Genetic Link Between Immune System and Lymphoma May Provide Insight

A recent study has found that those who inherit genetic alterations which affect the functionality of the immune system experience a higher risk for Hodgkin lymphoma development.

The study

At the Institute of Cancer Research in London, scientists were able to identify six genetic changes that were previously unseen in increasing one's risk of developing Hodgkin lymphoma.

In young adults, Hodgkin lymphoma is among the most common cancers. Unfortunately, there is very little evidence as to what its origins are, making this study a breakthrough.

The scientists found that a significant portion of the changes to DNA appeared to alter the normal effectiveness of the immune system. Three of the DNA changes were previously associated with multiple sclerosis, lupus, rheumatoid arthritis, and other autoimmune diseases. However, the researchers wanted to make it clear that this link does not imply that people with autoimmune diseases are naturally at a higher risk of developing lymphoma. The link can give more information and genetic clues that will give further insight into lymphoma and autoimmune diseases, though.

There is one specific genetic change that has a particularly strong impact, increasing the risk of developing Hodgkin lymphoma by over a third, while others can increase the risk by at least fifteen percent.

Scientists at The Institute of Cancer Research (ICR) were able to look over genetic data ranging from 5,214 cases of Hodgkin lymphoma and 16,749 controls, all taken from four different European studies.

The study was funded by many organizations such as Bloodwise, Cancer Research UK, and the Lymphoma Research Trust. To read the entire study, check out Nature Communications.

A cancer of white blood cells

During the study, the researchers found that six new single-letter changes in DNA were certainly connected to the development of Hodgkin lymphoma. Most of them, five to be exact, were able to change the way B cells develop, which are a type of white blood cell.

Why are these white blood cells important? Hodgkin lymphoma is a cancer of the B cells. Normally, they produce antibodies that help the immune system to operate effectively, but are unable to when Hodgkin lymphoma takes over.

There are two subtypes of Hodgkin lymphoma which operate slightly differently. They are nodular sclerosis Hodgkin Lymphoma (NSHL) and mixed cellularity Hodgkin Lymphoma (MCHL). The genetic risk is not the same for the two, as shown by a single-letter change in the DNA near the LPP gene being able to impact the risk of NSHL by a raise of 37 percent, but barely having an effect on the risk of developing MCHL.

Richard Houlston is a professor of Molecular and Population Genetics at The Institute of Cancer Research in London, and he explained further, "Hodgkin lymphoma is a cancer of immune cells called B cells, and our study links the risk of the disease to changes in the genes that control how B cells develop. Interestingly, we found that some of the genetic changes we have linked to Hodgkin lymphoma have previously been associated with the risk of autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. It doesn't mean that if you develop an autoimmune disease you are at an increased risk of lymphoma, but it does offer fascinating genetic clues to these diseases."

Read on to learn more about this important discovery.