Idiopathic Eosinophilia Syndrome

Q:  Can you tell me anything about "idiopathic eosinophilia syndrome"? I know that the prescription medication Gleevec is now available. Is this the best treatment?

A:  Eosinophils are white blood cells. White blood cells circulate in the bloodstream and fight infections. There are several kinds of white blood cells, each with different enzymes to attack different kinds of infections. Eosinophils are best at killing infections from parasites (like intestinal worms) and viruses.

In the process of killing infecting germs, all white cells cause inflammation: swelling, redness, and the discomfort associated with the ongoing war between your body and the attacking bacteria, virus, fungus, or parasite.

It is same type of inflammation that makes your throat sore and red and your nose run when you have a virus such as a cold. Inflammation is the necessary evil to cure the body of infection, and it is thankfully temporary: usually the body wins, and the inflammation goes away with the dead germ.

However, sometimes the white blood cell response is out of balance. In idiopathic eosinophilia syndrome, the bone marrow makes too many eosinophils, and no one knows why (the latter being the definition of "idiopathic").

Idiopathic eosinophilia syndrome is quite uncommon and can be benign (you may have many eosinophils in the blood but no prolonged inflammation). Or, it can cause serious problems, for example, making the heart valves scar and not pump blood as well.

The treatment for idiopathic eosinophilia depends on the severity and should be individualized. Given an uncommon and highly variable condition such as this, it's best to rely on the opinion of a specialist who knows you.

Julie L. Mitchell, MD, MS, is an Assistant Professor of Medicine at the Medical College of Wisconsin. She practices at the Froedtert & The Medical College of Wisconsin General Internal Medicine Clinic - East. Her column appears in the Milwaukee Journal-Sentinel.