George Washington University researchers have found a biomarker that could help diagnose bile duct fibrosis and cancer caused by liver fluke infection, according to a study published in PLoS Neglected Tropical Diseases.
Opisthorchis viverrini, the Asian liver fluke, is picked up from infected food such as uncooked fish, and affects around 10 million people in the northeastern (Isaan) region of Thailand and other areas of Southeast Asia. This food-borne trematode (parasitic flatworm) infests fish, seafood and turtle, and is associated with bile duct fibrosis and bile duct cancer (cholangiocarcinoma). It is the leading cause of cancer in this region, which has the highest levels of bile duct cancer in the world.
The researchers, along with a team from Khon Kaen University, Thailand, looked at nearly 4,000 people from the Khon Kaen Cholangiocarcinoma Cohort and found that blood levels of interleukin-6 (IL-6; a protein linked with inflammation) were 58 times higher in advanced fibrosis and 221 times higher in people with bile duct cancer. They also found that as levels of IL-6 rose, the chance of developing fibrosis and cancer rose.
As the levels of IL-6 are related to the bile duct disorders and not simply to the levels of infection, this could be used as a sensitive and specific marker to predict which people in areas with high levels of Asian liver fluke infections will go on to develop fibrosis or cancer. This will help physicians catch the cancer at an earlier stage and reduce the costs and casualties associated with the disease.
"Typically, bile duct cancer has a late presentation, and so a very high mortality rate. Now that we've identified the IL-6 biomarker, our hope is that earlier detection is possible and earlier treatment saves more lives," said Jeffrey M. Bethony, Ph.D., associate professor of microbiology, immunology, and tropical medicine at the GW School of Medicine and Health Sciences (SMHS).
Based on this research, the Thai Ministry of Public Health has already implemented testing for levels of plasma IL-6 for individuals between 20 and 60 in endemic regions of Isaan Thailand.