A hepatic function panel (HFP) is a blood test that measures substances produced or processed by the liver. Healthcare providers use this diagnostic tool to assess the liver’s overall condition and to identify potential issues. The results can help in detecting liver damage, inflammation, or problems with bile flow.
Components of a Hepatic Function Panel
A standard hepatic function panel typically includes several specific blood tests designed to evaluate different aspects of liver activity. These tests commonly measure liver enzymes, proteins, and bilirubin. The panel generally comprises Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), and Alkaline Phosphatase (ALP). It also assesses Total Bilirubin, which can be broken down into Direct Bilirubin. Additionally, the panel includes measurements for Albumin and Total Protein, which are indicators of the liver’s synthetic capabilities.
What Each Test Measures
Alanine Aminotransferase (ALT) is an enzyme primarily found in liver cells. When liver cells are damaged, ALT leaks into the bloodstream, leading to elevated levels. A high ALT level often suggests liver injury or inflammation. It is considered a relatively specific indicator of liver health.
Aspartate Aminotransferase (AST) is another enzyme found in the liver, but it is also found in other organs like the heart, muscles, and kidneys. Elevated AST levels can indicate liver damage, similar to ALT. However, because AST is present in multiple tissues, its elevation is less specific to the liver than ALT.
Alkaline Phosphatase (ALP) is an enzyme found in the liver, bones, kidneys, and digestive system. Elevated ALP levels can point to issues with bile ducts within the liver, such as blockage or inflammation. High ALP can also be associated with bone disorders.
Total Bilirubin is a yellowish waste product from the breakdown of old red blood cells. The liver is responsible for processing and excreting bilirubin. Elevated total bilirubin levels can indicate that the liver is not properly processing or clearing bilirubin, which may lead to jaundice.
Direct Bilirubin, also known as conjugated bilirubin, is the form of bilirubin that has been processed by the liver. High levels of direct bilirubin typically suggest a problem with the liver’s ability to excrete bile, often due to a blockage in the bile ducts.
Albumin is the most abundant protein in the blood plasma and is exclusively produced by the liver. It plays a crucial role in maintaining fluid balance within the body and transporting various substances, including hormones and drugs. Low albumin levels can indicate that the liver is not functioning properly and is unable to synthesize sufficient amounts of this protein. This can be a sign of chronic liver disease.
Total Protein measures the total amount of protein in the blood, encompassing albumin and other proteins called globulins. The total protein level provides a general overview of the body’s protein status, which can be influenced by liver function, kidney function, and nutritional status.
Reasons for a Hepatic Function Panel
Healthcare providers often order a hepatic function panel to assess liver health. One common reason is to investigate symptoms that could suggest liver problems, such as unexplained fatigue, nausea, vomiting, dark urine, or jaundice. The panel helps determine if these symptoms are indeed related to liver dysfunction. Another reason for ordering an HFP is to monitor the liver’s condition when a person is taking medications known to potentially cause liver damage, as regular testing can help detect early signs of drug-induced liver injury. This panel is also used to screen for or monitor the progression of liver diseases like hepatitis, cirrhosis, or fatty liver disease, helping to evaluate severity and guide treatment decisions.