First CTD symptom and first diagnosis in Jo-1 and non-Jo-1 patients
| Total cohort | Jo-1 patients | Non-Jo-1 patients | p Value (Jo-1 vs non-Jo-1) | |
|---|---|---|---|---|
| First CTD symptom | ||||
| Muscle | 47 (23.5%) | 36 (30.0%) | 11 (13.8%) | 0.008 |
| Joint | 42 (21.0%) | 32 (26.7%) | 10 (12.5%) | 0.016 |
| Pulmonary | 49 (24.5%) | 26 (21.7%) | 23 (28.8%) | 0.254 |
| Raynaud | 28 (14%) | 8 (6.7%) | 20 (25.0%) | 0.003 |
| Fatigue | 7 (3.5%) | 5 (4.2%) | 2 (2.5%) | 0.530 |
| Fever | 5 (2.5%) | 2 (1.7%) | 3 (3.8%) | 0.355 |
| Rash | 7 (3.5%) | 4 (3.3%) | 3 (3.8%) | 0.875 |
| First CTD diagnosis | ||||
| IIM | 133 (65.8%) | 101 (82.8%) | 32 (40.0%) | <0.001 |
| PM | 90 (44.6%) | 72 (59.0%) | 18 (22.5%) | <0.001 |
| DM | 43 (21.3%) | 29 (23.8%) | 14 (17.5%) | 0.287 |
| Overlap or UCTD | 59 (29.2%) | 21 (17.2%) | 38 (47.5%) | <0.001 |
| SSc | 10 (5.0%) | 0 (0.0%) | 10 (12.5%) | <0.001 |
| Organ involvement (ever): | ||||
| Muscle | 152 (75.2%) | 104 (85.2%) | 48 (60%) | 0.001 |
| CK (median)* | 11.8 (2–42) | 3.4 (0.6–10) | <0.01 | |
| Joint | 128 (63.3%) | 86 (70.5%) | 42 (52.5%) | 0.008 |
| Pulmonary fibrosis† | 136 (76.4%) | 76 (73.0%) | 60 (81.0%) | 0.210 |
| FVC% (baseline) | 62.1(mean) (N=75) | 56.7 (mean) (N=50) | 0.070 | |
| Primary PAH | 18 (14.8%) | 9 (11.5%) | 9 (20.9%) | 0.480 |
| Vascular | 104 (53.8%) | 47 (39.5%) | 57 (77.0%) | 0.001 |
| Gastrointestinal | 35 (17.3%) | 25 (20.5%) | 10 (12.5%) | 0.142 |
| Cutaneous | 95 (48%) | 48 (39.3%) | 47 (58.7%) | 0.007 |
*Median (IQR) of CK×time upper limit of normal.
†178 had chest radiograph or CT scan to evaluate pulmonary fibrosis.
CK, creatine kinase; CTD, connective tissue disease; DM, dermatomyositis; FVC, forced vital capacity; IIM, idiopathic inflammatory myopathy; PAH, pulmonary artery hypertension; PM, polymyositis; SSc, systemic sclerosis; UCTD, undifferentiated connective tissue disease.