Yale Researchers Uncover Key Insights into Long COVID

A team of scientists at Yale has identified unique immune and hormonal responses in patients suffering from long COVID, as opposed to those without the condition. Their research, which involved 268 participants, revealed notable variances in antibody and cortisol levels. These findings illuminate possible avenues for treatment, although the intricate nature of long COVID complicates the development of effective therapies.

Patients experiencing persistent symptoms such as cognitive impairment, confusion, pain, and severe fatigue after a COVID-19 infection exhibit distinct immune and hormonal reactions, a study by Yale School of Medicine and Icahn School of Medicine at Mount Sinai reveals.

This groundbreaking discovery of these unique responses paves the way for researchers to potentially understand the root causes and explore treatment options for this often debilitating condition, which has impacted millions globally. In the United States, approximately 7.5% of people who have contracted the SARS-CoV-2 virus later experience long COVID.

Distinct Biological Markers in Long COVID Sufferers

Yale’s Akiko Iwasaki, Sterling Professor of Immunobiology and a co-senior author of the study, noted that these indicators are not typically detected in routine lab tests.

This research was recently published in the journal Nature.

The study involved analyzing blood samples from 268 individuals, including those who had long COVID symptoms for around a year, those who had recovered from COVID-19, and those with no known prior infections. The researchers found significant disparities in circulating antibodies and immune system cells between the long COVID group and the others.

Changes in Immune and Hormonal Systems

The study also revealed that long COVID patients had a higher presence of antibodies fighting non-COVID-19 viruses, particularly those targeting the Epstein-Barr virus, a human herpesvirus linked to various cancers. Additionally, these patients showed significantly reduced cortisol levels, a stress-responsive steroid hormone.

These discoveries shed light on key biological mechanisms linked to long COVID, but the complexity of individual responses suggests that developing targeted treatments will be challenging, the authors note.

David Putrino, a co-senior author from Icahn Mount Sinai and director of the Cohen Center for Recovery From Complex Chronic Illness, emphasized the absence of a universal solution for long COVID, given its complex interaction with immune and hormonal systems.

Advancing Diagnosis and Treatment Approaches

However, these new insights offer crucial information that could aid in creating new diagnostic tools and treatments, according to Iwasaki.

“With further understanding of these biomarkers, we can begin to design appropriate trials to treat this condition,” she stated.

The research is titled “Distinguishing features of long COVID identified through immune profiling” and was published on September 25, 2023, in Nature. The DOI is 10.1038/s41586-023-06651-y.

Co-senior authors include Aaron Ring from Fred Hutchinson Cancer Center, formerly of Yale School of Medicine, and David van Dijk of the Icahn School of Medicine.

Jon Klein, Jillian Jaycox, Rahul Dhodapkar, Peiwin Lu, Jeff Gehlhausen, and Alexandra Tabachnikova, all affiliated with Yale, are co-lead authors of the study.

Frequently Asked Questions (FAQs) about Long COVID Research

More about Long COVID Research

• Yale School of Medicine
• Icahn School of Medicine at Mount Sinai
• Nature Journal
• DOI: 10.1038/s41586-023-06651-y