Mycophenolate compounds are therapeutic drugs that are routinely administered to solid organ transplant patients to suppress the immune system and prevent organ rejection. Mycophenolic Acid (MPA) and Mycophenolic Acid Glucuronide (MPAG) levels are routinely monitored to ensure concentrations remain within a narrow range where toxicity is minimized while still providing adequate therapeutic effects. MPA, the active agent in immunosuppression subsequently forms MPAG through glucuronidation. MPAG is the major metabolite of MPA and is tested to ensure normal metabolism of the drug. By testing the levels of both MPA/MPAG with LC-MS/MS one can obtain accurate measurements of levels consistent with active immunosuppression.<br/>MPA/MPAG were measured using a Shimadzu LC-MS 8060. Serum samples (25 uL) and internal standard solution (25 uL MPA-d3 and MPAG-d3) were extracted with 150 uL acetonitrile-methanol(1:1). The supernatant (0.1 uL) was injected into the LC. Chromatographic separation was acheived in 3.5 minutes. Detection of MPA/MPA-d3 was accomplished by electrospray ionization tandem mass spectrometry in the positive ion mode, while MPAG/MPAG-d3 analysis used negative electrospray ionization with multiple reaction monitoring. The precursor→product ion was monitored at 320.95→207.20 m/z for MPA, 324.05→210.15 m/z for MPA-d3, 495.16→3.19.20 m/z for MPAG, and 498.46→322.20 m/z for MPAG-d3. Control studies were performed on patients with no MPA exposure. The results of the test validations and patients’ serum were compared to control values.<br/>Using small serum sample volumes (25 uL), this method proved to be a fast, accurate, reproducible, and sensitive for the simultaneous quantitation of MPA and MPAG. The above method has been successfully validated and has shown it can be used for immunosuppressive therapeutic drug monitoring of MPA/MPAG. Due to decreased run time and use of small solvent volumes, this method allows for a more sustainable approach to therapeutic drug monitoring of MPA and MPAG to prevent organ rejection in solid organ transplant patients.

Rapid quantification of mycophenolic acid and its glucuronide in human serum for therapeutic drug monitoring using LC-MS/MS

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.