A 28-year-old woman presents with bilateral sequential optic neuritis over 3 months, with visual acuity counting fingers in both eyes. MRI shows longitudinally extensive transverse myelitis spanning 4 vertebral segments. Which antibody is most likely positive?
- A Anti-AQP4 (neuromyelitis optica) antibody ✓
- B Anti-acetylcholine receptor antibody
- C Anti-MOG antibody
- D Anti-GQ1b antibody
Correct answer: A. Anti-AQP4 (neuromyelitis optica) antibody
Explanation
Neuromyelitis optica spectrum disorder (NMOSD) classically presents with severe bilateral optic neuritis and longitudinally extensive transverse myelitis (spanning 3 or more vertebral segments). Anti-AQP4 antibody is positive in 70-80% of cases. Anti-MOG antibody can cause similar phenotypes but is less common. Anti-AChR is for myasthenia. Anti-GQ1b is for Miller Fisher syndrome.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.