A RAPID SERUM SCREENING TEST FOR INCREASED OSTEOBLASTIC ACTIVITY

Heat inactivation of serum alkaline phosphatase is the most rapid and simple method to demonstrate a raised osteoblastic activity. In this study a heat inactivation test is recommended in which serum samples are inactivated under optimal heat conditions. The reliability of the test as a measure of osteoblastic activity is verified by comparing its results with those of the separation of the alkaline phosphatase isoenzymes by agar gel electrophoresis, and with urinary hydroxyproline excretion, respectively. For liver patients, a rise of the original serum alkaline phosphatase activities was shown to be coupled with an increase of the residual percentage of activity. When interpreting the results of the test, this should be taken into account. If carefully executed and interpreted, the heat inactivation test provides a rapid, simple and reliable indication of osteoblastic activity, even in the case of a simultaneous bone and liver process. © 1968.