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LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012-.

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LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet].

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Glossary

Last Update: May 10, 2022.

Acinus

The main structural unit of the liver seen under the microscope; each acinus includes liver cells, sinusoids, central and portal areas with blood vessels, lymphatics and bile ducts.

Acute fatty liver

Rapid accumulation of fat in the liver usually caused by alcohol or medications that interfere with fat metabolism. Rarely, this can occur in the last trimester of pregnancy.

Acute liver disease

Liver disease that is limited in duration, but usually with a sudden and symptomatic onset.

Acute liver failure

Serious liver failure arising suddenly in a person without previous liver disease.

Acute hepatic necrosis

Sudden severe liver (hepatic) cell death (necrosis) that is typical of toxic injury to the liver.

Adenoma

A benign tumor of the liver that can grow large and rupture, causing internal bleeding.

Adenosine triphosphate (ATP)

The molecule within cells used for energy reactions.

Alanine aminotransferase (ALT)

An enzyme found in the blood that is elevated with liver injury, particularly hepatocellular (formerly SGPT). This is the most sensitive indicator of injury to the liver.

Alkaline phosphatase (Alk P)

An enzyme found in the blood that is elevated with liver injury, particularly cholestatic. This enzyme can also originate from other structures, like bone and bowel; if originating from the liver, other enzymes, such as the GGT, ALT, or liver fraction of the alkaline phosphatase will be abnormal.

Allogeneic

A transplant in which the recipient receives an organ or cells from another (usually related) person.

Aminotransferase

One of two enzymes (alanine or aspartate aminotransferase: ALT and AST) found in the blood that, when elevated, are sensitive indicators of liver injury.

Anicteric

Absence of jaundice (icterus).

Anorexia

Loss of appetite.

Antinuclear antibody

An antibody found in blood directed against the nucleus of cells, typically present in patients with autoimmune hepatitis.

Anti-smooth muscle antibody

An antibody found in blood directed against smooth muscles, typically present in patients with autoimmune hepatitis.

Apoptosis

Programmed cell death which is typical of the liver cell injury from hepatitis, as opposed to necrosis which is typical of toxic injury or shock.

Ascites

Accumulation of fluid in the abdominal cavity, which is usually caused by acute or chronic liver failure.

Aspartate aminotransferase (AST)

An enzyme found in the blood that is elevated with liver injury, particularly hepatocellular (formerly SGOT). Although elevated in liver disease, the enzyme can originate from other organs and muscle.

Asterixis

A jerking motion of the outstretched hands that is a sign of early stages of liver coma.

Autoantibodies

Antibodies in the blood that are directed against normal body proteins or cells, such as antinuclear antibody or anti-smooth muscle antibody.

Autoimmune features

Findings suggestive of an overactive immune system, such as high antibody levels and "autoantibodies".

Autoimmune hepatitis

A chronic liver disease in which an overactive immune system appears to damage the liver.

Autologous

A transplant in which the recipient receives his/her own organ or cells.

Ballooning degeneration

A form of liver cell (hepatocyte) degeneration associated with cell swelling.

Benign postoperative cholestasis

Jaundice after major surgery that is temporary and resolves without treatment.

Bile ducts

The small conduits (ducts) in the liver that allow the flow of bile from liver cells out through gradually larger bile ducts into the intestine.

Bilirubin

The chemical breakdown product of red blood cells that is normally removed by the liver and excreted in bile. Bilirubin can accumulate in the serum and lead to detectable jaundice when there is liver injury and dysfunction, obstruction to the flow of bile, or spontaneous red cell destruction (hemolysis).

Bland cholestasis

Cholestatic liver injury with minimal or no inflammation in the liver.

Bone marrow transplantation

Replacement of a person's bone marrow with that of another person, used to treat leukemia and other severe forms of cancer or genetic disease.

Budd-Chiari syndrome

A severe liver disease caused by clotting and blockage of the large veins that drain the liver.

Celiac disease

An inherited disease of the small intestine caused by allergy to wheat (gliadin).

Cerebral edema

Swelling of the brain due to accumulation of fluid, that can occur in liver failure.

Cholangiography

An X-ray that shows the large bile ducts that drain bile from the liver into the intestine.

Cholecystectomy

A surgical operation to remove the gallbladder.

Cholecystitis

Inflammation of the gallbladder, typically causing fever, nausea, and abdominal pain.

Choledocholithiasis

Gallstones which have passed into the bile ducts.

Cholelithiasis

Gallstones in the gallbladder.

Cholestatic injury

Liver injury in which interference with bile flow and jaundice are prominent.

