Reacción a "Reactions: specific antibodies found in blood samples from patients years before they develop multiple sclerosis"

The causes of multiple sclerosis (MS), an autoimmune disease and the second leading cause of disability in young people, are not fully understood. However, a genetic predisposition is acknowledged, and environmental factors have an impact on that predisposition. Some viral infections stand out amongst those factors, like the one caused by the Epstein-Barr virus.  

This study, published in a world-renowned journal (Nature Medicine), attempts to delve deeper into the processes involved in the years prior to the onset of symptoms in MS. It uses the same database of US military service patients (10 million) that was used in another study. This study was published in 2022 in the prestigious journal Science, and sought to deepen the relationship between the Epstein-Barr virus (responsible for the mononucleosis infection, also known as "the kissing disease") and MS.  

In this case, they collect samples from patients who subsequently develop MS (250 in total) for whom serum samples were available from about five years before and one year after the diagnosis. They are compared with a cohort of 250 other healthy individuals to analyse the spectrum of auto-antibodies (antibodies erroneously directed against self-structures) generated by the immune system before diagnosis, as well as their relationship to neuronal damage (measured by the light chain of neurofilaments in serum). In about 10% of MS patients, a different auto-antibody profile is observed, some of which may be cross-reactive with some pathogens (such as Epstein-Barr virus itself). This would indicate that the infection develops specific antibodies against the pathogen and, subsequently, these antibodies attack their own structures due to molecular similarity. 

The main use they see for these results is to use these autoantibodies to detect a possible MS in patients with a high risk of developing this pathology (e.g., relatives of patients). However, in the near future, there isn’t a clear prospect that these autoantibodies could be measured in clinical practice in the short or long term. 

Overall, the study is high quality, as required in a journal of this category. In addition, the findings are confirmed in an independent cohort, which makes the results more robust. However, the group they studied is small, which could introduce an understimation of associtation type of bias.