Table 1.
General features of JDM patients with and without anti-HSC70 autoantibodies
| Anti-HSC70 positive (N = 22) | Anti-HSC70 negative (N = 41) | P-value | |
|---|---|---|---|
| Age at diagnosis, median (IQR), years | 8.6 (7.0–10.9) | 8.0 (6.3–12.4) | 0.8 |
| Age at enrolment, median (IQR), years | 10.7 (8.8–14.6) | 11.2 (8.6–15.8) | 0.9 |
| Delay to diagnosis, median (IQR), months | 3.5 (2.0–6.8) | 5.0 (2.0–8.3) (N = 40) | 0.3 |
| Follow-up, median (IQR), years | 2.8 (1.9–6.4) | 3.1 (1.1–7.1) | 0.8 |
| Female, n/N (%) | 12/22 (55) | 30/41 (73) | 0.2 |
| Race, n/N (%) | |||
| White | 14/22 (64) | 28/41 (68) | 0.8 |
| Black | 3/22 (14) | 4/41 (10) | 0.7 |
| Hispanic | 1/22 (5) | 2/41 (5) | 1.0 |
| Asian | 0/22 (0) | 1/41 (2) | 1.0 |
| Biracial or multiracial | 4/22 (18) | 6/41 (15) | 0.7 |
| Myositis-associated autoantibodies, n/N (%) | 15/22 (68) | 16/41 (39) | <0.04 |
| Anti-NT5C1A | 11/16 (69) | 10/35 (29) | <0.02 |
| Anti-Ro52 | 9/21 (43) | 6/40 (15) | <0.03 |
| Anti-Ro | 6/22 (27) | 4/41 (10) | 0.08 |
| Anti-U1RNP | 1/22 (5) | 2/41 (5) | 1.0 |
| Anti-PM-SCL | 0/22 (0) | 1/41 (2) | 1.0 |
| Myositis-specific autoantibodies, n/N (%) | 20/22 (91) | 34/41 (83) | 0.5 |
| Anti-p155/140 (TIF-1) | 7/22 (32) | 16/41 (39) | 0.8 |
| Anti-NXP-2 | 6/22 (27) | 11/41 (27) | 1.0 |
| Anti-MDA5 | 6/22 (27) | 3/41 (7) | 0.06 |
| Anti-Mi-2 | 1/22 (5) | 1/41 (2) | 1.0 |
| Anti-KS | 0/22 (0) | 1/41 (2) | 1.0 |
| Anti-HMGCR | 0/22 (0) | 1/41 (2) | 1.0 |
| Anti-Jo1 | 0/22 (0) | 1/41 (2) | 1.0 |
Categorical variables were analysed by Fisher's exact tests and are presented as count/total (percentage). Continuous variables were analysed by the Mann–Whitney U-test and are expressed as median (IQR [Q1–Q3]). Myositis-associated autoantibodies (n) include anti-Ro (10), anti-Ro52 (15), anti-NT5C1A (21), anti-U1RNP (3) and anti-polymyositis-scleroderma antibodies (1). Myositis-specific autoantibodies (n) include anti-p155/140 (23), anti-NXP-2 (17), anti-MDA5 (9), anti-Mi-2 (2), anti-KS (1), anti-HMGCR (1) and anti-Jo1 (1) autoantibodies. HMGCR: 3-hydroxy-3-methylglutaryl-CoA reductase; IQR: interquartile range; Jo1: anti-histidyl tRNA synthetase; MDA5: melanoma differentiation associated protein-5; NT5C1A: cytosolic 5'-nucleotidase 1A; NXP-2: nuclear matrix protein-2; PM-SCL: polymyositis-scleroderma; TIF-1: transcription intermediary factor 1.