Th-2 type cytokine receptors in allergic rhinitis and in response to topical steroids

Objectives: Th-2 type cytokine production (Interleukin-4 [IL-4] and interle ukin-5 [IL-5]) has been demonstrated to play a significant role in the path ophysiology of allergic rhinitis (AR), and the treatment of AR with topical corticosteroids has been shown to reduce the expression of Th-2 type cytok ines in vivo. However, the contribution and expression of Th-2 type cytokin e receptors in AR and their response to corticosteroid treatment remain to be clarified. Objectives of the current study are 1. To examine the express ion of the cytokine IL-4 and IL-5 receptors (IL-4R and IL-5R in a nasal all ergen challenge model and to contrast this with the expression of the recep tor for the Th-1 type cytokine, interferon-gamma receptor (IFN-gamma R), an d 2. to examine the effects of pretreatment with topical corticosteroid bef ore allergen challenge on the expression of these same receptors. Study Des ign: Randomized prospective study involving 14 ragweed-allergic subjects ev enly divided between placebo and corticosteroid pretreatment. Methods: Immu nocytochemistry (alkaline phosphatase-antialkaline phosphatase labeling [AP AAP] technique) was used to stain nasal biopsy specimens before and after a llergen challenge. Antibodies used included anti-CD3, CD4, CD8, major basic protein (MBP), IL-4R, IL-5R, and IFN-gamma R Results: Following allergen c hallenge, we observed a significant increase in the Th-2 type cytokine rece ptors (IL-4R and IL-5R; P <.05), as well as a significant decrease in the e xpression of the Th-1 type cytokine receptor (IFN-gamma R P <.05). Pretreat ment with topical corticosteroids before nasal allergen challenge resulted in decreased expression of IL-4R (P <.05) and IL-5R (P <.05) and increased expression of IFN-gamma R (P <.05). Further, IL-4R and IL-5R expression cor related with eosinophil infiltration in the tissues. Conclusions: We have d emonstrated that in AR, cytokine receptors for IL-4, IL-5, and IFN-gamma fo llow a similar pattern to their ligands. In addition, pretreatment with top ical corticosteroids was shown to alter the cytokine receptor expression pa ttern from a Th-2 profile more toward a Th-1 profile.