[Cytokines and autoimmunity]

By enabling interactions to take place between the various cell populations which form the immune system, cytokines stand at a cross-road in the development of autoimmune phenomena. They also intervene in the activation of autoreactive cells and in the occurrence of the associated inflammatory processes. In some pathological situations they might be directly responsible for the loss of tolerance of the self by the immune system. A similar phenomenon is observed in immunotherapy with recumbent cytokines during which autoimmune manifestations are relatively frequent. Owing to our better knowledge of the role played by cytokines in the genesis and development of the autoimmune process, we can now understand better the mechanism of action of immunosuppressive drugs in autoimmune diseases. This knowledge also emphasizes the value of new pharmacological substances with a more finely targeted immunomodulator activity which are currently being evaluated in this type of diseases.