title: IgM nephropathy in children: clinicopathologic analysis.
abstract: BACKGROUND
  IgM nephropathy (IgMN) is a glomerulonephritis characterised by diffuse mesangial immunoglobulin M (IgM) deposits. It usually presents with nephrotic range proteinuria and, according to some previous work, it occurs most often in patients who are resistant to or dependent on steroid treatment.
  
  
  OBJECTIVE
  To perform a clinical, histological and immunopathological description and assess the response to steroid treatment of paediatric patients diagnosed with nephrotic syndrome and diffuse mesangial IgM deposits.
  
  
  METHODS
  This is a descriptive, retrospective study carried out in two hospitals, where the clinical records of paediatric patients with IgMN were analysed and the histological sections were re-assessed.
  
  
  RESULTS
  thirteen children were included in this study. IgMN corresponded to 5.17% of all paediatric renal biopsies. The age of patients ranged from 1 year to 12 years (median: 2 years), 46.7% were women. The most common morphological finding was diffuse mesangial hypercellularity (46.1%), followed by focal segmental glomerulosclerosis (30.8%) and minimal glomerular changes (23.1%). All patients received steroids; in 4 cases (30.7%) as the only immunosuppressant medication, 3 (23.1%) also received cyclophosphamide, 5 (38.4%) mycophenolate, and 1 (7.7%) cyclosporine. Seven patients (53.8%) had frequent relapses, 5 (38.5%) were cortico-resistant and 1 (7.7%) cortico-dependent. Two patients (15.38%) had chronic impairment of renal function.
  
  
  CONCLUSIONS
  The presence of diffuse mesangial IgM in paediatric patients with nephrotic syndrome is not a very uncommon finding; its clinical presentation has been associated with lower response to steroids. However, the long-term prognosis of these patients is still unknown.
authors.affiliation: Departamento de Patología, Facultad de Medicina, Universidad de Antioquia y Hospital Universitario San Vicente de Paúl, Medellín, Antioquia, Colombia.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Arias
authors.forename: M Claudia
authors.initials: MC
authors.lastname: Prada
authors.forename: Catalina
authors.initials: C
authors.lastname: Vélez-Echeverri
authors.forename: Lina M
authors.initials: LM
authors.lastname: Serna-Higuita
authors.forename: Ana K
authors.initials: AK
authors.lastname: Serrano-Gayubo
authors.forename: Carolina L
authors.initials: CL
authors.lastname: Ochoa
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Vanegas-Ruiz
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D005920:Glomerular Mesangium / Q000378:metabolism; D005921:Glomerulonephritis / Q000188:drug therapy / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D007223:Infant; D008297:Male; D012189:Retrospective Studies
chemical_list: D007075:Immunoglobulin M