Scientists Seek to Understand Lymphatic System’s Impact on Other Organ Systems

A growing body of evidence reveals that the lymphatic system influences the health of multiple organs, including the heart, lung, and brain. Experts across the National Institutes of Health (NIH) are seeking to spark new ways to explore the undiscovered links between the lymphatic network and other organ systems. At the end of September, NIH hosted a meeting designed to encourage researchers in other disciplines to consider studying how lymphatics influence their respective fields. 

The meeting, called “The Third Circulation: Lymphatics as Regulators in Health and Disease,” included a keynote address from Academy-Award winning actress Kathy Bates, who is the national spokesperson for the Lymphatic Education & Research Network. Bates spoke about her experience living with lymphedema. The condition is related to lymphatic system problems that can cause pain, infection, and severe swelling due to fluid build-up in tissues. Damage to the lymphatics system cannot be reversed, and most lymphedema treatments are aimed at controlling swelling.

“I was full of rage for a very long time,” said Bates, as she described her mood following her lymphedema diagnosis.  She explained she developed the condition following her successful cancer treatment, which required the removal of several lymph nodes. “Because surviving [cancer] is just the tip of the iceberg. Lymphatic disease is a life sentence.”

Lymphedema is among the range of lymphatic conditions — which includes lymphangioleiomyomatosis (LAM) and Gorham-Stout Disease (GSD) — NIH hopes will benefit from cross-disciplinary research, according to Dr. Eser Tolunay, a deputy branch chief at the National Heart, Lung, and Blood Institute (NHLBI.) Dr. Tolunay leads the Trans-NIH Coordinating Committee for Lymphatic Research, which seeks ways to increase interest in understanding lymphatics’ role throughout the body.

The lymphatic system is responsible for circulating lymph, a watery fluid that includes white blood cells, and keeping body fluids in balance. The network of lymphatic vessels can be thought similar to the blood vessel network in terms of reach through the body. Lymph nodes are glands within the lymphatic system that play a role in fighting infection. 

“There is still so much we have to learn about the pathobiology of disease,” said NHLBI Director Dr. Gary H. Gibbons, who spoke during the lymphatics symposium. He noted this was a topic being explored as part of the Institute’s crowd-sourced Strategic Visioning effort, which is designed to help set future NHLBI research priorities.

 “Over the last decade-and-a-half there have been great advances in understanding the development and function of the lymphatic system, however, there is very little research on investigating how the lymphatic system affects the function of other organs” explained Dr. Tolunay, Deputy Chief of the Vascular Biology and Hypertension Branch at NHLBI’s Division of Cardiovascular Sciences. One of the most recent findings was the discovery of lymphatic vessels in the brain, an organ previously thought to lack a lymphatic system.

The lymphatics conference featured speakers from academic labs across the country that are already looking at the lymphatic links with the heart, brain, digestive tract, eyes, and other organs. Dr. Tolunay and others across NIH hope that the symposium has planted the seeds for even more researchers to take on the challenges of exploring the lymphatics system’s impact on other organs in the body.

The symposium was recorded and can be viewed on NIH Videocast under past events by clicking on the following links: Day 1 and Day 2.

Symposium sponsors included: NHLBI; National Institute of Allergy and Infectious Disease; National Institute of Diabetes and Digestive and Kidney Disease; National Eye Institute; National Cancer Institute; and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.