Cholesterol-lowering statins can help fight infections

Statins are drugs that are widely used to help lower cholesterol, reducing the risk of heart disease. Now new research shows that they can also help the body fight bacterial infections such as pneumonia and sepsis.

Previous research had found that statins can help lower inflammation, suggesting that statins may be helping the body to reduce the severity of infections. But scientists at the University of California decided to consider an alternative explanation - that the statins might actually be helping the body to attack the underlying cause of the infection, rather than just reducing the symptoms.

So they looked in particular at the effect of statins on mice infected with Staphyloccocus aureus, a bacterium responsible for everything from minor skin infections to life-threatening meningitis and sepsis.

The researchers found that the white blood cells in the mice - the cells responsible for fighting infections - did not actually attack and kill more bacteria directly. Rather the presence of statins stimulated the cells to release "extracellular traps" – specialized webs of DNA-based filaments that can trap and kill the bacteria before they spread around the body.

The mice treated with the statins were more resistant to staph infections, and cells isolated from these mice were more effective at killing staph bacteria. When human white blood cells in a test tube were exposed to the statins, they markedly increased their ability to kill staph and other important disease causing bacteria.

Commenting on the results, study author Victor Nizet said : "We found these drugs fundamentally alter how white blood cells behave upon encountering bacteria. The net effect of statin treatment was to improve bacterial killing and extracellular trap formation."

These results, published in Cell Host & Microbe, shed light on the already noted fact that patients receiving statins have reduced risk of infection. Nizet recommends that future research explore whether the potential of cholesterol-lowering agents combined with antibiotics can be harnessed to optimize the treatment of certain difficult infectious disease conditions.

This article was published on Thu 18 November 2010