HSC 4555 Lecture Notes - Lecture 6: Prostaglandin, Complement System, Blood Transfusion
Document Summary
Autoimmune disorders occur when the immune system erroneously reacts with self tissues. These disorders are thought to be polygenic and multifactorial; however, the exact etiologic process is unknown. The antigenic mimicry theory proposes that since self and foreign antigens are composed of the same basic building blocks proteins, carbohydrates, nucleic acids, and lipids small alterations in self tissue may lead to immunogenic attack. The theory involving release of sequestered antigens suggests that self antigens that do not come in direct contact with lymphocytes during fetal development may cause autoimmune reactions if they are subsequently released from sequestration. A genetic component is probable, inasmuch as certain autoimmune disorders are more commonly associated with particular mhc types and female gender. Viruses may also be causative in the development of autoimmune disorders. Viruses may alter self cells, thus precipitating an immune attack. Formed antibodies may then cross-react with similar but uninfected cells.
