brenan said:
This has puzzled me for a while now:
A friend of mine has been told he has an auto-immune disease that has attacked
his right eye - something called ocre or maybe just ocr ?
If my understanding was correct that an auto imune disease can attack certain types of tissues why wouldn't he have this in both eyes? Why would it only attack the tissues
in one eye? He has had this for a few years now and apparently it can't be cured.
Autoimmune disease can be generalized (i.e. lupus) or organ specific (thyroiditis). It can be cell based (T cell lymphocytes) or humoral (antibodies in the blood and extracelluar fluids). Immune memory is acquired in pre-natal and early post natal life. This memory is based on the elaboration of human leukocyte antigen (HLA). The purging of anti-self lymphocytes in the thymus gland occurs during this period, but it's never complete. It's thought we all have some low level of anti self or autoimmune activity, but it's under genetic control. Some people have genetic predispositions to these diseases which interfere with their tolerance (look up immune tolerance in the wiki). Environmental factors also play a role in terms of stimulating immune responses to foreign antigens which "cross over" causing autoimmune activity. As we grow older, this becomes more common. Breakdown of tissue integrity may also allow "unrecognized" self antigens to be exposed, such as in the basement membranes of the epithelium of the inner lining of the eye. Once the autoimmune process is initiated at one such location, it may remain localized for some time.
http://www.sagepub.com/moody6study/study/articles/controversy2/Ramos-Casals.pdf
". .the elderly may originate altered cells which are not
removed, and immune responses may then cross-react
with the normal cell constituents, leading to the
autoimmune response. It has been hypothesized that
autoantibodies may play a role in the general
deterioration of the elderly through their participation
in subclinical chronic tissue damage.10,22–24 In Table 2,
we summarize the results of the main studies that have
analysed the prevalence of autoantibodies in the
elderly.20,25–48"