Accepted Manuscript
Increased Level of Interleukin 6 Associates With Increased 90-day and 1-yearMortality in Patients With End-stage Liver Disease
Johannes Remmler, Christoph Schneider, Theresa Treuner-Kaueroff, MichaelBartels, Daniel Seehofer, Markus Scholz, Thomas Berg, Thorsten Kaiser
PII: S1542-3565(17)31106-0DOI: 10.1016/j.cgh.2017.09.017Reference: YJCGH 55449
To appear in: Clinical Gastroenterology and HepatologyAccepted Date: 8 September 2017
Please cite this article as: Remmler J, Schneider C, Treuner-Kaueroff T, Bartels M, Seehofer D, ScholzM, Berg T, Kaiser T, Increased Level of Interleukin 6 Associates With Increased 90-day and 1-yearMortality in Patients With End-stage Liver Disease, Clinical Gastroenterology and Hepatology (2017),doi: 10.1016/j.cgh.2017.09.017.
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Title:
Increased Level of Interleukin 6 Associates With Increased 90-day and 1-year
Mortality in Patients With End-stage Liver Disease
Short Title:
Interleukin 6 and prognosis in liver disease
Authors:
Johannes Remmler1*; Christoph Schneider1*; Theresa Treuner-Kaueroff1; Michael
Bartels2; Daniel Seehofer2; Markus Scholz4; Thomas Berg3; Thorsten Kaiser1
* these authors contributed equally
1 Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics,
University Hospital Leipzig, Germany
2 Department of Visceral, Transplant, Thoracic and Vascular, Surgery, University
Hospital Leipzig, Germany
3 Section of Hepatology, Department of Gastroenterology and Rheumatology,
University Hospital Leipzig, Germany
4 Institute for Medical Informatics, Statistics and Epidemiology (IMISE), University
Hospital Leipzig, Germany
Grant Support:
The authors received no specific funding for this work.
Abbreviations:
AUC, Area under the curve
AUROC, Area under receiver operating characteristic
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ACLF, Acute-on-chronic liver failure
CRP, C-reactive protein
ECLIA, Electro-chemiluminescence immunoassay
EDTA, Ethylenediaminetetraacetic acid
IL6, Interleukin 6
INR, International normalized ratio
IQR, Interquartile range
MELD, Model for end-stage liver disease
MELD-Na, Model for end-stage liver disease including serum sodium
ROC, Receiver operating characteristic
WBC, White blood cell count
Correspondence:
Dr. med. Thorsten Kaiser
Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics
University Hospital Leipzig
Paul-List-Str. 13-15
04103 Leipzig
Germany
Telephone: +49 341 9722200
Fax: +49 341 22209
E-mail: [email protected]
Disclosures:
The authors declare no conflict of interests.
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Author Contributions:
study concept and design:
J.R.; C.S.; T.T-K.; M.B.; D.S.; M.S.; T.B.; T.K.
acquisition of data:
C.S.; T.T-K.;
analysis and/or interpretation of data:
J.R.; C.S.; T.T-K.; M.B.; D.S.; M.S.; T.B.; T.K.
statistical analysis:
J.R.; M.S.; T.K.
drafting the manuscript:
J.R.; C.S.; T.K.
critical revision of the manuscript for important intellectual content:
J.R.; C.S.; T.T-K.; M.B.; D.S.; M.S.; T.B.; T.K.
final approval of the version to be published:
J.R.; C.S.; T.T-K.; M.B.; D.S.; M.S.; T.B.; T.K.
study supervision:
T.K.
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Abstract
Background & Aims: Organ allocation for liver transplantation is based on
prognosis, using the model for end-stage liver disease (MELD) or MELD-Na score.
These scores do not consider systemic inflammation and septic complications. Blood
level of C-reactive protein (CRP), in addition to the MELD score, associates with
mortality in patients with end-stage liver disease, whereas levels of interleukin 6 (IL6)
have not been systematically studied.
