Generality
Liver health can be assessed with a simple and common drawing of blood from a vein in the forearm.
The blood sample thus obtained is then analyzed in the laboratory, in order to measure the markers of liver function and health (ie to establish the plasma concentration of the substances that have to do with the efficiency and structural integrity of the organ).
For this reason, in order to identify liver disease with certainty, in addition to comparing the values of several markers, it may be necessary to resort to ultrasound scans or organ biopsies.
| DETECTED CELL PHONE | |||
| ACUTE | CHRONIC | CHOLESTASIS | |
| Albumin | normal or diminished | normal or severely diminished | normal |
| Bilirubin | normal or strongly increased | normal or increased | increased |
| transaminases | strongly increased | increased | slightly increased |
| ALP | normal | normal | strongly increased |
| GGT | slightly increased | slightly increased | strongly increased |
| PT (prothrombin time) | normal | slightly increased | slightly increased |
What's this
The hepatic panel is a set of analyzes that allows to assess the state of health of the organ.
Normally, liver values are determined with analyzes performed at the same time on a blood sample.
Usually, the parameters included in this panel are:
- Total and fractionated bilirubin (conjugated and unconjugated);
- Enzymes (transaminases, alkaline phosphatase and gamma-glutamyltranspeptidase);
- Plasma proteins (albumin and globulin);
- Coagulation factors (prothrombin time and partial thromboplastin time).
In relation to the doctor's decisions and laboratory availability, liver function tests may also include the analysis of:
- Fibrinogen;
- Lactic dehydrogenase (LDH);
- Markers of viral hepatitis;
- Pseudocholinesterase.
Why do you measure
The hepatic panel is useful for assessing and monitoring acute and chronic inflammation (hepatitis), liver damage and / or disease (from cirrhosis to tumors).
When is the exam required?
The doctor can check the liver values when he suspects that the organ may have some known or suspected problems, or in cases where the patient is taking hepatotoxic drugs.
The hepatic panel is also indicated when symptoms of a liver disease are found, such as:
- Jaundice (yellow coloring of the skin, sclerae and other tissues, caused by an excess of circulating bilirubin);
- Dark urine;
- Nausea, vomiting and / or diarrhea;
- Loss of appetite;
- Feces with blood or dark traces;
- Swelling or pain in the belly;
- Changes in body weight;
- Fatigue or weakness.
One or more of these liver values can also be evaluated when a person habitually takes in excess alcohol or has been exposed to hepatitis viruses.
Normal values
| Values liver | Clinical meaning | Normal values |
| ALBUMIN | Synthesized by the liver, albumin is the most abundant protein in plasma. Its values decrease in the presence of chronic liver diseases, such as cirrhosis, due to the reduced synthesis. The same result can be had in the presence of chronic renal diseases (nephrotic syndrome), due to the abnormal loss of albumin in the urine, but also in the presence of severe malnutrition, prolonged fasting, protein catabolism and numerous other conditions. For this reason the ability of hepatic protein synthesis is evaluated by preferably dosing other markers, such as coagulation factors. | 3.9 - 5.0 g / dL |
| ALT | Alanine transaminase, more simply ALT, ALAT or SGPT, is an enzyme present in the mitochondria of liver cells (hepatocytes), involved in protein synthesis. When a hepatocyte is damaged it inevitably produces a leakage of this and other enzymes, which increase its concentration in the blood. As a result, ALT blood values increase significantly during acute organ damage, such as during an acute viral hepatitis, chronic hepatitis or an overdose of paracetamol (fulminant hepatitis). | 9 - 60 IU / L |
