title: Risk Factors for Symptomatic Avascular Necrosis in Childhood-onset Systemic Lupus Erythematosus.
abstract: OBJECTIVE
  To examine the frequency and risk factors for symptomatic avascular necrosis (AVN) in childhood-onset systemic lupus erythematosus (cSLE).
  
  
  METHODS
  A single-center, nested, matched, case-control design was used. There were 617 patients with cSLE followed at the Hospital for Sick Children (SickKids) Lupus Clinic between July 1982 and June 2013 included in the study. The AVN cohort consisted of 37 patients identified with clinical findings of symptomatic AVN and diagnosis was confirmed by 1 or more imaging modalities. Three controls were matched to each patient with AVN by date and age at diagnosis. Baseline clinical, laboratory, and treatment characteristics were compared between patients with AVN and controls by univariable analyses and if statistically significant, were included in a multivariable logistic regression model.
  
  
  RESULTS
  A total of 37/617 patients (6%) developed symptomatic AVN in 91 joints during followup at SickKids. The mean duration to disease was 2.3 years. The hip was the most commonly involved joint (26/37, 70%). Compared with the matched non-AVN cohort, patients with AVN had a higher incidence of central nervous system (CNS) involvement and nephritis, required greater cumulative prednisone (PRED) from cSLE diagnosis to AVN, received a greater maximal daily PRED dose, and had more frequent use of pulse methylprednisolone therapy. Multivariable regression analysis confirmed major organ involvement (CNS disease and/or nephritis) and maximal daily PRED dose as significant predictors of symptomatic AVN development.
  
  
  CONCLUSIONS
  Patients with cSLE with severe organ involvement including nephritis and CNS disease and higher maximal daily dose of PRED are more likely to develop symptomatic AVN.
authors.affiliation: From the Faculty of Medicine, University of Ottawa, Ottawa; Hospital for Sick Children; University of Toronto, Toronto, Ontario, Canada; Christian Medical College, Vellore, India.Y. Yang, BHSc, Faculty of Medicine, University of Ottawa; S. Kumar, MBBS, MD, DCH, Christian Medical College; L.S. Lim, MBBS, MRCPCH, FRCPC, PhD(c), Hospital for Sick Children, and University of Toronto; E.D. Silverman, MD, FRCPC, Hospital for Sick Children, and University of Toronto; D.M. Levy, MD, MS, FRCPC, Hospital for Sick Children, and University of Toronto.
authors.forename: Yelin
authors.initials: Y
authors.lastname: Yang
authors.affiliation: From the Faculty of Medicine, University of Ottawa, Ottawa; Hospital for Sick Children; University of Toronto, Toronto, Ontario, Canada; Christian Medical College, Vellore, India.Y. Yang, BHSc, Faculty of Medicine, University of Ottawa; S. Kumar, MBBS, MD, DCH, Christian Medical College; L.S. Lim, MBBS, MRCPCH, FRCPC, PhD(c), Hospital for Sick Children, and University of Toronto; E.D. Silverman, MD, FRCPC, Hospital for Sick Children, and University of Toronto; D.M. Levy, MD, MS, FRCPC, Hospital for Sick Children, and University of Toronto.
authors.forename: Sathish
authors.initials: S
authors.lastname: Kumar
authors.affiliation: From the Faculty of Medicine, University of Ottawa, Ottawa; Hospital for Sick Children; University of Toronto, Toronto, Ontario, Canada; Christian Medical College, Vellore, India.Y. Yang, BHSc, Faculty of Medicine, University of Ottawa; S. Kumar, MBBS, MD, DCH, Christian Medical College; L.S. Lim, MBBS, MRCPCH, FRCPC, PhD(c), Hospital for Sick Children, and University of Toronto; E.D. Silverman, MD, FRCPC, Hospital for Sick Children, and University of Toronto; D.M. Levy, MD, MS, FRCPC, Hospital for Sick Children, and University of Toronto.
authors.forename: Lily Siok Hoon
authors.initials: LS
authors.lastname: Lim
authors.affiliation: From the Faculty of Medicine, University of Ottawa, Ottawa; Hospital for Sick Children; University of Toronto, Toronto, Ontario, Canada; Christian Medical College, Vellore, India.Y. Yang, BHSc, Faculty of Medicine, University of Ottawa; S. Kumar, MBBS, MD, DCH, Christian Medical College; L.S. Lim, MBBS, MRCPCH, FRCPC, PhD(c), Hospital for Sick Children, and University of Toronto; E.D. Silverman, MD, FRCPC, Hospital for Sick Children, and University of Toronto; D.M. Levy, MD, MS, FRCPC, Hospital for Sick Children, and University of Toronto.
authors.forename: Earl D
authors.initials: ED
authors.lastname: Silverman
authors.affiliation: From the Faculty of Medicine, University of Ottawa, Ottawa; Hospital for Sick Children; University of Toronto, Toronto, Ontario, Canada; Christian Medical College, Vellore, India.Y. Yang, BHSc, Faculty of Medicine, University of Ottawa; S. Kumar, MBBS, MD, DCH, Christian Medical College; L.S. Lim, MBBS, MRCPCH, FRCPC, PhD(c), Hospital for Sick Children, and University of Toronto; E.D. Silverman, MD, FRCPC, Hospital for Sick Children, and University of Toronto; D.M. Levy, MD, MS, FRCPC, Hospital for Sick Children, and University of Toronto. Deborah.levy@sickkids.ca.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Levy
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000009:adverse effects* / Q000627:therapeutic use; D017677:Age Distribution; D017668:Age of Onset; D002648:Child; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D008297:Male; D015999:Multivariate Analysis; D009864:Ontario; D010020:Osteonecrosis / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000209:etiology; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution
chemical_list: D000305:Adrenal Cortex Hormones
keywords: AVASCULAR NECROSIS; CHILDHOOD-ONSET SYSTEMIC LUPUS ERYTHEMATOSUS; MAJOR ORGAN INVOLVEMENT; OSTEONECROSIS; RISK FACTORS