Alkaline Phosphatase heat stability analysis cannot be performed if the total ALP activity is less than 110 U/L in the blood sample, or is less than 5 U/L in the CSF sample.
If the remaining activity after heating is 90 - 100% of the total ALP then this indicates that the predominant isoenzyme is either of placental origin or is the Regan isoenzyme .
Uncertainy of measurement: 20%
# Result available within 3 hours, but not outside 0800 -1700 weekdays.
If the test is required out of hours, consult on call Chemical Pathologist.
Principle: Kinetic rate reaction
Reagent: Roche
Analyser: Cobas c702
The quantitative method used here is by heat denaturation - making use of the unique heat stable nature of Placental or Placental-like alkaline phosphatase (ALP) compare with other isoenzymes. Qualitative detection of placental ALP can be made by Alkaline phosphatase isoenzyme electrophoresis. (see separate section on Alkaline Phosphatase Isoenzyme in the test guide).
Typically in pregnancy, placental ALP activity starts to rise rapidly in the 3rd trimester but will quickly drop off postpartum leaving a mildly raised bone ALP for about 6 more weeks.
Placental or placental-like ALP (as Regan or Nagao isoenzyme) can be raised in tumours like lung, colorectal, breast, pancreas, gastric, ovarian cancers and germ cell tumours. Unless grossly raised, this method is not sensitive or specific enough for diagnosis or monitoring of these tumours. This method also cannot detect the low level rise in CSF placental ALP in primary intracranial germinomas.
See also Alkaline Phosphatase in the test guide
Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427