Prognosis of acute-on-chronic liver failure patients treated with artificial liver support system

Table 1 Patient baseline demographics and the treatment n (%)

Variable	Derivation cohort	Validation cohort	P value
	(n = 113)	(n = 68)
Age (yr)	44.6 (22-81)	46.1 (20-79)	0.529
Men	94 (83)	52 (76)	0.268
Etiology of liver failure
HBV	64 (56.6)	40 (59)	0.773
HBV + HEV	36 (31.9)	18 (26)	0.443
Other causes1	13 (11.5)	10 (15)	0.531
MELD score	24 (12-44)	26 (13-46)	0.659
Total bilirubin (mg/dL)	24.8 (5.9-51.8)	23.1 (5.7-50.1)	0.841
ALT (IU/mL)	262 (12-1757)	211 (23-1519)	0.169
AST (IU/mL)	232 (17-1634)	206 (20-1301)	0.326
Creatinine (mg/dL)	0.9 (0.3-6.8)	1.0 (0.3-7.1)	0.533
INR	2.4 (0.8-11.4)	2.6 (1.0-16.1)	0.285
Cirrhosis	58 (51.3)	45 (66.2)	0.051
Number of complications
1	57 (50.4)	39 (57.4)	0.367
2	27 (23.9)	13 (19.1)	0.453
3	20 (17.7)	10 (14.7)	0.600
4	8 (7.1)	4 (5.9)	0.996
5	1 (0.9)	2 (2.9)	0.654
Type of ALSS
PE	54 (47.8)	33 (48.5)	0.923
PE + PBA	59 (52.2)	35 (51.5)	0.923

¹Includes alcohol combined with drugs; autoimmune combined with drugs; schistosome combined with alcohol. Number (proportion) or median (interquartile range) are shown. HBV: Hepatitis B virus; HEV: Hepatitis E virus; MELD: The model for end stage liver disease; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; INR: International normalized ratio; ALSS: Artificial liver support system; PE: Plasma exchange; PBA: Plasma bilirubin adsorption.

Table 2 Univariate and multivariate analyses of risk factors for survival

Variable	Univariate		Multivariate
	HR (95%CI)	P value	HR (95%CI)	P value	Coefficient
Age	1.045 (1.024-1.067)	< 0.001	1.031 (1.008-1.054)	0.008	0.030
Gender1	0.704 (0.296-1.676)	0.428
Etiology2	0.736 (0.178-3.049)	0.673
MELD score	1.120 (1.080-1.161)	< 0.001	1.102 (1.056-1.150)	< 0.001	0.097
Total bilirubin	1.002 (1.000-1.003)	0.047
ALT	1.001 (1.000-1.002)	0.022
AST	1.001 (1.000-1.002)	0.011
Creatinine	1.003 (1.000-1.005)	0.055
BUN	1.083 (1.015-1.157)	0.017
INR	1.369 (1.209-1.550)	< 0.001
Times3	0.753 (0.549-1.034)	0.080
Complication4	2.246 (1.721-2.933)	< 0.001	1.694 (1.224-2.344)	0.001	0.527
ALSS5	0.455 (0.242-0.856)	0.015	0.454 (0.232-0.889)	0.021	-0.790

¹Gender: 0 = male, 1 = female;

²Etiology: 0 = nonviral, 1 = viral;

³Times of ALSS: 1 = 1, 1 = 1, 2 = 2, 3 = 3, 4 = 4, 5 = 5, 6 = 6;

⁴Number of complications: 1 = 1, 2 = 2, 3 = 3, 4 = 4, 5 = 5;

⁵Type of ALSS: 0 = PE, 1 = PE plus PBA. MELD: Model for end-stage liver disease; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase; INR: International normalized ratio; ALSS: Artificial liver support system.

Table 3 Calculation of probability of survival according to the risk score

Days	30	60	90	120	180	270
S0 (t)	92.50%	84.90%	79.70%	77.40%	71.80%	65.60%

S0(t) gives the estimated survival probabilities for a patient with a risk score of 3.7 which is the mean risk score of acute-on-chronic liver failure patients in the derivation cohort. To calculate the probability of survival at t days of a given patient use the following equation: S(t) = S0(t)^{exp(score-3.7)}.

Table 4 Prognosis in the derivation and validation cohorts according to risk score n (%)

Prognosis	Derivation cohort	Validation cohort	P value
	(n = 113)	(n = 68)
Good	36 (31.9)	21 (30.9)	0.891
Fair	55 (48.7)	32 (47.1)	0.833
Poor	22 (19.4)	15 (22.0)	0.676