Liver tests

Values

liver

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

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).

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.

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.

BILIRUBIN

TOTAL

BILIRUBIN

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

DIRECT

0-0.3 mg / dL

Gamma glutamyl transpeptidase (GGT) is an enzyme involved in hepatic detoxification mechanisms. Its levels increase significantly in ethyl alcohol poisoning (acute or chronic).

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.

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).

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