Table 1. Demographic and clinical features of the study population.
| Total patients (n = 197) |
Survivors (n = 171) |
Non-survivors (n = 26) |
P value | |
|---|---|---|---|---|
| Male:Female | 69:128 | 60:111 | 9:17 | 0.96 |
| Age at diagnosis (years) | 50.3 ± 14.0 | 48.8 ± 13.9 | 59.7 ± 10.5 | <0.001 |
| Age > 50 years | 113 (57.4) | 90 (52.6) | 23 (88.5) | <0.001 |
| Follow up period (months) | 33.6 ± 33.9 | 37.2 ± 34.5 | 9.5 ± 14.5 | <0.001 |
| IIM subtypes | 0.48 | |||
| PM | 44 (22.3) | 40 (23.4) | 4 (15.4) | |
| Classic DM | 115 (58.4) | 97 (56.7) | 18 (69.2) | |
| CADM | 38 (14.2) | 34 (19.9) | 4 (15.4) | |
| Overlap syndrome | 30 (15.2) | 27 (15.8) | 3 (11.5) | 0.77 |
| Extra-muscular manifestations | ||||
| Heliotrope rash | 50/153 (32.7) | 42/131 (32.1) | 8/22 (36.4) | 0.69 |
| Gottron's papule | 91/153 (59.5) | 75/131 (57.3) | 16/22 (72.7) | 0.17 |
| V neck sign | 64/153 (41.8) | 56/131 (42.7) | 8/22 (36.4) | 0.57 |
| Mechanic’s hand | 22/153 (14.4) | 21/131 (16.0) | 1/22 (4.5) | 0.20 |
| Fever | 35 (17.8) | 27 (15.8) | 8 (30.8) | 0.06 |
| Raynaud’s phenomenon | 25 (12.7) | 24 (14.0) | 1 (3.8) | 0.21 |
| Arthralgia/Arthritis | 77 (39.1) | 68 (39.8) | 9 (34.6) | 0.62 |
| Myocardial involvement | 2 (1.0) | 1 (0.6) | 1 (3.8) | 0.25 |
| ILD | 101 (51.3) | 81 (47.4) | 20 (76.9) | 0.005 |
| AIP | 13/101 (12.9) | 1/81 (1.2) | 12/20 (60.0) | <0.001 |
| Acute exacerbation of ILD | 40/101 (39.6) | 24/81 (29.6) | 16/20 (61.4) | <0.001 |
| Malignancy history | ||||
| > 2 years before IIM diagnosis | 5 (2.5) | 3 (2.9) | 2 (7.7) | 0.38 |
| Within ± 2 year from IIM diagnosis | 28 (14.2) | 23 (13.5) | 5 (19.2) | 0.43 |
| Within ± 1 year from IIM diagnosis | 23 (11.7) | 18 (10.5) | 5 (19.2) | 0.20 |
| WBC, mm3 | 7268 ± 4045 | 7364 ± 3750 | 9362 ± 5392 | 0.08 |
| ANC, mm3 | 5528 ± 3790 | 5206 ± 3498 | 7647 ± 4900 | 0.02 |
| Neutrophilia (ANC >7500) | 42 (21.3) | 32 (18.7) | 10 (38.5) | 0.02 |
| ALC, mm3 | 1369 ± 813 | 1432 ± 835 | 960 ± 490 | <0.001 |
| Lymphopenia (ALC <1000) | 69 (35.0) | 52 (30.4) | 17 (65.4) | <0.001 |
| Hemoglobin, g/dL | 12.1 ± 1.7 | 12.2 ± 1.7 | 11.6 ± 1.9 | 0.10 |
| Platelet, ×103/mm3 | 254 ± 102 | 257 ± 101 | 239 ± 113 | 0.41 |
| NLR, log-transformed | 1.364 ± 0.841 | 1.266 ± 0.822 | 2.002 ± 0.684 | <0.001 |
| ESR, mm/hr (n = 193) | 40 ± 24 | 39 ± 25 | 44 ± 18 | 0.27 |
| CRP, mg/dL | 1.94 ± 3.46 | 1.65 ± 3.10 | 3.90 ± 4.93 | 0.03 |
| Albumin, g/dL | 3.36 ± 0.53 | 3.43 ± 0.58 | 2.91 ± 0.76 | <0.001 |
| CAR, log-transformed | -2.176 ± 2.277 | -2.403 ± 2.245 | -0.687 ± 1.934 | <0.001 |
| Protein, g/dL | 6.64 ± 0.86 | 6.72 ± 0.82 | 6.03 ± 0.89 | <0.001 |
| Creatinine, mg/dL | 0.71 ± 0.42 | 0.68 ± 0.19 | 0.92 ± 1.03 | 0.25 |
| CPK, IU/L | 2661 ± 4793 | 2820 ± 5042 | 1614 ± 2435 | 0.05 |
| LDH, IU/L (n = 187) | 585 ± 471 | 596 ± 496 | 512 ± 225 | 0.42 |
| Anti-Jo-1 positivity | 26/178 (14.6) | 24/152 (15.8) | 2/26 (7.7) | 0.38 |
| Pulmonary function | ||||
| FVC (n = 130) | 2.60 ± 0.87 | 2.60 ± 0.88 | 2.64 ± 0.73 | 0.88 |
| FVC, percent predicted | 74.7 ± 18.2 | 74.5 ± 18.2 | 75.9 ± 19.0 | 0.79 |
| DLco (n = 121) | 13.4 ± 5.6 | 13.6 ± 5.7 | 11.9 ± 4.0 | 0.28 |
| DLco percent predicted | 68.3 ± 22.3 | 68.3 ± 22.8 | 67.7 ±18.6 | 0.91 |
| Treatment | ||||
| High-dose glucocorticoid* | 162 (82.2) | 138 (80.7) | 24 (92.3) | 0.18 |
| Cyclosporine A | 65 (33.0) | 54 (31.6) | 11 (42.3) | 0.28 |
| Cyclophosphamide | 18 (9.1) | 13 (7.6) | 5 (19.2) | 0.06 |
Values are presented as n (%) or mean ± standard deviation.
* > 30mg as the prednisolone equivalent dose a day
Abbreviation: IIM, idiopathic inflammatory myopathy; PM, polymyositis; DM, dermatomyositis; CADM, clinically amyopathic dermatomyositis; ILD, interstitial lung disease; AIP, acute interstitial pneumonia; WBC, white blood cells; ANC, absolute neutrophil count; ALC, absolute lymphocyte count; NLR, neutrophil-to-lymphocyte ratio; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; CAR, CRP-to-albumin ratio; CPK, creatine phosphokinase; LDH, lactate dehydrogenase; FVC, forced vital capacity; DLco, diffusion capacity for carbon monoxide.