Methods: We performed a retrospective observational cohort study of 474 patients
with end-stage liver disease (63.5% male; median age, 56.9 years), evaluated for
liver transplantation in Germany, with at least 1 year of follow up. Data were collected
on blood levels of CRP, IL6, and white blood cell count (WBC). Findings were
analyzed in relation to mortality and compared with patients’ model for end-stage
liver disease (MELD) scores and MELD-Na scores. For survival analysis, the cohort
was divided into quartiles of IL6, CRP, and WBC levels, as well as MELD scores.
Log-rank test and the Cox proportional hazards regression model were used to
compare the groups, and area under the receiver operating characteristic (AUROC)
values were calculated.
Results: Blood levels of IL6 and MELD scores associated with mortality: none of the
patients with levels of IL6 below the first quartile (below 5.3 pg/ml) died within 1 year.
In contrast, 67.7% of the patients in the highest quartile of IL6 level (37.0 pg/ml or
more) died within 1 year. MELD score also correlated with mortality: among patients
with MELD scores below 8.7, 0.9% died within 1 year, whereas in patients with
MELD scores of 18.0 or more, 67.4% died within 1 year. The predictive value of level
of IL6 (AUROC, 0.940) was higher than level of CRP (AUROC, 0.866) (P=.009) or
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WBC (AUROC, 0.773) (P<.001) for 90-day mortality. MELD scores associated with
90-day mortality (AUROC, 0.933) (P=.756) as did MELD-Na score (AUROC, 0.946)
(P=.771). Level of IL6 associated with 1-year mortality (AUROC, 0.916) to a greater
extent than liver synthesis or detoxification markers international normalized ratio
(AUROC, 0.839) (P=.007) or bilirubin (AUROC 0.846) (P=.007). Level of IL6 was an
independent, significant risk factor for mortality after adjustment for MELD score,
MELD-Na score, level of CRP, or WBC.
Conclusion: In a retrospective analysis, we found high blood levels of IL6 to
associate with 90-day and 1-year mortality in patients with end-stage liver disease; its
predictive value was comparable to that of MELD or MELD-Na score, and was higher
than that of level of CRP or WBC. Further studies should be performed to confirm the
results in different cohorts.
KEY WORDS: acute-on-chronic liver failure; biomarker; cytokine; cirrhosis.
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Introduction
Liver transplantation is the only curative therapy option for patients with end-stage
liver disease. In most countries, organ allocation is prioritized according to the
estimated risk of mortality (medical urgency), which is assessed using the model for
end-stage liver disease (MELD) score 1–3. Introduction of the MELD-based liver
allocation has reduced waiting list registrations, waiting time and, most importantly,
waiting list mortality 4. The MELD score is composed of bilirubin, creatinine and INR
(international normalized ratio). In the USA, the MELD-Na score is used since 2016,
additionally including serum sodium 5–7. The MELD/MELD-Na score does not
account for inflammation in determining mortality risk. However, complications due to
bacterial infections such as spontaneous bacterial peritonitis are associated with a
dramatically worse prognosis. Inflammation has also been considered a possible
prognostic determinant in patients with end-stage liver disease. Furthermore,
systemic inflammatory response syndrome (SIRS) leads to a poor outcome in
patients with cirrhosis 8,9. SIRS is an independent prognostic factor in these patients
10. Cervoni et al. demonstrated the prognostic value of C-reactive protein (CRP) in
cirrhotic patients 11,12. They were able to show that a prognostic model including
MELD, CRP and age predicts three-month mortality of cirrhotic patients better than
the MELD alone 13. The prognostic value of IL6 levels has not been systematically
studied yet in these patients, even though it is a measure of inflammation that is
detectable earlier and more sensitive than CRP 14. IL6 is produced in monocytes,
macrophages, T cells, fibroblasts and endothelial cells, initiates the production of
acute phase proteins and is an important inductor of infection defense 15,16. The aim
of our study was to compare the mortality prediction of IL6 to that of the
MELD/MELD-Na score, CRP and WBC in a large cohort of patients with end-stage
liver disease.
