Specimen Collection:
Tubes containing gel (SST and PST) are NOT acceptable
Laboratory notes:
Aliquot minimum 1mL plasma or serum, send on ice (2-8 degrees).
Check there are two points of ID on the sendaway tube
Place with a copy of the form in the Canterbury sendaway container in the walk-in fridge L3
Any queries please contact the Section Leader/Technical Specialist SCP- Chromatography
Diagnostic Use and Interpretation:
Mycophenolic acid (MPA, mycophenolate) is an immunosuppressive agent that inhibits inosine monophosphate dehydrogenase, an enzyme that controls the rate of synthesis of guanine monophosphate in the de novo pathway of purine synthesis used in the proliferation of B and T cells.
The benefits of therapeutic drug monitoring for MPA are controversial. The relationship between adverse events and MPA exposure is weak.
The total MPA concentration must be evaluated in the context of a patient's renal function and levels of albumin and bilirubin. Renal insufficiency may lead paradoxically to low total MPA levels: MPA clearance is increased as a result of displacement from plasma protein binding sites by increased levels of a metabolite MPAG, and levels of free MPA may be relatively unchanged. Similar perturbations can be observed in hypoalbuminaemia and hyperbilirubinaemia states. Free MPA levels may be informative but there is paucity of data on validated free MPA target values.
After a change in MPA drug dosing, testing should be done when steady state is achieved after 4 days.
Reference intervals are provided Canterbury Health Laboratories and are based on trough samples. Target values for total MPA may vary based on the type of organ transplant; use of concomitant immunosuppressive drugs; trough or timed samples. Transplant specialists should be consulted for organ specific target values.