This week's roundup of the latest scientific research on the novel coronavirus and efforts to find treatments and vaccines for COVID-19 suggest that lung diseases worsen COVID-19 by altering airway genes and survivors of mild cases of COVID-19 do not need to be screened later for heart problems.
New findings shed light on why chronic lung diseases that block the airways – such as chronic bronchitis, emphysema and pulmonary fibrosis – increase patients' risks for severe COVID-19.
The diseases cause genetic changes in the epithelial cells that line the airways, making the cells more vulnerable to attack from the coronavirus, researchers reported on Wednesday in Nature Communications.
Laboratory studies of these cells found changes in their molecular makeup that likely make it easier for the virus to enter the body, make copies of itself, and trigger out-of-control immune responses that fill the lungs with fluid and cause severe organ damage.
The researchers, led by Nicholas Banovich at Translational Genomics Research Institute in Phoenix, were only able to examine cells from lung-disease patients without COVID-19 but said their "study highlights crucial areas for future research."
Anemia, a blood disorder characterized by a low red blood cell count, should probably be added to the list of risk factors for poorer COVID-19 outcomes, according to researchers who studied 374 COVID-19 survivors who were hospitalized and then released, with tests showing the virus was gone from their systems.
They found that 104 patients needed to be rehospitalized, and rates of moderate or severe anemia – as indicated by levels of hemoglobin, a protein in red blood cells that carries oxygen – were higher among the readmitted patients in the year before their COVID-19 diagnosis and while they were sick with the coronavirus.
The study, published in iScience however, cannot prove that anemia caused or contributed to the readmissions. Still, the research team from data analytics company "nference" in Cambridge, Massachusetts said the "robust association" of anemia with rehospitalization calls for research into whether anemia treatments might be beneficial in some cases.
Survivors of mild cases of COVID-19 do not need to be screened later for heart problems, researchers advise.
Researchers performed cardiovascular magnetic resonance imaging on 74 health care workers who had recovered six months earlier from mild or asymptomatic coronavirus infections, and on 75 uninfected individuals matched for age, gender and ethnicity.
According to a report published Tuesday in the European Heart Journal: Cardiovascular Imaging, there were no differences between the survivor group and the control group in any parameters of heart structure or function or in lab tests that would suggest heart disease.
The researchers, led by George Joy of Barts Heart Center in London, conclude, "Our study provides societal reassurance for the cardiovascular health of working-aged individuals with convalescence from mild SARS-CoV-2. Screening asymptomatic individuals following mild diseases is not indicated."
The alpha, beta and gamma variants of the novel coronavirus increased patients' risks of hospitalization and death by 60% compared to earlier forms of the virus, and the delta variant was even more virulent, according to researchers who studied more than 211,000 patients in Canada diagnosed with COVID-19 between February and June 2021.
Alpha, beta and gamma – first seen in the United Kingdom, South Africa and Brazil – more than doubled the risk of needing intensive care, even though the patients were generally younger and healthier than those infected earlier in the pandemic.
With the delta variant, first identified in India and now becoming dominant in many countries, "risks of hospitalization and death more than doubled, and risk of intensive care unit (ICU) admission more than tripled" compared to earlier SARS-CoV-2 strains, said Dr. David Fisman of the University of Toronto, who coauthored a report posted Monday on medRxiv ahead of a peer review.
He told Reuters his team did find an overall downward trend in disease severity over time, likely because of vaccinations.