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Materials and methods
Study population
We performed a retrospective observational cohort study. The study population
consisted of 474 different patients that were evaluated for liver transplantation at the
Leipzig University Hospital. A biobank (-80°C) of s era of these patients was
established, allowing further characterization in addition to the routinely determined
biomarkers. Clinical information was collected from electronic patient records. Follow-
up time was at least one year. IL6, CRP, WBC and MELD were available in 474, 471,
461 and 468 of the patients, respectively. Clinical records of all patients deceased in
the university hospital were systematically analyzed for documented complications
and death causes (79 of 111 patients (71.2 %)). Clinical records of patients who
deceased outside our hospital were not available, in these cases the date of death
was received by contacting the hospital or the relatives of the patient. The study was
approved by the Leipzig University Faculty of Medicine ethics committee (reference
number: 039/14ff).
Quantification of WBC, MELD, IL6 and CRP
WBC and laboratory data for the MELD/MELD-Na score were measured routinely as
part of the evaluation process for liver transplantation. WBC was measured in EDTA
whole blood using the XN 9000 system (Sysmex, Kobe, Japan). Bilirubin (Total DPD
Gen. 2 kit, colorimetric assay), creatinine (Creatinine Plus Ver. 2 kit, enzymatic
method) and sodium (ion sensitive electrode Gen. 2) were measured in serum on the
cobas 8000 analyzer (Roche, Mannheim, Germany). INR was determined in citrate
plasma using the ACL TOP 700 System (Instrumentation Laboratory, Lexington,
USA). IL6 (Elecsys IL-6 kit, ECLIA) and CRP (Cobas c pack CRPL3 kit,
immunoturbidimetry) were determined in serum from the biobank using the cobas
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8000 analyzer. These samples were stored at -80°C a fter acquisition and thawed for
batched analysis.
The MELD and MELD-Na scores were calculated according to the UNOS (United
Network of Organ Sharing) guidelines using the formulas given below 6. In this study,
unlike in the routine procedure, MELD score as well as MELD-Na score were not
rounded to whole numbers for statistical analysis.
MELD score = 10 x {0.957 x Ln (creatinine [mg/dL]) + 0.378 x Ln (bilirubin [mg/dL]) +
1.120 x Ln (INR) + 0.643}
creatinine (mg/dL), bilirubin (mg/dL) and INR values that were lower than 1.0 were set to 1.0 for MELD
calculation. Maximum serum creatinine level was set to 4.0 mg/dL. Similarly, the maximum creatinine
level in dialysis patients was set to 4.0 mg/dL.
MELD-Na score = MELD + 1.32 x (137 - Na) - [0.033 x MELD x (137 - Na)]
Meld-Na score was applied only for patients with an MELD greater than 11. Sodium values less than
125 mmol/L were set to 125, and values greater than 137 mmol/L were set to 137.
The following reference values are used: WBC: 3.5-9.8 *10^9/l, bilirubin: <17,1
µmol/l, CRP: <5 mg/l. IL6 <7 pg/ml, creatinine: 45-84/59-104 µmol/l (female/male,
respectively).
Statistics
Statistical analysis was performed using SPSS 23 (SPSS Inc., Chicago, USA),
MedCalc 12 (MedCalc Software bvba, Ostend, Belgium) and R (R Foundation for
Statistical Computing, Vienna, Austria; www.r-project.org).
The characteristics of the cohort are shown as median and interquartile ranges
(IQR). For survival analysis, the cohort was divided into four groups, according to the
quartiles of the IL6, CRP and WBC measures as well as the MELD score. Log-rank
test and Cox Proportional Hazards Regression Model were used to statistically
compare the groups. Survival data of patients receiving liver transplants were
censored at the date of transplantation. Receiver operating characteristics (ROC)
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and area under ROC (AUROC) were computed to determine the mortality prediction
performance of IL6, CRP, WBC MELD and MELD-Na score. DeLong test was used
to compare AUROCs 17, using the pROC R-package 18. Mann-Whitney U test was
used to compare continuous characteristics between two groups, and Pearson’s chi-
squared test was used to compare categorical data. Optimal cut-off values were
obtained calculating the maximum Youden index.
