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

Multiple sclerosis is a disease in which B lymphocytes are key. B-lymphocytes, when mature, become cells that produce antibodies.  When these lymphocytes react against our own antigens (their molecular target), an autoimmune disease develops, such as MS. 

Autoantibodies have been described in many other diseases in which B-lymphocytes are key. These allow us, not only to better understand how the disease develops, but to also diagnose the diseases more accurately –since each autoimmune disease has autoantibodies that are specific to that disease, which can be measured in blood or cerebrospinal fluid–. Multiple sclerosis has always been an exception to this rule. Despite being a disease in which B-lymphocytes are crucial, no autoantibody has ever been found to explain the disease or to allow earlier diagnosis, despite persistent searches using multiple types of techniques. Some antibodies have been found that seem to be present in small groups of patients. This study is along the same line, but using a novel technique (phage immunoprecipitation) for mass detection of autoantibodies.  

The study has several implications for understanding the disease and for further research, although, I believe, these are not currently implementable in clinical practice. The first implication is that it seems clear that not all patients are immunologically the same. This is something we already sensed for other reasons, but the study reiterates it. Probably, what this means is that, from a mechanism and causes the point of view, MS is not one disease, but a collection of diseases that manifest in a similar way but have different mechanisms. The other important, and known, implication, is that there may be external pathogens (Epstein-Barr virus in particular) that, although they are not the only cause, they may play a triggering role in a predisposed population.  

The most important limitation is that in the vast majority of diseases in which B-lymphocytes are important, autoantibodies recognise molecules on the membranes (surface) of cells (because antibodies do not easily enter the cell), and those molecular targets have a complex three-dimensional conformation. But the antibody detection technique that was used in the study recognizes pieces of proteins (not complete proteins) that do not have the natural conformation and do not necessarily belong to membrane proteins; so, repeating the study with a technology that detects autoantibodies directed against complete proteins and, if possible, membrane proteins, would perhaps be a better approach.  

To summarize, this is an interesting study that uses a novel technique to detect a population of MS patients who share immunological mechanisms, but it is also a study in which some technical aspects, the low frecuency in which the autoantibodies were found and the complexity of the technique used, prevent us from defending this technique as something that can be used in clinical care at the present time.