Date of publication: 2017-09-02 00:52
Less common causes of abnormal liver enzymes in the United States include hemochromatosis ( iron overload ), Wilson s disease, alpha-6-antitrypsin deficiency , celiac disease, Crohn s disease , ulcerative colitis , and autoimmune hepatitis. Though not as common as hepatitis C , hepatitis B can cause chronic liver disease with persistently abnormal liver enzymes.
Other blood tests pertaining to the liver are measurements of some of the other enzymes found the liver. In addition to AST and ALT, alkaline phosphatase, 5' nucleotidase, and gamma-glutamyl transpeptidase (GGT) are a few of the other enzymes located in the liver. The focus of this article is mainly on the most common liver enzymes, AST and ALT.
If abnormal liver enzymes persist despite abstinence from alcohol, weight reduction, and stopping certain suspected drugs, other tests can be performed to help diagnose other possible treatable liver diseases. The blood can be tested for the presence of hepatitis B and C viruses and their related antibodies. Blood levels of iron, iron saturation, and ferritin (another measurement of the amount of iron stored in the body) are usually elevated in individuals with hemochromatosis. Blood levels of a substance called ceruloplasmin are usually decreased in people with Wilson s disease. Blood levels of certain antibodies (anti-nuclear antibody or ANA, anti-smooth muscle antibody, and anti-liver and kidney microsomal antibody) are elevated in individuals with autoimmune hepatitis.
There are other tests such as serum ammonia and serum lactate levels in their panels. There are home liver tests for blood enzyme levels and liver function however, individuals who use these tests should first discuss their use and results with their health-care professional.
Note that many hospitals and doctor s offices list a liver function panel as part of a lab workup. These panels vary and may consist of AST, ALT and some or all of the tests listed above. In addition, the normal panel values may vary somewhat, especially between adult men, women and children so viewing the normal ranges of test values is always recommended, and a thorough discussion with the physician is necessary. In addition, some clinicians recommend other tests such as serum ammonia and serum lactate levels in their panels.
AST and ALT serum levels in some liver conditions can range anywhere from ten times the upper limits of normal to thousands of units/liter. The highest levels of AST and ALT are found with disorders that cause rapid death of numerous liver cells (extensive hepatic necrosis). Although this degree of liver enzymes elevation is not common, it can occur in such conditions as:
Among the most sensitive and widely used liver enzymes are the aminotransferases. They include aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT). These enzymes are normally predominantly contained within liver cells and to a lesser degree in the muscle cells. If the liver is injured or damaged, the liver cells spill these enzymes into the blood, raising the AST and ALT enzyme blood levels and signaling liver disease.
However, the ranges of AST and ALT numbers may differ slightly depending on the technique and protocols used by different laboratories worldwide. However, normal reference ranges are routinely provided by each laboratory and printed with each patient s individual report.
Aside from AST and ALT, there are other enzymes including alkaline phosphatase, 5'-nucleotidase ("5 prime" nucleotidase), lactate dehydrogenase (LDH), and gamma-glutamyl transpeptidase (GGT) that are often used to detect for liver disease.
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Evaluation of healthy individuals with abnormal liver enzymes needs to be individualized. A doctor may ask for the patient s blood test data from old records for comparison. If no old records are available, the doctor may repeat blood tests in weeks to months to see whether these abnormalities persist.