Multiple sclerosis (MS) is a chronic inflammatory disease in which the immune system attacks the central nervous system. This impairs the transmission of signals between the brain and body and can lead to deficits in vision, motor control, sensation, and cognitive impairment. The causes of MS are still incompletely understood.

In a study of identical twins, a team led by PD Dr. Lisa Ann Gerdes (Institute of Clinical Neuroimmunology at LMU University Hospital and Biomedical Center) has shown that a type of immune cells, CD8-positive T cells, play a role in the early stages of the disease. The work is published in the journal Science Immunology .

Although it is known that CD8 T cells occur in inflammatory areas in the brains of MS patients, it was unclear what role they play in the disease: Are they a mere by-product or active facilitators of inflammation? And what prompts their entry from the blood into the central nervous system? The LMU team has now investigated these questions with the help of this unique patient cohort, comparing the CD8 T cells of monozygotic twin pairs, of which one twin suffers from MS while the other is asymptomatic. The twin cohort allows the analysis of high-risk patients Genes and the environment partially determine who might get MS. Monozygotic twins offer a unique insight into this, as these factors are largely identical.

As the healthy twin has an elevated risk (up to 25%) of also developing MS, they allow researchers to investigate the early sta.