Autoimmune Part 1: Understanding the immune system

Posted by Dr. Nina Mantione on Aug 27 2012

The immune system is a marvelous thing. It is a complex interaction between cells and chemicals that allows the body to fight infections. It is constantly changing and learning, based on exposures to infectious agents in our environments. Thanks to our immune systems, we have no problem surviving the common cold and any number of infectious agents that come our way.

Dogs and cats are similar to us in that they have highly effective immune systems in place to help keep their bodies safe from foreign invaders. Without a functioning immune system, we and our pets would succumb to even the most benign infections.

An immune response involves white blood cells, antibodies and a complex array of chemicals all working together to locate, attack and kill invading bacteria and viruses. Think of it as a highly trained tactical army that uses both soldiers (white blood cells) and chemical warfare to eradicate its enemy. Exposure to new and different bacteria or viruses switches the immune system on as it prepares the necessary defenses to fight off new threats.

There is no doubt that the immune system is one of the most complex aspects of our pets’ physiology. Still not entirely understood, scientists and clinicians are learning more each year about how to use our own defenses to battle infections, cancers and even inherited conditions.

As we learn more about the inner workings of the immune system, we also learn new ways to utilize it in our fight against disease. One way (in fact the oldest way) that we do this is thought the use of vaccines. Veterinarians assist the building and training of our pets’ internal armies by using vaccines to prep their immune systems for future potential infections. Vaccines help to stimulate antibody production, which is a large part of the defense against infectious diseases. Scientists are beginning to utilize vaccine technology to manipulate the immune system into fighting cancer, by turning the body’s defense system against abnormal cells.
However, our immune systems aren’t always working for us. Sometimes, the very defense mechanism that we rely on to keep us safe from infection mistakenly attacks the body’s own cells. These incidents of “defense gone awry” are called autoimmune disease, and they can lead to life-threatening illness.
In some instances, this “friendly fire “comes as a result of a primary problem, such as a tumor or infection that has turned the immune system on to the point that it cannot turn itself off; but other times, it is a random occurrence with no discernible underlying cause.
With an autoimmune disease, the immune system can attack any cells in the body it determines to be foreign. There are many different autoimmune diseases, each of which target a different cell type in the body, often with disastrous consequences. In the next few blogs, I will discuss some of the more common autoimmune diseases that can occur in our pets, including a type of anemia, lupus and rheumatoid arthritis.