Table 4 Clinical characteristics of study individuals

Age, years

52.8

16.2

37.2

19.8

Female, %

100

9

100

4

Ethnicity, %

Caucasian

77.8

7

50

2

Asian

22.2

2

25

1

Other

–

0

25

1

Smoking, %

Current

11.1

1

–

0

Past

22.2

2

25

1

Never

55.6

5

75

3

Unknown

11.1

1

–

0

Disease duration, years

10.4

7.0

Interstitial lung disease, %

11.1

1

Arthritis, %

11.1

1

Myositis, %

22.2

2

Raynaud’s, %

100

9

Anti-nuclear antibodies

Titer ≥ 1:80, %

100

9

Titer ≥ 1:160, %

66.7

6

Titer ≥ 1:640, %

55.6

5

Blood biochemical indices

C-reactive protein (CRP), mg/L

29.5

65.3^¶

Erythrocyte sedimentation rate, mm/hr

23.7

14.1

Abs. whole blood cell (WBC), K/μL

8.2

4.6

Abs. lymphocytes, K/μL

1.6

0.7

Abs. monocytes, K/μL

0.7

0.7^¶

Disease-specific variables

Limited skin disease, %

33.3

3

Diffuse skin disease, %

66.7

6

Immunosuppressive medication^§, %

33.3

3