Researchers at Mass General Brigham have uncovered evidence that the thymus, a small immune system organ long thought to lose its importance after childhood, may play a significant role in adult health. Two latest studies found that adults with healthier thymuses were more prone to live longer and fewer prone to develop serious diseases. The research also suggests that thymic health may influence how well cancer patients reply to immunotherapy.
The findings were published in two papers in the identical issue of Nature and challenge many years of assumptions concerning the thymus. The outcomes indicate that the organ stays necessary throughout maturity and will eventually help guide disease prevention strategies and cancer treatment decisions.
“The thymus has been neglected for many years and will be a missing piece in explaining why people age in a different way, and why cancer treatments fail in some patients,” said Hugo Aerts, PhD, corresponding creator on the papers and director of the Artificial Intelligence in Medicine (AIM) Program at Mass General Brigham. “Our findings suggest thymic health deserves way more attention and will open latest avenues for understanding find out how to protect the immune system as we age.”
What the Thymus Does
Positioned within the chest, the thymus helps train T cells, a style of immune cell that helps defend the body against infections and disease. Since the organ step by step shrinks after puberty and produces fewer latest T cells over time, many scientists assumed it played only a limited role in adult health.
Consequently, the thymus has received relatively little attention in large population studies. Earlier research connected T cell diversity to aging and declining immune function, but those studies were typically small and focused on blood samples.
The brand new research took a much wider approach. Investigators analyzed data from greater than 25,000 adults participating in a national lung cancer screening trial, together with greater than 2,500 people enrolled within the Framingham Heart Study, a long-running study that tracks the health of generally healthy adults.
AI Reveals Links to Longevity and Disease Risk
Using artificial intelligence (AI) to guage routine CT scans, the researchers measured the scale, structure, and composition of the thymus. From those measurements, they created a “thymic health” rating.
Individuals with higher thymic health scores experienced significantly higher outcomes. Compared with individuals who had poorer thymic health, they’d a couple of 50% lower risk of death from any cause, a 63% lower risk of death from heart problems, and a 36% lower risk of developing lung cancer. These relationships remained strong even after accounting for age and other health aspects.
The researchers consider that declines in thymic health may reduce T cell diversity, making it harder for the immune system to acknowledge and reply to latest threats equivalent to cancer and other diseases.
Their evaluation also identified several aspects related to poorer thymic health, including chronic inflammation, smoking, and better body weight. These findings suggest that lifestyle aspects and ongoing inflammation may affect the immune system’s ability to stay resilient over time.
Thymus Health and Cancer Immunotherapy
In a separate study, the team examined CT scans and clinical outcomes from greater than 1,200 cancer patients treated with immunotherapy.
The outcomes showed that patients with healthier thymuses tended to reply higher to treatment. They faced a couple of 37% lower risk of cancer progression and a 44% lower risk of death, even after researchers adjusted for differences in patients, tumors, and treatment approaches.
Based on the researchers, these findings highlight a potentially necessary but previously underrecognized role for the thymus in determining how effectively modern cancer immunotherapies work.
More Research Needed
The scientists emphasize that additional studies can be needed to substantiate the outcomes. In addition they note that the imaging technique used to measure thymic health shouldn’t be yet ready for routine use in clinical practice.
Although lifestyle aspects were related to thymic health, the studies didn’t investigate whether changing those aspects can directly improve thymus function.
The research team is continuous to explore other influences on thymic health. One ongoing study is examining whether unintended radiation exposure to the thymus during lung cancer treatment could affect patient outcomes.
“Improving our understanding and monitoring of thymic health could eventually help physicians higher assess disease risk and guide treatment decisions,” said Aerts.
Along with Aerts, study co-authors of the general adult health paper include Simon Bernatz, Vasco Prudente, Suraj Pai, Asbjørn Kjær, Yumeng Cao, Jiachen Chen, Asya Lyass, PhD, Borek Foldyna, Leonard Nürnberg, Christopher Abbosh, Charles Swanton, Mariam Jamal-Hanjani, MD, PhD, Michael T. Lu, Joanne M. Murabito, Kathryn L. Lunetta, and Nicolai J Birkbak.
Aerts’ co-authors of the immunotherapy outcomes paper include Simon Bernatz, Vasco Prudente, Suraj Pai, Asbjørn Kjær, Alessandro Di Federico, Andrew Rowan, Selvaraju Veeriah, Lars Dyrskjøt, Leonard Nürnberg, Joao V. Alessi, Patrick A. Ott, Elad Sharon, Allan Hackshaw, Nicholas McGranahan, Christopher Abbosh, Raymond H. Mak, Danielle Bitterman, Mark Awad, Biagio Ricciuti, Charles Swanton, Mariam Jamal-Hanjani, and Nicolai J Birkbak, PhD.
This research received funding support from the National Institutes of Health, European Research Council, Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Lundbeck Foundation, Novo Nordisk Foundation, and Savvaerksejer Jeppe Juhl og Hustru Ovita Juhl Research Stipend.