title: [IgG subclasses in healthy children and in children with frequent respiratory tract infections].
abstract: A group of 130 children presenting with frequent respiratory tract infections was examined for serum levels of IgG-subclasses IgG1, IgG2, IgG3 and IgG4 using radial immunodiffusion according to Mancini. Additionally a control group of 175 children not prone to infections was investigated. Both, low and high levels compared to controls were observed for IgG3 and IgG4. 11.5% of the children with frequent airway infections had IgG3 values below 2 SD below the mean for age compared to 2.8% in the control group (p less than 0.01). Likewise a low IgG4 level was observed more frequently in children prone to airway infections (9.8% versus 2.8% in control; p less than 0.05). IgG4 was undetectable (level less than 3.4 mg/dl) in 5 of the 175 control children. Despite an accumulation of low or undetectable IgG3 or IgG4 levels in children with frequent respiratory tract infections, no correlation between low IgG subclass-levels and the degree of the individual disease could be detected. Based on this lack of a simple causal relationship between frequent respiratory tract infections and the finding of low or undetectable IgG-subclass levels, an immunoglobulin replacement therapy has to be considered with reserve.
authors.affiliation: Kinderklinik, Heinrich-Heine-Universität Düsseldorf.
authors.forename: M
authors.initials: M
authors.lastname: Griese
authors.forename: M
authors.initials: M
authors.lastname: Walda
authors.forename: M
authors.initials: M
authors.lastname: Meuser
authors.forename: D
authors.initials: D
authors.lastname: Reinhardt
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000276:immunology; D004406:Dysgammaglobulinemia / Q000276:immunology*; D005260:Female; D006801:Humans; D017099:IgG Deficiency; D007074:Immunoglobulin G / Q000145:classification; D007223:Infant; D008297:Male; D012016:Reference Values; D012130:Respiratory Hypersensitivity / Q000276:immunology; D012141:Respiratory Tract Infections / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G
vernacular_title: IgG-Subklassen bei gesunden Kindern und bei Kindern mit häufigen Infekten der Atemwege.