Use of 2-[18F]fluoro-2-deoxyglucose as a potential agent in the prediction of graft rejection by positron emission tomography

We investigated the potential of predicting allograft rejection by measuring the ability of graft-infiltrating cells to take up 2-[18F]fluoro-2-deoxyglucose ([18F]FDG). This molecule is a positron emitting glucose analogue that is taken up by metabolically active cells and can be detected using positron emission tomography. Uptake of [18F]FDG during an alloresponse was measured both in vitro in mixed lymphocyte cultures and in vivo using allogeneic and syngeneic skin grafts. Uptake of [18F]FDG was seen in a mixed lymphocyte reaction. Using a mouse skin graft model, we found that mean [18F]FDG uptake was 1.5-2 times higher in allografts than in syngeneic grafts; the increase in uptake correlated with the level of T-cell infiltrate seen histologically. Assessing the metabolic activity of graft-infiltrating cells with [18F]FDG may be useful in the prediction of graft rejection episodes.