FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

[SPLEEN AN IMPORTANT ORGAN, BUT ONE YOU CAN LIVE WITHOUT]

Question: A person I know was injured in a car wreck and had his spleen removed. I'm sure we talked about the spleen in school, but that was some time ago. My American Heritage dictionary says the spleen is: A large, highly vascular lymphoid organ, lying in the human body to the left of the stomach below the diaphragm, serving to store blood, disintegrate old blood cells, filter foreign substances from the blood, and produce lymphocytes. But what does this mean? What does the spleen do, and what problems occur when you don't have one?

Answer: As your dictionary says, the spleen does several jobs that are important, but none of them are essential for life. The spleen is an important part of both the blood system and the immune system, and as a consequence, it has a very large blood supply. An injury that damages the spleen has the potential to cause life-threatening internal bleeding. It is probably this risk of hemorrhage that made it necessary for your friend to have his spleen removed. Unfortunately, this is not an unusual consequence of abdominal injury from a car wreck.

An important function of the spleen is to serve as a reservoir for certain blood components, particularly white blood cells that help fight infection and platelets that are necessary for clotting. B and T lymphocytes, specific types of white blood cells, are produced in great numbers within the spleen. These are released into circulation to combat bacteria wherever they are encountered, not just within the spleen.

The spleen also filters small particles from the blood - especially bits and pieces of worn out red blood cells. After scavenging these particles from the blood, the spleen recycles the components. Another important group of particles in the blood are bacterial invaders. The spleen captures these and then the immune system within the spleen begins its attack upon them.

In childhood the spleen also plays a role in forming new blood cells, but this is not so in adults. The important jobs done by the spleen can be taken over, in part, by other organs. Therefore, the spleen is not essential. Life is not compromised by its absence. Individuals without a spleen are at some increased risk from certain types of bacterial infection, however. Hemophilus influenzae and pneumococci are organisms that cause pneumonia and other forms of human illness. They are a particular threat to those who have had a splenectomy. Fortunately, there are effective immunizations to protect against the most common forms of these infections.

The blood of an individual without a spleen has some rather distinctive features when studied under the microscope. Mostly it has an abundance of worn out red blood cells that would have otherwise been filtered out by a healthy spleen. These changes are not serious, but it sure makes it easier for your doctor to tell if you've had your spleen removed!

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.