Results
Study population characteristics
The cohort consisted of patients with end-stage liver disease who were evaluated for
liver transplantation. The baseline characteristics of the cohort are summarized in
table 1. We included 474 patients, of which 63.5% were men. The median age was
56.9 years (IQR: 50.6 - 62.9). The most common cause of end-stage liver disease in
this cohort was alcohol abuse (62.9%), followed by cryptogenic liver cirrhosis (10.3%)
and viral hepatitis (8.4%). The median MELD score was 11.9 (IQR: 8.7 - 18.0).
During follow-up (median follow-up time: 549 days (IQR: 257 - 789)), 15.2% of the
patients received a liver transplant, and 27.6% of those who didn’t receive an organ
died. Clinical patient records revealed upper gastrointestinal bleeding in 26.8%,
hepatocellular carcinoma in 18.6% and spontaneous bacterial peritonitis in 14.6% of
the cases.
Survival analysis
Data of deceased and surviving patients were compared (table 2). There were no
significant differences in the ages or sex of surviving and deceased patients. Highly
significant differences (p < 0.001) could be observed for IL6, CRP and MELD score
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as well as bilirubin, creatinine and INR, and a less distinct difference was observed
for WBC (p = 0.003).
For a more detailed survival analysis the patients were divided into four groups
according to the quartiles of the baseline IL6, CRP and WBC measurements as well
as the baseline MELD score. Figure 1 shows the Kaplan-Meier curves for the first
year of follow-up. The detailed descriptive mortality data of the groups can be found
in Supporting documents, table 1. IL6, CRP and MELD score all showed strong
correlations with mortality, since survival of groups divided according to these
measures differed in a highly significant way (p < 0.001 in all cases, log-rank test with
three degrees of freedom). Survival of the groups divided according to WBC differed
less clearly, but still significantly (p = 0.001). In particular, elevated IL6 levels and
MELD scores were highly predictive for mortality. None of the patients from group Q1
(below the first IL6 quartile, < 5.3 pg/ml) died within one year. In contrast, 67.7% of
the patients in group Q4 (on and above the third IL6 quartile, ≥ 37.0 pg/ml) died
within one year. MELD score also correlated significantly with mortality; one-year
mortality for groups Q1 (MELD < 8.7) and Q4 (MELD ≥ 18.0) were 0.9% and 67.4%,
respectively. The differences in survival were less distinct for CRP groups and clearly
less distinct for WBC groups.
To study the possible role of biomarkers for inflammation on short-term mortality and
long-term survival, we separately analyzed patients who died between day 31 and
365 of follow-up. Here, the mortality differences among the groups were most distinct
for IL6 (0% and 38.5% for groups Q1 and Q4, p < 0.001), followed by MELD score
(0.9% and 34.8% for groups Q1 and Q4, p < 0.001). In contrast to this, no significant
differences in mortality between day 31 and 365 were observed in the WBC groups
Q1 (WBC < 4.6 *10^9/l, mortality 12.3%) and Q4 (WBC ≥ 8.2 *10^9/l, mortality
12.8%).
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The correlation of the baseline IL6, CRP and WBC measures as well as the baseline
MELD score with mortality was analyzed further using the Cox regression (table 3).
For IL6 groups, the risk of mortality was significantly higher for groups Q2, Q3 and
Q4 (hazard ratios: 11.1 (p = 0.021), 36.3 (p < 0.001) and 94.8 (p < 0.001),
respectively) than for group Q1. Baseline CRP levels also correlated strongly with the
risk of mortality, but hazard ratios were lower compared to IL6 (1.2 (p = 0.749), 3.0
(p = 0.003) and 8.7 (p < 0.001) for groups Q2, Q3 and Q4 compared to group Q1).
We also analyzed whether the inflammatory markers were still relevant predictors of
mortality after adjustment for MELD score. This was clearly the case for IL6 and
CRP. Even after adjustment for MELD/MELD-Na, CRP and WBC, IL6 levels
remained an independent factor for mortality (hazard ratios: 8.2/8.0
(p = 0.046/0.049), 17.3/17.6 (p = 0.006/0.006) and 22.5/21.4 (p = 0.004/0.004) for
groups Q2, Q3 and Q4 compared to group Q1). CRP, however, was no longer a
significant risk factor after adjustment for MELD/MELD-Na, WBC and IL6 (hazard
ratio 1.7/1.6 (p = 0.236/0.256) for group Q4 compared to Q1, hazard ratios and p-
values obtained adjusting for MELD/MELD-Na score, respectively).
