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Table 1 Demographic features of the JIIM participants by clinical and serologic subgroup included in the environmental analysis

From: Environmental factors associated with juvenile idiopathic inflammatory myopathy clinical and serologic phenotypes

 

Clinical Subgroups1

Serologic Subgroups2

 

JDM n = 87

N (%) or Median [IQR]

JCTM3n = 14

N (%) or Median [IQR]

JPM n = 5

N (%) or Median [IQR]

Anti-TIF-1 (p155/140) n = 33

N (%) or Median [IQR]

Anti-NXP2 (MJ) n = 30

N (%) or Median [IQR]

Anti-MDA5 n = 17

N (%) or Median [IQR]

MSA Negative n = 14

N (%) or Median [IQR]

Sex

 Female

54 (62.1)

9 (64.3)

3 (60.0)

26 (78.8)a

20 (66.7)

9 (52.9)

5 (35.7)

Age at Diagnosis (Years)

      

 Median

6.7 [4.0–10.3]e

10.9 [7.3–13.8]

12.2 [6.9–14.7]

6.1 [2.8–10.0]

7.4 [5.4–12.4]

6.8 [4.9–9.7]

11.8 [5.3–14.6]f

Disease Duration (Years)

 Median

1.5 [0.5–3.5]

1.6 [0.6–8.4]

1.5 [0.7–3.1]

2.7 [0.7–3.9]

2.0 [0.8–4.7]

1.0 [0.4–1.9]

1.0 [0.6–3.1]

Diagnosis Delay (Years)

 Median

0.4 [0.0–1.0]

0.3 [0.0–1.5]

0.0 [0.0–4.1]

0.2 [0.0–1.0]

0.9 [0.3–2.5]

0.3 [0.0–0.7]

0.4 [0.1–1.7]

Race

 Caucasian

61 (70.1)

6 (42.9)

3 (60.0)

28 (84.8)b

18 (60.0)

6 (35.3)

9 (64.3)

 Black

6 (6.9)

3 (21.4)

1 (20.0)

1 (3.0)

3 (10.0)

4 (23.5)c

1 (7.1)

 Hispanic

13 (14.9)

2 (14.3)

1 (20.0)

4 (12.1)

6 (20.0)

2 (11.8)

2 (14.3)

 Other

7 (8.0)

3 (21.4)

0 (0.0)

0 (0.0)

3 (10.0)

5 (29.4)d

2 (14.3)

Parental Education

 College or Graduate Degree

51 (60.0)

7 (53.8)

1 (25.0)

14 (45.2)

20 (65.5)

9 (52.9)

10 (71.4)

Urban residential location4

 Metropolitan area ≥ 1 million residents

51 (63.0)

7 (53.8)

3 (60.0)

19 (59.4)

18 (62.1)

13 (86.7)g

6 (46.2)

 Metropolitan area with less than 1 million residents

18 (22.2)

3 (23.1)

2 (40.0)

9 (28.1)h

5 (17.2)

0 (0.0)

5 (38.5)i

 Non-metropolitan area

12 (14.8)

3 (23.1)

0 (0.0)

4 (12.5)

7 (24.1)

2 (13.3)

2 (15.4)

Household Income5

 Median

$33,663 [$13,967–$75,057]

$64,156 [$15,591–$89,675]

$55,378 [$26,293–$76,561]

$68,371 [$45,459–$92,141]

$59,630 [$49,599–$86,282]

$61,066 [$40,982–$99,875]

$55,378 [$11,961–$79,220]

  1. Abbreviations: JDM juvenile dermatomyositis, JPM juvenile polymyositis, JCTM juvenile connective tissue myositis, IQR interquartile range, MSA myositis- specific autoantibody
  2. For diagnosis delay, three patients are missing, including two JDM and one JCTM from the clinical subgroups, and one autoantibody negative patient from the serologic subgroups. For parental education level, four patients are missing, including two JDM, one JCTM, and one JPM patients from the clinical subgroups, and two anti-TIF-1 and one anti-NXP2 autoantibody positive patients from the serologic subgroups. For household income level, six patients are missing, including five JDM and one JCTM from the clinical subgroups, and one anti-TIF-1, one anti-NXP2, two anti-MDA5 autoantibody patients, and one autoantibody negative patient from the serologic subgroups
  3. 1One patient with immune-mediated necrotizing myopathy was excluded from all analyses
  4. 2Patients excluded from the serologic subgroup analysis were two patients with anti-signal recognition particle, one with anti-Mi2 autoantibodies, two with indeterminate myositis autoantibodies, and three that had no myositis autoantibody results available. Three patients with anti-Jo1 autoantibodies and one with anti-PL-12 autoantibodies (i.e., those with anti-synthetase autoantibodies) were examined only descriptively and not included in Table 2
  5. 3Those with JCTM, met the criteria for myositis and at least one other autoimmune disease. The overlapping autoimmune diseases were systemic lupus erythematosus (four patients), celiac disease (three patients), scleroderma (two patients), and linear scleroderma, autoimmune hepatitis, type 1 diabetes mellitus, alopecia areata, and juvenile idiopathic arthritis (one patient each)
  6. 4Based on Urban Influence Codes of U.S. Department of Agriculture, using residential zip code at diagnosis and U.S.census data
  7. 5 From the American Community Survey, geocoding zip code at diagnosis to the centroid of the census tract level
  8. aP = 0.007 between anti-TIF-1 autoantibody positive and MSA-negative; bP = 0.001 between anti-TIF-1 and anti-MDA5 autoantibody positive; cP = 0.040 between anti-MDA5 and anti-TIF-1 autoantibody positive; dP = 0.030 between anti-MDA5 and anti-TIF-1 autoantibody positive; eP = 0.034 between JDM and JCTM; fP = 0.036 between anti-TIF-1 autoantibody positive and MSA-negative; gP = 0.042 between anti-MDA5 autoantibody positive and MSA-negative; hP = 0.042 between anti-TIF-1 autoantibody positive and anti-MDA5 autoantibody positive; iP = 0.013 between MSA-negative and anti-MDA5 autoantibody positive
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Pediatric Rheumatology

ISSN: 1546-0096