Immunoregulatory circuits and potential treatment of connective tissue diseases.

Connective tissue diseases are generated by different immunoregulatory alterations. Their better knowledge may lead to new treatment modalities. In systemic lupus erythematosus (SLE), increased IL-10 production by non-T cells might exert an inhibitory effect on Thl CD4+ T cells which would explain the decreased T cell functions observed in these patients. In rheumatoid arthritis (RA) patients, there may be a balance within the synovium, where the local production of IFN-gamma may limit the anti-inflammatory properties of IL- 10, thus leading to chronic damage. This article shows that rational approaches to therapy need to be individualized. In SLE, the potential therapeutic use of monoclonal antibodies to IL-10 seems to be gathering strength, whereas in RA exactly the opposite is contemplated: IL-10 is tried for its potential therapeutic use.