Study Underway on Irish Women Seemingly Immune to Hepatitis C

An interesting discovery about some Irish women exposed to the hepatitis C virus in the late 1970s has led scientists to study the possible existence of a super immune gene.

Researchers at Trinity College Dublin hope to discover why some of the women seem to be naturally protected against infection of the virus while others became infected, according to a news release from Trinity College Dublin. Hundreds of Irish women were given the blood product called anti-D between 1977 and 1979 that was later discovered to be contaminated with the hepatitis C virus.

Anti-D is given to women whose blood type rhesus negative (Rh-) is different from the rheusus positive (Rh+) blood type of their new-born baby in order to prevent mothers from building cells and molecules that could attack the fetus during a second pregnancy. So, while usually it can be a life saver for an unborn child, in this particular group of women it turned potentially harmful for those who received Anti-D immunoglobulin product that was unknowingly contaminated with hepatitis C, according to the release.

Many of the women became chronically infected with hepatitis C, a virus which can seriously damage the liver over time and lead to cirrhosis of the liver and possibly liver cancer, However, scientists discovered that nearly half of those women who received the contaminated blood product somehow avoided chronic infection of the virus, much to the surprise of researchers who until recently believed that high viral loads directly introduced to the blood stream would lead to infection.

“That means these women must have been naturally protected from the virus,” Cliona O’Farrelly, professor of comparative immunology at Trinity College Dublin, stated in the release. “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.”

A group of women who got infected with Hepatitis C have already been studied extensively, according to O’Farrelly. She and her and her team of researchers have launched a new study that aims to identify the genes that make some people more resistant to viral infections.

“This HCV outbreak has been well documented since it first came to light in the 1990's and large screening programmes were set up which have tested all the women at risk of receiving contaminated anti-D,” Mark Robinson, a member of the research team said in an email. “These screening programmes found a lot of women who were infected or had evidence of infection (~1000 women). We are interested however in the women who tested negative and had no evidence of infection.”

O’Farrelly’s team of researchers hope to recruit up to 350 women who received the highly infectious, contaminated anti-D batches but did not become infected. “We believe these women will allow us to identify mechanisms that provide innate immune protection against HCV,” said Robinson.

The study is noninvasive and is easy to participate in because it involves a simple swab inside the cheek, which can be done at home and mailed to the study site, the release states. Anyone, whether infected or not, who received the contaminated Anti-D immunoglobulin product may be eligible to participate in the study, according to the release.

Researchers plan to examine information stored in the genes of the naturally resistant women and then compare it to information from the genes of the women who became infected.They believe that if the investigation reveals the mechanism that enables natural resistance to the hepatitis C virus, the findings could lead to development of a vaccine and new anti-viral drugs.

Recruitment for the study is underway. Further information can be found here.

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