Detection of the inflammatory process in a Behçet's disease-like mouse model using 18F-fluorodeoxyglucose positron emission tomography.

Abstract

OBJECTIVES: The major role of herpes simplex virus (HSV) type 1 infection in Behçet's disease (BD) immunopathogenesis has been demonstrated and inoculating the earlobes of ICR mice with HSV produced a BD-like mouse model. (18)Ffluorodeoxyglucose positron emission tomography (FDG PET) is widely used for diagnosing numerous human diseases other than malignancies. The aim of our study was to evaluate the inflammatory activities of BD-like symptoms in a HSV type 1-induced BD-like mouse model by small-animal FDG PET.

METHODS: Five HSV-infected ICR mice with BD-like lesions, two asymptomatic HSV-infected mice, and two untreated mice were scanned with microPET, and autopsy specimens were histopathologically assessed to evaluate for infiltration by mixed inflammatory cells.

RESULTS: The histopathological evaluation of the inflammatory process in knee and elbow joints significantly correlated with the quantitative assessment of FDG accumulation in the same joints in BD-like ICR mice, HSV-infected asymptomatic mice, and untreated control mice. Small-animal FDG PET clearly detected asymptomatic joint inflammatory processes in both BD-like mice and HSV-infected asymptomatic mice. In addition, genital ulcers and skin ulcers with associated perilesional lymphadenopathies in BD-like models were detected by microPET. However, biodistributed PET-positive images from the stasis of secreted FDG into the bowel lumen could not be distinguished from the inflammatory bowel lesions of BD when compared to FDG uptake in control mice.

CONCLUSIONS: Our data indicate that FDG PET can non-invasively and quantitatively detect the inflammatory process in an HSV-induced BD-like mouse model.