According to a new study, with aging, human lymph nodes tend to gradually accumulate fat and lose their efficiency, making the immune system less efficient.
- “This is a first step in understanding why lipomatosis occurs, and towards the longer-term goal of finding ways to prevent its progression and lymph node destruction,” the co-author said. study, Tove Bekkhus.
- “What we observed is also very relevant for cancer research, because in several types of cancer, the lymph nodes are the first place where cancer cells spread,” says another co-author, Maria H. Ulvmar. .
- The researchers hypothesize that lipomatosis of the lymph nodes, even at an early stage, could be an important factor in the poorer response to vaccinations observed in the elderly.
Our immune system also tends to gain fat with age. Researchers from Uppsala University in Sweden explain in detail, in their new study published in The Journal of Pathologywhy human lymph nodes tend to accumulate fat over time and become less effective as we age, weakening the immune system over time.
Immune system: what are the lymph nodes for?
Lymph nodes are small, bean-shaped lymph tissue structures considered the “headquarters” of the human immune system. Whenever an infection develops, for example, immune cells such as lymphocytes gather in the lymph nodes, activate and proliferate to mount an effective immune defense.
However, as a person ages, studies show that normal lymph node tissue (stroma) tends to gradually disappear, being replaced by adipose tissue (fat). This is called “lipomatosis of the lymph nodes” and although it is very common and increases with age, little research has been done to understand lipomatosis.
How does lipomatosis transform certain cells into fat?
The study authors analyzed more than 200 lymph nodes, demonstrating that lipomatosis begins in the central part of the lymph node – the medulla. They also gathered evidence linking lipomatosis to the transformation of fibroblasts (lymph node supporting cells) into fat cells (adipocytes). In particular, certain specific types of fibroblasts located in the marrow were particularly susceptible to becoming adipocytes.
Even during the early stages of lipomatosis, researchers noted negative changes that interfered with the lymph nodes’ ability to provide effective immunity. Specifically, specialized blood and lymph vessels that normally provide channels for immune cells to enter and exit the lymph node were destroyed in the parts of the node where fat had formed. In some cases, fat could consume the entire lymph node, rendering it completely unable to function.
