Study links molecular changes to long COVID

Editor's Note

This study by researchers from the Icahn School of Medicine at Mount Sinai, New York City, is one of the first to link long COVID symptoms at more than 1 year with changes in gene expression that occurred during the acute stage of COVID-19.

The researchers examined blood samples from 567 individuals (495 hospitalized with COVID-19 and 72 healthy and hospitalized controls) between April and June 2020. They tested each gene expressed in the blood for association with each long COVID symptom and then tested for associations specific to each of 13 types of immune cells. These associations were then categorized by whether they matched up with changes in patients’ levels of COVID-19 antibodies.

For long COVID symptoms, like smell or taste problems, the researchers were able to connect the antibody gene expression in plasma cells with the levels of antibodies against COVID-19, showing a direct link to the body’s response to the virus.

The researchers were not able to connect the gene expression pattern for lung problems with COVID-19-specific antibody levels, highlighting the different immune processes leading to long COVID that are triggered by COVID-19.

The findings highlight the need for greater attention at the infection stage to better understand how the processes that begin then lead to long COVID, the researchers say.