Review article describes current status of research on the disease mechanisms of Long COVID

An international team of doctors and scientists has compiled a summary of the current state of research around the world on the biological causes and disease mechanisms of Long COVID. In order to do so, the authors contextualised the findings to date on the syndrome to better explain the biological processes that take place within the body. 

Despite important scientific insights already having been gathered, according to the authors the specific processes that occur in the body in connection with Long COVID are not yet fully understood. The evaluation did however show that multiple processes may occur in the bodies of people with Long COVID, sometimes even simultaneously. These include chronic inflammatory responses and an immune system that attacks the person’s own body. Residual components of the SARS-CoV-2 coronavirus as well as tiny blood clots can also play a role. These blood clots disrupt the flow of blood so that the organs at times may receive insufficient oxygen. Additionally, there are indications of damaged mitochondria (the powerhouse of the cell) and of a malfunctioning nervous system. These processes and changes were observed in differing combinations and severities in people with Long COVID, which led to differing clinical presentations of the syndrome according to the authors. Depending on the person, Long COVID may exhibit different symptoms most prominently, such as extreme exhaustion after physical activity, problems with memory or with the cardiovascular system.

The authors emphasise that Long COVID remains a major public health and economic challenge around the world. They highlight that research needed to identify definitive biomarkers in the blood or tissue for reliable diagnoses. These findings were also important to in future be able to develop tailored treatments for people with differing phenotypes of Long COVID. Until then, those affected should receive high-quality care that helps alleviate the symptoms and improve quality of life. The treatment should correspond with the state of the art (evidence-based care). They believe that close cooperation between the different fields of medicine as well as at international level is of central importance to help treat those affected.