Level of nerve growth factor and distribution of mast cells in the synovium of tumour necrosis factor transgenic arthritic mice

We have recently reported that nerve growth factor (NGF) increases in the synovium of patients affected by arthritis, as well as in animal models. We report here that the synovium of transgenic arthritic mice expressing human tumour necrosis factor (TNF) contains numerous mast cells (MC) and that their appearance is a phenomenon which was correlated to the local increase in NGF level. These findings provide further evidence that NGF plays a role in inflammation and suggest a functional link between NGF and MC.