title: Clinical and pathological features of microscopic polyangiitis in 20 children.
abstract: OBJECTIVE
  To explore the clinical and pathological features of microscopic polyangiitis (MPA) in children.
  
  
  METHODS
  A retrospective analysis was performed of patients with pediatric MPA in our hospital over 10 years.
  
  
  RESULTS
  Data for 20 patients were collected; 16 patients had primary MPA (4 boys, 12 girls), with a median age of 8.9 years at the time of disease onset; 4 patients, all female, had antithyroid drug (ATD)-associated MPA, with an age range of 12.5 to 16.2 years at the time of disease onset. All patients exhibited renal involvement. Renal biopsies were performed in 14 patients. Fibrinoid exudation and necrosis of the glomerular capillaries were observed in all biopsy specimens. Crescents and scleroses were noted in 92.9% and 85.7% of these cases, respectively. The most frequent extrarenal organs involved were lungs, followed by the central nervous system (CNS), skin, and digestive system. Ninety percent of patients were positive for perinuclear antineutrophil cytoplasmic antibody, 94.1% were positive for myeloperoxidase, and 88.2% were positive for both. Forty-five percent of the patients had received steroid plus cyclophosphamide (CTX) pulse therapy for more than 3 months, and varying degrees of remission had been achieved in 88.9% of the patients.
  
  
  CONCLUSIONS
  Both primary and ATD-associated MPA showed a female predisposition. Renal involvement was the most frequently observed condition, followed by involvement of lungs. CNS involvement was not rare in these pediatric patients. The efficacy of steroid plus CTX as induction therapy was evident in these patients.
authors.affiliation: From the Children's Kidney Disease Center, Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.L. Sun, MD, PhD, Associate Chief Physician; H. Wang, MD, Resident; X. Jiang, MD, PhD, Chief Physician; Y. Mo, MD, Associate Chief Physician; Z. Yue, MD, Associate Chief Physician; L. Huang, MD, Associate Chief Physician; T. Liu, Graduate Student. Drs. Sun and Wang contributed equally to this study. xyjiang-3208@163.com sunlzh@mail.sysu.edu.cn.
authors.forename: Liangzhong
authors.initials: L
authors.lastname: Sun
authors.affiliation: From the Children's Kidney Disease Center, Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.L. Sun, MD, PhD, Associate Chief Physician; H. Wang, MD, Resident; X. Jiang, MD, PhD, Chief Physician; Y. Mo, MD, Associate Chief Physician; Z. Yue, MD, Associate Chief Physician; L. Huang, MD, Associate Chief Physician; T. Liu, Graduate Student. Drs. Sun and Wang contributed equally to this study.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: From the Children's Kidney Disease Center, Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.L. Sun, MD, PhD, Associate Chief Physician; H. Wang, MD, Resident; X. Jiang, MD, PhD, Chief Physician; Y. Mo, MD, Associate Chief Physician; Z. Yue, MD, Associate Chief Physician; L. Huang, MD, Associate Chief Physician; T. Liu, Graduate Student. Drs. Sun and Wang contributed equally to this study. xyjiang-3208@163.com sunlzh@mail.sysu.edu.cn.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Jiang
authors.affiliation: From the Children's Kidney Disease Center, Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.L. Sun, MD, PhD, Associate Chief Physician; H. Wang, MD, Resident; X. Jiang, MD, PhD, Chief Physician; Y. Mo, MD, Associate Chief Physician; Z. Yue, MD, Associate Chief Physician; L. Huang, MD, Associate Chief Physician; T. Liu, Graduate Student. Drs. Sun and Wang contributed equally to this study.
authors.forename: Ying
authors.initials: Y
authors.lastname: Mo
authors.affiliation: From the Children's Kidney Disease Center, Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.L. Sun, MD, PhD, Associate Chief Physician; H. Wang, MD, Resident; X. Jiang, MD, PhD, Chief Physician; Y. Mo, MD, Associate Chief Physician; Z. Yue, MD, Associate Chief Physician; L. Huang, MD, Associate Chief Physician; T. Liu, Graduate Student. Drs. Sun and Wang contributed equally to this study.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Yue
authors.affiliation: From the Children's Kidney Disease Center, Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.L. Sun, MD, PhD, Associate Chief Physician; H. Wang, MD, Resident; X. Jiang, MD, PhD, Chief Physician; Y. Mo, MD, Associate Chief Physician; Z. Yue, MD, Associate Chief Physician; L. Huang, MD, Associate Chief Physician; T. Liu, Graduate Student. Drs. Sun and Wang contributed equally to this study.
authors.forename: Liuyi
authors.initials: L
authors.lastname: Huang
authors.affiliation: From the Children's Kidney Disease Center, Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, P.R. China.L. Sun, MD, PhD, Associate Chief Physician; H. Wang, MD, Resident; X. Jiang, MD, PhD, Chief Physician; Y. Mo, MD, Associate Chief Physician; Z. Yue, MD, Associate Chief Physician; L. Huang, MD, Associate Chief Physician; T. Liu, Graduate Student. Drs. Sun and Wang contributed equally to this study.
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D013956:Antithyroid Agents / Q000009:adverse effects; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007678:Kidney Glomerulus / Q000098:blood supply / Q000473:pathology*; D008297:Male; D055953:Microscopic Polyangiitis / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology*; D009195:Peroxidase / Q000097:blood*; D020551:Pulse Therapy, Drug; D012189:Retrospective Studies; D013256:Steroids / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D013956:Antithyroid Agents; D015415:Biomarkers; D013256:Steroids; D003520:Cyclophosphamide; D009195:Peroxidase
keywords: ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES; GLOMERULONEPHRITIS; MICROSCOPIC POLYANGIITIS; SYSTEMIC VASCULITIS