IgG subclasses: importance in pediatric practice.

Although many clinical studies provide evidence of a relation between IgG subclass deficiency and increased susceptibility to infection, a direct cause-and-effect relationship clearly does not exist. Each patient must be managed in the full context of clinical symptomatology, reliable measurement of IgG subclasses, and evaluation of specific antibody production. Future studies may clarify the factors that stimulate and regulate the production of IgG subclasses and improve our understanding of their role in the health of children.