Table 4 Comparison of pathological characteristics of IMNM and non-IIMs

Muscle fibre necrosis

65 (95.6)

21 (72.4)

9 (56.3)

<.0001^*

 Mild necrosis

28 (41.2)

17 (58.6)

7 (43.8)

 Severe necrosis

37 (54.4)

4 (13.8)

2 (12.5)

<.0001^*

Connective tissue proliferation

30 (44.1)

11 (37.9)

0

.005^†

MHC-I expression on sarcolemma

57 (83.8)

11 (37.9)

2 (12.5)

<.0001^*

 Focal expression

37 (54.4)

11 (37.9)

2 (12.5)

 Diffuse expression

16 (23.5)

0

0

<.0001^*

CD4⁺ T cell

61 (89.7)

15/28 (53.6)

8 (50)

<.0001^*

 Endomysia

41 (60.3)

15/28 (53.6)

7 (43.8)

.461

 Perimysium

21 (30.9)

2/28 (7.1)

2 (12.5)

.024^*

CD8⁺ T cell

45 (66.2)

14/28 (48.3)

5 (31.3)

.027

 Endomysia

29 (42.6)

14/28 (50)

5 (31.3)

.481

 Perimysium

12 (17.6)

2/28 (7.1)

1 (6.3)

.258

CD68⁺ macrophage

50/66 (75.8)

14/25 (56)

10/15 (66.7)

.179

 Endomysia

39/66 (59.1)

14/25 (56)

10 (66.7)

.798

 Perimysium

17/66 (25.8)

2/25 (8)

1/15 (6.7)

.066

MAC

46/66 (69.7)

16/25 (64)

3/15 (20)

.002^†

 Sarcolemma of non-necrotic muscle fibre

34/66 (51.5)

15/25 (60)

1/15 (6.7)

.002^†

 Capillaries

26/66 (39.4)

5/25 (20)

2/15 (14.3)

.068