title: IgG4-related disease: a systematic review of this unrecognized disease in pediatrics.
abstract: BACKGROUND
  Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibro-inflammatory condition with an unclear pathophysiological mechanism affecting different parts of the body. If untreated, the disease can lead to fibrosis and irreversible organ damage. IgG4-RD mostly has been described in adults, hence it is generally unknown among pediatricians. This systematic search of the literature provides an overview of all reports published on IgG4-RD in children in order to create awareness of IgG4-RD in pediatrics and to emphasize the broad clinical presentation of this disease.
  
  
  METHODS
  A systematic literature search of Embase, Medline, Web-of-Science, PubMed publisher, Cochrane and Google Scholar was performed for case reports on IgG4-RD in children.
  
  
  RESULTS
  Of total 740 articles identified by the search, 22 case reports including 25 cases of IgG4-RD in children were found. The median age of the children was 13 years, of which 64 % were girls. IgG4-related orbital disease (44 %) and autoimmune pancreatitis type 1/IgG4-related pancreatitis (12 %) predominantly occurred. Less frequently, other manifestations as pulmonary manifestation, cholangitis and lymphadenopathy were also found. Almost all cases were histologically proven. Prednisone was the first choice of treatment leading to favorable clinical response in 83 % of the cases. Maintenance therapy with steroid sparing agents was required in 43 % of the cases needing therapy. Rituximab was successful in all 4 cases, whereas, the disease modifying rheumatic drugs (DMARDs) mycophenolate mofetil, azathioprine and methotrexate were effective in almost 50 % of the cases.
  
  
  CONCLUSIONS
  IgG4-RD in children is a generally unknown disease among pediatricians, but several pediatric cases have been described. Prednisone is the first choice of treatment leading to disease remission in the majority of the cases. DMARDs and rituximab are alternative effective steroid sparing agents with more positive evidence for the latter.
authors.affiliation: Departments of Internal Medicine and Immunology Erasmus MC, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands. a.karim@erasmusmc.nl.
authors.forename: Faiz
authors.initials: F
authors.lastname: Karim
authors.affiliation: Department of Pediatrics Oncology, Erasmus MC-Sophia Children's hospital, Rotterdam, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Loeffen
authors.affiliation: Medical library, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Wichor
authors.initials: W
authors.lastname: Bramer
authors.affiliation: Departments of Internal Medicine and Immunology Erasmus MC, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.
authors.forename: Lauren
authors.initials: L
authors.lastname: Westenberg
authors.affiliation: Department of Pathology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Verdijk
authors.affiliation: Departments of Internal Medicine and Immunology Erasmus MC, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: van Hagen
authors.affiliation: Departments of Internal Medicine and Immunology Erasmus MC, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: van Laar
mesh_terms: D000293:Adolescent; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D015551:Autoimmunity; D002648:Child; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007249:Inflammation / Q000276:immunology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007074:Immunoglobulin G