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Table 2 Univariate comparison of characteristics of patients with and without antibodies to RNA polymerase III

From: Prevalence, correlates and clinical usefulness of antibodies to RNA polymerase III in systemic sclerosis: a cross-sectional analysis of data from an Australian cohort

  Anti-RNAP+ (n= 69) Anti-RNAP- (n= 382)  
Characteristic Totala n(%) or mean ± SD Totala n(%) or mean ± SD P value
Sex 69   382   
   Female   58 (84.1%)   339 (88.7%) 0.27
   Male   11 (15.9%)   42 (11.1%)  
Race 65   373   
   Caucasian   61 (93.9%)   352 (94.4%) 0.97
   Asian   3 (4.6%)   14 (3.8%)  
   Aboriginal-Islander   1 (1.5%)   7 (1.9%)  
Age (years)      
   At disease onsetb 68 47.0 ± 11.7 373 46.4 ± 14.0 0.70
   At recruitment 68 56.0 ± 12.1 380 58.4 ± 12.4 0.14
Disease duration (years)      
   At recruitment 68 9.0 ± 7.9 373 12.1 ± 10.3 0.02
   At the time of the studyc 68 11.4 ± 8.1 373 14.1 ± 10.7 0.06
Duration of follow-upc (years) 59 1.9 ± 0.9 256 1.9 ± 0.8 0.97
Disease subtyped 69   382   
   Limited   17 (24.6%)   302 (79.1%) < 0.0001
   Diffuse   52 (75.4%)   80 (20.9%)  
Disease manifestationse      
   Raynaud's phenomenon 66 66 (100%) 370 370 (100%) 1.0
   Digital ulcers 69 35 (50.7%) 382 159 (41.6%) 0.16
   Tendon friction rubs 69 8 (11.6%) 382 24 (6.3%) 0.12
   Joint contractures 69 51 (73.9%) 382 115 (30.1%) < 0.0001
   Highest mRSS during follow-upf 68 20.6 ± 12.4 366 10.1 ± 7.9 < 0.0001
   Synovitis 69 22 (31.9%) 382 76 (19.9%) 0.03
   Myositis 69 2 (2.9%) 382 2 (0.5%) 0.05
   Renal crisisg 69 17 (24.6%) 382 7 (1.8%) < 0.0001
   Systemic hypertensionh 69 41 (59.4%) 375 149 (39.7%) 1.0
   Gastrointestinal involvementi 69 69 (100%) 382 379 (100%) 0.75
   Pulmonary arterial hypertensionj 69 7 (10.1%) 382 42 (11.0%) 0.52
   Interstitial lung diseasek 69 19 (27.5%) 382 120 (31.4%) 0.80
   Cardiac involvementl 69 7 (10.1%) 382 24 (6.3%) 0.24
Serologic profilem 69     
   Antinuclear antibodies   67 (97.1%) 382 366 (95.8%) 0.61
   Anti-centromere pattern   4 (5.8%) 381 193 (50.7%) < 0.0001
   Anti-topoisomerase antibodies   1 (1.5%) 377 78 (20.7%) 0.0001
   Anti-histidyl-tRNA synthetase antibodies   0 (0%) 377 0 (0%) 1.0
   Anti-ribonucleoprotein antibodies   1 (1.5%) 376 3 (0.8%) 0.6
   Anti-Ro antibodies   3 (4.4%) 377 24 (6.4%) 0.52
   Anti-La antibodies   0 (0%) 377 6 (1.6%) 0.29
   Anti-Smith antibodies 44 0 (0%) 376 1 (0.3%) 0.67
   Anti-double stranded DNA antibodies 69 0 (0%) 254 6 (2.4%) 0.30
   Anti-polymyositis-scleroderma antibodies 64 0 (0%) 378 4 (1.1%) 0.39
   Anti-neutrophil cytoplasmic antibodies 64 10 (15.6%) 373 63 (16.9%) 0.80
Myeloperoxidase specificity 64 4 (16.3%) 372 8 (2.2%) 0.06
Proteinase-3 specificity 64 2 (13.1%) 372 13 (3.5%) 0.88
   Rheumatoid factor 65 8 (12.5%) 359 118 (32.9%) 0.001
   Anti-phospholipid antibodies 43 9 (13.9%) 371 129 (34.8%) 0.0008
   Lupus anticoagulant 69 0 (0%) 282 7 (12.5%) 0.30
Treatmente 69   382   
   Corticosteroids   40 (58.0%)   158 (41.4%) 0.01
   Antimalarialsn   10 (14.5%)   64 (16.8%) 0.64
   Immunosuppressiveso   40 (58.0%)   103 (27.0%) < 0.0001
   Biological therapiesp   1 (1.5%)   4 (1.1%) 0.77
