Health Consequences of Thymus Removal in Adults

Article published in New England Journal of Medicine analysis examines the health consequences of thymus removal (thymectomy) and provides evidence of an association between thymectomy and adverse outcomes, including increased mortality and higher risk of autoimmune disease. The study suggests that preserving the thymus should be a clinical priority whenever possible.

Thymectomy is a surgical procedure that involves the removal of the thymus gland. The thymus is a small organ located in the chest behind the breastbone and plays a crucial role in the development of the immune system, particularly in the maturation of T-cells. Thymectomy is performed for various reasons, including the treatment of certain diseases such as myasthenia gravis, thymoma (a tumor of the thymus), and other conditions. It is also performed in some cardiothoracic surgeries for better access to the heart and lungs. Thymectomy can be performed through different techniques, including open surgery (median sternotomy), minimally invasive approaches (video-assisted or robot-assisted), or transcervical dissection. The procedure involves carefully removing the thymus gland while minimizing damage to surrounding structures. Thymectomy in adulthood has been the focus of recent research to understand its impact on overall health and immune function.

Thymectomy in adulthood is associated with an increased risk of death from any cause and an increased risk of cancer. This association remains significant even after excluding patients with preoperative confounding conditions such as cancer, autoimmune disease, infection, myasthenia gravis, or thymoma. Thymectomy is also associated with an increased risk of postoperative autoimmune disease, particularly in patients without a history of confounding conditions. Patients who have undergone thymectomy are more likely to die from any cause and from cancer compared to controls and the general population, across different age groups. Thymectomy is associated with more aggressive and recurrent cancer in patients who develop postoperative cancer. Thymectomy leads to a proinflammatory modification of plasma cytokine levels, including elevated levels of type 2 and type 17 helper T cell-promoting factors, which have been experimentally associated with cancer and autoimmune disease. Thymectomy results in reduced production of newly formed T cells, as reflected by persistently depressed signal joint T-cell receptor excision circles

 (sjTREC) counts. Patients who have undergone thymectomy and have postoperative cancer exhibit oligoclonal, less diverse T cell receptor repertoires, which could contribute to the development of cancer and autoimmune disease.

Thymectomy in adulthood should be carefully considered due to the increased risk of death and cancer. Healthcare professionals need to weigh the potential benefits against these risks before recommending thymectomy. The association between thymectomy and postoperative autoimmune disease suggests a potential role of the thymus in maintaining immune homeostasis and preventing autoimmunity. Further research is needed to understand the underlying mechanisms and develop strategies to mitigate the risk of autoimmune diseases in patients who have undergone thymectomy. The increased risk of aggressive and recurrent cancer in patients who have undergone thymectomy highlights the importance of close monitoring and early detection in this population. Healthcare providers should be vigilant in managing cancer risk factors and implementing appropriate surveillance strategies. The proinflammatory modification of plasma cytokine levels after thymectomy suggests a dysregulation of the immune system. This finding may have implications for the development of targeted therapies to modulate the cytokine profiles and mitigate the associated risks. The reduced production of newly formed T cells and the altered T cell receptor repertoire in patients who have undergone thymectomy provide insights into the role of the thymus in T cell development and diversity. Understanding these changes may help in developing interventions to restore or enhance T cell function in patients who have undergone thymectomy.

In summary, the findings of this article analysis shed light on the potential consequences of thymectomy in adulthood, including increased mortality, cancer risk, autoimmune disease, immune dysregulation, and altered T cell dynamics. These findings have significant implications for clinical decision-making, patient management, and future research in the field of thymus-related immunology and disease.

Whole article can be found here: DOI: 10.1056/NEJMoa2302892