Serum glycomics as prognostic and diagnostic biomarkers of graft loss and hepatocellular carcinoma recurrence in liver transplant recipients

***Liver transplantation (LT) is the only currently available lifesaving
treatment for patients with end-stage liver disease, for a distinct subset of
patients with hepatocellular carcinoma (HCC), and in acute liver failure (ALF).
Due to improvements in surgical techniques and immunosuppressive regimens,
outcome has improved throughout the years, with current 1-year overall survival
in adults ranging between 86% and 92.1% (2, 3). The first 12 months after LT
are decisive in post-LT outcome, as almost half of deaths and two thirds of
graft loss requiring retransplantation occur in the first year after LT (2).
Due to the widespread success of liver transplantation, demand for
transplantable organs has increased and with it, morbidity and mortality of
patients on the waiting list(1). In order to compensate for the shortage of
donor organs, the most important evolution in adults is expansion of the donor
pool by use of ECD livers. These organs are, however, harvested from a
heterogeneous group of donors with either risk of disease transmission, or poor
graft function. The latter category is harvested from donors with advanced age,
steatotic livers, prolonged critical illness, or from donation after
circulatory death which in itself carries an augmented risk of
ischemia-reperfusion injury. *
Regardless of early (primary graft nonfunction, graft dysfunction or hepatic
artery thrombosis) or late (ischemic cholangiopathy, chronic rejection, tumor
or non-tumor disease recurrence) causes of graft loss, up to 10% of patients
experience graft loss requiring retransplantation.(2, 4)
Timely decision to retransplantation in primary non-function and severe graft
dysfunction are major determinants of graft and patient survival, making early
management of these complications of paramount importance in improving patient
outcome(5). Moreover, balancing the need and right timing for retransplantation
in individual patients with a complicated posttransplantation course is
currently a difficult challenge that relies on imperfect clinical variables and
biomarkers, as well as the experienced judgment of the transplant team.*

A large part (30%) of patients is transplanted because of hepatocellular
carcinoma, mostly in an cirrothic liver, next to the above mentioned risk of
graft failure an additional risk of recurrence of HCC influencing prognosis
plays a role in these patients. despite selection models (Milan criteria, AFP
model, UCSF criteria) we see recurrence in 12-15% of patients, posing an
additional risk for mortality. A improved selection tool to select the patients
benefiting most from transplantation with lowest risk of recurrence would
greatly improve the outcomes

Protein glycosylation, the addition of glycan structures to glycosylation
sites, is the most common and complex post-translational modification of
proteins. It occurs in the Golgi complex and endoplasmic reticulum and is
indispensable for a plethora of protein functions (20) Glycomics, the
systematic study of glycosylation, allows detection of alterations in the
abundance of particular glycans reflecting an altered physiological state (21).
The majority of N-glycans found in whole serum are attached to serum proteins
produced by hepatocytes and, to a lesser extent, to IgG that is secreted by
plasma cells. This makes serum glycomic profiling an attractive technique to
study alterations in liver homeostasis (22-24). In close collaboration with the
laboratory of Glycobiology from Prof. Dr. Nico Callewaert from the Vlaams
Instituut voor Biotechnologie (VIB, Zwijnaarde, Belgium), a high-throughput
platform to profile sialidase-treated N-glycans from whole serum was developed
based on DNA sequencer-assisted fluorophore-assisted capillary electrophoresis
(DSA-FACE) (25, 26). Exploitation of this platform has led to the development
of diagnostic and prognostic biomarkers based on the serum glycomic profile of
patients with chronic liver diseases, such as liver cirrhosis (25), fibrosis
(27) hepatocellular carcinoma (28, 29), and non-alcoholic steatohepatitis(30).
*

Primary Objective: * To validate the prognostic value of a serum glycomics
biomarker for graft survival at 3 months after liver transplantation. * To
validate the prognostic value of a serum glycomics biomarker for overall
survival at 3 months after liver transplantation. Secondary Objectives: To
validate the prognostic value of a serum glycomics biomarker for graft survival
at 12 months and 3 years after liver transplantation.* To validate the
prognostic value of a serum glycomics biomarker for overall survival at 12
months and 3 years after liver transplantation.* To study the value of repeated
glycomic measurements after liver transplantation.* To study the optimal
time-point of biomarker measurement.* To identify other serum glycomics
biomarkers for LT outcomes (graft survival, HCC recurrence) And in a subset of
patients receiving a liver transplantation for HCC: To validate a serum
glycomics biomarker as predictor of prognosis (HCC recurrence, liver-related
death, and overall death) when analysed before liver transplantation* To
explore the potential of serum glycomics as marker of early recurrence in
patients receiving liver transplantation for HCC when analysed after liver
transplantation

This research study will be composed of a prospective, multicentric,
interventional study design. The study will be performed together with the
liver transplantation centrers in Belgium and the Erasmus MC in the Netherlands
At specific time points an additional serum tube will be collected next to the
blood sample drawn via venipuncture for standard of care.
First collection will be at the moment of waitlist placement, the second on the
day of transplantation. After liver transplantation the samples will be
collected on specific time points as well. Day 1-14 daily; Week 3-6: weekly;
month 3-6: monthly; month 9- end of FU: 3 monthly. Always during standard of
care venipuncture.

This project starts from the medical unmet need for the prognostication of risk
of graft and patient survival in patients after liver transplantation. Current
models fall short in stratifying patients on an individual level. The
implementation of serum glycomics as a reliable and readily available marker of
graft function that is independently associated with graft survival could imply
a paradigm shift in transplantation management. More specifically, improving
prognosis of patients who benefit from retransplantation through timely
decision making and conversely, avoiding futile retransplantation could really
impact outcome of liver transplant recipients on a large scale in light of the
expansion of the donor pool by grafts with lesser quality.**

Furthermore, in the growing population of patients transplanted for HCC, there
is an unmet need for the correct estimation of the risk of recurrence in HCC
patients after liver transplantation. All current models fall short here and
recurrence of HCC after transplantation is still common. As such, the
implementation of personalised medicine in this field, based on powerful
biomarkers accounting for the tumour*s biological activity, could really change
clinical practice. More specifically, patients who are eligible for liver
transplantation based on the current criteria but who score *poorly* on the
glycomics biomarker should not undergo a liver transplantation. This will
prevent a futile liver transplant in this patient which will improve his
survival, and provide an extra organ in the donor pool for a patient who will
benefit. Moreover, patients who currently fall out of scope for liver
transplantion but score *good* on the glycomics biomarker could still be
selected. As such, the liver transplants could be used in a more efficient
manner.*

The included subjects will not directly benefit from inclusion in this study,
however it is impossible to perform this study in another population and the
risks in participating in this study are negligible, we do not ask for
additional interventions and all samples are collected during scheduled visits
and standard-of-care venipunctures.