Changes in Serum IL-12 Levels following the Administration of H1-Antihistamines in Patients with Chronic Spontaneous Urticaria

Introduction. Research regarding the role of the IL-12 cytokine family in modulating immune and inflammatory responses is continuously evolving. In this study, the contribution of the p35 and p40 subunits as monomers (noted as IL-12p35 and IL-12p40) and heterodimers (noted as IL-12p70 or IL-12p35/p40) was analysed in the pathophysiology and progression of chronic spontaneous urticaria (CSU). Materials and methods. We conducted a longitudinal, case–control study involving 42 CSU cases and 40 control cases comprising adults without associated conditions. Serial measurements were performed to assess the serum levels of IL-12p70, IL-12p35, and IL-12p40 at the onset of the disease (pre-therapy phase) and 6 weeks after the initiation of the treatment (post-therapy phase). Results. During the pre-therapeutic phase of CSU, elevated serum levels of IL-12 cytokine subtypes were detected compared to the control group. The relationship between IL-12 profiles and the course of CSU highlighted the pro-inflammatory role of IL-12p70 and the anti-inflammatory role of IL-12p35. Significant correlations were observed between IL-12p70 levels and the duration of the disease, as well as between IL-12 and the effectiveness of H1-antihistamines. Conclusions. The molecular background for the pleiotropic activities mediated by IL-12-derived cytokines in patients with CSU lies in the strict regulation of the production, signalling pathways, and cytokine-specific influences on the same pathophysiological events. The results of the present study suggest that the superficial layers of the skin serve as a cellular source of IL-12, a cytokine produced through antigenic stimulation. In patients with CSU, we identified independent, additive, or divergent functions of IL-12p70, IL-12p35, and IL-12p40, all relevant to systemic inflammation. These findings prove that the prototype programming of IL-12 is abnormal in CSU.