Virus Linked to Respiratory Infections May Also Trigger Brain Diseases Like MS

Joana Fernandes, PhD avatar

by Joana Fernandes, PhD |

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coronavirus and MS

A virus known to cause respiratory infections in people ā€” the human coronavirus (HCoV) ā€” may also be the source of neurological diseases thatĀ strike patients, seemingly out of the blue,Ā a new study reported.

Results obtained in the study, ā€œHuman Coronavirus OC43 Associated with Fatal Encephalitis,ā€Ā support the idea that diseases of unknown origin ā€” such as multiple sclerosis, Alzheimer’s, Parkinson’s, and, especially, encephalitis ā€” may be induced by this virus. ItĀ was published in the New England Journal of Medicine.

Researchers investigatedĀ the case of an 11-year-old boy withĀ severe immunodeficiency and symptoms of viral encephalitis. TheĀ virus, however, was not detected in this patient viaĀ conventional methods. The boy underwentĀ a stem cell transplant, andĀ died a month and a half after the treatment.

The team then usedĀ a modern laboratory technique thatĀ allows the detection of molecules produced by the virus, called deep sequencing, to analyze a brain biopsy sample. Through this technique,Ā theyĀ foundĀ theĀ presence of the human coronavirus (strand OC43) in the brain tissue, and confirmed itĀ withĀ other techniques as well.

ā€œAmong the methods used, deep sequencing of biopsy materials provides an important tool for the diagnosis of unexplained encephalitis, particularly in immunodeficient patients who have undergone stem cell transplantation,ā€ said Pierre Talbot, one of the authors of the study, in a news release.

ā€œThe human betacoronaviruses, including HCoV-OC43, are predominantly associated with respiratory tract infections,ā€ the team wrote. ā€œThe group includes viruses that cause the severe acute respiratory syndrome and the Middle East respiratory syndrome.ā€

Although this viral strand, HCoV-OC43, is typically ā€œassociated with mild upper respiratory tract infections,ā€ the researchers continued, ā€œit has been shown to have neuroinvasive properties.ā€Ā In vivo studies in mice, specifically, have demonstrated that ā€œHCoV-OC43 can infect neurons and cause encephalitis.ā€

Another studyĀ also detected this virus in the cerebrospinal fluid of a child with acute disseminated encephalomyelitis. In the case of multiple sclerosis, studies from the 1980sā€“90s have reported the presence of HCoV-OC43 in brain biopsies of MS patients.

The team concluded that the development of a standard method for identifying viruses or other pathogensĀ can aidĀ treatment decisions, namely in the choice of therapiesĀ for patients with neurologicalĀ disorders.