| AST | Aspartate transaminase (AST), also known as ASAT or SGOT, is another enzyme contained in liver cells; consequently its increase in blood recognizes the same hepatic causes, although it can be traced more easily to cardiac or muscular damage. It is therefore a non-specific index of liver function; its values can be related to those of ALT to trace the nature - hepatic or extra-hepatic - of the increase in these transaminases. If ALT is much more increased than AST, liver damage is plausible, vice versa cardiac. Comparison of these and other enzymes with creatine kinase values can confirm or deny the hepatic origin of the problem. In fact, creatine kinase increases in the presence of a muscle injury, so normal values associated with high ALT values suggest a liver problem. | 10 - 40 IU / L |
| ALP | Alkaline phosphatase (ALP) is an enzyme contained in the cells that line the innermost layer of the intrahepatic bile ducts. Therefore, an increase in ALP values in the blood can result from bile obstructions of various kinds (gallstones), intrahepatic cholestasis or infiltrative liver diseases (for example, a tumor). Its rise is common even in the presence of osee diseases. | 30 - 120 IU / L |
| BILIRUBIN TOTAL BILIRUBINE DIRECT | Bilirubin is a degradation product of EME, a key component of hemoglobin in red blood cells. Once synthesized (indirect or unconjugated bilirubin) it is made water-soluble in the liver (direct or conjugated bilirubin), and secreted in bile (which flows into the intestine). An increase in the total fraction with high conjugate fraction high and normal conjugate, can therefore reflect a problem of liver function (cirrhosis, viral hepatitis etc.) or an increased catabolism of red blood cells (haemolytic anemia). In contrast, an increase in the conjugate (direct) fraction may reflect an intra or extrahepatic biliary obstruction problem. Slightly increased indirect bilirubin levels, with all other normal liver function markers, are common in Gilbert's syndrome. The excess of bilirubin in the blood gives the skin and ocular sclerae a yellowish color (jaundice). | TOTAL 0.1-1.2 mg / dL DIRETTA 0-0.3 mg / dL |
| GGT | Gamma glutamyl transpeptidase (GGT) is an enzyme involved in hepatic detoxification mechanisms. Its levels increase significantly in ethyl alcohol poisoning (acute or chronic). | 0 to 51 IU / L |
| TIME TO PRO THROMBIN | This blood test measures the plasma clotting time; since the liver is the key organ in the synthesis of coagulation proteins, an increase in this range may indicate liver damage. See also INR. | 11 - 13 seconds |
| LACTATE Dehydro-Genasi | Lactate dehydrogenase (LDH) is an enzyme found in many tissues of the body, including the liver. It is therefore a highly non-specific index of liver function, and its increase can also, but not necessarily, indicate damage to the liver (in this case, the LDH 4 and LDH5 isoforms increase above all). | - |
| EXAMS immuno- LOGIC | In the presence of a suspicion on a possible viral hepatitis, immunological tests can be conducted on the blood sample in order to search for viruses and antibodies against them. The search for auto-antibodies can instead be carried out in the presence of suspicions on possible autoimmune liver diseases, triggered by the presence of abnormal antibodies against the same cells of the body (primary biliary cirrhosis, autoimmune hepatitis, primitive sclerosing cholangitis). |
High Values - Causes
Bilirubin
An excess of indirect bilirubin may be due to:
- Hemolytic diseases;
- Drug damage;
- Some hereditary diseases that alter the ability of the liver to convert indirect bilirubin into direct one, such as the Gilbert and Crigler-Najjar syndromes.
An increase in direct bilirubin may depend on:
- Liver diseases, such as cirrhosis, viral and toxic hepatitis;
- Biliary obstructions due, for example, to stones or tumors of the liver or pancreas.
transaminases
Extremely high values of transaminases indicate acute necrosis of liver cells or liver damage due to:
- Acute viral hepatitis;
- Hepatitis induced by toxins or drugs;
- Ischemic hepatitis or hepatic infarction.
In these cases, the liver values are high for days or, in the case of viral hepatitis, even for weeks.
