Monitoring of Inosine Monophosphate Dehydrogenase Activity and Expression during the Early Period of Mycophenolate Mofetil Therapy in De Novo Renal Transplant Patients

作者：Molinaro Mariadelfina^*; Chiarelli Laurent R; Biancone Luigi; Castagneto Marco; Boschiero Luigi; Pisani Francesco; Sabbatini Massimo; Sandrini Silvio; Arbustini Eloisa; Tinelli Carmine; Regazzi Mario; Schena Francesco P; Segoloni Giuseppe P

来源：Drug Metabolism and Pharmacokinetics, 2013, 28(2): 109-117.

DOI：10.2133/dmpk.DMPK-12-RG-048

• IMPDH activity
• IMPDH1/2 gene expression
• pharmacodynamics
• pharmacokinetics
• renal transplantation

Measurement of inosine-monophosphate dehydrogenase (IMPDH) activity or gene expression was used as a further approach in pharmacokinetics (PK)/pharmacodynamic (PD)-guided mycophenolate mofetil (MMF) therapy. Forty-four de novo kidney transplant patients were enrolled; 35 of these completed the study, and were followed for 24 weeks for clinical status, PK parameters, IMPDH activity and IMPDH1/2 gene expression. IMPDH activity and expression were measured in peripheral blood mononuclear cells before transplant and at week 2,4,12 and 24, drawn before (to) and 2 h (t(2h)) after MMF administration. No significant correlation was found between IMPDH activity/expression and PK parameters. For both genes, significant enhancement in t2h expression was observed, then decreases towards week 24 with a trend following steroid dosages. Seven patients experienced acute rejection (AR) and exhibited significantly higher pre-transplant expression of both IMPDH1 (median 3.42 vs. 0.84; p = 0.0025), and IMPDH2 genes (135 vs. 104; p = 0.0218) with respect to non-rejecting patients. A significant association was also found between pre-transplant IMPDH1 mRNA and haematological complications (p = 0.032). This study suggests that high steroid dosages may influence IMPDH1/2 expression, hampering their use as a PD biomarker, particularly during the early post-transplant period. The measurement of pre-transplant levels of IMPDH1/2 may contribute to prediction of individual drug responsiveness to improve the clinical management of patients in MMF therapy.

• 出版日期2013-4-25