IFN-γ/IL-6 and related cytokines in chronic spontaneous urticaria: evaluation of their pathogenetic role and changes during omalizumab therapy

Background: Recent studies highlight that high levels of cytokines may precede the onset of many systemic autoimmune disorders and may also be related to chronic spontaneous urticaria (CSU) activity. Methods: Eight patients with CSU candidate to omalizumab therapy were enrolled. Four healthy controls were included with the purpose of comparing baseline cytokine levels. We evaluated serum levels of IFN-γ, IL-2, 4, 6, 8, and 10, TNF-α, and GM-CSF. For the patient group, venous blood samples were drawn at T0, T1 (1 week after first drug administration), T2 (after 3 months), T3 (after 6 months), and in case of relapse. Cytokine levels were measured using the human cytokines 8-plex kit. Disease activity and effect of therapy were calculated by means of Urticaria Activity Score 7. Results: Higher levels of IL-6 and IFN-γ were found in patients with CSU compared to those observed in the control group. Moreover, a common trend between these cytokines and the clinical history of disease could be hypothesized, with a decrease in levels of IFN-γ and IL-6 following remission of CSU with omalizumab treatment. Levels of other tested cytokines were similar between patients and healthy subjects. Conclusion: IFN-γ and IL-6 are proinflammatory cytokines that are strongly related to autoimmunity. Despite being limited by the small sample size, our data offer new insight into a better understanding of the pathogenesis of CSU and support the need for further investigations.