SUPPRESSION OF EXPERIMENTAL AUTOIMMUNE NEURITIS BY PHOSPHODIESTERASE INHIBITOR PENTOXIFYLLINE

Phosphodiesterase inhibitor pentoxifylline (POX) has been shown to hav e multiple immunomodulatory effects in vitro and in vivo. It inhibits T cell proliferation, T helper I-type cytokines, and tumor necrosis fa ctor. We postulated that POX might have an in vivo immunomodulatory ef fect on a T-cell-mediated autoimmune peripheral nervous system disease , experimental autoimmune neuritis (EAN). We investigated the effect o f POX on EAN in rats immunized with peripheral nerve myelin containing neuritogenic peptide SP26. At 200 mg/kg/day, there was significant su ppression of clinical EAN, weight loss, and T cell proliferation to SP 26 compared to controls. Proliferation of T cells from immunized rats to SP26 was suppressed by POX in vitro. These studies demonstrate a be neficial role for POX in EAN, with potential applicability to human au toimmune demyelination.