To analyse the predictive value of the parameters of interest, receiver operating
characteristics (ROC) for baseline IL6, CRP and WBC measurements and
MELD/MELD-Na scores were analyzed. The ROC curves and the calculated area
under ROC (AUROC) values are shown in figure 2. Of the investigated markers, IL6
and MELD/MELD-Na score showed the highest mortality prediction for every time
period considered. For 90-day mortality, AUROC was 0.940/0.933 for IL6 and MELD,
respectively. Importantly, there were no significant differences between the AUROCs
of IL6 and the MELD score (p > 0.3 for all time periods). This was also the case for
comparison of IL6 and MELD-Na score. For 90-day mortality, AUROC for MELD-Na
was 0.946 (p = 0.771 compared to IL6, not shown). CRP was also a powerful
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predictor for mortality, yet it was significantly less predictive than IL6
(p = 0.014/0.009/0.013 for 30/90/365-day mortality, respectively). WBC predicted
mortality less precisely than the other inflammation parameters, especially in the long
term.
The analysis of clinical records of all deceased study patients in our hospital showed
with the exception of fulminant and acute on chronic liver failure that IL6 levels were
not associated with certain clinical complications. However, significantly elevated IL6
levels were found in patients with short time mortality (within 30 days). There was no
continued consumption of alcohol documented in the records (supporting documents,
table 2). The optimal cut-off value for the prediction of 90-day mortality by IL6 was
36.6 pg/ml (sensitivity 89.1 %, specificity 85.5 %) in our cohort. (Results for CRP,
WBC and MELD/MELD-Na with corresponding sensitivity and specificity are given in
supporting documents, table 3.)
Discussion
Our study is the first to identify the importance of IL6 as an excellent mortality
predictor in patients with end-stage liver disease. The predictive value of IL6 alone
was comparable to that of the MELD/MELD-Na score (which is composed of bilirubin,
creatinine, INR, and additional sodium for the MELD-Na score) and significantly
better than that of CRP or WBC. IL6 was also an independent risk factor for mortality
after adjustment for MELD. Some patients in this study had low MELD scores but
died within 90 days; the mortality risk for these patients could have been detected by
using elevated IL6 as an additional predictor of mortality (Supporting documents,
figure 1).
IL6 is not only a sensitive indicator; it also serves as a key mediator for inflammation.
IL6-dependent signaling in the liver is critical for the induction of the acute phase
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response 19. In patients with liver cirrhosis, the acute phase reaction is known to play
a role in clinical complications. CRP is an acute phase reactant and it’s elevation has
recently been associated with increased mortality in patients with liver cirrhosis 11–
13,20. Furthermore, inflammation plays a key role in the pathogenesis of ACLF (acute-
on-chronic liver failure), which is a major cause of unfavorable outcomes in patients
with chronic liver disease. Consequently, the recently introduced chronic liver failure
consortium (CLIF-C) ACLF score incorporates WBC as a measure of systemic
inflammation and predicts mortality better than the MELD score in patients with ACLF
21,22. This study confirms the predictive value of WBC and CRP. However, the
predictive value of IL6 elevation is distinctly higher than that of WBC and also clearly
and significantly higher than that of CRP. Unlike IL6, which is produced by T-cells
and macrophages, CRP is produced exclusively in the liver as a response to IL6 and
other cytokines in an acute phase reaction 15,16,23. Consequently, in the case of
severe liver insufficiency, limited synthesis capacity could lead to low CRP levels.
WBC may also not be an suitable parameter because white blood cell count does not
always increase in cases of severe systemic inflammation; it may also decrease due
to the loss of cells in the periphery 24.
