Alzheimer’s patients at higher risk for severe COVID-19

Brazilian scientists have found that Alzheimer’s disease is a risk factor for those contracting COVID-19, regardless of age. The study was published in Alzheimer’s & Dementia, a journal of the Chicago-based association specializing in the disease. The surveyed data stem from the UK health care system and encompass figures on 12,863 people aged 65 and older.

The research showed that, when a patient was hospitalized and already had Alzheimer’s, their risk of developing a more severe state because of the virus of COVID-19, Sars-CoV-2, was three times higher compared to those who did not have the disease. With patients aged 80 and older, the risk is six times as large. The disease did not increase the risk of hospitalizations when analyzed alongside other comorbidities.

“If a patient hospitalized with COVID-19 has Alzheimer’s, that is a significant aggravating factor for hospitalization,” said Sérgio Verjovski, PhD in biophysics and a scientific authority at the Butantan Institute’s Parasitology Laboratory. The study was also joined by researchers from the São Paulo University (USP) and the Federal University of Rio de Janeiro (UFRJ).

The data were split into three age groups: 66–74 years old (6,182 people), 75–79 (4,867 people), and 80 and older (1,814 people). Of these, 1,167 people had COVID-19. Verjovski explains that the British data bank was used as it covers over ten years of patients’ history, in addition to having the genome sequencing of most of them.

Prompt care

The expert notes that this discovery casts light on the importance of providing quick care for these patients, considering the chances of an aggravated state. “This underscores the fact that these patients need quicker hospitalization. Patients aged 65 though 70 had their risk of developing complications and passing away increased by nearly four times,” he pointed out.

Some hypotheses may explain this connection, and Verjovski stressed that relevant studies are still being carried out. However, one of the possible mechanisms has to do with the fact that, when Sars-CoV-2 infects an organism, the body responds with an inflammatory process to fight the virus.

“We know that Alzheimer’s includes the inflammation of brain vessels. This inflammation may weaken the blood–brain barrier—which allows the brain to receive nutrients and circulation and blocks infection factors. When inflammation takes place, which leads to the degeneration through Alzheimer’s, it may be undermine this barrier and increase the chances of infection with the virus,” he stated.

Genetic factors

The scientists are now seeking a link between genetic factors behind the development of Alzheimer’s and the aggravation of COVID-19, Verjovski went on to say. “We’re now trying to associate the clinical data with the figures on genetic variants surrounding Alzheimer’s to ascertain whether we can find among the genes causing Alzheimer’s a gene that increases the severity of COVID-19 which may lead us to a genetic mechanism.”

Originally, the laboratory headed by Verjovski conducts cancer research. After the pandemic began, however, studies were reoriented. “We have been given a grant for the research, which enabled us to use these data banks. Our staff specializes in carrying out analyses and handling equipment. Even though our focus is not on Alzheimer’s or COVID-19, we joined Sérgio Ferreira [PhD in biophysics and UFRJ professor] and used our know-how for large-scale genetic analysis.”