This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunity, Subject name: Pathology
[{'content': 'In myasthenia gravis, the antibodies are formed against? \nSelect and explain. \nA. Muscarinic receptor proteins, B. Acetylcholine receptors, C. Actin, D. Myosin', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Acetylcholine receptor Myasthenia gravis* It is a muscle disease caused by immune-mediated loss of acetylcholine receptors at neuromuscular (myoneural) junction, i.e. Nm type of nicotinic receptors.* The antibodies in myasthenia gravis attack the nicotinic acetylcholine receptor, or a related protein called MusK a muscle-specific kinase.* When arising before age 40 years, it is most commonly seen in women, but there is equal occurrence between the sexes in older patients. Thymic hyperplasia is found in 65% and thymoma in 15% of patients.* Analysis of neuromuscular transmission in myasthenia gravis shows a decrease in the number of muscle acetylcholine receptors (AChRs), and circulating antibodies to the AChR are present in nearly all patients with myasthenia gravis.* Patients show improvement in strength in response to administration of anticholinesterase agents. This remains a most useful test on clinical examination.", 'role': 'assistant'}]