Pharmacodynamic monitoring of the conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in stable kidney-allograft recipients

Background: The formulations of mycophenolic acid, i.e., mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS), seem to have different pharmacokinetic profiles. The aim of this study was to compare the effects MMF and EC-MPS on T-cell proliferation, T-cell activation, T-cell function, and lymphocyte subsets. Clinical study and methods: Ten stable kidney-transplant patients on standard maintenance therapy of tacrolimus and MMF (1 g/d), with or without steroids, were converted from MMF to EC-MPS at equivalent dose (720 mg/d). Tacrolimus and steroid doses remained unchanged before, and at 1, 2, 3, and 6 months (M) after conversion. Intra T-lymphocyte cytokines IL-2 and TNF-alpha, lymphocyte-activation surface markers (CD25 and CD71), T-cell proliferation (PCNA+ PIhigh), total lymphocyte count, as well as lymphocytes subsets (CD2, CD3, CD4, CD8, CD19, NK cells) were measured by flow cytometry before conversion and at M1, M2, M3, and M6. Results: We found no significant differences of MMF versus EC-MPS on lymphocyte function. T-cell proliferation and T-cell activation (CD25 and CD71 expression), but not cytokine expression (TNF-alpha and IL-2), showed a trend to increase after conversion from MMF to EC-MPS. Total lymphocyte, CD2, CD3, CD4, CD8, and NK cells counts were not significantly modified. Conclusion: This study revealed a trend to a lower immunosuppression with EC-MPS as compared to MMF in stable renal transplant patients. (c) 2008 Elsevier B.V. All rights reserved.