Should I Get an Immune System Test?
Q. I'm 73, in generally good health, but bothered by frequent colds and respiratory infections. I suspect I have a weakened immune system. Are there tests that will tell me if that is so?
A. Doctors order tests of the immune system quite often, but usually for conditions directly related to an immunological problem. And the tests tend to zero in on an aspect of the immune system, not its overall performance. So, for example, a test for a particular antibody, the antinuclear antibody, is often used in the diagnosis of lupus, one of the autoimmune disorders in which the immune system turns against the body. Another example: Doctors monitor the antibody (immunoglobulin) levels of patients with lymphoma or leukemia because levels can drop to dangerously low levels.
Some people do seem to catch colds (viral infections of the upper respiratory tract) more easily than others. Age may be a contributing factor; as we get older, antibody levels drop, and our white blood cells respond less nimbly to fresh infections.