Bone phosphatase (also called ostase or bone AP (bone-specific alkaline phosphatase)) is an isoenzyme of alkaline phosphatase. Alkaline phosphatase consists of a group of isoenzymes (liver AP, the bile duct AP, and the small intestine AP) that accompany many different metabolic processes in the body.
Bone phosphatase is the isoenzyme that has the highest bone specificity and is a marker for bone formation (osteoblast activity).
The procedure
Material needed
- Blood serum
Preparation of the patient
- Not necessary
Disruptive factors
- None known
Normal values for children
| Age | Normal values in U/L |
| <2 years of age (LY) | 19-131 |
| 2ND-10TH LJ | 14-102 |
Normal values for girls/women
| Age | Normal values in U/l |
| 11-12 LJ | 25-125 |
| 13-16 LJ | 3-55 |
| > 20. LJ | 1-13 |
| <55TH LY | 11,6-30,6 |
| > 56TH LJ | 14,8-43,4 |
Normal values for boys/men
| Age | Normal values in U/l |
| 11-14 LJ | 6-122 |
| 15-17 LJ | 28-72 |
| < 19. LJ | 7-23 |
| > 19. LJ | 15,0-41,3 |
Indications
- Suspected bone lesions such as bone metastases.
- Suspicion of osteoporosis or osteomalacia (softening of the bones).
Interpretation
Interpretation of increased values
- Fractures (bone fractures)
- Hyperparathyroidism (parathyroid hyperfunction).
- Bone metastases
- Bone tumors
- Body growth
- Paget’s disease (ostitis deformans) – bone disease associated with greatly increased bone remodeling.
- Osteomalacia (bone softening)
- Osteoporosis
- Renal osteodystrophy – bone changes that occur in chronic renal failure.
- Vitamin D deficiency
Interpretation of lowered values
- Hypoparathyroidism (hypothyroidism of the parathyroid gland).
- Drug therapy with steroids