How HCV affects the functions of the liver

One of the most significant stresses the liver has to contend with is man-made chemicals such as petrol, preservatives, pollutants, pesticides, cigarette smoke, recreational drugs and medication. Almost everything we eat, breathe in or put into our body has to be detoxified by the liver.

The liver has various ways of ways of dealing with toxins: breaking them down into safer substances, eliminating them through bile or repackaging them into a safer form. As a last resort the liver will even store toxins itself to protect the rest of the body.

The liver filters toxins through the sinusoid channels which are lined with immune cells called Kupffer cells. Like a pac-man in the space-invaders game they engulf the toxin, digest it and excrete it. This process is called Phagocytosis.

As most chemicals are relatively new it will takes thousands of years before our body properly adapts to them. If the liver cannot figure out what to do with them it simply stores them, often in fat tissue. This is obviously potentially harmful to the fabric of the liver.

The liver regulates the balance of sex hormones, thyroid hormones, cortisone and other adrenal hormones. It transforms or removes the excess hormones from the body. If the liver cannot properly do this then there is the risk of emotional imbalance often with emotional states lasting longer and being more volatile. The levels of white blood cells and antibodies may also decline so compromising immunity. Unfortunately hormonal imbalances are fairly common in chronic liver disease.

a) Sexual desire and function
Sexual desire depends upon a delicate balance of hormones. If this balance is upset by infection with hepatitis C then both men and women can suffer loss of libido. Men can develop elevated oestrogen levels that may affect sexual function. Women may suffer erratic hormone levels that cause severe PMT-type symptoms.

The fatigue that viral infections can cause may also make some people too tired to be interested in sex. There is a danger that this in itself can lead to frustration and a darker mood.

b) Adrenalin
The stress of modern life can lead to the production of excessive amounts of the stress hormone adrenaline. The liver is responsible for balancing and getting rid of adrenalin. If it cannot keep up with the levels of stress hormones produced, the liver is forced to store them, often for up to a year. The presence of stored adrenalin in the liver may add to emotional imbalance particularly anger, as well as impairing the immune system and therefore effecting the bodies ability to fight the virus. This means learning to identify stress and manage stress effectively is vital. See page on stress in the Wellness section

Lymph is a colourless fluid that circulates around the body in a network of channels which are punctuated with lymph nodes where immune cells neutralise bacteria and pathogens. This is called the lymphatic system, which is a vital part of the bodys immune system. Lymph also carries proteins, sodium, potassium and other minerals around the body.

About a third of the lymph that the body requires is manufactured in the liver. Lymph from the liver drains into the abdomen and the lymph channels. Although the liver itself does not have lymph nodes, HCV can infect the lymphatic system causing swelling of the lymph nodes.

The liver acts as a storage site for some vitamins, minerals and glucose - a vital source of energy for the body which the liver transforms into glycogen for more efficient storage - see metabolism below. The liver stores vitamins and minerals for times when they may be lacking in the diet. It can store enough vitamin A and vitamin B12 for four years and enough vitamin D for 4 months.

Vitamins

Vitamins are a group of organic compounds that act as catalysts in various chemical reactions, meaning they trigger these reactions and speed them up. To be classified as a vitamin it must be clear that a deficiency of it causes disease. Contrary to popular belief vitamins do not provide energy directly. As catalysts they are required for the release of energy from protein, fat and carbohydrates. They are essential for normal growth and development and specifically essential for the healthy functioning of red blood cells, hormones, genetic materials and the nervous system.

The liver stores vitamin A, D, E, K and B12. These first four are fat soluble vitamins. This means that the bile secreted during digestion is essential for absorbing them so that the body can use them. If bile production is compromised by liver damage then the proper absorption of these vitamins may be affected. When taking multivitamins it is important to make sure the recommended doses of fat soluble vitamins are not exceeded as this may result in liver damage.

Minerals

The liver stores iron (see Proteins iron below) and copper. Copper is essential as a vital link in many different chemical reactions and in the formation of proteins within the liver. It also plays a role in mobilising iron stores when they are needed.

The word metabolism comes from the Greek work metabole which means to change. In the context of the liver it means the processing of food digested by the stomach and intestine for its many uses by the body.

We derive our energy and build our cells and tissues using energy derived from the breakdown of three major classes of nutrients: carbohydrates (simple and complex sugar) lipids (various fats and oils) and proteins (large molecules found in plant and animal tissues made up of amino acids).
This process is called metabolism. The liver plays an essential role in the breaking down of all of these types of nutrients and converting them into substances essential to the body.

