Disclaimer: This HealthHearty article is for informative purposes only, and should not be used as a replacement for expert medical advice.
Alkaline phosphatase is an important enzyme that is present in the body. This enzyme is a type of hydrolase enzyme that deals with the removal of phosphate groups from different molecules. The process of removal is known as dephosphorylation. As is implied by the name, for optimal functioning of this enzyme, there is requirement of an alkaline environment. Hence, this enzyme works best in a pH of around eight. Although this enzyme is found in all the tissues of the body, it is especially concentrated in the liver, bile duct, kidneys, and bones. Thus, the exact levels are vital indicators of normal liver function.
When to Check the Levels
Normally, you can do a blood test if there are any signs and symptoms of a possible systemic disorder; especially one that is indicative of abnormal liver functioning. Thus, if a patient is showing symptoms like weakness, fatigue, loss of appetite, nausea, dark urine, lower abdomen pain, abdominal swelling, and jaundice, a blood test is often carried out. But sometimes these levels are also checked as a part of routine blood tests.
The way to calculate the normal levels in the blood is with the help of a routine blood test. There are many things to take into consideration before going in for such a test. There are certain drugs and medications that might adversely affect the results. Thus, the doctor will normally ask you to stay off such drugs for a while. Some of the drugs include allopurinol, antibiotics, cortisone, propranolol, and birth control pills. The normal range is around 44 to 147 IU/L.
There are many cases where the blood test results might point towards elevated levels. This is indicative of some kind of deviation for normal functioning of the liver. It is unclear as to why the level of this enzyme shoots up in only certain diseases like liver and bone diseases. Firstly, it may be indicative of bile duct obstruction or cholestasis. Also, other related conditions like bile duct inflammation (cholecystitis), cholangitis, fatty liver, hepatitis, and various infectious and non-infectious conditions of the liver. Other diseases that affect the skeletal system also reflect in these test results, such as the presence of Paget's disease, renal osteodystrophy, fractured bone, osteomalacia, rickets, and hyperparathyroidism. Other conditions which may be included in the differential diagnosis also include pregnancy, myelofibrosis, polycythemia vera, and seminoma.
The occurrence of lowered level is relatively rare as compared to the elevated levels. However, the former is indicative of various diseases like hypophosphatasia, malnutrition, hypothyroidism, pernicious anemia, aplastic anemia, and enteritis. Low alkaline phosphatase in children are seen when they suffer from congenital diseases like cretinism and achondroplasia. Low levels may also be seen in women that are suffering from osteoporosis post menopause.
Although this test is a very helpful tool in diagnosing a possible case of liver or bone disorder, one cannot solely rely on it for reaching a final diagnosis of a condition. Thus, one needs to take a detailed history, note the signs and symptoms, and match them with the blood test report, before reaching a final diagnosis of a disease.