Meta-analysis isolates iron rim lesions as markers of MS severity
Patients with IRLs tended to have higher EDSS scores, indicating more disability
A type of imaging finding called iron rim lesions are associated with more severe disability and a greater extent of brain damage in people with multiple sclerosis (MS), a new analysis suggests.
This specific imaging finding may help guide discussions about individualized treatments for MS, the study’s researchers said. The study, “Characterizing iron rim lesions in multiple sclerosis: a biomarker for disease activity and progression: a systematic review and meta-analysis,” was published in Neuroradiology.
In MS, the immune system attacks healthy nerve cells in the brain and spinal cord, leading to inflammation and damage. This disrupts nerve signals and leads to symptoms like muscle weakness and numbness. On MRI scans, damaged areas appear as spots called lesions or plaques, which help doctors track the disease’s activity and progression.
Iron rim lesions, or IRLs, are defined by a ring of immune cells laden with iron particles surrounding the damaged nerve tissue. Some studies suggest IRLs are associated with more severe disease in MS, but their relevance in MS progression and clinical care is poorly understood.
IRLs and disease severity in MS
Here, an international team of scientists conducted a meta-analysis to explore what’s currently known about IRLs in MS. In a meta-analysis, researchers pool data from multiple studies and analyze them collectively. This analysis included data from 13 studies, covering more than 900 people with MS. Slightly more than half the patients had IRLs and the rest didn’t.
Patients with IRLs tended to have significantly higher scores on the Expanded Disability Status Scale (EDSS), which indicates a greater degree of physical disability. Patients with IRLs also had significantly more brain atrophy (shrinkage) and more lesions in the brain’s white matter, which is tissue that helps form connections between different brain regions.
Rates of relapses, or disease flares, tended to be higher among patients with IRLs, but this difference wasn’t statistically significant, meaning it’s mathematically plausible it could just be random chance. Still, the data indicate “IRLs are central to both relapse dynamics and long-term neurodegeneration in MS,” the researchers said, adding the findings show “including IRL evaluations in routine clinical imaging” is needed to better understand and reduce their effect on MS progression.
The response to disease-modifying therapies (DMTs), which can slow the progression of MS, was similar in patients with or without IRLs, analyses showed. The researchers said trends indicated patients with IRLs might generally respond better to more intensive high-dose DMTs, but these weren’t statistically significant. Still, the data may inform discussions about how to create more personalized treatment approaches, they said.
“The specific challenges caused by IRLs in the management of MS need to be addressed by personalized therapeutic approaches, as this study illustrates,” the researchers wrote.
About the Author
