II. Labs: Muscle Enzymes
- Serum Aldolase
- Alanine Aminotransferase (ALT)
- Aspartate Aminotransferase (AST)
- Lactate Dehydrogenase (LDH)
- Creatine Phosphokinase (CPK)
- Carbonic Anhydrase (isoenzyme III)
- Limited availability
III. Lab: Rheumatologic
-
Erythrocyte Sedimentation Rate (ESR)
- Increased in 50% of cases
- Poor correlation with disease activity
-
Rheumatoid Factor
- Increased in 20% of cases
- Associated with overlap syndrome
-
Antinuclear Antibody (ANA)
- Seen in 80% of Dermatomyositis and Polymyositis patients
IV. Labs: Specific Autoantibodies
-
Anti-Jo1
- Seen in 20% of Dermatomyositis
- Anti-EJ
- Associated with Dermatomyositis
- Signal Recognition Particle (SRP)
- Seen in 5% of Polymyositis
- Associated in severe, acute-onset Polymyositis
- Treatment resistant Dermatomyositis, Polymyositis
- Associated with cardiac involvement
-
Anti-Mi2
- Seen in 15-20% of classic Dermatomyositis
- Associated conditions
- Treatment-responsive form
- Shawl sign in Dermatomyositis
- Prominent cuticular changes
- Anti-PM-Scl
- Seen in overlap syndrome
- Associated conditions
-
Anti-Ku
- Seen in overlap syndrome
- Associated conditions
V. Labs: Juvenile Dermatomyositis
- Neopterin
- Factor VIII-related Antigen (Von Willebrand Factor)
VI. Diagnostics: Electromyogram (EMG)
- False Negative in 10% of cases
- Myopathic or myogenic pattern
- Short duration, polyphasic motor unit potentials
- Spontaneous fibrillation potentials
VII. Monitoring: Ovarian Cancer Screening in Women
- Initial gynecologic exam and every 6-12 months x2 years
- Baseline CA-125 level
- Baseline Mammogram
- Baseline Transvaginal Ultrasound of the ovaries