Carbohydrate metabolism

Glucose or blood sugar is made when carbohydrates are broken down.
It is an essential energy source for all cells. Although we often eat at irregular intervals the energy supplied around the body to the cells remains extraordinarily constant. The liver plays a crucial role in this process. If more glucose is absorbed than the body needs at that moment then the excess is turned into a substance called glycogen and taken up by the liver for easier storage.

When blood concentrations of glucose begin to decline and the body needs to generate more energy and heat, the liver converts the glycogen back into glucose. It is then released back into the blood for transport to all other tissues.
Glycogen stores in the liver are limited but even if the supply of glycogen in the liver runs out, the liver has a back up strategy. Liver cells begin synthesizing glucose out of amino acids and other carbohydrates.

If the synthesis and storage of glucose is compromised by liver damage then the blood sugar levels may be affected and insufficient energy will reach the muscles and the brain leading to fatigue, a general sense of feeling unwell or slowed thinking and memory recall.

Fat metabolism

Fats or lipids are broken down in the liver for use as energy. They are then moved to fat tissue. More than 90% of body energy is stored here and it the main source of fuel storage for the body.

Fats are insoluble in blood and water and so the liver makes special fat- carrying proteins called lipoproteins. These lipoproteins circulate in the blood carrying essential fatty acids between the liver and body tissues.

The liver stores very little fat for its own use. Chronic hepatitis C can lead to accumulation of fatty deposits in the liver. This condition is called steatosis. It is thought to be linked to increased fibrosis progression and advanced liver damage and can cause a decreased response to treatment for hepatitis C.

The lipoproteins also transport cholesterol. Cholesterol has had a bad press, but it is essential for the healthy functioning of the body. It is needed to make bile salts, to synthesize vitamin D, to make sex hormones, to make other hormones for the immune system and in dealing with stress. Cholesterol is also vital for the health of nerve cells and for the brain.

Cholesterol becomes a problem when it builds up in the body in places it should not be. A healthy liver ensures that it is transported through the blood to tissues where it is needed and from the tissues where it is not needed and may cause harm.

If the liver is not functioning properly or is over burdened by cholesterol, fatty deposits containing cholesterol build up in the lining of arteries causing an obstruction to blood flow and can lead to heart attacks. It can also cause a build up of cholesterol concentrations in bile which results in the formation of gallstones.

Protein Synthesis

The liver is one of the most important organs for making proteins. It produces or transforms millions of protein molecules a day. Proteins are made from amino acids. Some of these amino acids are already in the body but others, called the essential amino acids can only be obtained from our diet.

Proteins have many vital functions: for the growth and maintenance of body tissues such as muscles, the heart, kidneys and blood vessels walls. The liver makes hundreds of different proteins with different functions: some transport vitamins (A, D B12) and minerals around the body, some acting as catalysts to speed up metabolic reactions (these proteins are called enzymes) and proteins that regulate the overall pattern of all the different activities within a cell.

Protein synthesis affected by HCV

Albumin
Albumin is usually present in high quantities in the blood and binds hormones and certain chemicals and drugs. Albumin also regulates the exchange of water between blood and tissues. If the concentration of water in the body fluids is not the same as the water concentration of the cells then there is a risk fluid will burst out of the cells. Throughout our life the liver constantly monitors the pressure level to ensure it is balanced. If the liver cannot synthesize enough albumin this may lead to a build up of fluid in the tissues. This is usually a symptom associated with cirrhosis where fluid may build up in the ankles feet or legs (Oedma) or in the abdomen (Ascites).

Iron
The liver stores and releases iron around the body as and when it is required. Iron on its own is toxic to the bodys cells, so it is always transported attached to a protein. In the liver it is bound to the protein ferritin.

If liver disease is associated with an increase in the amount of ferritin in the liver it may cause damage to the tissues and organs. This is called haemochromatosis.

Iron is also essential for making haemoglobin which helps transport oxygen in the bloodstream. If there is not enough iron to make haemoglobin then this may lead to lethargy and anaemia.

Ammonia Conversion

Ammonia is a toxic substance derived from the metabolism of proteins.
The liver converts ammonia to urea, which is water soluble and non-toxic and is excreted by the kidneys. Liver dysfunction in decompensated cirrhosis can lead to inability to convert ammonia, which then can build up in the blood.