Medical terms

ALT
Alanine aminotransferase (ALT) is a transaminase enzyme that is released from the liver when it is damaged. ALT blood levels fluctuate regularly with normal liver function but significant elevations in these levels can indicate liver injury or inflammation. The test for ALT is performed on blood samples taken from patients.

Anaemia
A deficiency in red blood cells. More specifically, anaemia is a deficiency of a protein called haemoglobin that is found inside red blood cells and is responsible for carrying oxygen around the body. 

Antibodies
Proteins of the immune system. Your body makes them as part of its defence against infection by helping to destroy ‘foreign’ molecules, such as those of the hepatitis C virus. 

AST
Aspartate aminotransferase (AST) is a transaminase enzyme that is released from the liver when it is damaged. In addition to the liver, AST is also present in other locations around the body and so is less specific for liver damage than another transaminase enzyme, ALT. AST blood levels fluctuate regularly with normal function but significant elevations in these levels can indicate liver injury or inflammation. The test for AST is performed on blood samples taken from patients.

Asymptomatic
A patient who is infected with a disease, but there are no signs or symptoms to show it. 

Biopsy
An invasive process where a small sample of organ tissue is removed for examination under a microscope.  Samples are assessed on their appearance and are graded depending on the level of disease. In the cases of hepatitis C, biopsies are used to determine the level of fibrosis or cirrhosis in a liver sample. 

Blood transfusion
The process of using blood from a donor to directly replenish the level of red blood cells in a recipient.

Chronic 
Persisting over long period of time. In the case of hepatitis C, patients are considered to have a chronic infection if they have been infected for more than six consecutive months.

Cirrhosis
The replacement of normal liver tissue with hardened scar tissue as a result of progressive disease. These changes can cause structural alteration of the liver and loss of normal function. 

Combination therapy
Use of more than one type of drug at the same time to achieve a combined benefit. Currently, the optimal treatment for hepatitis C is the combination therapy of pegylated interferon and ribavirin. 

Early virological response
A 100-fold drop in viral load after 12 consecutive weeks of treatment.

Fatigue
Extreme tiredness.

‘Fatty liver’
Development of excess fat within the liver. It can develop due to diseases such as diabetes, or due to a number of lifestyle factors such as poor diet or excess alcohol consumption. Fatty liver is sometimes known as ‘steatosis’.

Fibrosis
Development of scar tissue as a result of tissue damage or inflammation. Scar tissue appears in the form of excess fibrous tissue that is made as part of an uncontrolled healing process. In liver (hepatic) fibrosis, this excess tissue can sometimes disrupt blood flow to the organ. 

Fibrosis markers
A non-invasive test to measure fibrosis, based on the detection of certain molecules in the blood. 

Genotype
Many hepatitis C viruses have differences in their genetic sequences, but in general, each sequence can be grouped into one of six major types, called genotypes.

Haemodialysis
A procedure for artificially clearing metabolic waste products or toxic substances from the blood in the absence of normal kidney function.

Haemophilia
A blood clotting disorder that can cause excessive bleeding. People with haemophilia often need to receive clotting factors from the blood of donors, which can lead to the transmission of blood-borne infections such as hepatitis C if not properly screened.

Hepatitis C virus (HCV)
The infectious agent of hepatitis C. The virus was formerly known as non-A non-B hepatitis and is spread by direct contact with infected blood.  

Hepatitis
An inflammation of the liver (‘itis’ meaning inflammation in ancient Greek, and ‘hepat’ meaning relating to the liver).

Hepatocellular carcinoma (HCC)
A primary malignancy (cancer) of the liver. Sometimes also called hepatoma.

Human immunodeficiency virus (HIV)
A virus that causes serious deficiency of the human immune system over time and is the causative agent of Acquired Immunodeficiency syndrome (AIDS).

Inflammation
A complex immune reaction by body tissues that usually occurs in response to potentially harmful stimuli such as bacteria and viruses.   Inflammation can result in increased blood to the location concerned, build-up of fluid (swelling) and even nerve stimulation leading to pain.

Interferon
Protein ‘messengers’ (cytokines) of the immune system that are produced to stop viruses from replicating and also to stimulate an immune response to ‘foreign’ molecules, such as viruses – an antiviral response. Pharmaceutical companies are now able to produce interferons artificially for use as prescription therapeutics and these are designed to replicate an antiviral response. 

Jaundice
Yellowish discolouration of the skin and the whites of the eyes.

Local anaesthetic
A medicine that causes loss of feeling in a specific part of the body without loss of consciousness.

Monotherapy
Treatment of a condition with a single therapeutic agent. 

Nausea
Feeling sick or the urge to vomit.

Non-A, non-B hepatitis
The name given to hepatitis C before discovery of the hepatitis C virus in 1989.

Non-invasive tests
Medical procedures that do not involve penetration of the skin or a body cavity.   

Non-responders
Patients who have received treatment for hepatitis C but failed to achieve a reduction in viral load. 

Oedema
Swelling due to excess fluid accumulation.

Partial responders
Patients who have received treatment for hepatitis C and achieved a detectable decrease in viral load, but failed to achieve an SVR.

Pegylated interferon
Artificially produced interferons with synthetic polymers added on. This helps the drug to stay in the body for longer and have prolonged effect.  

Polymerase chain reaction (PCR)
A method of testing for the presence of specific genetic material, such as the RNA from hepatitis C virus. The method can also be used to determine genetic sequences (for example, genotyping) and also to determine the number of copies of a genetic sequence in a sample (for example, viral load).

Rapid virological response
Undetectable hepatitis C virus RNA in the blood after 4 consecutive weeks of treatment.

Relapsers
Patients who have received a complete course of treatment for hepatitis C managed to clear the virus to undetectable levels only for the levels to rebound at a later date. 

Ribavirin
An antiviral drug with proven activity against a number of different viruses, including hepatitis C. 

RNA
Ribonucleic acid (RNA) is the genetic material of hepatitis C virus.  

Side effects
Problems that arise from taking medications. 

Sustained virological response (SVR)
Undetectable hepatitis C virus RNA at the end of an entire course of treatment and after a further six months. 

Transaminases
Enzymes important for the production of amino acids and glucose metabolism.

Transient elastography
A non-invasive technique that can be used to assess the extent of fibrosis or cirrhosis in the liver. The technique measures the stiffness of the liver, which can be related to the degree of fibrosis.

Vaccine
Used to create or improve immunity to a specific disease. 

Variceal haemorrhage
Potentially serious bleeding from large veins/varices formed in the oesophagus or stomach.  The varices usually form as a consequence of cirrhosis obstructing blood flow  from the digestive system into liver (portal system). As the pressure rises  in the portal system new veins /varices form to bypass the obstruction in the liver.

Viral load
The amount of virus genetic material in a blood sample. Viral load is determined by PCR and for hepatitis C it is usually expressed as RNA International Units (IU) per millilitre (for example, 800,000 IU/mL). 

Virus inactivation
The process of rendering a virus inactive or non-infectious. Techniques used to inactivate viruses can include solvents, detergents, acids and heating.