Mycophenolic Acid (MPA), plasma

Alternate test name

Mycophenolate Mofetil (MMF)

Lab area

Clinical Biochemistry - TDM & Toxicology

Method and equipment

LC-MS/MS

Expected turn-around time

M-F, 1 day

Specimen type

Plasma (EDTA), Whole Blood (EDTA) may be sent if unable to seperate

Specimen requirements

250 uL plasma

Storage and transportation

4°C (transport with a cool pack if possible)

Special requirements

Whole Blood (EDTA) may be sent if unable to separate

Background and clinical significance

Mycophenolic acid (MPA), the active metabolite of Mycophenolate Mofetil (MMF), is being used increasingly as an adjunct in immunosuppressant therapy after solid organ transplantation. Its immunosuppressive activity is thought to reside in the inhibition of inosine monophosphate dehydrogenase (IMPDH), leading to a suppression of purine nucleotide synthesis in lymphocytes, thereby suppressing cell mitosis. MPA is converted in the liver mainly to the 7-O-glucuronide metabolite, mycophenolic acid glucuronide (MPAG), which does not have immunosuppressant activity. A second metabolite, acyl glucuronide (AcMPA) does have immunosuppressant activity but is present in much smaller concentrations.

The principal adverse effects of MMF reported in the transplantation studies are gastrointestinal (especially diarrhea and vomiting), haematological and infective.