Background: Persistent allergic airway diseases cause a great burden worldwide. Their pathogenesis is not clear enough. There is evidence that one of the recently described cytokine interleukin (IL) 22 may be involved in the pathogenesis of these diseases. Scientists argue if this cytokine acts as proinflammatory or anti-inflammatory agent. The aim of this study was to investigate IL-22 level in patients with persistent allergic airway diseases caused by house dust mite (HDM) in comparison with healthy individuals and to evaluate its relationship with IL-13 and IL-10 level, symptoms score and quality of life.
Methods: Patients with persistent allergic rhinitis caused by HDM and having symptoms for at least 2 years with or without allergic asthma were involved into the study. Measurements of IL-22, IL-13 and IL-10 and in serum and nasal lavage was performed by ELISA. Questionnaires assessing symptoms severity and quality of life were used.
Results: A tendency was observed that IL-22 in serum and nasal lavage was higher in patients with allergic airway diseases compared to control group (14.86 pg/ml vs. 7.04 pg/ml and 2.67 pg/ml vs. 1.28 pg/ml, respectively). Positive statistically significant correlation was estimated between serum IL-22 and serum IL-10 (rs = 0.57, p < 0.01) and IL-13 (rs = 0.44, p < 0.05) level. Moreover, positive significant correlation was found between IL-22 in nasal lavage and IL-10 in nasal lavage (rs = 0.37, p < 0.05). There was a negative statistically significant correlation between serum IL-22 and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) (rs = - 0.42, p < 0.05).
Conclusion: Our study showed a possible anti-inflammatory effect of IL-22 in patients with persistent allergic airway diseases caused by HDM.
Keywords: Allergic asthma; Allergic rhinitis; House dust mite; IL-22; Persistent allergic airway diseases.