Local IgE synthesis in allergic rhinitis and asthma.

Local IgE production has been a contentious concept for over 40 years. Although a host of clinical observations suggested a local source of IgE, co-localization of IgE to B cells in the nasal mucosa could not be demonstrated. In contrast, igE-producing B cells were observed in local lymphoid tissue. Definitive proof of local IgE synthesis in the nasal mucosa has now become available. Here, we review the recent developments in local IgE research in allergic rhinitis and asthma within their historical context, and speculate on the implications of both local IgE synthesis and ongoing research into local immunoglobulin isotype switching for patient therapy.