[IgG subclasses in children with recurrent respiratory diseases].

The authors examined IgG sub-classes, using the ELISA method, in 35 patients with relapsing respiratory diseases and 27 children of a control group aged 3-15 years. In children with relapsing respiratory diseases without deficiency of the main immunoglobulin classes they found a statistically significantly reduced value in sub-class IgG2 (P < or = 0.01). The changes found in other sub-classes were not statistically significant. The authors draw attention to the fact that deficiency in IgG sub-classes should be considered in case of repeated respiratory infections caused by encapsulated microorganisms--H. influenzae, Str. pneumoniae--and also when reduced levels of IgG and IgA are found. However, even normal levels do not rule out deficiency.