Hepatitis B is caused by HBV infection, which can progress to chronic HBV infection after 6 months. HBV infection is a global public health problem, which can affect liver function and even threaten life health. HBV infection is worldwide prevalent, but the infection rate varies greatly in different regions. According to World Health Organization (WHO), there are about 257 million chronic HBV infections worldwide. The western Pacific region and Africa are the most prevalent regions of HBV, with the adult infection rate of 6.2% and 6.1% respectively. Most of Asia is a medium-high epidemic area 1. In 2014, Center for Disease Control and Prevention (CDC) conducted a serological epidemiological survey on hepatitis B among the population aged 1-29 in China, and the results showed that the prevalence rate of HBsAg in the population aged 1-4, 5-14 and 15-29 was 0.32%, 0.94% and 4.38%, respectively. It is estimated that the prevalence of HBsAg in the general population of China is 5-6%, and there are about 70 million chronic HBV infections, among which there are about 20-30 million chronic hepatitis B (CHB) patients. Chronic HBV infection increases the risk of liver fibrosis and hepatocellular carcinoma (HCC). The annual incidence of cirrhosis is 2-10% in CHB patients without antiviral therapy, and the annual incidence of HCC in patients with cirrhosis is 3-6%2.~The China 2019 Prevention and Treatment Guidelines of Chronic Hepatitis B recommend that patients with positive HBV DNA and elevated ALT, and those above 30 years old with family history of liver cirrhosis or HCC should initiate antiviral treatment, after ruling out other potential causes. However, the guideline did not identify the specific reference value of upper limit of normal for ALT, neither with cut off value of HBV detection. In addition, there is no clear definition of 'family history'. So, the fuzzy boundaries in the HBV guidelines may cause confusion when providing treatment recommendations in clinical practice and the value of this study would contribute to solve this kind of problems.~In a recently published study this year, 432 CHB patients who had liver biopsy in Ruijin Hospital during 2011-2017 were reviewed. So based on this, In the present study, we estimated a sample size of 600.Chronic HBV infected patients from 4 sites who underwent liver biopsy between 2008 and 2020.12 will be enrolled.~Previous studies have shown that a high proportion of HBV-infected patients with normal ALT have significant liver injury, including significant inflammation or fibrosis, and even cirrhosis.~And studies also show that treatment naive patients with normal ALT, either HBeAg-positive or HBeAg-negative, have a higher risk of developing HCC and even death than those in immune-active patients who received antiviral treatment (AVT). Therefore, early identification of patients with normal ALT but with significant liver inflammation or fibrosis is crucial.
To explore whether normal alanine aminotransferase (ALT) is associated with liver injury in a cohort of hepatitis B virus (HBV) infected patients in grey zone