Soluble fibrinogen-like protein 2 in condyloma acuminatum lesions

An imbalance in type 1 (Th1) and type 2 (Th2) T helper cells is associated with the development and recurrence of condyloma acuminatum (CA); however, the mechanisms underlying this imbalance remain unknown. We investigated soluble fibrinogen-like protein 2 (sFGL2), which is an effector of regulatory T cells (Tregs), to determine its role in the Th1/Th2 imbalance of CA.

Lesion and blood samples were obtained from 30 CA patients, and these samples were compared with genital skin and blood samples from 20 control subjects. Serum sFGL2, mRNA, and protein levels were estimated using ELISA, quantitative real-time polymerase chain reaction, and western blot, respectively. Immunohistochemical analyses were also conducted.

Compared to controls, CA patients had decreased serum sFGL2 levels. However, sFGL2 mRNA and protein levels in the lesions of CA patients were significantly increased. Interleukin (IL)-4 and Foxp3 mRNA levels were upregulated, and interferon (IFN)-γ levels were downregulated in CA patients compared to those in controls. Additionally, the sFGL2 mRNA level positively correlated with Foxp3 and IL-4 levels and negatively correlated with IFN-γ and IL-17 levels.

sFGL2 contributes to the underlying Th1/Th2 imbalance in CA pathogenesis.