Table 3.
Characteristics of anti-MPO-positive vs anti-MPO-negative patients and anti-PR3-positive vs anti-PR3-negative patients
| Anti-MPO negative n = 1289 |
Anti-MPO positive n = 13 |
p | Anti-PR3 negative n = 1284 |
Anti-PR3 positive n = 18 |
p | |
|---|---|---|---|---|---|---|
| Female | 1115 (86.5%) | 9 (69.2%) | 0.089# | 1112 (86.6%) | 12 (66.7%) | 0.014 |
| Race | ||||||
| Caucasian | 1166 (90.5%) | 12 (92.3%) | 0.622# | 1164 (90.7%) | 14 (77.8%) | 0.024# |
| Asian | 57 (4.4%) | 1 (7.7%) | 54 (4.2%) | 4 (22.2%) | ||
| Aboriginal-Islander | 15 (1.2%) | 0 (0%) | 15 (1.2%) | 0 (0%) | ||
| Other | 18 (1.4%) | 0 (0%) | 18 (1.4%) | 0 (0%) | ||
| Type of disease | ||||||
| Limited | 966 (74.9%) | 8 (61.5%) | 0.268 | 963 (75.0%) | 11 (61.1%) | 0.178 |
| Diffuse | 323 (25.1%) | 5 (38.5%) | 321 (25.0%) | 7 (38.9%) | ||
| Age of scleroderma onset, years | 46.44 ± 14.27 | 42.23 ± 14.26 | 0.290 | 46.39 ± 14.29 | 46.86 ± 13.24 | 0.888 |
| Age at recruitment, years | 57.76 ± 12.52 | 53.07 ± 14.02 | 0.180 | 57.71 ± 12.56 | 58.02 ± 11.17 | 0.916 |
| Disease duration at recruitment, years | 8.31 (12.31) | 13.07 (17.33) | 0.924^ | 8.29 (13.30) | 11.31 (16.86) | 0.934^ |
| Duration of follow-up, years | 3.09 (4.50) | 3.36 (3.48) | 0.619^ | 3.09 (4.50) | 3.97 (3.83) | 0.640^ |
| Ever smoked | 633 (49.1%) | 6 (46.2%) | 0.832 | 634 (49.4%) | 5 (27.8%) | 0.069 |
| Autoantibodies | ||||||
| Anti-Scl-70 | 175 (13.6%) | 5 (38.5%) | 0.006 | 172 (13.4%) | 8 (44.4%) | < 0.001 |
| Anti-centromere | 612 (47.6%) | 1 (7.7%) | 0.004# | 608 (47.4%) | 5 (27.8%) | 0.092 |
| ANA | 1211 (93.9%) | 10 (76.9%) | 0.036# | 1205 (93.8%) | 16 (88.9%) | 0.285# |
| Rheumatoid factor | 335 (26.0%) | 2 (15.4%) | 0.532# | 333 (25.9%) | 4 (22.2%) | 0.793# |
| Anti-Ro | 87 (6.7%) | 0 (0.0%) | > 0.999# | 86 (6.7%) | 1 (5.6%) | > 0.999# |
| Anti-La | 20 (1.6%) | 0 (0.0%) | > 0.999# | 20 (1.6%) | 0 (0%) | > 0.999# |
| Anti-RNP | 26 (2.0%) | 0 (0.0%) | > 0.999# | 26 (2.0%) | 0 (0%) | > 0.999# |
| Anti-dsDNA | 41 (3.2%) | 1 (7.7%) | 0.385# | 40 (3.1%) | 2 (11.1%) | 0.157# |
| Anti-Sm | 8 (0.6%) | 0 (0.0%) | > 0.999# | 8 (0.6%) | 0 (0.0%) | > 0.999# |
| Anti-Jo-1 | 7 (0.5%) | 0 (0.0%) | > 0.999# | 7 (0.5%) | 0 (0.0%) | > 0.999# |
| Anti-PM/Scl | 15 (1.2%) | 0 (0.0%) | > 0.999# | 15 (1.2%) | 0 (0.0%) | > 0.999# |
| Anti phospholipid antibodies | 302 (23.4%) | 2 (15.4%) | > 0.999# | 397 (30.9%) | 7 (38.9%) | 0.105 |
| Anti-cardiolipin | 259 (20.1%) | 2 (15.4%) | > 0.999# | 234 (18.2%) | 7 (38.9%) | 0.600# |
| Anti-beta 2 glycoprotein | 93 (7.2%) | 1 (7.7%) | 0.539# | 93 (7.2%) | 1 (5.6%) | 0.668# |
| Lupus anticoagulant | 34 (2.6%) | 1 (7.7%) | 0.226# | 35 (2.7%) | 0 (0.0%) | > 0.999# |
| Anti-RNA polymerase | 113 (8.8%) | 3 (23.1%) | 0.136# | 116 (9.0%) | 0 (0.0%) | 0.149# |
| Clinical characteristics and complications | ||||||
| Pulmonary arterial hypertension | 121 (9.4%) | 1 (7.7%) | > 0.999# | 118 (9.2%) | 4 (22.2%) | 0.080# |
| Interstitial lung disease | 305 (23.7%) | 5 (38.5%) | 0.213 | 301 (23.4%) | 9 (50.0%) | 0.009 |
| Renal crisis | 35 (2.7%) | 0 (0.0%) | > 0.999# | 35 (2.7%) | 0 (0.0%) | > 0.999# |
| Digital ulcers | 639 (49.6%) | 6 (46.2%) | 0.806 | 635 (49.5%) | 10 (55.6%) | 0.607 |
