Scientists have found that the course of opisthorchiasis and the risk of developing severe complications, in particular, liver fibrosis, are related to certain genetic characteristics of the patient. These markers will help doctors identify at-risk patients early and prevent severe complications. The results of the study were published in the Journal Medical Council (Meditsinskiy Sovet).

Opisthorchiasis is the most common parasitic disease in Russia, particularly in Siberia and major river basins. It is caused by the cat fluke, a flatworm that attacks the liver and bile ducts. Infection occurs through undercooked fish. Once ingested, the parasite can survive for years, causing inflammation and leading to liver fibrosis. Some infected individuals experience a mild form of the disease, while others can have serious health problems.

Scientists from the Krasnoyarsk Scientific Center, Siberian Branch of the Russian Academy of Sciences have determined that the course of opisthorchiasis and the probability of developing liver fibrosis depend on a person's genetic makeup. By studying gene polymorphisms in hundreds of patients, the specialists found the markers that allow for identifying risk groups among those infected with feline fluke parasites.

The researchers examined whether two specific genes, IFNG and IL28B, affect severity of the disease. The first gene is responsible for the production of interferon gamma, a substance that regulates immunity. The second gene is also involved in antiviral and antiparasitic defenses. The scientists compared which variants of these genes are most common in patients with opisthorchiasis and how they relate to liver health.

It turned out that opisthorchiasis patients with different variants of the IFNG gene had different disease progressions. Some had a higher blood level of eosinophils, a special cell type that reacts to parasites, and changes in bile stasis indicators, while others had a higher incidence of liver scarring. Moreover, if we consider all carriers of one variant of this gene, fibrosis is approximately twice as common in them as in patients with other variants.

"We have shown that the parasitic infection has varying consequences for the human body, depending on the genetic polymorphism of immune response mediators. Having analyzed the results obtained, we concluded that the patients with opisthorchiasis who have a certain variant of the IFNG gene should be identified during follow-up as a risk group to prevent the development of complications, including liver fibrosis," says Natalia Veselova, gastroenterologist, junior researcher at the Research Institute for Medical Problems of the North.