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IgG4 responses to HDM allergens and bacteria

This study investigates how some mite allergic adults and children, exposed to H influenzae endotoxins, can in tandem produce antigen/allergen specific IgG4. An antibody associated with protection or in short term sensitisation and anaphylactic reactions.
The study raises questions on the possibility of antigen/allergen interactions and asks if this interaction can encourage the development of asthma and allergy in early life. In adults it may prolong symptoms of asthma or rhinitis following a respiratory infection or a heavy cold.

Quoted from the study: 'H influenzae endotoxin can directly trigger the release of inflammatory mediators from basophils and eosinophils, and there is evidence from the release of eosinophil cationic protein that they do this in the lungs. 'Infants can make IgG4 antibody as shown in food allergy and responses to vaccines and virus infections.'

Once triggered, either by mite allergens or bacterial endotoxins, basophils in the blood and mast cells in the lung can release histamine, elastase and tryptase, some of the many pro-inflammatory markers in respiratory disease.


Differences in the antibody response to a mucosal bacterial antigen between allergic and non-allergic subjects. Hales BJ, Pearce LJ, Kusel MMH, Holt PG, Sly PD, Thomas WR. Thorax 2008; 63: 221-27