title: Deficiency of humoral immunity in cartilage-hair hypoplasia.
abstract: OBJECTIVE
  Cartilage-hair hypoplasia (CHH), a metaphyseal chondrodysplasia, is usually associated with impaired cellular immunity. This study evaluates humoral immunity in patients with CHH.
  
  
  METHODS
  The concentrations of immunoglobulins G, A, and M (IgG, IgA, and IgM) and IgG subclasses were studied in 20 patients. Data for 5 additional patients with recurrent infections were retrospectively reviewed.
  
  
  RESULTS
  Seven of the prospectively evaluated patients (35%) had defective humoral immunity. Three patients had IgA deficiency. Four patients had IgG2 deficiency, accompanied by IgA deficiency, IgG4 deficiency, or both in 3 patients. IgG4 was low in most patients. Increased infections were usually associated with supranormal IgG and IgG1 and subnormal IgA, IgG2, or IgG4 concentrations. One retrospectively reviewed patient had severe hypogammaglobulinemia, and 3 had multiple IgG subclass deficiencies.
  
  
  CONCLUSIONS
  Humoral immunity is impaired in CHH and contributes to the increased susceptibility to infections.
authors.affiliation: Hospital for Children and Adolescents, Helsinki, Finland.
authors.forename: O
authors.initials: O
authors.lastname: Mäkitie
authors.forename: I
authors.initials: I
authors.lastname: Kaitila
authors.forename: E
authors.initials: E
authors.lastname: Savilahti
mesh_terms: D000293:Adolescent; D002357:Cartilage Diseases / Q000097:blood / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D006201:Hair Diseases / Q000097:blood / Q000276:immunology*; D006801:Humans; D017098:IgA Deficiency / Q000097:blood / Q000150:complications*; D017099:IgG Deficiency / Q000097:blood / Q000150:complications*; D007075:Immunoglobulin M / Q000097:blood / Q000172:deficiency*; D007223:Infant; D007239:Infections / Q000453:epidemiology / Q000276:immunology; D011446:Prospective Studies; D012189:Retrospective Studies
chemical_list: D007075:Immunoglobulin M