Values higher than normal can also be determined by:
- Liver cirrhosis due to any cause;
- Non-alcoholic steatosis;
- Cholestatic disorders;
- Hepatocellular carcinoma;
- Hepatic metastases;
- Acute exacerbation of autoimmune hepatitis;
- Reactivation of chronic hepatitis B;
- Acute Budd-Chiari syndrome;
- Hepatic steatosis of pregnancy.
Moderate increases can be observed in chronic liver disorders (chronic and alcoholic hepatitis) and in bile duct obstruction.
The increase in ALT (alanine aminotransferase) may also depend on diseases that affect organs and tissues other than the liver: for example, muscular dystrophies, circulatory decompensation, trauma, obesity, pancreatitis, destruction of red blood cells (hemolysis) and mononucleosis (the so-called kiss disease).
Alkaline phosphatase
The ALP values increase considerably when there is an alteration of the biliary tract (such as an obstruction) and, to a lesser extent, in the case of liver disorders, such as:
- Hepatitis;
- Cirrhosis;
- Cancer;
- Infiltrative disorders (amyloidosis, sarcoidosis, TB, abscesses and metastases).
Occasionally, isolated increases may occur even in the absence of obvious hepatic or biliary disorders:
- Some tumors without obvious hepatic involvement;
- After ingestion of high fat meals;
- Pregnancy;
- Children and adolescents in the growth phase (due to bone development);
- Chronic renal failure.
Gamma-glutamyl transpeptidase (GGT)
High GGT values are found in hepatobiliary dysfunctions, particularly in cholestasis.
The increase in gamma-glutamyl transpeptidase is also observed during alcohol consumption and in some diseases, such as congestive heart failure.
When alkaline phosphatase is increased, even if GGT is, then hepatic or biliary dysfunction can be suspected; if, on the other hand, gamma-glutamyl transpeptidase is normal, it is more likely that the increase in alkaline phosphatase is a sign of bone disease.
Prothrombin time (PT)
A lengthening of the PT can be observed in liver diseases, in vitamin K deficiency, during the use of drugs that reduce the risk of thrombosis (warfarin), and in the lack of coagulation factors.
Low Values - Causes
Prothrombin time (PT)
Prothrombin time also evaluates liver function, since there is a correlation between coagulation abnormalities, measured by prothrombin time, and the degree of organ dysfunction. When the liver is significantly damaged, in fact, coagulation factors are not normally produced.
Albumin
In the case of chronic liver disease (eg cirrhosis), serum albumin levels (and its synthesis) are decreased. Alcoholism, chronic inflammation and protein malnutrition also reduce the synthesis of this protein.
Another cause can be excessive loss through the kidneys (nephrotic syndrome), intestines or skin (eg severe burns).
Bilirubin
A decrease in bilirubin levels can be caused by:
- Some types of anemias (aplastic and sideropenic);
- Intake of certain sedatives (eg barbiturates).
Alkaline phosphatase
A decrease in alkaline phosphatase can also be caused by hypothyroidism, anemia, malnutrition or old age.
Gamma-glutamyl transpeptidase (GGT)
Low or normal GGT levels do not raise concerns, as they are indicative of good liver function: the chances of the patient suffering from a liver disease are, therefore, low. In some cases, the reduction in GGT may depend on taking certain drugs, such as the contraceptive pill or clofibrates.
How to measure them
The liver values are measured on a blood sample taken from a vein in the arm.
Preparation
Liver values are determined after a fast of 10-12 hours.
Interpretation of Results
The hepatic panel examinations are not diagnostic for a specific pathology, but give an indication about the existence, extent and type of problem affecting the liver, namely:
- Obstruction of the biliary tract;
- Acute hepatocellular damage;
- Chronic liver disease.
Once the results of the liver panel have been assessed as a whole, the main clinical pictures are differentiated and the doctor indicates the execution of specific and specific in-depth tests to understand what is the cause of the damage and / or liver disease. The use of several laboratory tests improves the possibility of detecting hepatobiliary abnormalities, helps to differentiate clinically suspected pathologies and defines the severity of the disease involving the liver.
