1 Introduction
Chronic rhinosinusitis (CRS) is a heterogenous disease accompanied with persistent mucosal inflammation, which makes an impact on 3% to 6.4% of the whole population(1). CRS could be grouped into two phenotype based on the presence or absense of nasal polyps(2). Although the relative prevalence of CRSwNP phenotype is about 20%, CRSwNP shows more serious condition and a greater degree of impairment for quality of life(3, 4). Meanwhile, a few reports have shown that over thirty percentage of patients suffered from CRSwNP continue to be clinically uncontrolled after standard therapy(5, 6). Therefore, several biomarkers have been applied for predicting the prognosis and guiding the therapy and follow-up.
Recently, the clinical parameters such as blood eosinophil count and paranasal sinus compute tomography (CT) score have been proposed as markers for identifying phenotypes of CRSwNP and predicting disease severity(7-9). For example, the parameter about CT scores like the ES/MS ratio could be an predictor in diagnosis of eosinophilic CRS and prediction of CRSwNP recurrence(10). Ho, et al reported that blood eosinophil number can be used as a systemic predictor of eosinophilic CRS(11). In addition, paranasal sinus CT findings combined with eosinophilia in peripheral blood can be used for predicting the treatment outcome and the degree of disease severity of CRSwNP(12). Furthermore, our recent study showed that blood eosinophilia is an independent risk factor related to poor disease control in patients with CRSwNP(5). Together, these studies suggest that paranasal sinus CT and blood eosinophilia as useful markers may play important roles in prediction of phenotype and prognosis of CRS. However, few studies focus on the relationship between paranasal sinus CT and blood eosinophilia, and whether the imaging features of paranasal sinus CT could be closely related to the phenotype of nasal polyps with blood eosinophilia remains unknown.
Here, we hypothesized that the specific findings in paranasal sinus CT of CRSwNP patients may be associated with systemic eosinophilia. For the sake of confirming the hypothesis, we performed the retrospective study to determine the relationship between paranasal sinus CT features and blood eosinophilia in CRSwNP.