Smoking ever 65 30 (46.2%) 371 153 (41.2%) 0.44
Malignancye 69 14 (13.0%) 382 50 (13.2%) 0.37
   Solid organq   9 (13.0%)   26 (6.8%)  
   Hematopoieticr   0 (0%)   7 (1.8%)  
   Skin (nonmelanoma)s   4 (5.8%)   9 (2.4%)  
   Melanoma   1 (1.5%)   5 (1.3%)  
   Othert   0 (0%)   3 (0.8%)  
Malignancy diagnosed within 5 years of onset of SScu,v 45 6 (13.3%) 254 10 (3.9%) 0.01
Time interval between SSc onset and malignancy diagnosis (years)u 9 4.1 ± 3.1 37 11.7 ± 9.1 0.0002
Malignancy in inception cohorte,w 31   120   0.42
   Solid organq   4   6  
   Hematopoieticr   0   1  
   Skin (nonmelanoma)s   1   3  
   Melanoma   0   0  
   Othert   0   0  
  1. anti-RNAP, anti-RNA polymerase III antibodies; mRSS, modified Rodnan skin score; n (%), number (percentage); SD, standard deviation; SSc, systemic sclerosis. aRefers to the total number of patients in whom data were available for analysis. bDisease onset defined as date of onset of first SSc-related manifestation other than Raynaud's phenomenon. cAs at 13 December 2010. dDisease subtype classified based extent of skin involvement, with limited disease being confined to extremities and face. eEver from birth to most recent visit. fScores range from 0 to 51, with higher scores indicating more severe skin involvement. gRenal crisis defined as abrupt-onset severe hypertension (systolic blood pressure (BP) ≥ 180 mmHg and/or diastolic BP ≥ 100 mmHg) without an alternate etiology, with or without microangiopathic anemia or decline in renal function. hDiastolic BP ≥ 90 mmHg or systolic BP ≥ 140 mmHg. iGastrointestinal involvement defined as one or more of reflux esophagitis, esophageal stricture or dysmotility, gastric antral vascular ectasia, bowel dysmotility or pseudo-obstruction. jPulmonary arterial hypertension defined as mean pulmonary arterial pressure ≥ 25 mmHg at rest with pulmonary capillary wedge pressure ≤ 15 mmHg. kInterstitial lung disease defined by high-resolution computerized tomography scan of the chest. lPresence of either left ventricular systolic or diastolic dysfunction where no other cause was identified, or a conduction disturbance unexplained by other mechanisms, or a characteristic histological picture on endomyocardial biopsy. mAt recruitment. nHydroxychloroquine. oIncludes methotrexate, azathioprine, mycophenolate mofetil, cyclosporine and cyclophosphamide. pIncludes TNF antagonists and rituximab. qIncludes breast, lung, colorectal, genitourinary and reproductive tract malignancies. rIncludes lymphoma, leukemia and multiple myeloma. sIncludes basal cell and squamous cell carcinomas. tIncludes neoplastic variants and pre-neoplastic disorders. uExcluding nonmelanoma skin cancers and the 'other' category; here SSc onset defined based on onset of skin change. vDenominator of 299 determined by adding the number of patients who had malignancy diagnosed within 5 years of diagnosis of SSc and all other patients in whom a diagnosis of malignancy had not been made but whose disease duration was ≥ 5 years as of 13 December 2010 (date at which data were censored for analysis). wPatients recruited within 5 years of onset of SSc skin changes.