PubMed1999
Inflammatory islet damage mediated by cytokines and oxygen radicals may limit the success of clinical islet transplantation for treatment of insulin-dependent diabetes mellitus. In this study, we investigated whether drugs such as currently used in islet-transplanted patients inhibit the release of IL-1beta, TNFalpha, and superoxide from mononuclear blood cells in vitro. Methylprednisolone (10 microg/ml) inhibited the release of IL-1beta and TNFalpha, but had no effect on superoxide generation. Both pentoxifylline (66 microg/ml) and cyclosporin A (300 ng/ml) slightly inhibited TNFalpha release without affecting IL-1beta or superoxide generation. Nicotinamide (0.25 mM) did not interfere with the generation TNFalpha or superoxide and only slightly inhibited IL-1beta production. A combination of methylprednisolone, pentoxifylline, cyclosporin A, and nicotinamide (concentrations for each substance as described above) inhibited TNFalpha generation by 74+/-6% (mean value+/-SEM, mononuclear blood cells from seven diabetic patients) without affecting IL-1beta or superoxide generation. These data show that standard immunosuppressive therapy in islet transplanted patients may partially inhibit cytokine release but does not affect the generation of potentially islet-toxic superoxide from mononuclear cells.
Diabetes Mellitus, Type 1↗