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Published on: December 9, 2015
Progression independent of relapsing biology in multiple sclerosis: a real-word study
Heather Y F Yong1,2, Carlos Camara-Lemarroy1,2
1Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.
Abstract:
Progression independent of relapse activity (PIRA) implies disability progression in people with relapsing-remitting multiple sclerosis (RRMS) secondary to neurodegeneration. Mechanistically and biologically PIRA could impact the traditional distinction between progressive and relapsing-MS. Herein, we estimated progression independent of relapsing biology (PIRB) in a cohort of 823 participants with clinically-isolated syndrome/RRMS in Calgary, Canada using a modified criterion [excluding relapses, inflammatory MRI activity, interim disability worsening/improvement over the observation period, and progression secondary to alternative causes including formal conversion to secondary-progressive MS]. PIRB was rare and rates remained consistent across disease-modifying therapies (3.75% dimethyl fumarate, 3.67% fingolimod, 3.72% ocrelizumab, 3.52% minocycline) despite varied rates of disability progression. PIRB may offer a practical alternative to the concept of PIRA.
Insights
Progression Independent of Relapsing Biology (PIRB) was rare in relapsing-remitting multiple sclerosis (RRMS) patients, occurring consistently across various disease-modifying therapies. This finding suggests PIRB may be a practical alternative to Progression Independent of Relapse Activity (PIRA).
Area of Science:
- Neuroscience
- Immunology
- Clinical Neurology
Background:
- Relapsing-remitting multiple sclerosis (RRMS) is characterized by relapses and progressive disability.
- Progression Independent of Relapse Activity (PIRA) describes disability worsening not linked to relapses, suggesting neurodegeneration.
- The distinction between relapsing and progressive MS may be blurred by PIRA.
Purpose of the Study:
- To estimate the occurrence of Progression Independent of Relapsing Biology (PIRB) in a cohort of clinically-isolated syndrome/RRMS patients.
- To assess if PIRB rates differ across various disease-modifying therapies (DMTs).
- To evaluate PIRB as a potential alternative to the PIRA concept.
Main Methods:
- A modified criterion was used to define and estimate PIRB in 823 participants with CIS/RRMS.
- The criterion excluded relapses, inflammatory MRI activity, interim disability changes, and progression from other causes.
- PIRB rates were analyzed across patients treated with dimethyl fumarate, fingolimod, ocrelizumab, and minocycline.
Main Results:
- Progression Independent of Relapsing Biology (PIRB) was found to be rare in the study cohort.
- PIRB rates remained consistent across different DMTs, including dimethyl fumarate (3.75%), fingolimod (3.67%), ocrelizumab (3.72%), and minocycline (3.52%).
- Disability progression rates varied among the DMTs, but PIRB incidence did not.
Conclusions:
- Progression Independent of Relapsing Biology (PIRB) is an infrequent event in RRMS.
- PIRB rates are consistent across various disease-modifying therapies, irrespective of their efficacy in managing disability progression.
- PIRB presents a potentially practical and measurable alternative to the concept of PIRA in multiple sclerosis research and clinical practice.
