The COVID-19 pandemic has to date killed several million people globally and sickened tens of millions more. Even in the current situation with effective vaccines developed, the SARS-CoV-2 virus continues to be a global threat. Further knowledge of who may be at increased risk could lead to improved care.
Claudia Morris (Emory University) and coworkers recently reported that the levels of arginine—an amino acid—in blood plasma are considerably less in adults and children with COVID-19, compared with healthy controls. This doesn’t mean that low blood arginine levels cause COVID-19; merely that the two may be related, and worthy of study for its possible medical pertinence.
Morris and coworkers studied a group of 52 hospitalized patients and 28 healthy controls in Atlanta, Georgia (US). All of the original data is open source: available to the public at no charge.
53% of the COVID-19-positive adults, and 67% of the COVID-19 positive children, had blood plasma arginine concentrations less than 50 micromoles per liter. Such a low arginine concentration impairs the functioning of the immune system.
Only 4% of the healthy controls had such low concentrations. Morris and coworkers’ arginine deficiency results are consistent with a recent study in France.
There were other anomalies in blood plasma amino acid concentrations. For example, tryptophan levels were reduced, which may have implications for brain health.
What does this mean for therapeutic efforts? A recent study proposed reducing arginine levels as a treatment for COVID-19. Such an approach may be unwise, given the results reported here.
Morris and coworkers suggest that arginine supplementation may be a possible therapeutic option for COVID-19 in resource-limited settings. It’s important to note that at this point they’re simply advocating future study, rather than making recommendations for current clinical practice.
There are currently insufficient data to warrant pertinent changes in care for people who have COVID-19. Furthermore, there’s no indication that going out and buying pertinent supplements will help prevent you from acquiring a SARS-CoV-2 infection or minimizing your symptoms. This is early-stage research only.
Limitations of Morris and coworkers’ study include the fact that they don’t know the reasons for the imbalance in arginine or the other amino acids; e.g., renal disorder or reduced intake. Furthermore, the relatively small sample size of the study hindered the researchers’ evaluation of statistical significance.
The SARS-CoV-2 virus affects many of the body’s organs in ways that researchers don’t fully understand. Learning more about the physiology of COVID-19 initiation and progression will help medical practitioners treat COVID-19 and future pandemics.
*The National Institutes of Health, the Wilbur and Hilda Glenn Family Foundation, the Woodruff Health Sciences Center, the Scott Hudgens Family Foundation, and individual donors funded Rees et al.’s research.