Allergy. 2021 Sep 22. doi: 10.1111/all.15107. Online ahead of print.
ABSTRACT
BACKGROUND: IgG2 responses are associated with repeated antigen exposure and display highly mutated variable domains. A recent study highlighted a role of IgG2+ memory B cells and allergen-specific IgG2 levels after a 3rd consecutive pre-seasonal sublingual allergen immunotherapy (AIT) with grass pollen tablet. Herein, we aim to explore changes in allergen-specific IgG2 in individuals undergoing house dust mite immunotherapy (HDM-AIT) and explore whether the interrelationship with other humoral responses (i.e. IgG4 and IgE) may discriminate between high and low responders.
METHODS: Levels of serum D. pteronyssinus- and D. farinae-specific IgG2, IgG4 and IgE antibodies were measured by ELISA or ImmunoCap in a sub-group of individuals enrolled in a randomized, double-blind, placebo-controlled, sublingual AIT study evaluating the safety and efficacy of a 300 IR HDM tablet.
RESULTS: After 1-year sublingual AIT, HDM-specific serum IgG2 responses increase mostly in high versus low responders and are distinctive according to the clinical benefit. Higher correlation between HDM-specific IgG2, IgE and/or IgG4 responses are seen in subjects benefiting the most from HDM-AIT as indicated by changes in Average Total Combined Scores. More strikingly, statistically significant correlation between HDM-specific IgG2 and IgE responses are only observed in individuals stratified as high responders.
CONCLUSIONS: We provide evidence for coordinated serum immune responses upon AIT in HDM-allergic subjects exhibiting high clinical benefit when compared with low responders. Assessing HDM-specific IgE, IgG2 and IgG4 in serum could be used as follow-up combined markers to support decision as to AIT continuation and/or adaptation.
PMID:34551124 | DOI:10.1111/all.15107
