A 50-year-old woman presents with progressive proximal muscle weakness over 4 months, mechanic's hands, Raynaud phenomenon, and interstitial lung disease on HRCT. Her CK is 3200 U/L and anti-Jo-1 antibody is positive. What is this constellation of findings best described as?
- A Antisynthetase syndrome ✓
- B Dermatomyositis
- C Inclusion body myositis
- D Polymyositis
Correct answer: A. Antisynthetase syndrome
Explanation
Antisynthetase syndrome is defined by the presence of anti-aminoacyl-tRNA synthetase antibodies (most commonly anti-Jo-1), myositis, interstitial lung disease, Raynaud phenomenon, mechanic's hands, and arthritis. While polymyositis and dermatomyositis overlap with this syndrome, the specific antisynthetase antibody identifies a distinct clinical entity. Inclusion body myositis typically causes asymmetric distal weakness and lacks these extra-muscular features.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.