title: The Challenge of Immunoglobulin-G Subclass Deficiency and Specific Polysaccharide Antibody Deficiency--a Dutch Pediatric Cohort Study.
abstract: OBJECTIVE
  Immunoglobulin(Ig)G-subclass deficiency and specific polysaccharide antibody deficiency (SPAD) are among the most frequent causes of recurrent respiratory infections in children. Little is known about their prevalence, clinical presentation and prognosis. No study has been published in a Western-European nor in a mainly non-tertiary cohort until now. Therefore, we performed this observational cohort study in children recruited from secondary and tertiary pediatric practices all over The Netherlands.
  
  
  METHODS
  Dutch pediatricians were monthly asked to report patients with IgG-subclass deficiency and/or SPAD. Demographic, clinical and laboratory characteristics were collected. Separate informed consent was asked from parents and children (≥ 12 years of age) for annual update of the medical status.
  
  
  RESULTS
  49 children with confirmed IgG-subclass deficiency and/or SPAD were included. The majority of children (69%) was reported by four (out of 12) secondary hospitals with a pediatric immunologist in the staff. 45 children had ≥ 1 low IgG-subclass level and 11 had SPAD. IgG2 deficiency was the most prevalent IgG-subclass deficiency (37/49;76%). 10% of these children already showed bronchiectasis. Two-thirds were male (33/49;67%, p = 0.015). From 10 years of age, only boys were left and only boys showed progressive immunodeficiency during follow-up (11/24; 46%).
  
  
  CONCLUSIONS
  This is the first Western-European mainly non-tertiary cohort of children with IgG-subclass deficiency and/or SPAD. The disease course is not always benign, especially in boys. Most children were reported and managed in secondary hospitals with a pediatric immunologist in the staff. To identify more patients, the awareness of these diseases among general pediatricians should increase.
authors: Department of Pediatrics, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands.
authors: Ellen J H
authors: EJ
authors: Schatorjé
authors: Department of Pediatrics, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands.
authors: Everieke
authors: E
authors: de Jong
authors: Department of Linguistics, Radboud University, Nijmegen, The Netherlands.
authors: Roeland W N M
authors: RW
authors: van Hout
authors: Department of Pediatrics, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands.
authors: Yumely
authors: Y
authors: García Vivas
authors: Department of Pediatrics, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands. esid@estherdevries.nl.|Department Tranzo, Tilburg University, Tilburg, The Netherlands. esid@estherdevries.nl.
authors: Esther
authors: E
authors: de Vries
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017099:IgG Deficiency / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007132:Immunoglobulin Isotypes / Q000097:blood / Q000276:immunology; D008297:Male; D009426:Netherlands; D010641:Phenotype; D011134:Polysaccharides / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial
keywords: IgG subclass deficiency; Primary immunodeficiency; antibody deficiency; child; specific polysaccharide antibody deficiency