Interestingly, the predictive value of IL6 concerning 365-day mortality (AUROC
0.916) was higher even than that of the liver synthesis and detoxification markers
INR (AUROC 0.839, p = 0.007) and bilirubin (AUROC 0.846, p = 0.007) and tended
to be higher for the prediction of 90-day mortality (AUROCs 0.916 for IL6, compared
to 0.887 for INR (p = 0.058) and 0.894 for bilirubin (p = 0.065), respectively) (Not
shown).
The reason for this observation remains to be elucidated. Even after exclusion of
short-time mortality (within 30 days), high IL6 concentrations in the blood were still
highly significantly associated with increased mortality. In our opinion, this indicates
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that the prognostic value cannot be explained by acute infections or infection-related
mortality alone.
IL6 is a cytokine with pleiotropic effects. It indicates infection complications, drives
inflammation and promotes tumorigenesis. A negative correlation between
biomarkers for liver synthesis and IL6 has been demonstrated by Streetz KL et al. 25.
In patients with acute alcoholic hepatitis higher IL6 levels were associated with
increased mortality 26. Recently, an association between high IL6 levels, impairment
of liver function and increased mortality has been observed in small cohorts of
cirrhotic patients with hepatocellular carcinoma and variceal bleeding 27,28.
On the other hand, experimental studies in rodents have repeatedly shown that IL6
may have protective effects in liver failure. This may be caused by a positive effect of
IL6 on liver regeneration and recovery from liver failure 29–33. However, most of these
studies focused on rodent models of liver disease, liver insufficiency and acute liver
failure. Our contrary findings in patients with end-stage liver disease may be
explained by the pathophysiological differences between acute and chronic liver
failure as well as by different IL6 effects over time in our patients suffering from
chronic liver diseases. Acute and only shortly elevated IL6 levels may be
advantageous for liver regeneration whereas chronic IL6 elevations may have
disadvantageous effects for the liver and other organs. A previous study in mice
demonstrated that IL6 can improve hepatic regeneration and repair in acute
situations, but chronic exposure sensitizes the liver to injury and cell death 34. In our
study increased IL6 levels revealed an unexpected high prognostic value for
mortality. Therefore, we assume a direct deleterious effect of long lasting interleukin
6 levels on the progression of liver cirrhosis in patients with chronic liver disease.
This study has some limitations. It is retrospective and designed to quantify and
compare the prognostic power of the inflammatory biomarkers IL6, CRP and WBC.
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Procalcitonin (PCT) levels were not measured in this study, as similar to CRP PCT is
secondarily induced by IL6 35. Due to the study design, the reasons for the strong
association between IL6 and mortality cannot be determined by this study. Since we
aimed to analyze the diagnostic power of standardized biomarkers available in a
clinical routine, we did not quantify the soluble IL6 receptor or gp130, which
complexes with IL6 36. Furthermore, the study population was heterogeneous in
terms of the etiology of end-stage liver disease. However, the majority (62.9%) of the
patients in this study suffered from alcoholic cirrhosis, and subgroup analysis (i.e., for
patients with HCC) provided comparable results.
To the best of our knowledge, this is the first study of patients with liver disease that
has shown IL6 alone to predict mortality with comparable accuracy as the
MELD/MELD-Na score and significantly better than the inflammatory biomarkers
CRP and WBC. IL6 could be a promising candidate to create an improved prognostic
score for predicting mortality in patients with end-stage liver disease. However,
further studies with cohorts of liver disease patients with different etiologies are
necessary to validate and confirm the predictive value of IL6 37.
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Tables Table 1: Baseline characteristics of the cohort.
Asterisks indicate significantly higher values than the other sex (p-value *<0.05, **<0.01, ***<0.001).
