In myasthenia gravis (MG), the MG-ADL score is used for clinical monitoring. Which antibody subtype predicts a significantly BETTER response to thymectomy compared to seronegative MG?

• A Anti-acetylcholine receptor (AChR) antibody positive, generalised MG ✓
• B Anti-MuSK antibody positive MG
• C Anti-LRP4 antibody positive MG
• D Seronegative double-negative MG

Explanation

The MGTX trial (NEJM 2016) demonstrated that thymectomy + prednisone was superior to prednisone alone in AChR antibody-positive, non-thymomatous generalised MG — significantly reducing time-weighted average MG-ADL scores and prednisone requirements over 3 years. Anti-MuSK positive MG has inconsistent thymectomy benefit and the thymus shows fewer germinal centres. Anti-LRP4 and seronegative MG subtypes have limited evidence for thymectomy benefit.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.