Alkaline phosphatase is an enzyme present in various tissues in the body, but mostly in bones and in the liver. As a result of damage to those tissues, the level of alkaline phosphatase in the blood increases. This elevation can then be followed to assess the level of damage to the bones or liver, and track the recovery after treatment.
Facts about Alkaline Phosphatase
The alkaline phosphatase level is part of a battery of tests called the hepatic or liver panel. This set of labs measures enzymes and substances that could be affected in the face of liver disease. Alkaline phosphatase is also found in large quantities in bone. Therefore, elevation of the alkaline phosphatase level can also correlate with bone disease. According to Lab Tests Online, cells called osteoblasts, which help in bone formation, produce alkaline phosphatase.
Causes of Alkaline Phosphatase Elevation
Bone conditions that cause excessive bone formation or bone turnover can result in elevations of the alkaline phosphatase level. According to a 2006 article in "Pediatrics in Review," these include fractures, osteomalacia, or decreased mineralization of bone, and rickets, which results from a deficiency in vitamin D, an important nutritional component that helps in the growth and maintenance of bone. Paget's disease of the bone, a condition that causes excessive formation and breakdown of bone and results in bone weakening, can also cause elevation of the alkaline phosphatase level. Lastly, children and adolescents can have elevated alkaline phosphatase levels because of the continuous growth of their bones.
Symptoms
The symptoms of conditions that elevate the level of alkaline phosphatase vary. In general, bone pain and difficulty moving extremities are symptoms of conditions that can elevate the level of that enzyme. Paget's disease and osteomalacia present with weakening of the bone, which predisposes an individual to frequent fractures, sometimes in the face of minor trauma. Rickets causes soft, weak bones, and presents in infants and children with irritability, poor growth, bone pain, fractures, and bowing of the long bones.
Treatment
The treatments for these bones conditions vary, but the level of alkaline phosphatase can help determine if the therapy is working. Fractures need immobilization, either with a splint or a cast, and severe fractures need surgical intervention. According to the MayoClinic.com, Paget's disease can be treated with the same medicines used to treat osteoporosis. Rickets responds to vitamin D supplementation. In all these cases, a decrease in the alkaline phosphatase level reflects an improvement in the condition.
