Table 1.

Characteristics of 20 patients with juvenile dermatomyositis in the present study.

CharacteristicsValues
Age at evaluation, yrs12.1 (9.3–15.7)
Female sex13 (65.0)
Race
  White17 (85.0)
  African American1 (5.0)
  Asian1 (5.0)
  White and Hispanic1 (4.5)
Myositis-specific autoantibodies
  Anti-p155/140 (TIF1)7 (35.0)
  Anti-MJ (NXP2)3 (15.0)
  Anti-MDA56 (30.0)
  Other MSA (Jo1, Mi-2, HMGCR)3 (15.0)
  MSA-negative1 (5.0)
Disease measures
  Physician’s global activity score, 0–10 cm VAS2.7 (1.6–4.4)
  Patient’s/parent’s global activity score, 0–10 cm VAS4.2 (2.1–5.6)
  Physician’s global damage, 0–10 cm VAS1.9 (0.7–2.9)
Physical function
  HAQ or CHAQ, 0–30.4 (0.1–1.1)
  CMAS, 0–5245.5 (37.3–49.0)
Muscle strength
  MMT-8, 0–8075.0 (68.5–78.8)
Muscle enzymes
  CK, 26–252 u/l39.5 (29.0–66.0)
  Aldolase, 1–7 u/l5.8 (4.7–5.8)
  AST, 0–34 u/l30.5 (23.3–35.8)
  LDH, 105–226 u/l204 (170–241)
MDAAT VAS Organ System Scores
  Cutaneous, 0–10 cm VAS2.6 (1.9–5.0)
  Muscle, 0–10 cm VAS2.1 (0.6–3.4)
  Constitutional, 0–10 cm VAS1.0 (0.4–1.4)
  Pulmonary, 0–10 cm VAS0.6 (0–1.0)
  Skeletal, 0–10 cm VAS0 (0–0.3)
  Gastrointestinal, 0–10 cm VAS0 (0–0.5)
  Extramuscular VAS score, 0–604.6 (3.2–7.1)
Disease Activity Score
  Total, 0–2010 (8–12)
  Muscle, 0–115 (3–6)
  Cutaneous, 0–96 (5–7)
Myositis Damage Index
  Total Extent of Damage score, 0–385.0 (3.0–8.5)
  Total Severity of Damage score, 0–1105.5 (3.3–8.0)
  Muscle Severity of Damage, 0–10 cm VAS1.5 (0.1–2.5)
  Skeletal Severity of Damage, 0–10 cm VAS1.5 (0.9–2.8)
  Endocrine Severity of Damage, 0–10 cm VAS0.6 (0–1.0)
  Pulmonary Severity of Damage, 0–10 cm VAS0 (0–0.9)
Other measures
  MRI T1 atrophy and fatty muscle infiltration score, 0–40 (0–0.5)
  Brachial artery flow mediated dilation, % change9.1 (8.0–14.8)
  Periungual nailfold capillary density, mm8.0 (6.8–10.0)
  Delay to diagnosis, mos4.0 (2.0–9.0)
Laboratory
  White blood cell count, 3.4–9.6, × 103/mcl6.9 (4.7–8.5)
  Platelet count, 161–380, × 103/mcl300 (250–343)
  Erythrocyte sedimentation rate, ULN 42, mm/h19.0 (6.0–44.0)
  Fasting serum insulin, mIU/l15.1 (10.7–25.6)
  LDL, ULN 159, mg/dl118 (108–151)
  Total cholesterol, ULN 240, mg/dl202 (176–244)
Medications
  Daily oral prednisone dose, mg/day15.0 (6.4–23.1)
  Oral prednisone usage18 (90.0)
  Intravenous methylprednisolone usage16 (80.0)
  Methotrexate usage20 (100)
  Intravenous immunoglobulin usage12 (60.0)
  Other immunosuppressive usage§9 (45.0)
  Hydroxychloroquine usage15 (75.0)
  • Values are n (%) or median (interquartile range).

  • Other myositis-specific autoantibodies included 1 patient each with anti-Jo1, anti-Mi-2, and anti-HMGCR.

  • Cardiovascular MDAAT and gastrointestinal and peripheral vascular severity of damage scores were all 0.

  • § Other immunosuppressives include azathioprine, mycophenolate mofetil, cyclosporine, cyclophosphamide, or antitumor necrosis factor therapy (etanercept and infliximab). AST: aspartate aminotransferase; (C)HAQ: (Childhood) Health Assessment Questionnaire; CK: creatine kinase; CMAS: Childhood Myositis Assessment Scale; HMGCR: 3-hydroxy-3-methylglutaryl-CoA reductase; LDH: lactate dehydrogenase; LDL: low-density lipoprotein; MDAAT: Myositis Disease Activity Assessment tool; MDA5: melanoma differentiation–associated gene 5; MMT: Manual Muscle Testing; MRI: magnetic resonance imaging; MSA: myositis-specific autoantibodies; NXP2: nuclear matrix protein 2; STIR: short-tau inversion recovery; TIF1: transcriptional intermediary factor 1; ULN: upper limit of normal; VAS: visual analog scale.