IgG Subclass Deficiency and Recurrent Respiratory Tract Disease in Childhood

Abnormalities in IgG subclasses have been associated with a wide variety of conditions. An area that has received particular attention is the relationship between specific IgG subclass concentrations and respiratory tract diseases. Low values of IgG₂, IgG₃, and IgG₄ are associated with recurrent respiratory tract infections, while elevated concentrations of IgG₄ may be found in allergic conditions. In this paper we review the relationship between IgG subclass abnormalities and respiratory tract disease, and describe our approach toward evaluating and treating patients with IgG subclass deficiencies.