Tx - Transplantation, HBV - Hepatitis B virus, HCV - Hepatitis C virus, PBC - Primary biliary cirrhosis,
PSC - Primary sclerosing cholangitis, NASH - Non-alcoholic steatohepatitis, HCC - hepatocellular
carcinoma, SBP - spontaneous bacterial peritonitis, GI - gastrointestinal.
male (n=301 (63.5%)) female (n=173 (36.5%)) all (n=474)
age [years], median (IQR) 57.3 (51.7 - 62.7) 55.3 (49.4 - 62.9) 56.9 (50.6 - 62.9)
MELD, median (IQR) 12.1 (9.0 - 17.6) n=298 11.5 (7.8 - 19.1) n=170 11.9 (8.7 - 18.0) n=468
bilirubin [µmol/l], median (IQR) 26.9 (14.2 - 52.3) 27.0 (14.7 - 75.8) 27.0 (14.2 - 56.6)
creatinine [µmol/l], median (IQR) 84.0 (69.0 - 110.0) *** 72.0 (57.0 - 97.3) 80.0 (65.0 - 105.0)
INR, median (IQR) 1.3 (1.1 - 1.5) 1.3 (1.1 - 1.6) 1.3 (1.1 - 1.5)
IL6 [pg/ml], median (IQR) 12.4 (5.8 - 40.7) 10.4 (4.7 - 34.3) 11.6 (5.3 - 37.0)
CRP [mg/l], median (IQR) 6.3 (3.0 - 15.2) n=299 * 4.3 (2.1 - 12.8) n=172 5.8 (2.5 - 14.2) n=471
WBC [*10^9/l], median (IQR) 5.8 (4.6 - 7.9) n=295 6.3 (4.5 - 8.6) n=166 6.1 (4.6 - 8.2) n=461
follow-up time [days], median (IQR) 536 (281 - 783) 617 (201 - 793) 549 (257 - 789)
Tx received within follow-up-time (%) 47 (15.6) 25 (14.5) 72 (15.2)
mortality (patients that received Tx during the respective period were excluded)
within 7 days (%) 11 (3.7) n=295 8 (4.7) n=170 19 (4.1) n=465
within 30 days (%) 17 (5.9) n=290 14 (8.4) n=167 31 (6.8) n=457
within 90 days (%) 31 (10.7) n=290 23 (14.1) n=163 54 (11.9) n=453
within 365 days (%) 53 (19.7) n=269 39 (24.7) n=158 92 (21.5) n=427
within total follow-up time (%) 68 (26.8) n=254 43 (29.1) n=148 111 (27.6) n=402
etiology (more than 1 per patient possible)
alcoholic (%) 219 (72.8) *** 79 (45.7) 298 (62.9)
viral hepatitis (%) HBV (%) HCV (%)
28 (9.3) 10 (3.3) 19 (6.3)
12 (6.9) 2 (1.2) 11 (6.4)
40 (8.4) 12 (2.5) 30 (6.3)
autoimmune hepatitis (%) 8 (2.7) 16 (9.2) ** 24 (5.1)
PBC (%) 0 (0.0) 14 (8.1) *** 14 (3.0)
PSC (%) 9 (3.0) 5 (2.9) 14 (3.0)
NASH (%) 20 (6.6) 15 (8.7) 35 (7.4)
other (%) 5 (1.7) 22 (12.7) *** 27 (5.7)
cryptogenic (%) 23 (7.6) 26 (15.0) 49 (10.3)
complications/comorbidities (more than 1 per patient possible)
HCC (%) 74 (24.6) *** 14 (8.1) 88 (18.6)
SBP (%) 46 (15.3) 23 (13.3) 69 (14.6)
upper GI bleeding (%) 82 (27.2) 45 (26.0) 127 (26.8)
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Table 2: Comparisons of deceased and surviving patients.
Patients who received liver transplants during follow-up were excluded from this analysis.
deceased patients (n=111) surviving patients (n=291) p-value
age [years], median (IQR) 57.0 (51.7 - 62.4) 56.3 (50.4 - 63.9) 0.930
sex [m=male, f=female] (%) m: 68 (61.3); f: 43 (38.7) m: 186 (63.9), f: 105 (36.1) 0.622
MELD, median (IQR) 19.7 (14.4 - 26.2) 9.9 (7.8 - 13.2) <0.001
bilirubin [µmol/l], median (IQR) 61.4 (32.4 - 172.8) 18.8 (12.0 - 33.7) <0.001
creatinine [µmol/l], median
(IQR) 105 (72.3 - 159.5) 75 (63.3 - 91.0) <0.001
INR, median (IQR) 1.6 (1.3 - 1.9) 1.2 (1.1 - 1.3) <0.001
IL6 [pg/ml], median (IQR) 56.2 (21.9 - 142.3) 7.7 (4.4 - 14.3) <0.001
CRP [mg/l], median (IQR) 16.5 (7.5 - 37.3) 4.0 (2.0 - 8.2) <0.001
WBC [*10^9/l], median (IQR) 6.6 (4.7 - 10.9) 5.8 (4.5 - 7.9) 0.003
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Table 3: Cox proportional-hazard analysis.
