Prediction of hepatic inflammation in chronic hepatitis B patients with a random forest-backward feature elimination algorithm

Table 1 Clinical characteristics of patients with chronic hepatitis B virus infection

Parameter	HBeAg-positive patients (n = 402)	HBeAg-negative patients (n = 248)	P value
Gender, male	79.4.4% (319/402)	76.2% (189/248)	0.38
Age (yr)	36.35 ± 10.36	41.67 ± 9.65	< 0.001
BMI (kg/m2)	23.12 ± 3.31	23.62 ± 2.84	0.01
HBsAg (log10 IU/mL)	3.83 ± 0.81	3.16 ± 0.73	< 0.001
HBV DNA (log10IU/mL)	6.93 ± 1.66	4.82 ± 1.64	< 0.001
ALT (U/L)	106.74 ± 139.40	80.58 ± 105.61	< 0.001
AST (U/L)	65.48 ± 78.67	56.69 ± 70.06	0.029
TC (mmol/L)	4.61 ± 3.05	4.44 ± 0.98	0.691
TBil (μmol/L)	16.54 ± 15.48	18.49 ± 27.32	0.009
DBil (μmol/L)	5.61 ± 7.54	5.77 ± 6.59	0.527
Albumin (g/L)	43.72 ± 5.14	44.91 ± 6.07	0.011
PT (s)	12.81 ± 1.49	12.55 ± 1.49	0.035
Cr (μmol/L)	70.21 ± 25.41	69.19 ± 15.93	0.818
BUN (mmol/L)	5.28 ± 5.57	4.90 ± 1.33	0.681
Platelet counts (× 109/L)	178.6 ± 56.18	158.5 ± 55.28	< 0.001
Histology (n, %)
HAI 0-4	38.31% (154/402)	44.35% (110/248)	0.14
HAI ≥ 5	61.69% (248/402)	55.64% (138/248)
Fibrosis score 0-2	38.06% (153/402)	59.27% (147/248)	< 0.001
Fibrosis score ≥ 3	61.49% (249/402)	40.73% (101/248)

BMI: Body mass index; HBsAg: Hepatitis B surface antigen; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; TC: Total cholesterol; TBil: Total bilirubin; DBil: Direct bilirubin; PT: Prothrombin time; Cr: Creatinine; BUN: Blood urea nitrogen; HAI: Histology activity index.

Table 2 Selected features for predicting moderate-to-severe inflammation in patients with chronic hepatitis B virus infection (more than 40 votes)

Feature name	HBeAg-positive patients			HBeAg-negative patients
	Votes	Spearman’r (95%CI)1	P value1	Votes	Spearman r (95%CI)1	P value1
ALT	100	0.45 (0.36-0.53)	< 0.001	100	0.44 (0.33-0.53)	< 0.001
AST	100	0.51 (0.43-0.58)	< 0.001	100	0.49 (0.38-0.58)	< 0.001
qAnti-HBc	100	0.55 (0.47-0.62)	< 0.001	100	0.49 (0.39-0.58)	< 0.001
CXCL10	46	0.34 (0.25-0.43)	< 0.001	51	0.35 (0.23-0.46)	< 0.001
CXCL11	100	0.34 (0.25-0.43)	< 0.001	100	0.33 (0.21-0.44)	< 0.001
IL-2R	71	0.30 (0.20-0.39)	< 0.001	44	0.27 (0.14-0.38)	< 0.001
CCL2	42	-0.01 (-0.09-0.07)	0.79	52	0.03 (-0.10-0.16)	0.65
TNF-α	56	0.01 (-0.17-0.09)	0.78	62	0.01 (-0.17-0.09)	0.78
IL-1β	27	-0.10 (-0.23-0.03)	0.12	54	0.15 (0.03-0.28)	0.02

¹Correlation between features and scores of histological activity in patients with chronic hepatitis B virus infection. ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; qAnti-HBc: Quantitative hepatitis B core antibody; IL: Interleukin; TNF: Tumor necrosis factor; CI: Confidence interval.

Table 3 Receiver operating characteristic curve analysis of inflammation scores in patients with chronic hepatitis B virus infection

	Cutoff value	Se (%)	Spe (%)	PPV (%)	NPV (%)	Accuracy (%)	AUROC (95%CI)	P value
All patients
I-3A	< 0.41	69.17	81.44	84.49	64.37	73.8	0.82 (0.79-0.85)	< 0.0001
qAnti-HBc	> 4.20 log10 IU/mL	83.94	55.68	73.47	70.33	72.13	0.76 (0.72-0.79)
HBeAg-positive patients
I-3A	< 0.41	70.16	80.52	85.29	62.63	74.13	0.83 (0.79-0.87)	< 0.0001
qAnti-HBc	> 4.20 log10 IU/ml	83.06	60.39	77.15	68.89	74.38	0.77 (0.73-0.81)
HBeAg-negative patients
I-3A	< 0.44	73.19	78.18	80.8	69.92	75.4	0.81 (0.76-0.86)	0.002
qAnti-HBc	> 4.40 log10 IU/mL	76.81	61.13	71.62	68	70.16	0.75 (0.70-0.81)

Se: Sensitivity; Spe: Specificity; PPV: Positive predictive value; NPV: Negative predictive value; AUROC: Area under the receiver operating characteristics curve; CI: Confidence interval; HBeAg: Hepatitis B e antigen; qAnti-HBc: Quantitative hepatitis B core antibody.