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
The chemical pathology team can be reached via email: chemicalpathologist@adhb.govt.nz or via Lablink (09) 307 4949 ext 22000 or 09-3078995
Emails will receive priority attention from the on-call chemical pathologist. Include the patients NHI.
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
- Dr Sakunthala Jayasinghe Saku.Jayasinghe@adhb.govt.nz
- Dr Owen Yi WenyiYi@adhb.govt.nz