Doctors Explain The Link Between Autoimmune And Heart Diseases

Autoimmune
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Researcher at Washington University School of Medicine in St. Louis recently conducted a study that perhaps explains why people with autoimmune diseases are at a high risk of developing cardiovascular disease as well, reports Medical Xpress. Their findings were published today in Cell Metabolism.

While studying mice with a psoriasis like condition, researchers found that the mice’s blood vessels were stiff. These mice apparently had cholesterol trapped in the walls of their inflexible blood vessels. Typically, cholesterol would circulate freely between the blood and tissues, which was not occurring in these mice. This finding means that the trapped cholesterol in these mice promotes plaque build up that can cause heart attacks and strokes.

Gwendalyn Randolph, Ph.D., the Emil R. Unanue Distinguished Professor of Immunology and a professor of medicine, stated some of these findings show links between autoimmune disorders and cardiovascular health.

“For decades it’s been known that the trapping of cholesterol drives disease, and now we have a mechanism for how certain immune responses typical of autoimmune diseases might make that worse. In the mouse, the signs of cardiovascular disease scarcely arose when we neutralized these immune components. In people, it’s hard to be sure, but we would predict it would be preventable, too.”

Those suffering with autoimmune diseases, such as psoriasis and lupus, are two to eight times more likely to suffer from a heart attack than those without these diseases, the report shows. Young and middle-aged adults with rheumatoid arthritis, another autoimmune disease, see cardiovascular disease as a top cause of death, in fact.

Researchers followed the fluorescent cholesterol carrier and saw that HDL cholesterol was delayed in getting out of the bloodstream in the mice that received the compound. This was true not only in the skin, but in internal arteries near the heart. In addition, the skin and blood vessels were more densely interlaced with collagen and more resistant to stretching, cites Medical Xpress. What’s more, when the researchers fed mice a high-cholesterol diet for three weeks while also painting their ears, the mice in the experimental psoriasis group developed significantly larger cholesterol deposits in their blood vessels.

Randolph and first author Li-Hao “Paul” Huang, Ph.D., an instructor of pathology, suspected that the walls of blood vessels also might be webbed with too much collagen. He explained these findings further.

“The skin-driven immune response can drive systemic changes. Once immune cells are programmed by reactions to the inflamed skin, they move around the body to other skin sites and arteries to be ready for the next insult, enhancing the collagen density wherever they go. It’ll take a few years before we know for sure, but we predict that the anti-IL-17 antibodies that already are being used to treat autoimmune diseases will be effective at reducing risk of cardiovascular disease. This would be important because some other drugs on the market seem to improve the skin disease but not reduce cardiovascular risk.”