Newswise — Cytomegalovirus (CMV) is a widespread herpesvirus globally. Its impact on the population varies, affecting anywhere from 40% to 90% depending on location. While asymptomatic in healthy individuals, managing this persistent infection demands constant effort from the immune system to suppress it. A research team from the University of Cordoba (UCO) and Cordoba’s Maimonides Biomedical Research Institute (IMIBIC) examined the influence of SARS-CoV-2 coronavirus infection in patients with mild or asymptomatic COVID-19, who were also coinfected with CMV. Findings indicated that individuals coinfected with both pathogens experience accelerated immune system aging, correlating with an elevated risk of cardiovascular disease at an earlier stage in life.
According to Dr. Alejandra Pera, the lead researcher of the study, it is important to note that the presence of both cytomegalovirus (CMV) and SARS-CoV-2 does not guarantee the development of cardiovascular issues. However, considering the widespread prevalence of these viruses, it becomes another factor that should be considered when evaluating a patient's medical history. It should be added to the existing list of risk factors, including alcohol and tobacco consumption, regular consumption of high-saturated fat foods, and a sedentary lifestyle.
T-cells, in the right measure
The study conducted a comparative analysis of the immune systems of individuals with and without chronic cytomegalovirus (CMV) infection. The analysis took place at 3 and 12 months after experiencing a mild or asymptomatic infection with SARS-CoV-2, the coronavirus responsible for COVID-19. The findings revealed that individuals coinfected with both viruses exhibited an expansion of T-cells that displayed enhanced functionality. These T-cells are memory-endowed lymphocytes crucial for the body's defense mechanisms. However, when excessively activated, they can trigger inflammation and potentially harm the vascular endothelium—a layer of cells that lines the interior of blood vessels. The researcher further explains that cytomegalovirus alone already induces an increase in these cells, but the study uncovered an additional impact from SARS-CoV-2.
A notable aspect of the study is that the observed effect was observed even in individuals who had mild or asymptomatic cases of COVID-19. While the scientific community is primarily investigating the impact on patients with severe symptoms, the researchers emphasize that COVID-19 can also have medium- and long-term consequences in individuals who experienced the disease without complications. This finding highlights the importance of considering these potential consequences and incorporating them into our understanding of the disease's overall impact, as emphasized by the study's lead author.
Vaccines as prevention
Led by UCO predoctoral researcher Pablo Álvarez, the study found that individuals with prior cytomegalovirus infection experience an increase in cells linked to cardiovascular disease after being infected with SARS-CoV-2. However, this phenomenon does not occur in individuals who were previously vaccinated and subsequently contracted COVID-19. Dr. Pera emphasized the need for further research to consider the impact of various waves and variants of the coronavirus. Nonetheless, the results suggest that vaccines can prevent and mitigate the excessive expansion of T cells that have the potential to cause cardiovascular damage.