Table 3.
Myopathologic markers of muscle biopsy slides
| Characteristics | Number | SSc-overlap (n = 24) | Number | PM (n = 24) | Significance ( P value) |
|---|---|---|---|---|---|
| Necrotic muscle fibers |
24 |
23 (96%) |
24 |
16 (67%) |
0.023b† |
| Lymphocytic infiltrates |
24 |
15 (63%) |
24 |
13 (54%) |
NS |
| Positive MHC class I staining |
12 |
11 (92%) |
18 |
12 (67%) |
NS |
| Inflammationa |
24 |
19 (79%) |
24 |
18 (75%) |
NS |
| MAC staining |
10 |
5 (50%) |
13 |
5 (39%) |
NS |
| Fibrosis |
19 |
5 (26%) |
24 |
2 (8%) |
NS |
| Presence of COX-negative fibers | 10 | 3 (30%) | 10 | 6 (60%) | NS |
MAC, Membrane attack complex; NA, not applicable; NS, not significant.
aInflammation is defined as positive MHC class I staining or/and presence of lymphocytic infiltrates.
bStatistically significant.