What is PBC

Primary biliary cirrhosis (PBC) is a chronic autoimmune disease where the body's immune system begins creating antibodies that attack, damage, and eventually destroy the liver. The immune system's job is to protect the body, but with PBC, antimitochondrial antibodies (AMAs) are produced and, in turn, the antibodies attack the mitochondria in liver cells. In the medical field, the disease is sometimes called “a loss of self tolerance.”

According to the Mayo Clinic Online, the liver produces bile: a fluid that has a significant role in ridding the body of toxins, red blood cells, and cholesterol. In people suffering from PBC, the bile ducts are destroyed over the course of time. Bile is a necessary part of the digestive process; the fluid travels from the liver into bile ducts, the gallbladder, and small intestines where it aids in the digestion of fats and several fat-soluble vitamins (A, D, E, and K).

The destruction of bile ducts starts with the accumulation of T lymphocytes in the liver. T lymphocytes (pronounced: lim-fuh-sytes), are sometimes called T cells. The T cells are one of two kinds of lymphocytes that are supposed to protect the body from germs and invasions. Lymphocytes are what help the body to recognize and remember invaders and destroy them. In those that have PBC, the T cells start to attack and destroy the lining of cells belonging to the small bile ducts in the liver. The small bile ducts become inflamed and nearby liver cells are destroyed over the course of time. When the liver cells are destroyed it results in scarring (fibrosis). The fibrosis eventually leads to cirrhosis of the liver.

Primary biliary cirrhosis is often diagnosed in middle aged women between the ages of 40 and 60, but there have been cases diagnosed in people as young as 20 and as old as 90 years of age. This disease is most prominent in women, with about 90 percent of sufferers being female and 10 percent being male: this results in a ratio of women to men who get PBC of 10:1.  The number of people affected by PBC every year varies, depending on the part of the world.  There is a higher rate of disease occurrence in Wales and England, although a reason for this is unknown - one in every 3,000 individuals is afflicted by primary biliary cirrhosis.  According to a review appearing in the Journal of Hepatology (2010, vol 52, pages 754-758), the highest incidents of the disease are not only in England, but in Scotland, the Northern United States, and Minnesota.  According to the Cleveland Clinic in Ohio, the incidence of PBC in Japan is lower than in other areas of the world; the same site shares estimates on PBC prevelance ranging between 40 to 400 cases per 1,ooo,ooo people, with about 4 to 30 new cases per 1,000,000 occurring each year.

The causes of primary biliary cirrhosis are unknown, but there are a number of theories pertaining to the origin of the disease. This disease has nothing to do with the excessive consumption of alcohol. The word “primary” suggests “spontaneous” since a specific cause for the disease is unknown. The word “biliary” indicates that the bile ducts are affected. The word “cirrhosis” indicates the eventual outcome of the disease. The inclusion of the word “cirrhosis” in the name of the disease is somewhat misleading; cirrhosis is not immediately present during the early stages of the disease and only appears in the end stages of PBC. Primary biliary cirrhosis is also less commonly called “Primary Autoimmune Cholangitis” and “Chronic Nonsuppurative Destructive Cholangitis.” It is surmised that the disease originates from genetic factors, environmental factors, or a combination of the two.

To date, there is still no cure for PBC. The disease progresses slowly, and the use of medications can slow the course of the disease. At the end stages of the disease however, due to the extensive damage of the liver, a transplant is required for survival. Not all individuals with PBC will reach the end stage of the disease as medications can slow the progression down. The effectiveness of medications varies from one individual to the next, but the earlier a person is diagnosed, the better.