A 22-year-old presents with ascending flaccid paralysis 2 weeks after a diarrhoeal illness. CSF shows albumin-cytological dissociation (protein 180 mg/dL, cells 2/mm³). Nerve conduction studies show prolonged distal latencies, slow conduction velocities, and conduction blocks. Which antibody is MOST commonly associated with acute inflammatory demyelinating polyneuropathy (AIDP)?

• A Anti-GQ1b antibodies
• B Anti-MAG antibodies
• C Anti-neurofascin antibodies
• D Anti-ganglioside antibodies (anti-GM1) in some subtypes but AIDP itself often antibody-negative ✓

Explanation

AIDP (the most common GBS variant in Western countries) is predominantly a T-cell and complement-mediated demyelinating neuropathy; specific antibodies are not consistently identified in most AIDP patients. Anti-GM1 IgG is more specifically associated with the axonal variant AMAN (acute motor axonal neuropathy) following Campylobacter jejuni infection. Anti-GQ1b antibodies are characteristic of Miller Fisher syndrome (ophthalmoplegia, ataxia, areflexia). Anti-MAG antibodies are associated with IgM paraprotein-associated neuropathy.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.