Nasal allergen-specific IgG4 antibodies: novel biomarker for grass pollen immunotherapy
Published online: November 13, 2018
Allergic rhinitis (AR), also known as hay fever, is an inflammation of the lining of the nasal mucosa resulting from exposure to aeroallergens. Individuals suffering from AR are most commonly treated with short-term over-the-counter relievers such as anti-histamines and corticosteroids. Grass pollen injection immunotherapy (subcutaneous immunotherapy, SCIT), provides a curative treatment for allergic rhinitis and is associated with a reduction in clinical symptoms and an improvement in the quality of life. Most importantly, it confers long-lasting clinical benefit after cessation of treatment. Despite this, not all patients respond optimally to immunotherapy and there is a clear need for a reliable biomarker to identify those who are responding or are unlikely to respond to SCIT.
In a recent study published in The Journal of Allergy and Clinical Immunology (JACI), Shamji and colleagues assessed the level of nasal grass pollen-specific IgE and IgG4 in a cross-sectional, controlled study involving healthy controls, untreated allergic patients and SCIT-treated patients. Further to this, the functional ability of IgG4 antibodies to block IgE-mediated responses was assessed.
The authors found that levels of nasal and serum grass pollen-specific IgEs were higher in untreated allergic compared to healthy controls and SCIT-treated group. In contrast, nasal IgG4 level was found elevated in the SCIT-treated group, compared to the untreated allergic group during the grass pollen season. Allergen-IgE immune complexes binding to CD23 on the surface of B cells was reduced by 93% in nose and 66% in serum. The inhibitory activity was found to be higher in the SCIT-treated group compared to the untreated allergic group. Most importantly, this inhibitory activity observed in both nasal fluid and serum correlated with an improvement of global symptom score.
In view of these novel findings, the authors concluded that the inhibitory activity mediated by nasal IgG4 antibodies correlated closely with the clinical response to allergen immunotherapy.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.
17-1546, Nasal allergen neutralizing IgG4 antibodies block IgE-mediated responses: novel biomarker of subcutaneous grass pollen immunotherapy