Elevated levels of LD (aka LDH) and changes in the ratio of the LD isoenzymes usually indicate som...
Elevated levels of LD (aka LDH) and changes in the ratio of the LD isoenzymes usually indicate some type of tissue damage. Usually LD levels will rise as the cellular destruction begins, peak after some time period, and then begin to fall. For instance, when someone has a heart attack, blood levels of total LD will rise within 24 to 48 hours, peak in 2 to 3 days, and return to normal in 10 to 14 days. LD levels are elevated in many other conditions reflecting its widespread tissue distribution
Raised alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values indicate leakage from cells due to inflammation or cell death. Liver disease is more likely when the values of AST and ALT are higher, ALT rising more than AST in acute liver damage such as hepatitis. When there is doubt about values, a raised creatine kinase (CK) will confirm muscle damage and measurement of troponin will show whether it is the heart that is damaged. Gamma-glutamyl transferase (GGT) seems to be more sensitive than ALT and AST for detecting liver damage from drugs and alcohol, Raised GGT concentrations indicate that something is going on with your liver but not specifically what. In general, the higher the result the greater the damage to your liver. Elevated concentrations may be due to liver disease, but they may also be due to congestive heart failure, drinking alcohol, and use of many prescription and non-prescription drugs including nonsteroidal anti-inflammatory drugs (NSAIDs), lipid-lowering drugs, antibiotics, histamine blockers (used to treat excess stomach acid production), antifungal agents, anticonvulsants (seizure control medications), antidepressants, and hormones such as testosterone. Oral contraceptives (birth control pills) and clofibrate can decrease GGT concentrations.
Certain drugs may raise the concentration of ALT and/or AST in the bloodstream by causing liver damage. This occurs in a very small percentage of patients, and is true of both prescription drugs and some 'natural' health products.
A raised total bilirubin is usually due to liver disease or blockage of the passage of bile to the gut, for example by gall stones. Bilirubin is made water soluble (conjugated) by the liver and is then excreted in the urine, the stools becoming pale. However, a raised bilirubin can also occur in conditions where the breakdown of red blood cells produces more unconjugated bilirubin than the liver can handle, for example in newborn babies. If this is suspected, both total and conjugated bilirubin are measured and monitored.
Liver disease and blockage of the bile ducts also increase alkaline phosphatase (ALP). This is believed to be due to increased bile duct pressure causing the liver to make more ALP. If there are localised lesions within the liver, for example deposits of cancer cells, then ALP may be stimulated to rise but there may be sufficient normal liver around the deposits to keep bilirubin normal. Bone disease can also increase ALP. In patients with a normal bilirubin and a raised ALP, the measurement of 5’-nucleotidase (5’-NT) can help. It rises with liver ALP but is normal in bone disease.
Albumin is made only in the liver and may be low when there has been extensive loss of liver tissue in long-standing disease. Other causes of a low albumin include malnutrition (which may accompany alcoholic liver disease), kidney disease, due to loss of protein in the urine, and inflammatory conditions anywhere in the body when the liver switches to making other proteins.
Total protein is usually normal in liver disease. The difference between its concentration and that of albumin, called globulin, tends to increase when albumin falls, but very high values are seen most commonly in alcoholic hepatitis and in hepatitis caused by the body producing antibodies against its own liver (autoimmune hepatitis).