A research team at the University of Turku has identified a new predictor for the progression of multiple sclerosis (MS), linking the thickness of inflammatory lesion edges in the brain to how aggressively the disease develops.
The finding, published on Tuesday in Nature Medicine, could help personalise treatment and accelerate the development of new MS therapies.
The study was led by Professor Laura Airas, head of the InFLAMES research group.
Researchers found that the wider the rim around an MS lesion in the brain, the faster the disease tends to progress. The edges, formed by malfunctioning microglial cells, extend deeper into healthy brain tissue and cause more damage.
"Microglia are supposed to defend the brain from external threats like viruses," Airas said. "In MS and other brain diseases, they start to behave abnormally and attack brain tissue instead."
The study combined brain imaging data from 114 Finnish MS patients with tissue samples collected post-mortem in the Netherlands. Using PET scans, the researchers could detect the location and structure of the lesions. They then correlated these imaging results with the microscopic features observed in tissue samples.
Airas used a tennis ball analogy to explain the effect. “In a calm lesion, the surface resembles a soft fuzz. In an aggressive lesion, the surface would have long bristles, penetrating further into healthy brain areas.”
This so-called "rim effect" could be used both to guide patient treatment and assess drug candidates during clinical trials.
"If we see that a new drug molecule reduces the thickness of the lesion rim, we can be quite confident it’s having a therapeutic effect," Airas said. "That helps us decide to move forward in drug development."
MS is the most common central nervous system disease in young adults that affects mobility and daily functioning. It exists in two forms: a relapsing type with clear flare-ups, and a progressive type where symptoms steadily worsen without distinct episodes.
According to Airas, the new discovery is relevant to both types of the disease and may lead to more targeted treatments for patients with faster-progressing forms of MS.
HT
