dc.description.abstract | Oral Tolerance
Uveitis is one of the leading causes of blindness. It was estimated that IO% of the blindness was caused by uveitis in USA. The treatment is mainly topical and systemic corticosteroid, and some of these patients may require the use of a variety of iminunomodulatory, corticosteroid-sparing agents, such as cyclosporine or cytotoxic agents. To date, clinically oriented approaches have centered on the administration of pharmacologic substances that have a nonspecific effect on the immune response. The development of more effective treatment of organ-specific inflammatory disorders of putative autoimmune origin is an ongoing goal in many specialties of clinical medicine, Recently, alternative therapeutic strategies have been suggested based on our better understanding of immunologic mechanisms that lead to organ-specific inflammatory responses. The induction of immunologic tolerance, defined as a state of specific immunologic unresponsiveness to an antigen after exposure to that antigen,
is one such approach that has gained attention recently. One effective method of inducing immunologic tolerance is through the oral administration of antigen. The tolerance induced is called oral tolerance. One feature of oral tolerance is that ¡§bystander¡¨ suppressive effect can be elicited to the organ or tissue that harboring the antigen. Oral tolerance has been tested in various animal models of autoimmune disorders, such as experimental autoimmune encephalomyelitis, collagen and adjuvant arthritis, experimental autoimmune diabetes, and experimental autoimmune uveitis. The effect of oral tolerance has also been tested in several clinical conditions in small scale with encouraging results, such as multiple sclerosis, theurnatoid arthritis, juvenile diabetes, Behcet¡¦s disease and other intractable uveites.
The most common disease entity of uveites in Taiwan is acute anterior uveitis (AAU). It is the recurrent nature of AAU that can result in blindness and socioeconomic loss though various complications, including glaucoma, cataract, and cystoid macular edema. Experimental autoimmune anterior uveitis (EAAU) has been established to simulate human AAU, It involves the use of melanin associated antigen extracted from bovine uveal tissue. In this report, we investigated the effect of oral tolerance in EAAU both as primary and secondary prevention, i.e. in unprimed and in primed animals. By feeding Lewis rats with insoluble melanin associated antigen the experimental autoimmune anterior uveitis was not suppressed. This unsuccessful induction of tolerance might be related to the use of insoluble melanin associated antigen, which is pro-inflammatoy itself. To repeat the whole experiment by using soluble MAA may well be the goal of next project. | en |