Table 1 General characteristics of adult patients with idiopathic inflammatory myopathies, according to presence or absence of anti-PM/Scl autoantibodies

Age at disease diagnosis (years)

42 (29–59)

41 (31–53)

0.607

Female sex

13 (81.3)

60 (77.9)

> 0.999

White ethnicity

14 (87.5)

57 (74.0)

0.342

Initial disease diagnosis

 Dermatomyositis

11 (68.8)

55 (71.4)

> 0.999

 Polymyositis

5 (31.2)

22 (28.6)

> 0.999

Fever

3 (18.8)

17 (22.1)

> 0.999

Weight loss

9 (56.2)

33 (42.9)

0.411

Gottron’s sign / papules

10 (62.4)

48 (62.3)

> 0.999

Heliotrope rash

7 (43.8)

46 (59.7)

0.276

Facial rash

2 (12.5)

33 (42.9)

0.025

“V”-neck sign

1 (6.3)

33 (42.9)

0.005

“Shawl” sign

0

21 (27.3)

-

Periungual hyperemia

8 (50.0)

30 (39.0)

0.420

Raynaud’s phenomenon

11 (68.8)

29 (37.7)

0.028

Vasculopathy

0

14 (18.2)

-

“Mechanics’ hands”

11 (68.8)

17 (22.1)

0.001

“Hiker’s feet”

8 (50.0)

5 (6.5)

< 0.001

Skin ulcers

2 (12.5)

9 (11.7)

> 0.999

Calcinosis

0

4 (5.2)

-

Muscle strength (MRC)

 Upper limbs

  V degree

3 (18.8)

16 (20.8)

> 0.999

  IV degree

10 (62.4)

44 (57.1)

  III degree

3 (18.8)

14 (18.2)

  II degree

0

3 (3.9)

 Lower limbs

  V degree

0

16 (20.8)

> 0.999

  IV degree

14 (87.5)

42 (54.5)

  III degree

2 (12.5)

18 (23.4)

  II degree

0

1 (1.3)

Dysphagia

7 (43.8)

30 (39.0)

0.784

Arthritis

10 (62.4)

24 (31.2)

0.024

Lung involvement

 Dyspnea

10 (62.4)

27 (35.1)

0.005

 Interstitial pneumopathy

14 (87.5)

25 (32.5)

< 0.001

 Ground glass opacities

11 (68.8)

21 (27.3)

0.003

 Fibrosis

8 (50.0)

11 (14.3)

0.003

Maximum levels of muscle enzymes

 Creatine phosphokinase (U/L)

544 (202–3819)

277 (67-1748)

0.228

 Aspartate aminotransferase (U/L)

45 (28–155)

47 (27–131)

0.891

 Alanine aminotransferase (U/L)

40 (28–121)

40 (24–133)

0.935

 Lactic dehydrogenase (U/L)

545 (350–867)

592 (372–833)

0.695

Antinuclear antibodies

16 (100)

55 (71.4)

0.034