Anti-Jo-1 myositis antibody vs Anti-Mi-2 and anti-SRP myositis antibodies
How to tell Anti-Jo-1 myositis antibody and Anti-Mi-2 and anti-SRP myositis antibodies apart when a board question makes them look alike.
Anti-Jo-1 is antisynthetase lung/hands; Mi-2 is classic dermatomyositis; SRP is severe necrotizing myopathy.
Side by side
Anti-Jo-1 is antisynthetase syndrome with myositis, interstitial lung disease, mechanic hands, Raynaud, arthritis, and fever.
Anti-Mi-2 supports classic dermatomyositis with good response; anti-SRP supports severe necrotizing myopathy with marked weakness and high CK.
Anti-Jo-1 is antisynthetase syndrome with myositis, interstitial lung disease, mechanic hands, Raynaud, arthritis, and fever.
Anti-Mi-2 supports classic dermatomyositis with good response; anti-SRP supports severe necrotizing myopathy with marked weakness and high CK.
The repair move
Before naming the answer, force the stem through the separator: Anti-Jo-1 is antisynthetase lung/hands; Mi-2 is classic dermatomyositis; SRP is severe necrotizing myopathy.
Try a free question
CoreA 48-year-old woman has 6 months of progressive symmetric proximal muscle weakness (difficulty climbing stairs, lifting arms overhead), painful 'mechanic hands' with cracked fingertip skin, Raynaud phenomenon, polyarthritis, and progressive dyspnea. Pulmonary function tests show restrictive lung disease; CT shows interstitial lung disease. CPK is elevated. Which autoantibody is most likely positive?
Show answer and explanation
Answer: A. Anti-Jo-1 (antisynthetase syndrome). Anti-Jo-1 (anti-histidyl-tRNA synthetase) is the most common antisynthetase antibody, defining antisynthetase syndrome: myositis, interstitial lung disease, mechanic hands, Raynaud, arthritis, and fever. ILD often dominates prognosis. Treat with corticosteroids plus immunosuppression.
Why the other choices are tempting
- B. Anti-Mi-2 is associated with classic dermatomyositis with good treatment response and less ILD.
- C. Anti-SRP is associated with severe necrotizing myopathy with marked weakness and very high CK, less ILD.
- D. Anti-dsDNA is associated with SLE, not myositis.
- E. Anti-CCP is associated with rheumatoid arthritis.
Flashcards
Tap a card to flip it.
What clue supports Anti-Jo-1 myositis antibody?
Choose Anti-Jo-1 myositis antibody when the stem gives this pattern: Anti-Jo-1 is antisynthetase syndrome with myositis, interstitial lung disease, mechanic hands, Raynaud, arthritis, and fever.
What clue supports Anti-Mi-2 and anti-SRP myositis antibodies?
Choose Anti-Mi-2 and anti-SRP myositis antibodies when the stem gives this contrasting pattern: Anti-Mi-2 supports classic dermatomyositis with good response; anti-SRP supports severe necrotizing myopathy with marked weakness and high CK.
Quick answers
What is the fastest way to tell Anti-Jo-1 myositis antibody from Anti-Mi-2 and anti-SRP myositis antibodies?
Anti-Jo-1 is antisynthetase lung/hands; Mi-2 is classic dermatomyositis; SRP is severe necrotizing myopathy.
What is the key clue for Anti-Jo-1 myositis antibody?
Anti-Jo-1 is antisynthetase syndrome with myositis, interstitial lung disease, mechanic hands, Raynaud, arthritis, and fever.
What is the key clue for Anti-Mi-2 and anti-SRP myositis antibodies?
Anti-Mi-2 supports classic dermatomyositis with good response; anti-SRP supports severe necrotizing myopathy with marked weakness and high CK.