Reduced levels of interleukin-37 in serum of patients with allergic rhinitis or asthma

Abstract

BackgroundCytokines are suggested to play an important role in pathogenesis of allergic rhinitis (AR) and asthma (AS). Among these are members of the Interleukin (IL)-1 family that has been expanded to include 11 cytokines with pro-inflammatory and anti-inflammatory activities. The newly assigned member of this family, IL-37, has been recognized to exhibit a wide range of anti-inflammatory effects and its role in AR and AS pathogenesis has been proposed. ObjectivesThis study explored serum levels of IL-37 in patients with AR and AS to assess its significance as a biomarker for both types of respiratory allergy. MethodsA case-control study was conducted on 52 AR patients, 60 AS patients and 61 controls. IL-37 level was determined using enzyme-linked-immunosorbent-assay kit. ResultsMedian level of IL-37 was significantly decreased in AR and AS patients (105.9 and 88.1 and pg/mL, respectively) compared to controls (180.2pg/mL; P-value<0.001). The lowest level was observed in the age group>40 years of AR and AS patients, and in AR patients who were classified under disease duration<5 years. AR and AS patients classified by gender, family history of allergy, symptoms, type of allergen and atopy showed no significant differences in the distributions of IL-37 levels. Receiver operating characteristic curve analysis revealed that IL-37 occupied a significant area under curve in AR and AS (0.781 and 0.897, respectively; P-value<0.001). ConclusionsIL-37 was down-regulated in serum of AR and AS patients, particularly in patients older than 40 years of age.