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Table 2 Disease-specific characteristics

From: Scleroderma-polymyositis overlap syndrome versus idiopathic polymyositis and systemic sclerosis: a descriptive study on clinical features and myopathology

Characteristics Number SSc-overlap (n = 25) Number SSc (n = 397) Number PM (n = 40) P value
Scleroderma features        
Raynaud phenomena 25 21 (84%) 397 379 (96%) 40 13 (33%) <0.001
Digital ulcers 25 6 (24%) 397 164 (41%) 40 3 (8%) <0.001
Pitting scars   - 397 160 (40%)   NA NA
Rodnan skin score (median) 15 6 (5–11) 372 7 (4–12)   NA NS
Renal crisis 25 1 (4%) 397 17 (4%)   NA NS
Myositis features        
Serum CK elevation 25 24 (96%) 397 48 (12%) 40 34 (85%) <0.001
Proximal muscle weakness 25 25 (100%) 397 21 (5%) 40 37 (93%) <0.001
Myopathic EMG findings 25 22 (88%)   NA 29 24 (83%) NS
Mechanic hands   NA   NA 40 7 (18%) NS
Internal complications        
Arthritis 25 5 (20%) 397 46 (12%) 40 7 (18%) NS
Interstitial lung disease        
 HRCT fibrosis 18 15 (83%) 346 170 (49%) 19 10 (53%) 0.044
 TLC ≤70% of predicted 21 4 (19%) 364 68 (19%) 23 9 (39%) NS
 TLCO ≤70% of predicted 17 17 (100%) 347 260 (75%) 20 13 (65%) 0.001
Diastolic dysfunction by cardiac ultrasound 19 7 (37%) 352 146 (42%) 19 4 (21%) NS
PH suspicion by cardiac ultrasound 20 3 (15%) 352 89 (25%) 19 2 (11%) 0.042
PH by cardiac catherization 5 0 182 57 (31%) 2 1 (50%) 0.002
Myocarditis 25 1 (4%)   NA 40 0 NS
Malignancy 25 2 (8%)   NA 40 5 (13%) NS
  1. NA, not applicable; NS, not significant; TLC, total lung capacity; HRCT, high-resolution CT scan; TLCO, transfer factor of the lung for carbon monoxide; PH, pulmonary hypertension.
  2. Defined >2 times upper limit of normal (ULN).