Liquid Chromatography鈥揅oupled Tandem Mass Spectrometry Based Assay to Evaluate Inosine-5鈥?monophosphate Dehydrogenase Activity in Peripheral Blood Mononuclear Cells from Stem Cell Transplant Recipient
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- 作者：Isabelle Laverdi猫re ; Patrick Caron ; F茅lix Couture ; Chantal Guillemette ; 脡ric L茅vesque
- 刊名：Analytical Chemistry
- 出版年：2012
- 出版时间：January 3, 2012
- 年：2012
- 卷：84
- 期：1
- 页码：216-223
- 全文大小：834K
- 年卷期：v.84,no.1(January 3, 2012)
- ISSN：1520-6882
文摘
Combinations of immunosuppressive drugs are routinely used post-transplantation to prevent rejection and/or other complications and optimize outcomes. The prodrug ester mycophenolate mofetil (MMF) is frequently used in solid-organ and stem cell transplantation settings. A growing body of evidence supports therapeutic monitoring of this immunosuppressant to optimize its efficacy and reduce toxicity. Thus, pharmacodynamic monitoring of MMF is a strategy that could potentially improve patient outcomes. Pharmacodynamic measurements require evaluation of inosine-5鈥?monophosphate dehydrogenase (IMPDH) activity, the target enzyme of the active moiety mycophenolic acid. Various nonradioactive methods using chromatographic separations have been used to quantify xanthosine monophosphate, the catalytic product of the enzyme, to indirectly evaluate IMPDH activity. However, no methods have used mass spectrometry based detection, which provides more specificity and sensitivity. Here, we describe a liquid chromatography鈥揷oupled tandem mass spectrometry (LC鈥揗S/MS) method for the quantification of xanthosine monophosphate and adenosine monophosphate (for normalization) in lysates of peripheral blood mononuclear cells (PBMCs) from hematopoietic stem cell transplant (HSCT) recipients. Linearity, precision, and accuracy were validated over a large range of concentrations for each compound. The method could measure analytes with high sensitivity, accuracy (93鈥?16%), and reproducibility (CV < 7.5%). Its clinical application was validated in PBMC lysates obtained from healthy individuals (n = 43) and HSCT recipients (n = 19). This reliable and validated LC鈥揗S/MS method could be a useful tool for pharmacodynamic monitoring of patients treated with MMF.