Hepatitis B surface antigen-negative but hepatitis B envelope antigen-positive false occult hepatitis B virus infection: A case report

Table 2 Clinical characteristics and hepatitis B virus markers of occult hepatitis B infection patients positive for hepatitis B envelope antigen

Ref.	Case	Biochemical and virological characteristics	Serological characteristics	History of HBV infection history and treatment	Sequencing of the S gene
Han et al[4] 2015, China	Case 1: A 56-year-old man	ALT (U/L): Normal; AST (U/L): Normal; HBV DNA (IU/mL): 234-567	HBsAg: -	Assumed to have resolved HBV infection, treatment naive	Double mutations (A1762T and G1764A) in BCP; no mutations in the preC/C gene; the α determinant sequences were all mutant type
			HBsAb: +
			HBeAg: +
			HBeAb: -
			HBcAb: +
	Case 2: An 81-year-old man	ALT (U/L): Normal; AST (U/L): Normal; HBV DNA (IU/mL): 1130-135	HBsAg: -	Diagnosed with HCC with no known HBV infection history	Double mutations (A1762T and G1764A) in BCP; no mutations in the preC/C gene; three residue substitutions in the α determinant
			HBsAb: +
			HBeAg: +
			HBeAb: -
			HBcAb: +
Zhou et al[5] 2009, China	Case 1: A 50-year-old man	ALT (U/L): Normal; AST (U/L): Not done; HBV DNA: 370-491 copies/mL	HBsAg: -	Not known	The insertion is a perfect repeat of the preceding 15 nts. This insert resulted in an insertion of 5 amino acids between residues 128 and 129 in HBsAg, which is located in the α determinant. HBV variant had mutations both in preS2 and S proteins
			HBsAb: +
			HBeAg: +
			HBeAb: -
			HBcAb: +
Paparella et al[6] 2010, Italy	Case 1: A 76-year-old man	ALT(U/L): Normal; HBV DNA: < 40 IU/mL	HBsAg: -	Peritoneal dialysis since 2004 and regarded as naturally immune to HBV in 2007	Serotype adw2, one immune escape mutation (G145R), and no drug resistance mutations
			HBsAb: +
			HBeAg: +
			HBeAb: -
			HBcAb: -

ALT: Alanine transaminase; AST: Aspartate aminotransferase; HBV: Hepatitis B virus; HBsAg: Hepatitis B surface antigen; HBeAg: Hepatitis B envelope antigen; HCC: Hepatocelluar carcinoma; BCP: Basic core promoter; HBsAb: Hepatitis B surface antibody; HBeAb: Hepatitis B e antibody; HBcAb: Hepatitis B c antibody; nts: Nucleotides.