Patients: clinical and laboratory characteristics
| Patient No | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | |
| Clinical features: | |||||||||||
| Onset age (y) | 23 | 63 | 18 | 36 | 42 | 42 | 54 | 56 | 55 | 58 | 61 |
| Sex | F | F | F | M | F | F | F | F | F | F | F |
| Proximal weakness | ++ | ++ | + | ++ | + | + | + | + | + | + | ++ |
| Muscle pain | + | + | + | + | + | + | + | + | + | + | + |
| Dyspnoea and cough | + | + | + | − | − | − | − | − | − | − | − |
| Arthritis | + | + | + | + | + | + | − | + | − | − | |
| Skin rash | + | − | − | − | + | + | − | − | − | − | − |
| Mechanic's hands | − | − | − | + | + | + | − | − | − | − | − |
| Raynaud's phenomenon | − | − | + | − | + | − | − | − | − | − | − |
| Steroid response | + | + | + | + | + | + | + | + | + | ||
| Laboratory data: | |||||||||||
| Creatine kinase (IU/l) | 35 000 | 10000 | 500 | 4700 | 2100 | 390 | 1500 | 230 | 1600 | 110 | 1000 |
| Packed cell volume | 32 | 31 | WNL | WNL | WNL | 34 | 42 | 36 | 34 | ||
| Erythrocyte sedimentation rate (mm/h) | 132 | 72 | 31 | 6 | 25 | 60 | 42 | 60 | 42 | ||
| Antinuclear antibody | 1:5120 | − | − | − | − | − | − | 1:40 | 1:80 | ||
| Muscle pathology: | |||||||||||
| Inflammation: | |||||||||||
| Perimysial | ++ | +++ | ++ | + | ++ | ++ | ++ | ++ | ++ | ++ | + |
| Endomysial | − | ++ | ++ | − | − | − | − | − | − | − | − |
| Perivascular | − | − | − | + | − | − | − | − | − | − | − |
| Perifascicular muscle fibre pathology | +++ | +++/Diffuse | ++ | + | Patchy | ++ | ++ | ++ | + | + | + |
| Perimysial connective tissue fragmentation | ++ | + | + | + | + | ++ | ++ | +++ | + | + | + |
| Acid phosphatase: perimysial staining | ++ | + | + | + | ++ | ++ | ++ | ++ | + | + | + |
| Alkaline phosphatase: perimysial staining | +++ | ++ | ++ | + | ++ | − | + | + | + | + | ++ |
| Alkaline phosphatase: small vessel staining | − | − | − | − | − | + | − | − | − | − | − |
| Cytochrome oxidase negative muscle fibres | − | − | − | − | − | − | − | − | − | + | − |
Weakness: ++=Moderate to severe (MRC grade strength⩽ 3 in some muscles); +=Mild (MRC grade strength ⩾4 in all muscles).
Other features: +=present; ++=moderately increased; +++=markedly increased; −=negative/absent; ±=equivocal; F=female; M=male.