth [MD], 1.65), cerebellar cortical volume loss (MD, 2.15), cortical lesions load at diagnosis (MD, 2.47) and its increase after 2 years (MD, 3.15), age (MD, 3.30), Expanded Disability Status Scale (MD, 4.10), and the white matter lesions total number at diagnosis of relapsing remitting MS (MD, 4.17).
Using the Ensemble Mortality, study researchers identified 3 risk groups: high, medium, and low risk.
In the high-risk group 46 of 55 patients (85.5%) converted to secondary progressive phase during the follow-up period (median interval, 7 years), while in the medium group only 9 (17.7%) patients converted to secondary progressive phase (median interval, 8.5 years). All the patients in the low-risk group remained in the relapsing-remitting phase for the entire study period.
The probability to convert to secondary progressive phase within 10 years from the diagnosis was 92% with a SP-RiSc of at least 17.7, while patients with SP-RiSc less than 17.7 had 87% probability of remaining in the relapsing remitting phase.
The study had several limitations, including the subjective definition of the clinical onset of the progressive phase, the missing data on symptoms at disease onset in the study model, and the relatively small sample size.
“The SP-RiSc yielded a high performance in identifying MS patients with high probability to develop SPMS [secondary progressive MS], which can help improve management strategies. These findings are the premise of further larger prospective studies to assess its use in clinical settings,” concluded the study researchers.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Pisani AI, Scalfari A, Crescenzo F, Romualdi C, Calabrese M. A novel prognostic score to assess the risk of progression in relapsing-remitting multiple sclerosis patients. Eur J Neurol. Published online April 9, 2021. doi:10.1111/ene.14859