It depends how “high.” If the value was really way above normal, either the test needs repeating, or there really is autoantibody present. Then it is important to talk with the doctor: can this indicate that the pathological process has started, but there are no symptoms yet? There should be several follow-up tests that could help decide what’s going on.
Well, you don’t catch asthma from anyone. One interpretation of the data is that the kids in day care get a lot of exposure to bacteria and viruses, and maybe old fashioned dirt, that “exercises and educates” their immune systems so that they don’t overreact to harmless stuff like foods and pollens. Isolated kids would not have that exposure.
Some things are the same, and some are very special. For viruses, if you have antibody present before you are exposed (usually from immunization) you will clear the virus from your system without getting infected. If not, your cells get infected and then you need to develop killer T cells which recognize the infected cells and ask them to commit suicide. For bacteria, antibody is made and binds to the bacteria; “complement” is activated and many white cells are attracted, to eat and destroy the bacteria. For bacteria that like to live within cells, we have helper T cells that attract many macrophages to do the job.
Well, if you take my graduate course you can learn about 8 reasons! One we understand quite well: Something out there enters our body so we make an immune response to it. But it looks a lot like some structure in our own body, so the immune response cross-reacts with our body structure, causing damage. So, some people develop heart disease after a streptococcal infection. In most other cases we don’t know the exact causes, as the immune system is very complex, and a lot of small parts may get broken, causing disease.
I call it a “chronic frustrated immune response disease.” In celiac, if you have the right genetic predisposition, you can make a strong helper T cell response to gliadin, a protein in wheat, barley, and rye. Most of us can’t make this response. If you do, the body treats gliadin as if it were dangerous, and strong inflammation follows. The response is frustrated because you can never rid your gut of gliadin if you go on eating gluten; so inflammation becomes chronic and destructive. If you stop eating gluten permanently, your gut can go right back to normal.
We’ll talk about that on the last evening. For now: we do make anti-cancer immune responses, but cancer cells, (which have the same genomes that our normal cells do) come up with all sorts of tricks to evade immunity. So our approaches need to take that into account. You’ll hear about some of those.
High uric acid is associated with the disease gout, which is metabolic, not immune. There is not one single test, but there are many tests for autoimmunity. If you have symptoms of hyperthyroidism, for example, I’ll want to know if your blood contains antibodies against your thyroid, for example the TPO antibody referred to above.