AIDP is characterized by which pathophysiology?

• A. Immune mediated attack on Schwann cells causing demyelination
• B. Autoimmune attack on muscle fibers
• C. Degeneration of anterior horn cells
• D. Autoimmune attack on CNS myelin

Answer: (B)

The key idea is that AIDP represents an autoimmune attack on the peripheral nervous system’s myelin, produced by Schwann cells. This immune attack damages the myelin sheath surrounding peripheral nerves, slowing or blocking nerve conduction and leading to the rapid, ascending weakness and sensory changes seen in Guillain-Barré syndrome. Because the damage is to peripheral nerve myelin, not to muscle fibers, motor neurons, or CNS myelin, it fits AIDP best. In contrast, autoimmune attack on muscle fibers would be an inflammatory myopathy; degeneration of anterior horn cells points to a motor neuron illness like poliomyelitis; and autoimmune attack on CNS myelin describes a central nervous system demyelinating process such as multiple sclerosis.