| SIBO | 37 (2.9%) | 0 (0.0%) | > 0.999# | 37 (2.9%) | 0 (0.0%) | > 0.999# |
| GAVE | 112 (8.7%) | 0 (0.0%) | 0.616# | 112 (8.7%) | 0 (0.0%) | 0.393# |
| Oesophageal dysmotility | 130 (10.1%) | 1 (7.7%) | > 0.999# | 130 (10.1%) | 1 (5.6%) | > 0.999# |
| Oesphageal stricture | 143 (11.1%) | 3 (23.1%) | 0.171# | 145 (11.3%) | 1 (5.6%) | 0.711# |
| Synovitis | 509 (39.5%) | 7 (53.8%) | 0.292 | 505 (39.3%) | 11 (61.1%) | 0.061 |
| Malignancy | 250 (19.6%) | 2 (15.4%) | > 0.999# | 249 (19.4%) | 3 (16.7%) | > 0.999# |
| Hospitalised | 484 (37.5%) | 6 (46.2%) | 0.524 | 481 (37.5%) | 9 (50.0%) | 0.276 |
| Deep vein thrombosis | 89 (6.9%) | 1 (7.7%) | 0.608# | 89 (6.9%) | 1 (5.6%) | > 0.999# |
| Pulmonary embolus | 44 (3.4%) | 1 (7.7%) | 0.368# | 42 (3.3%) | 3 (16.7%) | 0.022# |
| Overlap features with another connective tissue disease | 74 (5.7%) | 2 (15.4%) | 0.173# | 74 (5.8%) | 2 (11.1%) | 0.283# |
| Overlap syndrome with rheumatoid arthritis | 25 (1.9%) | 2 (15.4%) | 0.028# | 25 (1.9%) | 2 (11.1%) | 0.052# |
| Overlap syndrome with polymyositis | 13 (1.0%) | 0 (0.0%) | > 0.999# | 13 (1.0%) | 0 (0.0%) | > 0.999# |
| Overlap syndrome with Sjogren’s | 24 (1.9%) | 0 (0.0%) | > 0.999# | 24 (1.9%) | 0 (0.0%) | > 0.999# |
| Overlap syndrome with SLE | 12 (0.9%) | 0 (0.0%) | > 0.999# | 12 (0.9%) | 0 (0.0%) | > 0.999# |
| Overlap syndrome with dermatomyositis | 1 (0.1%) | 0 (0.0%) | > 0.999# | 1 (0.1%) | 0 (0.0%) | > 0.999# |
| Treatments | ||||||
| Prednisolone | 570 (44.2%) | 9 (69.2%) | 0.093# | 568 (44.2%) | 11 (61.1%) | 0.153 |
| Azathioprine | 101 (7.8%) | 3 (23.1%) | 0.079# | 101 (7.9%) | 3 (16.7%) | 0.169# |
| Mycophenolate | 100 (7.8%) | 2 (15.4%) | 0.271# | 98 (7.6%) | 4 (22.2%) | 0.046# |
| Cyclophosphamide | 113 (8.8%) | 4 (30.8%) | 0.023# | 113 (8.8%) | 4 (22.2%) | 0.071# |
| Calcium channel antagonist | 836 (64.9%) | 10 (76.9%) | 0.364# | 833 (64.9%) | 13 (72.2%) | 0.516 |
| Topical vasodilator | 103 (8.0%) | 2 (15.4%) | 0.283# | 103 (8.0%) | 2 (11.1%) | 0.651# |
| Iloprost | 160 (12.4%) | 1 (7.7%) | > 0.999# | 159 (12.4%) | 2 (11.1%) | > 0.999# |
| Operation for peripheral vascular disease | 14 (1.1%) | 0 (0.0%) | > 0.999# | 14 (1.1%) | 0 (0%) | > 0.999# |
| Penicillamine | 105 (8.1%) | 3 (23.1%) | 0.086# | 105 (8.2%) | 3 (16.7%) | 0.183# |
| Rituximab | 10 (0.8%) | 1 (7.7%) | 0.105# | 10 (0.8%) | 1 (5.6%) | 0.142# |
| Abatacept | 1 (0.1%) | 0 (0.0%) | > 0.999# | 1 (0.1%) | 0 (0%) | > 0.999# |
| TNF alpha inhibitor | 11 (0.9%) | 0 (0.0%) | > 0.999# | 11 (0.9%) | 0 (0%) | > 0.999# |
| Tocilizumab | 5 (0.4%) | 0 (0.0%) | > 0.999 | 5 (0.4%) | 0 (0%) | > 0.999 |
| Biologics ever | 25 (1.9%) | 1 (7.7%) | 0.232# | 25 (1.5%) | 1 (5.6%) | 0.306# |
Values are given as number (%), mean ± SD or median (IQR)
Abbreviations: ANA anti nuclear antibodies, ANCA anti-neutrophil cytoplasmic antibodies, anti-phospholipid antibodies: any one or combination of anti-cardiolipin, anti-beta-2-glycoprotein and lupus anticoagulant, anti-dsDNA anti-double stranded deoxyribonucleic acid, anti-RNP ribonucleoprotein, SIBO small intestinal bacterial overgrowth, SLE systemic lupus erythematosus, anti-Sm anti-Smith
^Rank sum test
#Fisher’s exact test