In brackets: adjusted for MELD. In brackets and italics: adjusted for MELD and the other two
inflammation parameters (MELD: adjusted for the three inflammation parameters). Q1 was used as
reference category.
n hazard ratio [95%-CI] p-value
IL6 (pg/ml); reference value <7 pg/ml
Q2 (5.3 ≤ x < 11.6) 118 (116) (115)
11.1 [1.5 - 86.2] (8.4 [1.1 - 65.7]) (8.2 [1.0 - 64.5])
0.021 (0.043) (0.046)
Q3 (11.6 ≤ x < 37.0) 118 (117) (113)
36.3 [4.9 - 266] (21.2 [2.8 - 159]) (17.3 [2.2 - 135])
<0.001 (0.003) (0.006)
Q4 (≥ 37.0) 119 (118) (111)
94.8 [13.2 - 683] (37.5 [5.0 - 283]) (22.5 [2.7 - 184])
<0.001 (<0.001) (0.004)
CRP (mg/l); reference value <5 mg/l
Q2 (2.5 ≤ x < 5.8) 117 (115) (116)
1.2 [0.5 - 2.7] (1.0 [0.4 - 2.4]) (0.8 [0.3 - 2.1])
0.749 (0.985) (0.684)
Q3 (5.8 ≤ x < 14.2) 118 (118) (113)
3.0 [1.4 - 6.1] (1.8 [0.9 - 3.7]) (1.0 [0.5 - 2.3])
0.003 (0.123) (0.980)
Q4 (≥ 14.2) 118 (116) (110)
8.7 [4.4 - 16.9] (3.8 [1.9 - 7.6]) (1.7 [0.7 - 3.9])
<0.001 (<0.001) (0.236)
WBC (*10^9/l); reference value 3.5-9.8 *10^9/l
Q2 (4.6 ≤ x < 6.1) 115 (115) (115)
0.9 [0.5 - 1.7] (1.0 [0.5 - 1.8]) (0.9 [0.5 - 1.6])
0.713 (0.924) (0.671)
Q3 (6.1 ≤ x < 8.2) 112 (110) (109)
1.3 [0.7 - 2.3] (1.1 [0.6 - 2.0]) (1.0 [0.6 - 1.8])
0.435 (0.725) (0.981)
Q4 (≥ 8.2) 119 (118) (118)
2.0 [1.1 - 3.3] (1.4 [0.8 - 2.4]) (0.9 [0.5 - 1.6])
0.014 (0.279) (0.758)
MELD
Q2 (8.7 ≤ x < 11.9) 117 (115)
2.9 [0.9 - 9.0] (1.4 [0.4 - 4.5])
0.066 (0.562)
Q3 (11.9 ≤ x < 18.0) 117 (113)
7.5 [2.6 - 21.5] (3.2 [1.1 - 9.3])
<0.001 (0.037)
Q4 (≥ 18.0) 117 (110)
21.9 [8.0 - 60.0] (5.1 [1.7 - 15.0])
<0.001 (0.003)
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Figure legends
Figure 1: Kaplan-Meier curves for the first 365 days of follow-up.
Patients were divided into four groups (Q1-Q4) according to the quartile levels of the respective
biomarker. Censored survival data due to received transplantation are indicated by +.
Figure 2: ROC-curves for prediction of mortality.
Different time periods were considered and AUROC values were calculated. Patients receiving a liver
transplantation in the analyzed time frame were removed. p-values are given, obtained by comparing
with AUROC values for IL6.
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