Spleen May Help Heart Recover From Disease

July 31 -- THURSDAY, July 30 (HealthDay News) -- Though its reputation doesn't rank down there with the appendix, the spleen isn't exactly known as a vital organ. In fact, plenty of people do fine without it.

But new research suggests the spleen plays a bigger role in the immune system than previously thought.

In mice, scientists found, the spleen serves as a home for a type of white blood cell that scavenges dead tissue and helps produce inflammation, which contributes to healing. In particular, the researchers discovered that the spleen helps the heart recover from disease.

"While the spleen may not be essential for your survival, it plays a crucial role once you are sick," said study author Filip K. Swirski, an immunology instructor at Harvard Medical School and Massachusetts General Hospital, Boston.

The findings could lead to a better understanding of the immune system, including its response to cancer, Swirski said. And it definitely improves the profile of a little-understood organ.

It's much more obscure than, say, the liver or kidneys, but the spleen still takes up a lot of space. In humans, it's about the size of a large eggplant and shaped like a kidney, Swirski said.

Scientists have known that the spleen recycles red blood cells and scans the blood for germs. "It serves as a filtering system," Swirski said. "It captures viruses or bacteria, and can elicit an inflammatory response."

Inflammation -- think of the redness around a wound -- indicates that the immune system is rushing in to defend the body.

But people often do just fine without their spleens. Traumatic injuries, such as those sustained in traffic accidents, often result in surgery to remove the spleen. And surgeons remove spleens from people with some medical conditions, including non-Hodgkin lymphoma.

In their study, the researchers examined mice to see if having a spleen helped the mice recover from induced heart disease. A 1977 study of veterans who'd had their spleens removed suggested they had twice the risk of dying of heart disease, Swirski said.