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


CONCLUSIONS
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.
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008407:Mast Cells / Q000276:immunology; D008875:Middle Aged; D008925:Mites / Q000276:immunology; D009297:Nasal Mucosa / Q000276:immunology* / Q000473:pathology; D010950:Plasma Cells / Q000276:immunology; D011058:Pollen / Q000276:immunology; D012220:Rhinitis / Q000276:immunology* / Q000473:pathology; D012221:Rhinitis, Allergic, Perennial / Q000276:immunology / Q000473:pathology
D000485:Allergens; D007073:Immunoglobulin E