Table 7.

Variables used in the development of new classification criteria for idiopathic inflammatory myopathies (29)

Variable
Age of onset of first symptom assumed to be related to the disease ≥ 18 years and < 40 years
Age of onset of first symptom assumed to be related to the disease ≥ 40 years
Objective symmetric weakness, usually progressive, of the proximal upper extremities
Objective symmetric weakness, usually progressive, of the proximal lower extremities
Neck flexors are relatively weaker than neck extensors
In the legs proximal muscles are relatively weaker than distal muscles
Heliotrope rash
Gottron´s papules
Gottron’s sign
Dysphagia or esophageal dysmotility
Anti-Jo-1 (anti-histidyl-tRNA synthetase) autoantibody present
Elevated serum levels of creatine kinase (CK)* or lactate dehydrogenase (LDH)* or aspartate aminotransferase (ASAT/AST/SGOT)* or alanine aminotransferase (ALAT/ALT/SGPT)*
Muscle biopsy features- presence of:
Endomysial infiltration of mononuclear cells surrounding, but not invading, myofibres
Perimysial and/or perivascular infiltration of mononuclear cells
Perifascicular atrophy
Rimmed vacuoles

^*Serum levels above the upper limit of normal