Increased level of interleukin-13, but not interleukin-4 and interferon-γ in chronic rhinosinusitis with nasal polyps

Background This study was performed to investigate the serum level of interleukin (IL)-13, IL-4, and interferon (IFN)-γ in chronic rhinosinusitis with nasal polyps (CRSwNP) and subsequent inflammation pattern and comorbidities including asthma and aspirin intolerance. Methods A case–control study was conducted on 60 adult patients with CRSwNP with mean age of 37.7 ± 12.7 (ranging from 18 to 70) years, and on 20 healthy controls. Serum levels of IL-13, IL-4, and IFN-γ were assessed, using enzyme-linked immunosorbent assay to be compared between case and control groups. Serum level of total immunoglobulin (Ig) E was also assessed in the patients with CRSwNP. Results Serum level of IL-13 in the patients with CRSwNP was significantly higher than the controls (0.98 ± 1.56 vs. 0.34 ± 0.16 pg/ml, respectively, p = 0.002). IL-4 and IFN-γ did not differ significantly between the two groups. Total IgE level was significantly increased in the patients with CRSwNP, compared to the normal values (301.43 ± 516.54 IU/ml, p = 0.033). Among the patients with CRSwNP, 12/60 (20%) had aspirin intolerance and 44/60 (73.3%) had asthma. IgE was also higher in asthmatics than non-asthmatics patients (364.9 ± 586.6 vs. 126.7 ± 135.7, respectively, p = 0.015). Patients with aspirin intolerance had higher levels of IFN-γ (4.7 ± 1.4 vs. 4.1 ± 0.6, respectively, p = 0.022). Conclusions IL-13 with high level of total IgE was observed in the patients with CRSwNP, which predisposes them to have concomitant asthma. IFN-γ seems to be down-regulated in the patients with CRSwNP, but could be over-expressed in the presence of aspirin intolerance.