27th June 2023

A 68-year-old man presents with weakness of his legs. He finds this to be worse in the morning but improves on activity

A 68-year-old man presents with weakness of his legs. He finds this to be worse in the morning but improves on activity. He has also noticed dry mouth and slurred speech. He comes to see you as his wife is very concerned about his swallowing after he choked on a piece of meat. He has lost 3kg of weight in the last month. On examination, he has proximal weakness of the upper and lower limbs and is areflexic. The degree of weakness is variable. He is diagnosed with a type of neuromuscular junction disorder.

Select the SINGLE most likely autoantibody identified in his blood from the list below. Select ONE option only.