USMLE Forum Archives - USMLE Step 1 - Pathology 63
Pathology 63
TheOne - 09-01-07 18:09
A 45-year-old man presents to a physician with complaints of double vision and ptosis. The patient has noticed that these problems are minor in the early morning, but become progressively more severe during the course of the day. Symptoms markedly improve after a test dose of edrophonium. This condition is usually related to autoantibodies directed against which of the following?
A. Acetylcholine receptor
B. Double-stranded DNA
C. Neutrophil cytoplasmic proteins
D. SS-A (Ro)
E. TSH receptor
TheOne - 09-01-07 18:09
A 45-year-old man presents to a physician with complaints of double vision and ptosis. The patient has noticed that these problems are minor in the early morning, but become progressively more severe during the course of the day. Symptoms markedly improve after a test dose of edrophonium. This condition is usually related to autoantibodies directed against which of the following?
A. Acetylcholine receptor
B. Double-stranded DNA
C. Neutrophil cytoplasmic proteins
D. SS-A (Ro)
E. TSH receptor
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#3
Re: Pathology 63
TheOne - 09-13-07 15:35 The correct answer is A. The disease is myasthenia gravis, which is the result of autoantibodies directed against the acetylcholine receptor at the neuromuscular junction. Many patients with myasthenia gravis have related thymic hyperplasia or thymoma. Antibodies to double-stranded DNA (choice B) are a feature of systemic lupus erythematosus, a collagen-vascular disease. Antibodies to neutrophil cytoplasmic proteins (choice C), called antineutrophil cytoplasmic autoantibodies (ANCA), are a feature of Wegener's granulomatosis. Antibodies to SS-A (choice D) are a feature of Sjogren's syndrome, characterized by autoimmune inflammation of the lacrimal and salivary glands Antibodies to the TSH receptor (choice E) are a feature of Graves' disease. Stimulation of the receptor by the autoantibodies is responsible for producing a hyperthyroid state.
#4
Re: Pathology 63 galaxy - 05-28-10 03:15 A 45-year-old man presents to a physician with complaints of double vision and ptosis. The patient has noticed that these problems are minor in the early morning, but become progressively more severe during the course of the day. Symptoms markedly improve after a test dose of edrophonium. This condition is usually related to autoantibodies directed against which of the following?
A. Acetylcholine receptor..myasthenia gravis
#5
Re: Pathology 63 bingousmle - 05-28-10 07:21 The man is suffering from myasthenia gravis, which is the result of autoantibodies directed against the acetylcholine receptor at the neuromuscular junction...
#6
Re: Pathology 63 babbu5508 - 05-29-10 01:39 Myasthenia gravis is a neuromuscular disorder characterized by variable weakness of voluntary muscles, which often improves with rest and worsens with activity..autoantibodies to ach receptors..
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