Influenza A virus infection induces liver injury in mice.

Respiratory infections such as SARS-CoV in humans are often accompanied by mild and self-limiting hepatitis. As a respiratory disease, influenza A virus (IAV) infection can lead to hepatitis, but the mechanism remains unclear. This study aimed to investigate the occurrence of hepatitis by establishing a model for infected mice for three different subtypes of respiratory IAVs (H1N1, H5N1, and H7N2). Histological analysis was performed, and results showed increase serum aminotransferase (ALT and AST) levels and evident liver injury on days 3 and 7, especially on day 5 post infection. Immunohistochemistry (IHC) results indicated a wide distribution of IAV's positive signals in the liver of infected mice. Real-time PCR results further revealed a similar viral titer to IHC that presented a remarkedly positive correlation with histology injury. All these data showed that the mouse model suitably contributed valuable information about the mechanism underlying the occurrence of hepatitis induced by respiratory influenza virus.