ABSTRACT
This chapter discusses from principles why endocrine autoimmune diseases arise. Equally puzzling is the fact that some endocrine organs virtually never get autoimmune diseases. Whatever the precise route to autoimmune disease, the presence of auto-reactive T cells provides a potential fragility to self-attack. Autoimmune surveillance needs to detect the hyper-secreting cells in order to eliminate them. Thus, the antigens it detects must be in the production pathway of the hormone. In type-1 diabetes, beta cells are attacked and killed by the body’s own immune system. The organs that get organ-specific autoimmune disease share the same circuit motif as beta cells and thyroid cells. In the PT gland, high levels of calcium caused by mutant expansion are bad but not lethal. This gland has a biphasic mechanism to protect against strong hyper-secreting mutants. In beta cells, a hyper-secreting mutant expansion is lethal, because it causes low glucose.
