Table 1.
Demographics of IIM participant
| Participant | Symptom duration | Time since diagnosis | Age | Sex | Diagnosis | Myositis specific antibodies | CK level | MMT Deltoid/10 | MMT Vastus Lateralis/10 | Medications at the time of US | Echo deltoid (1–4) | Echo vastus lateralis (1–4) | PD Deltoid (0–4) | PD vastus lateralis (0–4) | MRI deltoid | MRI vastus lateralis | Muscle biopsy deltoid | Muscle biopsy vastus lateralis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | < 1 yr | < 1 mth | 30 | F | NAM | Seronegative | 9350 | 9 | 9 | Prednisolone, methotrexate | 1 | 2 | 1 | 1 | Oedema | N/A | N/A | N/A |
| 2 | < 1 mth | < 1 mth | 54 | F | NAM | Anti-HMGCR | 9390 | 8 | 9 | Prednisolone, methotrexate | 2 | 2 | 0 | 0 | N/A | Oedema | N/A | N/A |
| 3 | < 6 mth | < 1 mth | 66 | F | NAM | Seronegative | 10,600 | 9 | 10 | Nil | 2 | 3 | 0 | 0 | N/A | Fatty infiltration | N/A | Atrophy |
| 4 | < 1 yr | < 6 mth | 79 | F | DM | Anti-OJ, Anti-NXP2 | 553 | 9 | 9 | Nil | 1 | 2 | 0 | 1 | N/A | N/A | N/A | Fatty infiltration |
| 5 | < 5 yrs | < 1 mth | 70 | F | IBM | Seronegative | N/A | 9 | 9 | Nil | 2 | 3 | 0 | 1 | N/A | Atrophy, fatty infiltration | N/A | N/A |
| 6 | ≥ 5 yrs | < 1 mth | 60 | F | OM | Anti-Ro-52, Anti-NXP2 | N/A | 10 | 8 | Nil | 2 | 3 | 2 | 0 | N/A | Oedema | N/A | Inflammation, fibrosis, fatty infiltration |
| 7 | < 5 yrs | < 1 mth | 74 | M | IBM | Seronegative | 359 | 10 | N/A | Nil | 1 | 2 | 0 | 1 | N/A | N/A | N/A | N/A |
| 8 | < 1 mth | < 1 mth | 20 | M | DM | Anti-Mi2a | 14,900 | 1 | 3 | Prednisolone | 1 | 2 | 3 | 0 | N/A | Oedema | N/A | Inflammation, fibrosis, fatty infiltration |
| 9 | ≥ 5 yrs | < 1 yr | 60 | M | DM | Anti-Ro-52, Anti-NXP2 | 6410 | 1 | 1 | Prednisolone, mycophenolate | 1 | 1 | 1 | 2 | N/A | Oedema, fatty infiltration | N/A | N/A |
| 10 | < 5 yrs | < 6 mths | 70 | M | IBM | Seronegative | N/A | 10 | 8 | Nil | 1 | 4 | 0 | 0 | N/A | N/A | N/A | Inflammation, fibrosis, fatty infiltration |
| 11 | < 5 yrs | < 1 mth | 63 | M | IBM | Anti-CN1A | 261 | 10 | 2 | Nil | 1 | 3 | 2 | 0 | N/A | N/A | N/A | Inflammation, fibrosis, fatty infiltration |
| 12 | < 1 yr | < 6 mths | 65 | M | IBM | Seronegative | 1070 | 10 | 9 | Nil | 2 | 3 | 0 | 0 | N/A | Oedema, fatty infiltration | N/A | Inflammation, fibrosis, fatty infiltration |
| 13 | < 1 yr | < 1 mth | 26 | F | DM | Anti-NXP2 | 287 | 8 | 9 | Prednisolone, methotrexate | 1 | 2 | 1 | 0 | N/A | Oedema | N/A | Inflammation |
| 14 | ≥ 5 yrs | < 1 mth | 69 | M | NAM | Anti-SRP | 436 | 10 | 8 | Nil | 1 | 2 | 1 | 2 | N/A | N/A | N/A | N/A |
| 15 | ≥ 5 yrs | < 6 mth | 70 | M | IBM | Seronegative | 69 | 10 | 10 | Nil | 1 | 1 | 1 | 1 | N/A | Normal | Normal | N/A |
| 16 | < 1 yr | < 1 mth | 65 | F | NAM | Seronegative | 11 | 10 | 9 | Prednisolone, mycophenolate | 3 | 3 | 0 | 0 | N/A | Oedema, fatty infiltration | N/A | Inflammation, fatty infiltration |
| 17 | < 1 yr | < 1 mth | 33 | F | NAM | Seronegative | 4010 | 9 | 7 | Prednisolone, hydroxychloroquine, mycophenolate | 3 | 3 | 0 | 1 | Oedema, atrophy | N/A | Inflammation, fibrosis, fatty infiltration | N/A |
| 18 | < 1 yr–< 5 yrs | < 6 mth | 54 | F | DM | Seronegative | 19 | 10 | 5 | Mycophenolate, prednisolone, IVIG | 2 | 2 | 0 | 0 | N/A | Oedema | N/A | Fatty infiltration and fibrosis |
| 19 | < 6 mth | < 6 mth | 61 | M | NAM | Anti -HMGCR | 19,000 | 8 | 5 | Prednisolone, methotrexate | 1 | 3 | 0 | 0 | Oedema | Oedema | N/A | Inflammation, fibrosis, fatty infiltration |
| 20 | ≥ 5 yrs | < 1 mth | 79 | F | DM | Anti-SAE | 87 | 9 | 7 | Nil | 3 | 3 | 1 | 1 | N/A | Atrophy, fatty infiltration | N/A | Inflammation, fibrosis, fatty infiltration |
| Median/SD | – | – | 64/17 | – | – | – | 553/3 | 10 | 8 | – | 1/1 | 3/1 | 0/1 | 0/1 | – | – | – | – |
NAM: Necrotising autoimmune myopathy, DM: dermatomyositis, IBM: inclusion body myositis, OM: overlap myositis, CK: creatinine kinase, MMT: manual muscle testing, PD: power Doppler, MRI: magnetic resonance imaging, mths: months, yrs: years, N/A: not available. SD: standard deviation, Echo; echogenicity