Link Between Mononucleosis and Increased Risk of Rare Liver Disease

Recent research has uncovered a significant connection between infectious mononucleosis, commonly known as mono, and the development of primary sclerosing cholangitis (PSC), a rare and severe liver disease. PSC is characterized by the progressive destruction and scarring of bile ducts, often leading to liver failure and the necessity for transplantation. Despite its severity, the exact cause of PSC remains elusive. However, scientists from the University of Oslo have identified immune system changes linked to the Epstein-Barr virus (EBV), the primary cause of mono, which may play a critical role.

In a groundbreaking study published in Nature Medicine, researchers found that individuals who experience infectious mononucleosis are 12 times more likely to develop PSC compared to those who have not had mono. This study is the first to establish a strong association between EBV infection and the development of PSC, emphasizing the potential role of immune system responses.

The study involved detailed analysis of immune cells in PSC patients, revealing elevated levels of T cells and B cells that recognize EBV. These immune cells, particularly those producing antibodies against the virus, suggest prior or ongoing viral activity. The findings hint that EBV may trigger immune responses that inadvertently target bile ducts, contributing to disease progression.

EBV, a member of the herpesvirus family, infects over 95% of people during their lifetime, usually causing mild symptoms. In some cases, it leads to infectious mononucleosis, characterized by sore throat, high fever, body aches, swollen lymph nodes, and sometimes an enlarged liver and spleen. While most recover fully, the virus can remain dormant in the body, potentially reactivating later.

The researchers utilized advanced immunological techniques, including T cell receptor sequencing, to identify increased activity of EBV-specific T cells in PSC patients. Additionally, they examined health records of over 116 million individuals, discovering that those with a history of mono are much more susceptible to developing PSC.

This discovery opens new possibilities for prevention and treatment. Scientists suggest that developing an EBV vaccine could significantly reduce the risk of PSC and other chronic diseases linked to the virus, such as multiple sclerosis. Moreover, targeting viral infections or modulating immune responses might provide future therapeutic strategies.

The study’s findings also deepen our understanding of how genetic factors related to immune system recognition influence PSC risk. Ongoing research aims to clarify how early EBV infection contributes to disease onset and progression. Ultimately, this research highlights the importance of viral infections in autoimmune and liver diseases, paving the way for innovative approaches to prevention and therapy.

For further details, the full study is available in Nature Medicine, DOI: 10.1038/s41591-025-03692-w.

Source: https://medicalxpress.com/news/2025-06-mono-infection-higher-rare-liver.html