New study launched to discover how ‘super’ immune system can prevent hepatitis c

Posted on: 20 September 2016

Scientists from Trinity College Dublin are seeking volunteers who were exposed to anti-D contaminated with hepatitis C virus (HCV) between 1977 and 1979 as they attempt to discover why some people are naturally protected from HCV infection, while others are not.

In 1977-79, hundreds of Irish women fell victim to HCV infection when they were given virus-contaminated anti-D. Usually anti-D is a blood product of great benefit given to women with blood groups incompatible with their new-born baby. It prevents the mother from building cells and molecules that would attack and destroy the foetus during a second pregnancy. Hence, it saves the life of the unborn child that would otherwise become ill or perhaps die.

However, in 1977-79 this normally beneficial product was unknowingly contaminated with HCV, which can invade and gradually destroy the liver. Until recently, researchers believed that receiving HCV-contaminated blood products, where high viral loads directly enter the blood stream, would inevitably lead to infection.

But in the aftermath of the 1977-79 outbreak, researchers made an interesting discovery: when screened for HCV almost half of the women who clearly had contact with the virus showed no signs of infection.

Professor of Comparative Immunology at Trinity College Dublin, Cliona O’Farrelly, said: “That means these women must have been naturally protected from the virus. We believe these women have an extra-special ‘super’ immune system that is able to fight viral invaders. We now want to find out why – and how – this system does such a good job.”

To do this, Professor O’Farrelly and her team will look at the information stored within the genes of naturally resistant people. The team will then compare it to the information from the genes of people who are unable to resist infection. If they uncover the mechanism behind the mystery of natural HCV-resistance, they can exploit this knowledge to find new ways to make vaccines and anti-viral drugs.

For this research project, the team seek volunteers who were exposed to HCV via contaminated anti-D in 1977-79 to help with the study. Women who became infected with HCV as well as those who show no signs of infection are invited to participate. Participation in the study is easy, and non-invasive, but could have a major impact on fighting viruses. All that is needed is a saliva sample, which can be easily collected at home and mailed to the team.

If you are interested in participating or would like to receive further information, please contact us by phone (087-791-3600) or email (TCDStudy2016@tcd.ie). Visit our website for more information: https://www.tcd.ie/Biochemistry/research/cig_hepatitisc.php 

The project is funded by Science Foundation Ireland and is led by Cliona O’Farrelly, Professor of Comparative Immunology at Trinity College Dublin.

About hepatitis C-contaminated anti-D immunoglobulin

• In Ireland two hepatitis C virus (HCV) outbreaks have occurred due to HCV-contaminated anti-D immunoglobulin – the first occurred between 1977 and 1979, and the second between 1991 and 1994
• Anti-D immunoglobulin is a blood-derived medical product given to women who have the rhesus negative (Rh-) blood group and who have a rhesus positive (Rh+) baby. The anti-D immunoglobulin prevents the development of rhesus haemolytic disease of the newborn, which arises in subsequent pregnancies
• Over 1,000 women were infected with HCV in Ireland due to HCV-contaminated anti-D immunoglobulin. Of these women, approximately half had evidence of past infection (antibodies) but no circulating virus, while the other half developed chronic infection
• During the 1977-1979 outbreak ~50% of women who received high-risk HCV-contaminated anti-D batches were infected, but the rest of the women who received these high-risk batches were able to resist this infection

About hepatitis C (HCV)

• Hepatitis C was not discovered until 1989. Prior to this, it was known in medicine as non-A, non-B viral hepatitis
• The hepatitis C virus is a blood-borne virus. The most common mode of infection prior to the discovery of the virus was via medical equipment that had been inadequately sterilized, and via the transfusion of unscreened blood and blood products. This mode of infection remains a problem in developing countries.
• Presently, the most common mode of infection in developed countries is via unsafe injection practices
• Hepatitis C is a virus that targets, invades and gradually damages the liver. This irreversible liver damage is called liver cirrhosis
• Up to 20% of chronically infected individuals will develop cirrhosis of the liver over a 20 to 25-year period. Approximately 3% – 4% of patients with cirrhosis will develop hepatocellular carcinoma (HCC) per year
• Over 1% of the world’s population is chronically infected with HCV
• Approximately 700,000 people die each year from HCV-related liver diseases
• New antiviral medicines available in the last 2-3 years can cure up to 90% of persons with hepatitis C infection, but these therapies are extremely expensive.
• There is currently no vaccine for hepatitis C