Th1 and Th2 cell population in chronic ethmoidal rhinosinusitis: A chemokine receptor assay

Background: It is necessary for the immune system in the nasal and paranasal sinus mucosa to possess appropriate responses to infective agents as well as allergic responses. Recently, the T helper (Th)1/Th2 paradigm has been proposed as a new concept to explain various immunologic phenomena. Objective. Toward the goal of better understanding chronic rhino-sinusitis, we have tried to define the predominating helper T-cell subsets among patients with chronic rhino-sinusitis through characterizing the expressed chemokine receptors by these cells to find out the relation between these chemokine receptors' expression and the underlying pathogenesis of chronic rhinosinusitis. Methods: Thirty patients with ethmoidal chronic rhinosinusitis were used in our study. Patients were divided into atopic and nonatopic groups according to their serum immunoglobulin (Ig)E levels. Samples from ethmoidal sinus mucosa were processed as follows: frozen sections were examined immunohistochemically for detection of CCR4, CCR5, and EG2 positive cells and the mRNA of CCR4, and CCR5 transcripts were then examined by real-time quantitative polymerase chain reaction (PCR). Results: By immunohistochemistry, atopic patients showed high expression of CCR4 and EG2 positive cells, whereas nonatopic patients showed high expression of CCR5 positive cells. The expression of CCR4 and CCR5 mRNA, detected by real-time quantitative PCR supported the data obtained by immunohistochemistry. Conclusion: The present study suggests that eosinophil recruitment associated with Th2 cell infiltration is the main factor responsible for the pathology of atopic rhinosinusitis.