Comparisons of clinical characteristics in antisynthetase antibody–positive patients with idiopathic inflammatory myopathy. Pairwise comparisons were further analyzed when overall p value was < 0.05. Data are presented as n (%) or mean ± SD.
| Variables | Overall, n = 124 | Jo1, n = 62 | PL7, n = 31 | PL12, n = 12 | EJ, n = 19 | p |
|---|---|---|---|---|---|---|
| Mean age at onset, yrs | 50.4 ± 11.8 | 49.9 ± 10.4 | 51.7 ± 12.5 | 54 ± 12.6 | 47.6 ± 14.5 | 0.459 |
| Female | 94 (75.8) | 44 (71) | 25 (80.6) | 9 (75) | 16 (84.2) | 0.648 |
| Duration, mos | 12.9 ± 31.2 | 11.3 ± 30.9 | 14.0 ± 15.9 | 15.9 ± 33.5 | 14.2 ± 27.4 | 0.952 |
| Clinical characteristics | ||||||
| Muscle weakness | 79 (63.7) | 39 (62.9) | 22 (71) | 8 (66.7) | 10 (52.6) | 0.635 |
| Myalgia | 45 (36.3) | 22 (35.5) | 12 (38.7) | 3 (25) | 8 (42.1) | 0.829 |
| ILD | 117 (94.4) | 60 (96.8) | 26 (83.9) | 12 (100) | 19 (100) | 0.053 |
| RP-ILD | 11 (8.9) | 3 (4.8) | 6 (19.4) | 1 (8.3) | 1 (5.3) | 0.127 |
| Mechanic’s hands | 57 (46.0) | 29 (46.8) | 14 (45.2) | 5 (41.7) | 9 (47.4) | 0.992 |
| Raynaud phenomenon | 12 (9.7) | 8 (12.9) | 1 (3.2) | 2 (16.7) | 1 (5.3) | 0.351 |
| Gottron papules | 55 (44.4) | 26 (41.9) | 15 (48.4) | 8 (66.7) | 6 (31.6) | 0.265 |
| Heliotrope rash | 27 (21.8) | 7 (11.3) | 15 (48.4) | 2 (16.7) | 3 (15.8) | 0.001a |
| Arthritis/arthralgia | 67 (54.0) | 44 (71) | 13 (41.9) | 5 (41.7) | 5 (26.3) | 0.001b |
| Dysphagia | 14 (11.3) | 5 (8.1) | 6 (19.4) | 1 (8.3) | 2 (10.5) | 0.449 |
| Malignancy | 8 (6.5) | 4 (6.5) | 2 (6.5) | 1 (8.3) | 1 (5.3) | 1.000 |
| Pericarditis | 13 (10.5) | 3 (4.8) | 6 (19.4) | 2 (16.7) | 2 (10.5) | 0.100 |
| ANA | 69 (55.6) | 24 (38.7) | 20 (64.5) | 10 (83.3) | 15 (78.9) | 0.001c |
| Anti-Ro52 | 36 (29.0) | 6 (9.7) | 12 (38.7) | 8 (66.7) | 10 (52.6) | < 0.0001c |
| Anti- Ro60 | 38 (30.6) | 24 (38.7) | 7 (22.6) | 1 (8.3) | 6 (31.6) | 0.129 |
| Anti-RNP | 5 (4.0) | 3 (4.8) | 1 (3.2) | 0 | 1 (5.3) | 1.000 |
| With other CTD | 23 (18.5) | 13 (21) | 4 (12.9) | 2 (16.7) | 4 (21.1) | 0.830 |
| CK, IU/l | 811.7 ± 1473.6 | 732.6 ± 1183.7 | 1061.8 ± 2203.2 | 172.9 ± 259.2 | 1070.1 ± 1246.8 | 0.277 |
| CRP, mg/dl | 2.3 ± 4.1 | 1.8 ± 3.2 | 3.4 ± 6.5 | 2.9 ± 2.7 | 1.8 ± 2.6 | 0.361 |
| Serum ferritin, ng/ml | 448.6 ± 710.4 | 428.7 ± 856.8 | 491.8 ± 637.3 | 629 ± 592.9 | 308.2 ± 338.6 | 0.849 |
| Lymphocyte, cell | 1584 ± 10,006 | 1708 ± 1068 | 1509 ± 1076 | 1238 ± 650 | 1625 ± 936 | 0.559 |
| CD3+, cell/ul | 1120 ± 755 | 1197 ± 849 | 1118 ± 780 | 893 ± 554 | 1062 ± 539 | 0.677 |
| CD3+CD4+, cell/ul | 654 ± 414 | 691 ± 359 | 685 ± 509 | 560 ± 385 | 588 ± 290 | 0.593 |
| CD3+CD8+, cell/ul | 433 ± 386 | 468 ± 479 | 403 ± 288 | 403 ± 288 | 475 ± 330 | 0.610 |
| B1, % | 4.1 ± 3.9 | 3.9 ± 3.5 | 4 ± 4.5 | 3 ± 2.5 | 5.4 ± 4.2 | 0.531 |
| B2, % | 11.2 ± 8.3 | 10.6 ± 7.4 | 12 ± 9.4 | 14.7 ± 12.5 | 8.6 ± 4.7 | 0.291 |
↵a p < 0.05 between anti-PL7 and anti-Jo1 or anti-EJ.
↵b p < 0.05 between anti-Jo1 and anti-PL7 or anti-EJ.
↵c p < 0.05 between anti-Jo1 and anti-PL7, anti-PL12, or anti-EJ. ILD: interstitial lung disease; RP-ILD: rapidly progressive ILD; ANA: antinuclear antibodies; CTD: connective tissue disease; CK: creatine kinase; CRP: C-reactive protein; B1: lymphocyte subset 1; B2: lymphocyte subset 2.