A new study published in a medical journal has identified a previously unknown risk factor for arteriosclerosis — an out-of-balance immune system.
Following a blood infection, the first class of antibodies produced by the immune system are IgM (immunoglobulin M) antibodies. They form the vanguard of the immune response, before other cells are activated to fight the infection. Some people are deficient or completely lack these antibodies, so that they develop congenital immune deficiency. Austrian researchers have now discovered how this deficiency can also lead to an increased risk of arteriosclerosis and potentially to serious cardiovascular diseases.
In the human immune system, IgM antibodies not only play a primary role in the immune response but also maintain an important balance: they control the formation of B cells, which are responsible for managing antibody production and distribution. They therefore also regulate the blood concentration of IgE (immunoglobulin E) antibodies, ensuring that this is kept in check and always restored to the correct level, thus helping ensure the immune system is in healthy balance.
However, if there is a lack of IgM antibodies, this balance cannot be maintained. The uncontrolled IgE antibodies, which also play a significant role in the development of allergic reactions, lead to the increased formation of plaques, activation of mast cells and inflammatory processes as well as constrict and damage blood vessels, as shown by the study authors in an animal model.
Study co-researcher Christoph Binder asserts, “For the first time, we were able to show that IgE antibodies can themselves provoke inflammatory reactions in vessels and that inhibition of these IgE antibodies prevents damage to the vessels,” explains Binder. He adds that the knowledge revealed in this new research could open up new healthcare options by restoring the balance of the immune system. “We were able to identify a completely new function of IgM antibodies, which also probably plays a major role in the development of allergies,” adds lead author Dimitrios Tsiantoulas.
“Increased Plasma IgE Accelerate Atherosclerosis in Secreted IgM Deficiency.” Tsiantoulas,et al. Circ Res. 2017;