Description: An Alkaline Phosphatase test or ALP is a blood test that is used to screen for and monitor liver disease, bone disorders, and gallbladder disease.
Also Known As: ALP Test, Alk Phos Test, Alkp Test
Collection Method: Blood Draw
Specimen Type: Serum
Test Preparation: No preparation required
When is an Alkaline Phosphatase test ordered?
An ALP test may be requested as a standard laboratory test, frequently in conjunction with a liver panel of further assays. When a person exhibits signs of a liver or bone issue, it is frequently requested in conjunction with a number of additional tests.
What does an Alkaline Phosphatase test check for?
An enzyme called alkaline phosphatase is present in many bodily tissues. The cells that make up bone and the liver have the highest quantities of ALP. Liver illness or bone diseases are the most frequent causes of high blood levels of ALP. The blood's concentration of ALP is determined by this test.
ALP is located in the liver on the margins of cells that converge to form bile ducts, which are minuscule tubes that transport bile from the liver to the bowels, where it is required to aid in the digestion of dietary fat. Osteoblasts, specialized cells involved in bone production, are responsible for producing ALP in bone. Isoenzymes, which are produced in unique forms by each type of tissue, are ALP.
For instance, when one or more bile ducts are obstructed, ALP blood levels may significantly rise. Gallbladder inflammation or gallstones may be the cause of this. Blood ALP levels rise slightly more subtly in cirrhosis, liver cancer, hepatitis, and when liver-toxic medications are used.
Increased ALP levels can result from any condition that promotes excessive bone growth, including bone diseases like Paget's disease. Because their bones are still growing, children and adolescents often have higher blood ALP levels. Because of this, the ALP test needs to be interpreted differently for children and adults.
It is feasible to distinguish between the various ALP forms generated by various bodily tissues. A test may be run to identify which isoenzyme is elevated in the blood if it is unclear from clinical signs and symptoms whether the cause of a high ALP test result is liver or bone illness.
Lab tests often ordered with an Alkaline Phosphatase test:
- Comprehensive Metabolic Panel
- Hepatic Function Panel
- Alkaline Phosphatase Isoenzymes
Conditions where an Alkaline Phosphatase test is recommended:
- Lier Disease
- Paget’s Disease
- Vitamin D Deficiency
How does my health care provider use an Alkaline Phosphatase test?
Using the alkaline phosphatase test, liver disease and bone diseases can be found.
Damaged liver cells produce more ALP into the blood under situations that harm the liver. Because ALP levels are particularly high at the margins of the cells that unite to form bile ducts, this test is frequently used to identify obstructed bile ducts. Blood levels of ALP are frequently high when one or more of them are blocked, such as by a tumor.
ALP levels in the blood can be impacted by any illness or disease that hinders bone development or increases bone cell activity. For instance, an ALP test may be used to identify tumors that have metastasized to the bones or to identify Paget's disease, a condition that results in deformed bones. This examination could occasionally be used to track the progress of patients being treated for Paget's disease or other bone disorders such vitamin D insufficiency.
Tests for the ALP isoenzyme may be performed to identify the cause if ALP readings are elevated but it is unclear whether this is related to liver or bone illness. To distinguish between liver and bone illness, one may additionally perform a GGT test and/or a test for 5'-nucleotidase. The levels of GGT and 5'-nucleotidase are elevated in liver illness but not in disorders of the bones.
What do my Alkaline Phosphatase test results mean?
High ALP typically indicates the presence of a disease that increases bone cell activity or liver damage.
The liver is typically where the elevated ALP is coming from if other liver tests, such as bilirubin, aspartate aminotransferase, or alanine aminotransferase, are also high. The high ALP is probably the result of liver illness if GGT or 5-nucleotidase levels are also elevated. If one of these two tests comes out normal, a bone issue is probably to blame for the high ALP. The ALP is typically coming from bone if calcium and/or phosphorus readings are abnormal.
A test for ALP isoenzymes may be required to differentiate between bone and liver ALP if it is unclear from signs and symptoms or other regular testing whether the high ALP is from the liver or bone.
ALP test findings are typically analyzed alongside those of other liver disease testing. ALP is commonly significantly less increased than AST and ALT in several types of liver illness, such as hepatitis. ALP and bilirubin may increase substantially higher than AST or ALT when the bile ducts are obstructed. ALP levels in liver cancer may also be higher.
ALP may be elevated in some bone illnesses, such as Paget's disease, which causes enlarged and misshapen bones, or in some cancers that extend to the bone.
ALP levels will eventually drop or return to normal if Paget's disease is successfully treated in a patient. ALP levels should fall if someone with liver or bone cancer responds to therapy.
Other illnesses include Hodgkin's lymphoma, congestive heart failure, ulcerative colitis, and specific bacterial infections can cause moderately high ALP.
ALP levels may briefly drop after cardiac bypass surgery or blood transfusions. Levels may drop as a result of a zinc deficiency. Hypophosphatasia, a rare genetic bone metabolism condition, can result in extremely low levels of ALP that persist for a long time. Wilson disease, protein insufficiency, and malnutrition are further potential reasons of low ALP.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.