The search for biomarkers to enable detection and monitoring of disease progression from NAFLD to NASH and NASH itself; Amsterdam NASH cohort

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of
liver dysfunction in the Western world and is strongly associated with obesity,
insulin resistance and the metabolic syndrome. NAFLD is defined as hepatic fat
accumulation (hepatic steatosis) in the absence of excessive alcohol
consumption. It represents a spectrum of liver disease that ranges from simple
steatosis, through non-alcoholic steatohepatitis (NASH) to advanced fibrosis
and cirrhosis, which may ultimately be complicated by hepatocellular carcinoma
(HCC). Transition from NAFLD to NASH gives an increased risk of cardiovascular
disease and increases mortality of liver-related disease and can only be
diagnosed based on histological examination of liver tissue obtained by biopsy.
Furthermore, liver cirrhosis originated from NASH is expected to become the
primary indication for liver transplantation in the USA in the next 10 years.
However, since no treatment options are available at this moment to prevent
progression of NAFLD to NASH, identified patients are not regularly followed at
an outpatient clinic. This as most patients with NAFLD only exhibit steatosis
and do not progress towards NASH, whereas a distinct subgroup advances to overt
liver disease like NASH and fibrosis with the mechanisms underlying this
distinctive disease course remaining poorly understood. Since progression from
NAFLD to NASH is associated with significantly increased risk of morbidity and
mortality, there is a clinical imperative to identify the NAFLD patients that
rapidly progress to NASH from those who will remain in the NAFLD stage, in
order to better monitor these patients and to reduce their risk. Our study aims
to identify novel risk factors in subjects with hepatic steatosis, as well as
to validate noninvasive imaging modalities, in order to better discern the
patients who progress to NASH from non-progressing NAFLD patients. Our rigorous
baseline biomarker validation against biopsy proven NAFLD-NASH progression over
5 years has the goal to reduce the need for future liver biopsies in NAFLD-NASH
in the clinical setting. As there are currently no registered treatment
modalities for NASH besides dietary intervention, improved understanding of the
pathophysiological mechanisms as well as their relationship to metabolic
disturbances are of crucial importance to discover new diagnostic and
therapeutical targets in NAFLD/NASH.

We aim to identify hepatic, plasma, genetic and gutmicrobial markers that,
alone or in combination, enable detection and monitoring of disease progression
from NAFLD to NASH and subsequent progression from NASH to cirrhosis.

prospective cohort study.

Participants will be recruited from patients that visited the outpatient clinic
of internal medicine and gastroenterology at AMC in the last 6 years and in
whom an ultrasound was made that reports presence of hepatic steatosis. After
informed consent, biological samples (including saliva, blood and faeces
sample) will be collected; also, subjects will undergo MRI of the liver and
visceral fat. The study participation is estimated to take a total of 8 hours.
Despite ample noninvasive efforts in small groups of NAFLD/NASH patients over
the last decade, a liver biopsy is still regarded as the gold standard for
discerning between NAFLD and NASH. Moreover, there is currently no registered
treatment that helps to prevent neither progression from NAFLD to NASH nor
progression from NASH to cirrhosis. Our study participants will be referred to
our AMC intervention radiology department for liver biopsy to assess liver
histology and gene expression (RNAseq) in liver tissue. Thereafter, subjects
are seen again at the AMC after 5 years to measure the same parameters and a
repeated ultrasound guided liver biopsy will be taken to study histological
progression. Currently, about 25% of all adults in USA has NAFLD whereas 5-6%
has NASH. Smaller studies have suggested that about 25% of NAFLD patients
progresses per 5-10 years into NASH, of whom subsequent 25% develops fibrosis
and cirrhosis in the next 5-10 years thereafter (Petäjä et al., 2013). When
participants are found to have NASH in their baseline liver biopsy, they will
be referred to the department of gastroenterology and hepatology for clinical
follow-up and dietary counselling.
As an experienced interventional radiologist or hepatologist will perform the
liver biopsy ultrasound-guided, the risk (comprising mostly bleeding from the
biopsy sites) of complications will be very low (<0.1%). Moreover, local
hemostasis after the procedure will be observed and bleeding disorders are an
exclusion criterion. Taken together with the fact that there is no other
method to diagnose NASH and progression from NAFLD to NASH is associated with
significantly increased risk of morbidity and mortality, we feel that the
benefits outweigh the risks of study participation. Moreover, our study will
help to provide (noninvasive) algorithm based risk scores validated against
gold standard diagnostics (biopsy) to improve identification of subjects that
will rapidly move from NAFLD to NASH (progressors) and those that have no
progression at all (non-progressors). This will reduce the necessity for liver
biopsies for NAFLD-NASH patients in the future. Total blood volume collected
over 5 years is 100 ml.