Objective: To determine the expression of the cytokines transforming growth factor-beta1 (TGF-beta1), interferon-gamma (IFN-gamma), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) in serum from patients with Peyronie's disease (PD) compared to healthy controls.
Materials and methods: Ninety-one consecutive PD patients aged 20 - 74 years were included in this study. All patients were diagnosed with symptomatic PD for the first time and had a palpable penile plaque. The patients previously had the disease for 6 - 72 months. None of the patients had a severe infectious disease or known systemic illness. For cytokine analyses, peripheral venous blood samples were obtained before treatment. Fifty healthy male blood donors aged 22 - 64 years served as the control group. TGF-beta1, IFN-gamma, Il-6, and TNF-alpha were analyzed quantitatively with commercial immunoassays.
Results: Mean cytokine levels in serum from patients were increased for TGF-beta1 and IFN-gamma compared to healthy controls. The difference for TGF-beta1 was considered statistically significant (p < 0.001). IL-6 was not detectable in PD patients (p < 0.01) and TNF-alpha was decreased (p < 0.0001).
Conclusion: The significantly elevated serum level of the profibrotic TGF-beta1 cytokine underscores the effect of cytokines in the pathophysiology of PD. The significantly decreased TNF-alpha serum level suggested no acute immunomodulatory process. Therefore, the relevance for therapeutic administration of TNF-alpha should be further investigated. Quantification of TGF-beta1 in serum of PD patients provides a possible diagnostic tool and target for therapy. The data on altered cytokine levels in PD patients also provide a new understanding for etiopathogenesis of PD, which warrants further investigation.