Evidence for an inflammatory pathophysiology in idiopathic rhinitis.
BACKGROUND
The pathophysiology of idiopathic rhinitis is unknown but the disease is classified as being non-allergic on the basis of negative serum IgE radioallergosorbent assay (RAST) and skin prick tests. In contrast, allergic rhinitis has a Th2 type inflammatory pathology mediated by IgE and mast cells.


OBJECTIVE
To test the null hypothesis that there would be no difference in the cellular infiltrate for key Th2-associated inflammatory cells between allergic and idiopathic rhinitis.


METHODS
We applied strict selection criteria in the recruitment of allergic and idiopathic rhinitis cases. In contrast to previous studies which used cytology or small biopsies, we studied all layers of the mucosa by using whole, full-thickness nasal turbinate specimens with an average length of 2.5 cm. Immunohistochemistry and in situ hybridization techniques were used to compare the distribution and cell populations of mast cells, IgE positive (IgE+) cells, eosinophils and plasma cells in perennial allergic (n = 11) and idiopathic (n = 17) rhinitis, and control nasal mucosal tissue (n = 9).


RESULTS
Mast cells and IgE+ cells were significantly increased within the epithelium of allergic and idiopathic mucosa compared to normal mucosa (P < 0.05). More IgE+ cells were present in the allergic group compared to the idiopathic group with the majority of IgE+ cells being mast cells. Both rhinitic groups showed increased eosinophilia localized to the superficial submucosa compared to normal mucosa (P < 0.05). More plasma cells were present in the allergic rhinitic tissue.


CONCLUSIONS
Idiopathic and allergic rhinitic mucosa show similarities in their inflammatory infiltrate suggesting that both groups share a highly localized Th2, IgE-mediated cellular immunopathology.
Powe
D G
DG
Division of Pathology, Department of Clinical Laboratory Sciences, University Hospital Queen's Medical Centre, Nottingham, UK. Des.Powe@nottingham.ac.uk
Huskisson
R S
RS
Carney
A S
AS
Jenkins
D
D
Jones
N S
NS
D000293:Adolescent; D000328:Adult; D015550:Cell Degranulation / Q000502:physiology; D004804:Eosinophils / Q000276:immunology / Q000378:metabolism; D004847:Epithelial Cells / Q000737:chemistry / Q000378:metabolism; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007150:Immunohistochemistry; D007958:Leukocyte Count; D008297:Male; D008407:Mast Cells / Q000166:cytology; D008875:Middle Aged; D009297:Nasal Mucosa / Q000378:metabolism; D010950:Plasma Cells / Q000378:metabolism; D012220:Rhinitis / Q000378:metabolism / Q000503:physiopathology*; D012221:Rhinitis, Allergic, Perennial / Q000378:metabolism / Q000503:physiopathology; D013194:Staining and Labeling
D007073:Immunoglobulin E