Cholesterol

The major form of fat in the body, most of which is produced in the liver.

Chronic liver disease

Persistent, long term liver disease often with vague or mild symptoms and slow onset. Conventionally, disease has been present for more than 6 months.

Chronic liver failure

Serious liver failure arising gradually in a person with a chronic liver disease.

Cirrhosis

Scarring and permanent injury to the liver, usually the result of chronic, long term damage.

Clinical phenotype

A pattern of clinical presentation and course of liver injury that is typical for a specific disease or injury from a specific medication.

Clinical signs

Findings on physical examination such as rash, fever, enlarged or tender liver and jaundice.

Clinical symptoms

Patient complaints such as fatigue, nausea, poor appetite, dark urine or yellow discoloration of the skin (jaundice).

Coagulopathy

Abnormal bleeding tendency which can be caused by lack of clotting factors that are made by the liver.

Collagen

The major protein found in scars and that is increased in cirrhosis of the liver.

Dark urine

Dark or tea-colored urine is a symptom of liver disease caused by elevations in serum bilirubin and secretion of bilirubin in the urine.

Dietary Supplements

Dietary supplements contain one or more dietary ingredients such as vitamins, minerals, herbals or other botanicals, amino acids or organ extracts that are intended to supplement the diet.

Ductopenia

Finding on liver histology of a decrease or lack of small bile ducts in the liver.

Ductules

The smallest bile ducts that can be seen on liver histology.

Edema

Tissue swelling of the feet, ankles or other parts of the body caused by abnormal accumulation of fluid which can be the result of heart, kidney or liver failure.

Eosinophilia

Increased eosinophils in the blood (the white blood cells that are active in allergic reactions).

Elastography

A noninvasive X-ray method of measuring stiffness of the liver, which is increased with advancing fibrosis and cirrhosis.

Encephalopathy

Mental confusion and altered level of consciousness that can occur in liver failure.

Endothelial cell

The cells in the liver that line the blood channels (sinusoids).

Esophagus

The muscular swallowing tube that runs from the mouth to the stomach.

Fatty acid

The breakdown product of triglycerides and fat that are taken up by the liver and used as a source of energy or to make triglycerides.

Fibrosis

The presence of scarring in the liver, usually shown by liver biopsy histology.

Focal nodular hyperplasia

A benign tumor of the liver.

Gamma glutamyl transpeptidase (GGT)

An enzyme found in the blood that is elevated with liver injury, particularly cholestatic. This is also commonly elevated in recent alcohol consumption.

Glutathione

A substance made in the liver that binds to and helps remove drugs and toxins.

Glycogen

The principal storage form of glucose (sugar) in the liver.

Granulomatous hepatitis

Liver injury in which granulomas (small collections of inflammatory cells) are found in the liver biopsy.

Graves' disease

A disease of the thyroid (hyperthyroidism)

Hepatic encephalopathy

Confusion, mental dullness, drowsiness and even coma caused by liver failure.

Hepatitis A

Infectious liver disease, spread primarily through the fecal-oral route, caused by the hepatitis A virus; now preventable by vaccine. Most people recover and the infection does not become chronic.

Hepatitis B

Infectious liver disease caused by the hepatitis B virus, spread primarily through sexual contact or through perinatal (vertical) transmission; now preventable by vaccine. Approximately 5% of acute hepatitis B cases become chronic.

Hepatitis C

Infectious liver disease caused by the hepatitis C virus for which there is no vaccine and which commonly becomes chronic; now the most common cause of cirrhosis in the United States.

Hepatitis D

Rare but severe liver disease caused by the hepatitis D virus, which only affects persons who are also infected with hepatitis B.

Hepatitis E

Infectious form of viral hepatitis that is rare in the United States but common in the developing world; may also be spread by contact with pigs or wild boar.

Hepatocellular injury

Liver injury in which liver cell damage and inflammation are prominent.

Hepatocyte

The major cells in the liver responsible for its function.

Hepatotoxicity

Toxin injury to the liver due to a medication, chemical, herbal or dietary supplement; another term for drug induced liver injury.

Hemangioma

A benign tumor of the liver.

Hematopoietic cell transplantation

Transplantation of blood elements such as bone marrow or stem cells.

Hepatic venous pressure gradient

A diagnostic measurement of the pressure inside the veins of the liver that is increased in cirrhosis.

Hepatomegaly

Enlargement of the liver.

Hyperammonemia

High levels of ammonia in the blood which can occur in liver failure.

Hyperlipidemia

Abnormally high levels of lipids (cholesterol, triglycerides) in the blood.

