or Life Depends On The Liver!
Introduction

The liver is the largest organ in the body, weighing 1-1.5 kg. Its shape is determined by the cavity available in the upper right part of the abdomen, between the diaphragm and the rib margin. The liver makes and breaks down various substances, stores nutrients absorbed from the intestines and detoxifies the blood. There are many causes of liver disease, the most common being alcohol, viral hepatitis (for example Hepatitis B, C¹ and the glandular fever virus EBV²), autoimmune diseases, poisons/drugs (for example paracetamol in overdose, some antibiotics, arthritis drugs) and inherited disorders. Blockage of the biliary system³ causes liver problems and jaundice as well.

The Liver's Normal Function

The liver receives the blood from the gut after a meal and turns sugar(glucose) into glycogen (storage molecule). This is turned back into glucose when required keeping blood glucose levels stable. The liver also makes proteins (mostly blood proteins eg clotting factors and albumin, and hormones), bile acids (essential for fat digestion and vitamin absorption) and converts excess protein into energy. Water-soluble toxins and waste products can be eliminated via the kidneys in the urine, but non-water soluble toxins need to be chemically modified by the liver to allow this process to occur. The liver has many enzymes with a wide specificity to tackle both waste products of the body and xenobiotics (chemicals not produced by the body).

The Diseased Liver

The initial response of the liver to disease is inflammation and fatty change. Prolonged or severe inflammation leads to cirrhosis (scarring of the liver). When a section of liver is removed the liver will regenerate, but scarring in cirrhosis stops this regeneration and so the damage is irreversible. The most obvious sign of liver disease is jaundice, where the skin and whites of the eyes (sclera) are yellow. Other symptoms include itching, nausea and pain in the right upper area of the abdomen. The complications of liver cirrhosis include: lack of albumin causing swollen legs and abdomen; lack of clotting factors causing easy bruising and internal haemorrhages (haematomas); impaired mental state from low blood sugar and toxins normally removed by the liver. Death is usually from infection from a suppressed immune system or vomiting blood from abnormal vessels in the oesophagus (varices). The only treatment for liver failure is transplantation
currently.

Diagnosis

Liver disease is often first detected because of abnormal liver blood tests, often called liver function tests (although they are not actually a measure of liver function). Abnormal albumin and blood clotting tests demonstrate abnormal liver function. The pattern of the abnormalities of LFTs points to whether the problem is the liver, haemolytic anaemia⁴ or the biliary system. Antibodies may be checked for viral hepatitis and autoimmune liver diseases. Iron levels check for iron overload (haemachromatosis) and copper levels look for Wilson's disease, both inherited diseases. An ultrasound will show blockage of the bile duct, fatty liver, cirrhosis and liver tumours. A liver biopsy may be necessary to examine the liver under the microscope, stain for iron or copper, or determine the amount of virus present.

Treatment

The main aim of treatment of liver disease is to prevent cirrhosis. Obviously alcohol consumption must stop. Hepatitides B and C can be treated with antiviral drugs. Where the patient's immune system is attacking the liver powerful suppressants of the immune system are given. N-Acetylcysteine is given to prevent damage from paracetamol overdoses. Iron or copper overload can be treated with chelating agents that help the body to eliminate the excess heavy metals.