A group of researchers from the Environmental Factors in Degenerative Diseases team at the Health Research Institute of the San Carlos Clinical University Hospital (IdISSC), in Madrid, has developed a study in which differentiated "antiviral footprints" have been identified depending on the type of multiple sclerosis, which opens the way to "possible targeted therapies".
The work, published in the specialized journal 'Scientific Reports' and supported by the Inflammatory Diseases Network (REI), concludes that "the way the immune system responds to certain viruses could influence the clinical evolution of multiple sclerosis," a disease whose World Day is commemorated this Saturday, May 30.
The research "provides a more precise view of how viral factors could be involved in different ways depending on the type of multiple sclerosis," indicated one of its leaders, Dr. María Inmaculada Domínguez Mozo, who signs the work along with Drs. Roberto Álvarez Lafuente and Stefano Ruberto.
According to this specialist, "the results indicated that each clinical form of multiple sclerosis has a different antiviral immunological footprint." To delve deeper into this aspect, the team analyzed how different antibody patterns against viruses relate to the various clinical forms of the disease and to markers of neurological damage.
As the authors detail, "antiviral antibodies are proteins produced by the immune system to recognize and defend the body against specific viruses." "Their presence in the blood allows us to know if a person has been exposed to certain viruses and how they have responded immunologically to them," they add, while recalling that "markers of neurological damage are molecules or biological indicators that reflect injury or deterioration of the nervous system."
Viruses analyzed and types of multiple sclerosis
In this regard, they specify that "in multiple sclerosis", these markers "help to evaluate the degree of neuronal damage and the evolution of the disease". In the study, "antibodies against several viruses of the herpesvirus family were evaluated: Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), and cytomegalovirus (CMV), selected because their possible involvement in multiple sclerosis has already been described in previous research".
The researchers recall that "until now, research on viruses and multiple sclerosis had identified general associations, especially with EBV, but the different clinical forms of the disease had not been clearly characterized according to the antiviral serological profile". "Our results suggest that the interaction between different viruses could influence the clinical trajectory of the disease and that CMV could be linked to progression mechanisms rather than acute inflammation," Domínguez Mozo pointed out.
Specifically, the team has observed that "people with primary progressive multiple sclerosis showed significantly higher levels and prevalence of IgG antibodies (immunoglobulin G) against cytomegalovirus than patients with relapsing-remitting forms". "IgG antibodies usually appear after infection or after prolonged exposure to a virus, so they usually indicate immunological memory and an already established immune response," they recalled.
On the contrary, they point out that "antibody levels against EBV were lower in the primary progressive form compared to the relapsing-remitting and secondary progressive forms". "Finally, patients with relapsing-remitting multiple sclerosis showed higher levels of IgM antibodies - which are produced in the early stages of an infection - against HHV-6 than those with secondary progressive multiple sclerosis," they added.
Even so, they warn that "these results do not allow establishing a direct causal relationship between the three viruses analyzed and the development of different types of multiple sclerosis", although "they do reinforce the hypothesis that the antiviral immune response could play a relevant role in the disease". "These findings contribute to a better understanding of the biological mechanisms underlying the progression of the disease", Domínguez Mozo remarked.
In his opinion, "the results support the use of antiviral serology as a complementary tool to improve patient stratification and move towards more personalized medicine", and he emphasizes that "furthermore, they open the door to future research on targeted therapeutic strategies, especially in progressive forms, where current options remain limited".