Hyperthermia

Abnormally high body temperature, usually due to heat shock, which can cause liver injury.

Hypotension

Abnormally low blood pressure, which can cause liver injury (ischemic hepatitis).

Hypoxia

Low oxygen tension in the blood which can cause liver injury (ischemic hepatitis).

Icteric

Presence of jaundice, which is typically first evident in the whites of the eyes (sclera) followed by skin.

Icterus

Another name for jaundice, used to describe a yellowish tinge to the skin and eyes.

Idiopathic

A medical term meaning "of unknown cause".

Immunoallergic hepatitis

Liver injury with prominent features of allergy or hypersensitivity. Typically, this includes fever, rash, and/or hives.

Immunoglobulin

A class of blood proteins that include antibodies.

Interlobular bile ducts

The larger bile ducts in the liver that allow the flow of bile from intralobular bile ducts to the larger bile ducts that, ultimately, direct bile to the gallbladder and intestine.

Intralobular bile ducts

The small conduits (ducts) in the liver than allow the flow of bile from liver cells to the larger, interlobular bile ducts.

Ischemic hepatitis

Severe hypotension (shock), lack of oxygen (anoxia), or sudden heart failure that leads to decreased blood flow to the liver; usually resolves quickly if the sudden insult is corrected.

Itching

Irritating skin sensation that provokes scratching, a symptom of liver disease, particularly cholestatic (also known as "pruritus").

Jaundice of sepsis

Jaundice occurring in the setting of severe bacterial infections (sepsis) that resolves if the infection in treated; liver biopsy shows prominent cholestasis.

Jaundice

Yellowish tinge to the skin or whites of the eyes caused by elevation in bilirubin in the blood; also called "icterus".

Lactic acidosis

High levels of lactic acid in the blood, usually caused by failure of mitochondrial function in the liver.

Large bile ducts

The bile ducts in the liver (right and left hepatic duct) and outside of the liver (common bile duct) allow the flow of bile to the gallbladder and intestine.

Latency

The duration between ingestion, or exposure, to a drug, toxin, or infectious agent and the onset of disease.

Likelihood score

A 5-point scale [A to E] that estimates whether a medication is a of cause liver injury: A=Well known cause; B=Highly likely cause; C=Probable cause; D=Possible cause; E=Unlikely cause; E*=Suspected but unproven cause; X=Unknown.

Liver histology

Findings on microscopic assessment of a liver biopsy.

Liver inflammation

Findings of white blood cells (inflammatory cells) in the liver on microscopic assessment of a liver biopsy.

Liver test abnormalities

Blood tests results that indicate liver injury such ALT, AST, alkaline phosphatase, bilirubin, albumin and prothrombin time (or INR).

Liver transplantation

Replacement of a person's liver with that of another person, used to treat end stage liver disease, acute liver failure, liver cancer and rare genetic disorders.

Lymphocyte

A type of white blood cell that is responsible for immune responses.

Macrophage

A large cell found in the liver that engulfs foreign material and takes part in inflammation.

Macrovesicular fat

Abnormal large droplets of fat found in liver cells; typically, the nucleus is pushed to one side of the cell by fat droplets.

Mallory bodies

Abnormal twisted rope-like bodies seen by microscope in fatty liver disease.

Matrix

The proteins that surround and support cells.

Microvesicular fat

Abnormal numbers of small droplets of fat in liver cells; typically, the nucleus remains in the center of the cell.

Mitochondria

A component found in all living cells that is responsible for producing energy and is essential for health.

Mixed injury

Liver injury with features of both hepatocellular and cholestatic injury.

Monoclonal antibody

Antibodies produced in mice that are highly specific for a single protein or substance, which can be used to treat serious diseases such as cancer (rituximab) or arthritis (infliximab).

Mononucleosis

Acute illness caused by the Epstein Barr virus that can cause liver disease that resembles acute viral hepatitis.

Mononucleosis

Acute illness caused by the Epstein Barr virus that can cause liver disease that resembles acute viral hepatitis.

M & V Scale

A causality assessment method similar to RUCAM developed by Drs. Maria and Victorino.

Myeloablation

Deliberate destruction of the bone marrow by chemotherapy, done in preparation of bone marrow transplantation.

Myopathy

Disease of the muscles.

Naranjo Scale

A causality assessment method for assessing all forms of drug induced adverse events.

Neuropathy

Disease of the brain, nerves or nervous system.

Neutropenia

Decrease in neutrophils, a white blood cell important in defense against infections.

Neutrophil

A white blood cell which is an important defense in bacterial infections.

