Primary biliary cirrhosis (PBC) is a chronic and progressive liver disease. PBC starts at the small bile duct located in the liver - intrahepatic bile ducts - which are then destroyed in the course of the disease. As a consequence, since bile cannot be excreted into the gut, it is retained and accelerates liver damage.
Frequency of the disease
About 90% of PBC is seen in women. Children are rarely affected. PBC is much more frequent than presumed with a former life expectancy of an untreated PBC patient being 12 years. Today the course of the disease can be prolonged by medical therapy. When liver transplantation should become necessary most of the patients can be cured.
Stages of the disease
Stage I: In this stage inflammation is confined to the small intrahepatic bile ducts - non-suppurative bile duct destruction and the surrounding connective tissue. Destruction is performed by so called immune competent cells which are able to destroy the biliary tree and later on the complete liver.
Stage II: In this stage besides bile duct destruction, the number of small bile ducts is now increased. Inflammatory cells infiltrate in the surrounding of the bile ducts and small blood vessels are dense and in some areas invade the neighbouring liver nodule.
Stage III: Increasing numbers of bile ducts are being destroyed and occluded bile duct rarification takes place, again inflammatory cells invade the liver lobule and the amount of connective tissues are augmented.
Stage IV: The amount of connective tissue has further increased markedly and divides the liver tissue into areas of different size. So called regeneration nodules of varied diameters will develop. By this the liver surface has become irregular. In this late stage of disease, destruction of the small bile ducts and inflammation is reduced or even ceases. Finally, the classical picture of liver cirrhosis has developed.
How to recognise PBC
One of the first symptoms of PBC may be a mild, strong or even excessive itching, which occurs predominantly at night. This pruritus (severe itching of the skin) affects the arms, back and lower part of the legs. Further characteristic signs are cumbersome fatigue and a reduction of vitality.
In the course of progression of the disease, yellow-greyish fat deposits (xanthelasma) may develop in the nasal area of the eyelids. Making diagnosis of PBC was formerly rather difficult but today sample blood examinations permit an early diagnosis usually in stage I or II, which means long before the development of liver cirrhosis.
Characteristic alterations can be seen in the serum of the patients, in nearly 100%, antimitochondrial antibodies (AMA) are present. AMAs are not the cause of PBC, they do not reflect the severity of the disease, but as special markers they prove the existence of PBC. Further the typical markers for bile duct inflammation and cholestasis are an increase in serum alkaline phosphatase (ALP) and gamma-glutamyl transpeptidase. Also typical is an increase of another serum protein - the immunoglobulin M (IgM). When serum concentrations of these parameters are augmented and when a second investigation confirms the existence of AMAs, the diagnosis of PBC is certain even when the patient is without any symptoms.
In some patients, PBC is accompanied by pain in joints, Hashimoto’s thyroiditis, Sicca syndrome, osteoporosis, steatorrhoea, vitamin deficiency and in the later stage of PBC - skin alteration, ascites, swollen legs, oesophageal varices and encephalopathy may accompany as well. Nowadays, medical therapy and liver transplantation are available.
The writer is a Consultant at the Cardicare Heart and General Hospital.