R U H Bath, return to home page

Pathology Departments Requesting & Reporting Blood Test Information Phlebotomy Guide Contact us
Blood Sciences

Blood Test Information

Alkaline Phosphatase - bone specific
minimum sample volume required ~ 5ml

  back to assay index

Test Code: BSA

Tube type: SST

Special instructions
Sent away to Charing Cross Hospital
Contact Laboratory before requesting

Reference range

Turnaround Time
21 days

Department: Biochemistry

Clinical Application
Serum Alkaline Phosphatase (ALP) measurements are used in the diagnosis and treatment of hepatobiliary and bone diseases and form part of the liver function and calcium profiles. ALP refers to a group of phosphatases (pH optimum ~10) found in almost every tissue in the body. Most ALP in normal adult serum is from the liver or biliary tract. Normal ALP levels are age dependent; young children and adolescents have much higher levels than adults. Adult males tend to have higher levels than females, but pregnant females have increased levels due to placental secretion of ALP. Elevation of ALP occurs in diseases such as hepatitis, cirrhosis, malignancy, chemical toxicity, metastatic carcinoma, rickets, Paget’s disease, and osteomalacia. Moderate increases in ALP have been observed in Hodgkin’s disease, congestive heart failure, ulcerative colitis, regional enteritis, and intra-abdominal bacterial infections. Measurement of ALP is helpful in the differential diagnosis of liver disease: elevation indicates involvement of the biliary system. Normal ALP levels are elevated during periods of active bone growth due to increased osteoblast activity following accelerated bone growth, eg. in young children and adolescents. Measurement of gamma-GT may help in seeking cause of an elevated ALP: if GGT is not raised, then the source is likely to be bone. However elevated GGT does not necessarily indicate a liver origin of a raised ALP. ALP isoenzyme analysis may be helpful, but is only likely to produce useful results if ALP>140 IU/L. Bone-specific ALP may also be measured.


back to top