Nodular regenerative hyperplasia

Unusual transformation of the normal liver structure into nodules. Typically, there is little or no scar tissue, differentiating this from cirrhosis.

Nonparenchymal

A liver histology term referring to those parts of the liver other than the major hepatocytes (liver cells) including the endothelial cells, macrophages, veins, arteries and bile ducts.

Nystagmus

Involuntary jerking motion of the eyes that occurs with brain injury and liver coma.

Optic neuritis

Inflammation of the nerves of the eye, which can cause blindness.

Pancreatitis

Inflammation and injury of the pancreas.

Parenchymal

A liver histology term referring to the part of the liver with hepatocytes (liver cells) as opposed to the areas with supporting cells, veins, arteries and bile ducts.

Percutaneous liver biopsy

A liver biopsy that is done by passing a needle through the skin into the liver.

Plasma cell

A cell that makes antibodies, which is often found in liver inflammation caused by autoimmune reactions.

Portal hypertension

Abnormally increased pressure in the portal vein that delivers blood from the intestine to the liver, which is caused by cirrhosis and can result in bleeding and fluid retention (ascites).

Portal inflammation

Findings of inflammatory cells on liver biopsy in areas around the veins, arteries and bile ducts entering the liver.

Primary biliary cirrhosis

A chronic liver disease marked by gradual autoimmune loss of bile ducts leading ultimately to cirrhosis.

Primary sclerosing cholangitis

A chronic autoimmune disease marked by damage and loss of the large bile ducts that can lead to liver damage and cirrhosis.

Prodromal

In acute liver disease, the period of symptoms, frequently vague, immediately before appearance of jaundice.

Prognosis

Prediction or likelihood of an outcome (good or bad) of an illness.

Prothrombin time

A measure of clotting ability that becomes abnormal (prolonged) with liver failure.

Pruritus

Itchiness of the skin, a symptom of liver disease, particularly cholestatic.

Radio-mimetic

Resembling radiation effects.

Rechallenge

Reexposure, deliberate or accidental, of a patient to a medication that was believed to have caused an adverse side effect, such as drug induced liver injury.

Reticulin

A stain used on liver biopsies to visualize elastic fibers.

Reye's syndrome

An acute and severe liver disease of children that follows an acute viral illness and aspirin use.

RUCAM

The Roussel Uclaf Causality Assessment Method for evaluating the likelihood that a medication has caused drug induced liver injury.

R value

The ratio of alanine aminotransferase (ALT) to alkaline phosphatase (Alk P) values, both expressed as multiples of the upper limit of normal. An R value of >5.0 is used to define hepatocellular injury, R <2.0 as cholestatic injury, and R between 2.0 to 5.0 as mixed hepatocellular-cholestatic injury.

Sinusoids

The small passages between liver cells in which blood flows from the portal areas to the central veins.

Sinusoidal-obstruction syndrome (SOS)

Liver histology findings indicating a blockage of blood flow out of the liver.

Splenomegaly

Enlargement of the spleen.

Status epilepticus

Persistent, uninterrupted seizures.

Steatohepatitis

Excess fat with inflammation and damage in the liver.

Steatosis

An abnormal amount of fat in the liver.

Stellate cells

Fat storing cells in the liver that make collagen (fibrosis).

Stevens-Johnson syndrome

Sudden onset of fever and severe body rash often due to an allergic reaction to a medication.

Synthesis

Production or making of a substance.

Tachycardia

Rapid heart rate.

Tachypnea

Rapid breathing rate.

Thrombocytopenia

Abnormal decrease in the numbers of blood platelets, which are small elements needed for clotting.

Transjugular liver biopsy

A liver biopsy that is done by passing a needle in a flexible tube from a vein in the neck into the liver.

Triglycerides

One of the major forms of fat that is produced in the liver and found in the blood.

Varices

Abnormal, large veins that are found in the esophagus and intestine when there is portal hypertension.

Vanishing bile duct syndrome (VBDS)

A chronic form of liver disease in which there is a gradual loss of small bile ducts in the liver (ductopenia).

Veno-occlusive disease (VOD)

Another term for "sinusoidal-obstruction syndrome" or liver histology findings indicating a blockage of blood flow out of the liver.

Vinyl chloride

Chemical used in manufacturing that can harm the liver.

Viral hepatitis

Liver disease caused by one of 5 hepatitis viruses (A, B, C, D or E).

Wilson disease

An inherited disease marked by accumulation of copper in the liver, brain and other tissues that can cause cirrhosis and be fatal if not detected early and treated.