Acute hepatitis B or exacerbation of chronic hepatitis B-that is the question

Table 1 Comparison of the serological markers in acute HBV and in exacerbation of chronic HBV infections

Serological markers	Acute infection	Chronic exacerbation	Comments
HBeAg	-	+	Not different, and also not helpful in infections with HBeAg-negative strains
Anti-HBe	-	+	Low sensitivity and specificity, and also not helpful in infections with HBeAg-negative strains
Anti-HBe level, and complexes of HBeAg/anti-HBe	↓	↑	Not helpful in infections with HBeAg-negative strains
IgM anti-HBc	> 1:1000	< 1:1000	Low sensitivity, specificity, NPV and PPV
Sample/cutoff ratio for IgM anti-HBc	> 10	< 10	High sensitivity, specificity, NPV and PPV
Anti-HBc avidity index	< 0.7	> 0.7	High sensitivity, specificity, NPV and PPV
HBsAg	↓	↑	Useful in HBeAg-negative cases
HBV-DNA	< 0.5 pg/mL	> 0.5 pg/mL	Sensitivity: 96%
	≤ 141 500 copies/mL	≥ 141 500 copies/mL	Specificity: 86%