. 2010 Apr;59(4):S17–S22.

Table 1. Phases of chronic HBV infection.

Phase	ALT levels	Liver histology	HBV DNA/HBeAg levels
Immune tolerant phase^a	Normal or minimally elevated	Active or inactive minimal inflammation or fibrosis	• >20,000 IU/mL, HBeAg+
Immune active phase^a	Elevated	Active: Liver biopsy shows chronic hepatitis	• >20,000 IU/mL while HBeAg+
			• >20,000 IU/mL after loss of HBeAg and development of antibody to HBeAg
Inactive phase^a	Persistently normal	Inactive: Liver biopsy shows variable, usually minimal fibrosis	• <2000 IU/mL, HBeAg–
Resolution^b	Normal	Inactive: Scant fibrosis	• No detectable serum HBV DNA (low levels might be detectable in liver)
			• HBeAg– and HBsAg–
Reactivation phase^b	Elevated, often fluctuating levels	Active: Liver biopsy showing variable amount of fibrosis	• Moderate, often fluctuating levels >2000 IU/mL

ALT, alanine aminotransferase; HBeAg, hepatitis B e antigen; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus.

^aMcMahon BJ, et al. Hepatology. 2009;49(5 suppl):S45-S55.

^bKeeffe EB, et al. Clin Gastroenterol Hepatol. 2008;6:1315-1341.