If the immune system mediated an aggressive attack on the whole peripheral nervous system and killed the entire nerves of the body what are symptoms?
Death. Although i just answered your question, important to understand that this would involve a rare progressive irreversible anaphylactic allergic reaction, and this really affects numerous organ systems. However, consider that there are chronic immune disorders that attack peripheral nerves (cidp), and nerves in central brain and spinal cord (ms). This is almost never an all or none situation.
What happens if the peripheral nerves are targeted in a severe immune response and kill the peripheral nervous system? Does the body shut down?
Depends on the nerve. What happens depends on the type of nerve affected by the immune response. If sensory nerves are affected there can be loss of sensation; if motor nerves are affected there can be weakness or paralysis. One example of this is guillain barre syndrome. Sometimes the autonomic nervous system is also affected leading to changes in pulse and blood pressure. Read more...
Can the immune system attack directly peripheral nervous system go beyond mylein sheath and destroy the whole of the nerve?
Neuropathy. Yes. Immune mediated neuropathies can occur where the primary target is the myelin and the process is so severe that axonal injury (nerve core) can occur. Immune response primarily directed to the axon (nerve core) cam also occur and are typically more severe and less likely to recover from. Secondary myelin injury always occurs in this type of axonal injury. Read more...