Unlocking the Secrets: How Content Study Reveals Critical Distinctions in Heart Inflammation

A team of researchers from Berlin, collaborating with international scientists, has identified distinct patterns of heart inflammation caused by COVID-19, anti-COVID-19 vaccines, and non-COVID-19 myocarditis. These findings could lead to more personalized therapies for the condition. The study was published in “Nature Cardiovascular Research.”

Myocarditis, or heart inflammation, varies depending on its cause. Dr. Henrike Maatz of the Genetics and Genomics of Cardiovascular Diseases lab at Professor Norbert Hübner’s Max Delbrück Center led a collaborative effort with international researchers to examine immune signatures in myocarditis caused by SARS-CoV-2 infection, mRNA vaccines, and non-COVID-19 heart inflammation. The study found clear differences in immune activation across the three groups.

“This knowledge might help us develop new and more personalized therapies that are tailored to specific types of inflammation,” said Dr. Maatz, a co-author of the paper.

During the pandemic, researchers at Max Delbrück Center, Berlin Institute of Health (BIH) at Charité, and Charité – Universitätsmedizin Berlin saw an opportunity to study myocarditis on a cellular and molecular level depending on its cause. The Hübner lab has long had an interest in studying cardiac disease using single-cell analysis techniques.

They collaborated with Professor Carsten Tschöpe of Deutsches Herzzentrum der Charité (DHZC), who leads the BIH research group for Immunocardiology and is a principal investigator at Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK). His team collected biopsy samples from patients suspected to have myocarditis. At DHZC, they operate a widely recognized Myocarditis Unit specializing in performing endomyocardial biopsies.

“We are deeply grateful for the support of our specialist heart failure nurses, who play an essential role in identifying patients and ensuring meticulous data management,” said Tschöpe.

Researchers at Max Delbrück Center performed single-nucleus RNA sequencing (snRNA-seq) on biopsied heart tissue to study gene expression patterns and identify different cell types within the heart. They examined molecular changes across three sets of myocarditis samples: COVID-19 positive, mRNA vaccine-related cases, and non-COVID-19 viral infections.

The researchers found some overlapping gene expression changes but significant differences in immune cell activation levels among the groups. For instance, CD4 T-cells were more abundant post-vaccination, while CD8 T cells dominated after SARS-CoV-2 infection. Non-COVID myocarditis samples showed a roughly 50/50 ratio of these two types of immune cells.

“These findings suggest a stronger immune response in COVID-19-induced myocarditis compared to pre-pandemic forms, while vaccine-related inflammation appeared milder,” said Professor Norbert Hübner.

The study’s implications could lead to improved treatment tailored to specific types of inflammation. Dr. Maatz noted that the results also suggest potential new therapies for controlling side effects from vaccines.

However, conducting single-nucleus RNA sequencing with such small biopsy samples posed a challenge. “But I think the resolution and depth of insight we were able to generate really shows the power of this method – perhaps in future diagnostic settings as well,” said Maatz.