Profiling and multivariate analysis of serum cytokines in patients with generalized pustular psoriasis

Introduction: Generalized pustular psoriasis (GPP) is a chronic autoinflammatory disease characterized by fever, erythema, and sterile pustules occurring over large areas of the skin. The immunopathogenesis of GPP remains poorly understood. We aimed to profile serum cytokine levels in patients with GPP and analyze treatment-associated changes in cytokine levels. Methods: Twenty-four patients who were diagnosed with GPP and received drug treatment, together with 28 unaffected controls, were recruited in this study. Levels of 27 cytokines in serum samples from pre- and post-treated patients as well as unaffected controls were assessed using a Bio-Plex multiplex immunoassay. Multivariate analysis of cytokine levels and clinical parameters was conducted. Results: Serum levels of interleukins interleukin (IL)-1 beta, IL-1Ra, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p70), IL-13, IL-17, granulocyte colony-stimulating factor (G-CSF), interferon-gamma (IFN-gamma), IFN-gamma-induced protein 10 (IP-10), monocyte chemoattractant protein-1, tumor necrosis factor-alpha, and vascular endothelial growth factor were significantly elevated (p < .05) in patients with GPP compared with controls. Serum levels of IL-6, G-CSF, IL-8, IFN-gamma, IL1-Ra, IL-10, IL-13, and IL-1 beta were correlated with GPP severity (r > 0.4, p < .001). Following treatment, serum levels of IL-6, IL-7, IL-12, IFN-gamma, IL-1 beta, IL-4, IL-8, IL-10, IL-13, G-CSF, and IP-10 were significantly decreased (p < .05) compared with pretreatment levels. Among these cytokines, levels of IL-6, IL-7, IL-8, IL-12, IL-13, and IP-10 were reduced to normal levels. Conclusion: GPP patients exhibited markedly elevated levels of cytokines and chemokines involved in both type 1 and type 2 immune responses, suggesting hypercytokinemia occurs in GPP patients. IL-6 showed the strongest correlation with GPP disease severity and other clinical parameters such as CRP level and fever, thus representing an index for GPP severity. Our data comprehensively documented the cytokine profiles of GPP patients and may provide insights into GPP pathogenesis.