Table 1.
Fold-ratio compared to normal for microarray measured ISG15 pathway transcripts in dermatomyositis muscle with and without PFA (DM-PFA N=7 and DM-NO-PFA N=7) compared to other inflammatory myopathies (OtherIM; N=62), both compared to normal muscle (N=12). ISG15 pathway transcript elevation for ISG15, HERC5, and USP18 are relatively specific to DM and highly specific to patients with DM and the presence of perifascicular atrophy (PFA) present on H&E stained muscle sections.
| Transcript | Ubiquitin-like (Ubl) role |
DM-PFA Fold |
DM-NO- PFA |
OtherIM- Fold |
p-value All DM vs Other IM |
p-value DM-PFA vs DM-NO-PFA |
|---|---|---|---|---|---|---|
| ISG15 | Ub-like modifier | 339 | 49/13* | 8 | 0.001 | 0.0001 |
| Ube1L | E1 enzyme | 9 | 2/2* | 3 | 0.160 | 0.0317 |
| Ube2L6 | E2 enzyme | 21 | 6/6* | 6 | 0.018 | 0.0007 |
| HERC5 | E3 enzyme | 62 | 6/1.7* | 1.2 | 0.010 | 0.0093 |
| USP18 | De-Ubl enzyme | 68 | 6/1.7* | 1.3 | 0.005 | 0.0013 |
1 of 7 DM-NO-PFA samples had very high ISG15, HERC5, and USP18 transcript levels as shown in Figure 1D; the mean fold-ratios for the remaining 6 DM-NO-PFA samples is indicated by *.