TB(+)

(n = 12)

TB(−)

(n = 24)

P

value

Demographic features

Age at DM/PM diagnosis (years)

45.3 ± 14.1

44.7 ± 13.8

0.894

DM/PM diagnosis―symptom onset (mo)

3.0 [2.3 - 8.5]

4.0 [2.3 - 6.8]

0.665

TB diagnosis―symptom onset (mo)

23.0 [10.3 - 80.5]

54.0 [6.8 - 83.5]

0.728

Female gender

9 (75.0)

18 (75.0)

1.000

White ethnicity

10 (83.3)

20 (83.3)

1.000

Patients with DM

9 (75.0)

18 (75.0)

1.000

Patients with PM

3 (25.0)

6 (25.0)

1.000

Initial and cumulative features

Constitutional symptoms

9 (75.0)

13 (54.2)

0.292

Heliotrope rash and/or Gottron’s papules

9 (75.0)

18 (75.0)

1.000

Muscle strength

Upper limbs

IV [IV - IV]

IV [IV - IV]

0.631

Lower limbs

IV [IV - IV]

IV [IV - IV]

0.882

Upper dysphagia

4 (33.3)

12 (50.0)

0.298

Joint involvement

9 (75.0)

9 (37.5)

0.075

Pulmonary involvement

9 (75.0)

10 (41.7)

0.083

Incipient pneumonia

5 (41.7)

7 (29.2)

0.479

Pulmonary ground-glass opacity

6 (50.0)

5 (20.8)

0.124