Differentiation of acute and chronic hepatitis B in IgM anti-HBc positive patients

Table 1 Comparison clinical features between acute hepatitis B and chronic hepatitis B with acute exacerbation

Variables	Total (n = 82)	AHB (n = 53)	CHB-AE (n = 29)	P value
Age (yr)1	41.9 ± 12.7	40.2 ± 13.4	45.0 ± 11.0	0.023
Sex (male, %)	52 (63.4%)	30 (56.6%)	22 (75.9%)	0.098
WBC (× 103/μL)1	6.0 ± 1.9	6.1 ± 2.1	5.9 ± 1.6	0.808
Hb (g/dL)1	14.0 ± 1.7	13.9 ± 1.8	14.2 ± 1.7	0.782
Platelet (× 103/μL)1	212.1 ± 84.3	232.8 ± 85.9	174.3 ± 67.4	0.001
ALT (IU/L)1	1864.2 ± 1397.2	2273.2 ± 1373.1	1116.8 ± 1118.3	< 0.001
Total bilirubin (mg/dL)1	6.2 ± 5.6	7.0 ± 4.6	4.7 ± 7.0	< 0.001
Albumin (g/dL)1	3.5 ± 0.5	3.6 ± 0.5	3.4 ± 0.5	0.151
INR1	1.4 ± 0.9	1.5 ± 1.1	1.3 ± 0.5	0.861
HBeAg positivity (+, %)2	53 (64.6%)	31 (60.8%)	22 (75.9%)	0.226
HBeAg titer (S/CO)1	133.5 ± 261.5	49.2 ± 60.9	415.7 ± 367.8	0.001
IgM anti-HBc titer (S/CO)1	16.4 ± 10.7	22.3 ± 7.1	6.0 ± 6.9	< 0.001
HBV DNA (log10 IU/mL)1	5.3 ± 1.8	4.5 ± 1.6	6.7 ± 1.4	< 0.001

¹Mean ± SD;

²HBeAg was not checked in two patients of AHB group. AHB: Acute hepatitis B; CHB-AE: Chronic hepatitis B with acute exacerbation; WBC: White blood cell; Hb: Hemoglobin; ALT: Alanine aminotransferase; INR: International normalized ratio; HBeAg: hepatitis B e antigen; IgM anti-HBc: Immunoglobulin M antibody to hepatitis B core antigen; S/CO: Sample/cutoff value; HBV: Hepatitis B virus.

Table 2 Multivariate analysis for predicting acute hepatitis B

Variables	RR	95%CI	P value
Age (yr)	0.957	0.895-1.023	0.197
Platelet (× 103/μL)	1.001	0.988-1.014	0.934
Total bilirubin (mg/dL)	1.071	0.927-1.237	0.350
ALT (IU/L)	1.001	1.000-1.001	0.055
HBV DNA (log10 IU/mL)	0.323	0.135-0.773	0.011
IgM anti-HBc titer (S/CO)	1.293	1.125-1.486	< 0.001

AHB: Acute hepatitis B; RR: Relative risk; ALT: Alanine aminotransferase; HBV: Hepatitis B virus; IgM anti-HBc: Immunoglobulin M antibody to hepatitis B core antigen; S/CO: Sample/cutoff value.

Table 3 Diagnostic performance of laboratory tests for acute hepatitis B

	Sensitivity	Specificity	PPV	NPV
IgM anti-HBc (S/Co)
≥ 7	98.1	82.8	91.2	96.0
≥ 8	96.2	89.7	94.4	92.9
≥ 9	94.3	86.2	92.6	89.3
HBV DNA (log10 IU/mL)
< 5	56.6	86.2	88.2	52.1
< 5.5	81.1	72.4	84.3	67.7
< 6	83.0	65.5	81.5	67.9
Combination1	98.1	86.2	92.7	92.6

¹Combination obtained from variable 0.2303*IgM anti-HBc-1.0694*Log HBV-DNA. The values are expressed in percent. PPV: Positive predictive value; NPV: Negative predictive value; IgM anti-HBc: Immunoglobulin M antibody to hepatitis B core antigen; S/CO: Sample to the cutoff value; HBV: Hepatitis B virus.