Hardcore Research

IgG4 responses to mite and bacteria

The study noted here investigated how some mite allergic adults and children, exposed to H influenzae endotoxin (outer membrane protein) can in tandem produce antigen/allergen specific IgG4, an antibody associated with 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.

A quote from the study: 'H influenza endotoxin can directly trigger the release of inflammatory mediators from basophils and eosinophils, and there is evidence from the release of eosinophil cationic protein 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. Furthermore, there also is evidence to suggest that dual exposure to house dust mites and viral infections in sensitised people can have a synergistic effect and cause severe asthma exacerbation.

This study may be important in the research of cot deaths caused by the possibility of modified-anaphylaxis. To explore this further please refer to: 'Sudden Infant Death Syndrome' (Monograph) :Coombs RRA, Parish WE, Walls AF, Cambridge Publications (2000)

References

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

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