Worldwide over 2 million people live with multiple sclerosis, affecting a wide range of people including 8,000 individuals under the age of 18 and people as old as 75 developing it. Most individuals are diagnosed between the ages of 20 and 50, with women two to three times more likely to develop multiple sclerosis than men. Multiple sclerosis is a common cause of disability in young adults and can lead to severe complications such as sensory problems, pain, and signs of paralysis. A recent study published in Cell examines the role of immune cells in inflammation and lesion formation in the brain during multiple sclerosis, potentially leading to novel treatment options.
Multiple Sclerosis is a disease of the central nervous system, consisting of the brain and spinal cord, in which the immune system, specifically T cells, attack the protective sheath covering nerve fibers. When this sheath, known as the myelin sheath, is attacked communication between the brain and the rest of the body can be inhibited. As the disease progresses, the nerves themselves may be damaged permanently or deteriorate. Individuals may experience long periods of remission without any symptoms while others with severe multiple sclerosis may lose the ability to walk independently. Other symptoms may include vision loss, numbness or weakness in limbs, tremors, fatigue, and dizziness.
There is currently no cure for multiple sclerosis, treatment includes recovery from attacks, slowing the progression of the disease, and managing symptoms. A wide variety of drugs can be used for treatment after attacks, as well as preventing progression and controlling symptoms. A class of multiple sclerosis drugs, Rituximab and Ocrelizumab, that eliminate B cells led researchers to hypothesize that B cells may play an essential role in multiple sclerosis. Researchers at the University of Zurich, led by neurologist Roland Martin and immunologist Mireia Sospedra, uncovered a key aspect of pathogenesis in multiple sclerosis. "We were able to show for the first time that certain B cells -- the cells of the immune system that produce antibodies -- activate the specific T cells that cause inflammation in the brain and nerve cell lesions," says Roland Martin.
The researchers examined the role of B cells using an in-vitro system that analyzes blood samples from individuals with multiple sclerosis. The study showed that increased levels of activation and cellular division were present for T cells attacking the myelin sheaths. The role of T cells in multiple sclerosis was previously studied and had been the focus of most research. However, this study found that B cells interacting with T cells was actually the underlying cause of pathogensis. Elimination of B cells in the study showed that proliferation of T cells was effectively inhibited. The team also found that activated T cells migrate to the brain and destroy nerve tissue there as well leading to brain lesions. "Our findings not only explain how new MS drugs take effect but also pave the way for novel approaches in basic research and therapy for MS," concludes Roland Martin.
To learn more about multiple sclerosis watch the video below!