Nakamura M C, Nakamura R M
Division of Rheumatology, School of Medicine, University of California, San Francisco.
J Clin Lab Anal. 1992;6(5):275-89. doi: 10.1002/jcla.1860060506.
No single theory or mechanism can explain the phenomenon of autoimmunity and autoimmune diseases. Not all autoimmune responses are harmful or "forbidden." Considerable research has indicated that autoimmune response may be normal and important in the regulation of the immune system. Autoimmunity may play a role in a wide range of clinical states including physiological clearance of dead cells, and cell components, aging, response to viral and microbial infections, and generalized immunological diseases. There are many factors involved in autoimmunity including genetic, hormonal, immunological, and environmental factors. The susceptibility to autoimmune diseases is multifactorial and polygenic. There is a definite association of the autoimmune diseases with MHC alleles. Also, non-MHC genes are involved in disease susceptibility. Numerous mechanisms of autoimmunity have been discussed. There may be an alteration with dysregulation of the immune system with defective generation of normal suppressor mechanisms or an altered neuroendocrine regulation. The altered immune system will make the host more susceptible to autoimmune disease. Autoimmune reactions can occur in a host with a normal immune system. Some examples are as follows: 1. Infection or damage to host target organ with release or alteration of autoantigen 2. Molecular mimicry or cross-reactivity between virus or bacteria and host autoantigens 3. Abnormal expression of MHC molecules by antigen-presenting cells in target cells resulting in activation of autoreactive T-cells. 4. Drug administration
没有单一的理论或机制能够解释自身免疫现象和自身免疫性疾病。并非所有的自身免疫反应都是有害的或“被禁止的”。大量研究表明，自身免疫反应在免疫系统的调节中可能是正常且重要的。自身免疫可能在多种临床状态中发挥作用，包括死细胞和细胞成分的生理清除、衰老、对病毒和微生物感染的反应以及全身性免疫疾病。自身免疫涉及许多因素，包括遗传、激素、免疫和环境因素。自身免疫性疾病的易感性是多因素和多基因的。自身免疫性疾病与主要组织相容性复合体（MHC）等位基因有明确的关联。此外，非MHC基因也参与疾病易感性。已经讨论了许多自身免疫的机制。可能存在免疫系统失调，正常抑制机制的产生存在缺陷，或者神经内分泌调节发生改变。改变的免疫系统会使宿主更容易患自身免疫性疾病。自身免疫反应可发生在免疫系统正常的宿主中。一些例子如下：1. 宿主靶器官受到感染或损伤，自身抗原释放或改变；2. 病毒或细菌与宿主自身抗原之间的分子模拟或交叉反应；3. 靶细胞中抗原呈递细胞异常表达MHC分子，导致自身反应性T细胞活化；4. 药物给药
