Changes in serum calcitonin gene-related peptide, substance P, neuropeptide Y, and interleukin-31 levels after omalizumab treatment in chronic urticaria patients

Introduction and Purpose:There is still no blood parameter that is recommended to be routinely checked in the diagnosis of chronic spontaneous urticaria (CSU) and in the follow-up of omalizumab treatment. We conducted our study to better elucidate the pathophysiology of CSU and to better evaluate the omalizumab treatment response. Materials and Methods:30 CSU patients and 20 healthy volunteers who applied to the Gaziantep University Faculty of Medicine Dermatology clinic between October 2021 and March 2022 and planned to start omalizumab were included in our study. Patients received 6 doses of 300 mg omalizumab by injection every 28 days. 10 cc of blood was drawn from the patients before the start of the treatment, at the 3rd and 6th months of the treatment, and only once from the healthy volunteers. Serum Substance P (SP), Calcitonin Gene-Related Peptide (CGRP), Neuropeptide Y (NPY) and Interleukin-31 (IL-31) levels were measured by the ELISA method. Results:While the mean age and standard deviation of the patient group were 39.83 ± 11.67, it was 31.85 ± 6.77 in the control group. There was a statistically significant difference in the UAS7 and UCT scores in the patient group. Serum SP, CGRP, NPY and IL-31 levels were all statistically significantly lower in the patient group. A statistically significant increase was observed in serum SP and CGRP levels, which were measured in the patient group before and after omalizumab treatment.There was no statistically significant difference in serum NPY levels. A statistically significant decrease was observed in serum IL-31 levels. Conclusion:The statistically significant increase in serum CGRP and SP levels observed after omalizumab treatment may indicate that SP and CGRP are unable to degranulate mast cells. The fact that the NPY level is found to be low in CSU patients but does not change with omalizumab treatment may indicate that NPY may play a role in itching through pathways independent of mast cell degranulation. The decrease observed in serum IL-31 levels with omalizumab treatment may indicate that omalizumab may also affect the immunological response and T cell response. Keywords:Chronic spontaneous urticaria, Omalizumab, Calcitonin Gene-Related Peptide, Substance P, Neuropeptide Y, Interleukin-31