Mucosal Cytokine Expression in Allergic Rhinitis

Allergic rhinitis Cytokines immunoreactivity Mast Cells Correspondence to: Dr. Peter H. Howarth, Immunopharmacology Group, University Medicine Level D, Centre Block Southampton General Hospital, Southampton, SO9 4XY (UK) Introduction Allergic rhinitis is associated with mucosal inflammation characterised by an epithelial accumulation of activated mast cells and eosinophils, an increase in eosinophils within the lamina propria and local up-regulation of the en-dothelial expression of leucocyte endothelial cell adhesion molecules. These cellular changes, which are triggered by antigen recognition, are considered to be cytokine orchestrated [1]. Attention has focused on the interleukin (IL)-4 family of cytokines encoded on chromosome 5 [IL-3, IL-4, IL-5, IL-13 and granulocyte/macrophagecolony-stimulat-ing factor (GM-CSF)] as potential key cytokines in this process, along with tumour necrosis factor (TNF)-α). These cytokines may be generated by the Th2 subpopulation of T lymphocytes, because the cytokine profile of this cell population includes IL-3, IL-4, IL-5, IL13, TNF-α and GM-CSF. To investigate the expression of cytokines relevant to allergic inflammation and to identify their cellular localisation within the nasal mucosa, we have undertaken specific immunohistochemistry staining of thin sections of inferior turbinate biopsies from patients with perennial allergic rhinitis and, for comparison, from non-atopic healthy volunteers [2,3]. Subjects and Methods Fifteen atopic house-dust-mite-allergic patients with perennial rhinitis (7 men/8 women, mean age 40.5 years) and 12 healthy non-atopic non-rhinitic volunteers (4 men/8 women, mean age 35.6 years) participated in the study. None of the rhinitic subjects, who were all symptomatic, were receiving topical or systemic corticosteroids. Nasal biopsies were taken under direct vision from the inferior or inferomedian border of the inferior turbinate after prior local anaesthesia with topical 1% tetracaine containing 1:10,000 adrenaline. The biopsies were immediately fixed in ice-cooled acetone and processed subsquently into glycolmethacrylate resin. Immunostaining was undertaken for IL-4 using monoclonal antibodies (mAbs) 4D9 and 3H4, IL-5 (mAbs 7 and 8), IL-6 (mAb 104-B11), IL-8