Mayo Clinic Research Identifies Genetic Predisposition in Patients with Primary Biliary Cirrhosis

Tuesday, February 26, 2008

Mayo Clinic researchers have found that patients who have primary biliary cirrhosis (PBC) are more likely to have specific inherited variations of particular immune genes, and that the specific gene alterations may be responsible for progression of the disease. This new information may help physicians better predict patient outcomes and choose the most effective treatment for each individual with PBC. These findings are published in this month's issue of Hepatology.

Primary biliary cirrhosis is a chronic liver disease that affects nearly 50,000 people (primarily women) in North America. It is thought to be an autoimmune disease, in which the body attacks its own liver cells due to exposure to something in the environment, such as a virus, a bacteria or a chemical. This exposure, in combination with a patient's genetic makeup, makes that person more susceptible. In those who have the disease, cells lining the bile ducts of the liver are attacked. This causes harmful substances to build up in the liver and sometimes results in irreversible scarring and liver failure. About half of the people with PBC have no symptoms and are diagnosed following abnormal results of routine liver tests.

The Mayo Clinic study, the largest of its kind, compared the interaction among three variations of two immune receptor genes in 351 adult PBC patients and 205 healthy adults. The group of patients having one specific combination of immune receptor gene variations was three times more likely to have PBC. Additionally, patients with another specific combination of gene variations were more prone that PBC would eventually require liver transplantation.

"We found that the interaction of genetic variations of immune receptor genes are likely important to the development of PBC, and that genetic susceptibility may also be responsible for the progression of PBC patients to the point of liver transplantation," says Konstantinos Lazaridis, M.D., the study's lead author and a hepatologist at Mayo Clinic. "This study provides new information about better ways to assess the prognosis of patients with PBC and may aid physicians in developing more appropriate treatment plans."

According to Dr. Lazaridis, the next step for his research team is to systematically study the genetic variations of the entire group of immune/inflammatory genes that exist in the genome of PBC patients to further examine the cause, prognosis and most effective management of this disease.

Each year, physicians at Mayo Clinic's campuses in Arizona, Florida and Minnesota treat approximately 600 patients who have primary biliary cirrhosis. For more information on the treatment at Mayo Clinic, visit www.mayoclinic.org/primary-biliary-cirrhosis.

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