Autoimmune Diseases

These are diseases in which the immune system produces antibodies against an endogenous antigen forms (autoantigen). The following hypersensitivity reactions, there may be: Type II: loaded with antibodies cells as each loaded similarly foreign body, the complement system activated with resultant tissue damage. Type III: The collection of antibody-antigen complexes is involved in the injury process. Type IV: injuries are T-cell mediated. Notes to certain autoimmune diseases s. elsewhere in the Merck Manual. Women are affected more often than men. Etiology mechanisms the attacks of the body against itself, various mechanisms underlying: autoantigens, all possible alterations are immunogenic. Antibodies against a foreign antigen can cross-react with unmodified antigen (eg., Antibodies against streptococcal M protein may cross-react with human heart muscle). Normally secreted by the immune system antigens are exposed and trigger an autoimmune reaction of (z. B. systemic release of melanin-containing cells uveal after an eye injury triggers a sympathetic ophthalmia off). Autoantigens can be immunogenic by chemical, physical or biological alterations. Chemical: Certain chemical substances couple to proteins of the body and make them immunogenic (as in drug-induced hemolytic anemia). Physical: For example, ultraviolet light induced apoptosis of keratinocytes and then an altered immunogenicity of antigens, which results in light sensitivity, as occurs in a cutaneous lupus erythematosus. Biological: For example, it comes in animal models by a persistent infection with a RNA virus, which connects to host tissue to biological autoantigen changes, which similarly leads to autoimmune diseases SLE. Genetic factors relatives of patients with autoimmune diseases often have autoantibodies. The specificity of autoantibodies in patients and their relatives is often, but not always similar. The incidence of autoimmune diseases in monozygotic twins is higher than in dizygotic twins. Most autoimmune diseases have a polygenic etiology and almost always carry allelic variants within the HLA locus to bei.Abwehrmechanismen Normally potentially pathological autoimmune reactions are prevented by the immune tolerance mechanism of clonal deletion and clonal anergy. All autoreactive lymphocytes, which are not controlled by these mechanisms are usually retained by Foxp3 + regulatory T cells. A regulatory T cell defect may interfere with each of these protective mechanisms, resulting in autoimmunity. Anti-idiotype antibodies (antibodies against the antigen binding sites of other antibodies) may interfere with the regulation of antibody activity.

Health Life Media Team

Leave a Reply