Khaberni - American researchers have discovered a new cellular mechanism that explains how an infection with the "Influenza A" virus can damage the heart.
The study, conducted by a team from Mount Sinai Hospital in America and published in the February 9 issue of the journal "Immunity", was based on animal models and human data, simultaneously providing evidence of the effectiveness of an advanced experimental treatment based on modified messenger RNA technology, capable of reducing cardiac muscle damage following viral infection without affecting the natural antiviral immune response.
It is estimated that Influenza A viruses cause about a billion infections annually around the world, ranging from mild seasonal cases to widespread global pandemics. Though most cases are mild and recover spontaneously, the virus can be fatal in some cases, especially when it reaches the heart and causes death of the cardiac muscle cells responsible for pumping blood.
During the autopsy analysis of 35 patients who died from influenza during hospital admission, researchers found that more than 85% of them suffered from at least one cardiovascular disease, such as high blood pressure, while the majority had multiple diseases, including atherosclerosis and myocardial fibrosis, confirming that heart diseases play a major role in increasing influenza-related mortality.
The research team also revealed the precise mechanism of heart damage, where it was found that a rare type of white blood cell known as "plasmacytoid dendritic cell 3" becomes infected with the virus in the lungs, then moves to the heart and produces large amounts of type I interferon. Instead of eliminating the virus, this reaction leads to the death of heart muscle cells and decreases the efficiency of blood pumping.
In this context, Jeffrey Downey, the lead researcher in the study, explained that these cells act as a "Trojan horse" within the immune system, transporting the virus from the lung to the heart and causing an excessive immune response that inflicts severe damage to the heart muscle.
He added that the new treatment based on modified messenger RNA successfully reduced indicators of heart damage, such as lowered troponin levels, and improved heart function measured by the increase in the left ventricular ejection fraction.
The team is currently working, in collaboration with researchers at the Icahn School of Medicine, on developing a safe and effective method to deliver this treatment to heart muscle cells through systemic injection, instead of the direct injection used in the initial experimental phase. The researchers are also focused on understanding why "plasmacytoid dendritic cell 3" is susceptible to influenza infection, and how its protective role can be utilized to reduce cardiac damage, especially in heart patients.
In a comment, Professor Philip Swirski, the supervisor of the study, said: "As pathogens continue to evolve and emerge, our strategies to combat them must also evolve. Understanding how influenza affects the entire body, especially the heart, paves the way for a new era of advanced medical care."
