The following is a brief roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.
Coronavirus tricks the body into attacking the brain
Numerous neurological problems such as tremors, seizures, and impaired consciousness have been linked to severe COVID-19, and a small German study may have uncovered a mechanism by which the virus appears to trick the body into attacking the brain. Researchers have been seeing these symptoms without finding the coronavirus in the cerebrospinal fluid circulating through the brain and spinal cord. It appears that patients’ immune systems are producing what are known as autoantibodies that mistakenly target a person’s own tissues or organs, researchers reported on Monday on medRxiv, in advance of peer review. “Remarkably, all 11 patients examined in the present study had strong autoantibodies targeting the brain, which are not normally found in cerebrospinal fluid of healthy people,” study coauthor Dr. Christiana Franke of Charité – Universitätsmedizin in Berlin told Reuters. The absence of other explanations for the neurological problems suggests these autoantibodies are to blame, she added. Researchers are working to learn how the coronavirus triggers production of autoantibodies, whether other organs are similarly attacked by the immune system, and whether this also happens as patients are recovering, Franke said. After the 1918 flu virus pandemic, she noted, around 1 million patients had persistent neurological complaints.
Heartburn drugs tied to higher coronavirus risk
Widely used heartburn drugs that have been linked with numerous complications including higher risk for kidney disease and dementia with long-term use may also be tied to a higher risk for COVID-19, researchers have found. The class of drugs known as proton pump inhibitors (PPIs) that include omeprazole (Prilosec), lansoprazole (Prevacid), pantoprazole (Protonix), and esomeprazole (Nexium) work by stopping the stomach from producing too much acid. Researchers conducted a survey of more than 53,000 people, including nearly 4,000 who said they had tested positive for COVID-19. They found that those taking a PPI once a day had more than a two-fold higher risk of coronavirus infection, and people taking them twice a day had more than a three-fold higher risk than those not using the medicines, according to the study led by Dr. Brennan Spiegel of Cedars-Sinai Medical Center in Los Angeles and released on Tuesday by the American Journal of Gastroenterology. Individuals taking heartburn drugs called histamine-2 receptor antagonists (H2RAs) were not at elevated risk, the researchers said. The study only shows a correlation and does not prove that PPIs caused the increase in coronavirus infections. “Further studies examining the association between PPIs and COVID-19 are needed,” Spiegel’s team says.
Inflammation of organs not necessarily tied to viral load in fatal COVID-19
In fatal cases of COVID-19, the places in the body with the worst inflammation and organ damage are not necessarily the places with the highest amount of virus, or viral load, according to a small study. Autopsies of 11 patients who died from COVID-19 showed that some tissues – including the intestine, liver and kidney – contained a high amount of virus but were not inflamed, while tissues with inconsistent or patchy virus levels – in particular, the lungs – were severely inflamed. The fact that virus levels do not correlate with organ damage in these fatal cases may mean some tissues tolerate the virus better than others, and “suggests that treatments that reduce inflammation in the lung could be particularly effective, since the virus alone may not be causing tissue damage,” researcher David Dorward of University of Edinburgh Center for Inflammation Research told Reuters. Dorward and colleagues posted their study report on medRxiv in advance of peer review.
Obesity increases respiratory failure risk in COVID-19
The obesity epidemic may at least partly explain the extensive need for invasive ventilator use among coronavirus patients in the United States, where the rate of obesity is roughly 40%, New York City researchers say. They studied 1,687 adults hospitalized with COVID-19, about one in three of whom was obese. After accounting for other health risk factors, obesity alone did not increase their risk of dying in the hospital but it did increase their risk for respiratory failure. The findings “support the need to consider the community-specific prevalence of obesity when planning a community’s COVID-19 response,” the research team wrote on Monday in Annals of Internal Medicine.