MD Musculoskeletal and Connective Tissue 2 — Questions and Answers
Question 1: A 45-year-old woman presents with bilateral wrist pain, swan-neck deformities, and positive anti-CCP antibodies. Which mechanism best explains joint destruction in her condition?
- Pannus formation eroding cartilage and bone (Correct answer)
- Urate crystal deposition in synovial fluid
- Calcium pyrophosphate deposition in cartilage
- Bacterial seeding of the joint space
Correct answer: Pannus formation eroding cartilage and bone
Rheumatoid arthritis causes pannus (proliferative synovial tissue) that invades and destroys cartilage and subchondral bone.
Question 2: A 70-year-old man develops sudden severe pain in his great toe after a night of heavy alcohol consumption. Synovial fluid analysis shows negatively birefringent needle-shaped crystals. What is the first-line acute treatment?
- Indomethacin or colchicine (Correct answer)
- Allopurinol
- Probenecid
- Methotrexate
Correct answer: Indomethacin or colchicine
Acute gout is treated with NSAIDs (e.g., indomethacin) or colchicine; urate-lowering therapy like allopurinol is not started during an acute attack.
Question 3: A 35-year-old woman with SLE develops proximal muscle weakness and a heliotrope rash around her eyes. Creatine kinase is markedly elevated. Which autoantibody is most specific for her inflammatory myopathy?
- Anti-Jo-1 (Correct answer)
- Anti-dsDNA
- Anti-Smith
- Anti-Ro/SSA
Correct answer: Anti-Jo-1
Anti-Jo-1 (anti-synthetase antibody) is the most specific marker for polymyositis/dermatomyositis and is associated with interstitial lung disease.
Question 4: A 55-year-old man with limited cutaneous systemic sclerosis presents with Raynaud phenomenon, telangiectasias, and pulmonary hypertension. Which antibody is most commonly associated with this subset?
- Anti-centromere antibody (Correct answer)
- Anti-Scl-70 (topoisomerase I)
- Anti-Jo-1
- Anti-dsDNA
Correct answer: Anti-centromere antibody
Anti-centromere antibodies are characteristically associated with limited cutaneous systemic sclerosis (formerly CREST syndrome).
Question 5: A 28-year-old man presents with low back pain that improves with exercise, uveitis, and HLA-B27 positivity. X-ray shows sacroiliitis. What is the most likely diagnosis?
- Ankylosing spondylitis (Correct answer)
- Reactive arthritis
- Psoriatic arthritis
- Enteropathic arthritis
Correct answer: Ankylosing spondylitis
Ankylosing spondylitis presents with inflammatory back pain, sacroiliitis on imaging, and is strongly associated with HLA-B27.
Question 6: A 60-year-old woman on long-term corticosteroids develops back pain. DEXA scan shows T-score of -2.8. Which medication addresses the underlying pathophysiology of her bone loss?
- Alendronate (bisphosphonate) (Correct answer)
- Calcium supplementation alone
- Vitamin D supplementation alone
- Calcitonin
Correct answer: Alendronate (bisphosphonate)
Bisphosphonates inhibit osteoclast-mediated bone resorption and are first-line for glucocorticoid-induced osteoporosis with T-score ≤-2.5.
Question 7: A 40-year-old woman presents with dry eyes, dry mouth, parotid enlargement, and positive anti-Ro/SSA antibodies. A lip biopsy shows focal lymphocytic sialadenitis. What is the diagnosis?
- Sjögren syndrome (Correct answer)
- Sarcoidosis
- Mumps
- Rheumatoid arthritis with sicca symptoms
Correct answer: Sjögren syndrome
Sjögren syndrome is diagnosed by the combination of sicca symptoms, anti-Ro/SSA antibodies, and focal lymphocytic sialadenitis on minor salivary gland biopsy.
MD Musculoskeletal and Connective Tissue 2
A 45-year-old woman presents with bilateral wrist pain, swan-neck deformities, and positive anti-CCP antibodies.
Which mechanism best explains joint destruction in her condition?