Entopy’: localized mucosal allergic disease in the absence of systemic responses for atopy


D. G. Powe, Division of Pathology, Department of Clinical Laboratory Sciences, University Hospital, Queen's Medical Centre, Nottingham NG7 2UH, UK.
E-mail: Des.Powe@Nottingham.ac.uk


Background The Th2 immune response in the nasal mucosa of subjects with allergic rhinitis is mediated by allergen-specific IgE. Moreover, these subjects show positive responses for markers of systemic atopy, including allergen-specific skin sensitivity and raised serum IgE titres. In contrast, idiopathic rhinitis (IR) subjects with similar histological nasal mucosal features differ in being defined as non-allergic because they have negative atopic responses.

Objective We hypothesized that it is possible to have an allergic Th2 disease pathway localized in the nasal mucosa of ‘non-allergic’ rhinitis subjects despite an absence of atopic responses.

Methods The presence of house dust mite and grass pollen-specific IgE antibodies was investigated in non-atopic (n=10) and atopic (n=11) subjects with persistent rhinitis and compared to normal (n=12) control subjects. Biotin-labelled allergen was used to localize specific allergen-binding antibodies in situ in sections of nasal mucosa.

Results Grass pollen allergen binding was detected in the nasal mucosa of 3/10 non-atopic IR subjects but, in contrast, dust mite-specific antibodies were not detected. Specific antibodies were present in a total of 8/11 mucosal samples from the allergic group, but none was detected in normal control tissues.

Conclusion These findings support the concept of localized nasal allergy in ‘non-atopic’ rhinitis subjects. We propose the term ‘entopy’ to define this phenomenon and believe that this concept has a wider implication for localized allergic responses in other mucosal sites.