HHV-6 found in 22% of acute liver failure of “unknown etiology”

A third of patients with acute liver failure were found to have a betaherpesvirus infection when tested for all herpesviruses. HHV-6 was the most common infection, followed by CMV and HHV-7. No other herpesviruses were found.

Investigators in Brazil used multiplex qPCR to test both serum and liver biopsies of 27 patients with failing livers. Typically, acute liver failure patients are tested for hepatitis A & B, parvovirus, adenovirus and herpes simplex, but are rarely tested for HHV-6 or 7. Of interest, HHV-7 was only found as a co-infection with either HHV-6 or CMV.

Acute liver failure is characterized by the rapid deterioration of liver function, frequently requiring a liver transplant. The investigators were able to retrieve serum from all 27 cases, but biopsies from only 14 of the explanted livers due to the high death rate. It is difficult to diagnose HHV-6 liver disease because in most cases, the infection is localized, and often the HHV-6 DNA load in the blood is below the level of detection (Phan 2017, Buyse 2013).

A 2006 study in Finland found HHV-6 in the explanted livers of most cases of acute liver failure of “unknown origin” and determined that these patients were more likely to reactivate with HHV-6 and liver dysfunction post-transplant (Harma 2006). HHV-6 primary infection is also known to cause liver failure in children and transplant patients.

The authors note that early detection of these viral infections could improve the outcome for these patients.

Read the full text: Raposo 2019