An Unexplored Molecule in the Diagnosis of Allergic Rhinitis: LL-37

Objective: Cathelicidin (LL-37) is an innate immune endogenous peptide. Although its activity has been proven in many diseases in the literature, there is no information about the role of LL-37 in allergic rhinitis. It acts as an immunomodulator for the emergence of inflammatory molecules in allergic rhinitis. Methods: A total of 40 patients with allergic rhinitis and 40 control patients without any known disease were treated in the otorhinolaryngology clinic. At the end of the study, the relationship between serum cathelicidin level and disease was revealed. Results: Total immunoglobulin E levels were 268 I mu/L for the allergic rhinitis group and 10.2 for the control group. There was a significant difference between the 2 groups in terms of immunoglobulin E (<.001). Levels of LL-37 were 4.67 (2.1-7.2) for the allergic rhinitis group and 2.8 (2.1-5.4) for the control group. There was a significant difference between the 2 groups in terms of LL-37 (<.001). Conclusion: This study showed that cathelicidin (LL-37) is an eosinophilic activating peptide. The inflammatory process of LL-37 has been shown to be responsible for tissue damage in allergic rhinitis.