Trial Title:
FGF19 in Obstructive Cholestasis: "Unveil the Signal"
NCT ID:
NCT05718349
Condition:
Cholestasis
Icterus
Cholangiocarcinoma
Pancreatic Neoplasms
Liver Metastasis Colon Cancer
Conditions: Official terms:
Cholangiocarcinoma
Pancreatic Neoplasms
Cholestasis
Study type:
Observational
Overall status:
Recruiting
Study design:
Time perspective:
Prospective
Intervention:
Intervention type:
Other
Intervention name:
Biospecimen sampling
Description:
From the patients participating in the study i) blood, ii) tissue from resected material,
iii) bile, iv) stool, v) urine, vi) jejunal content and vii) information on the itch
severity will be collected.
Arm group label:
Cholestasis
Arm group label:
Drained
Arm group label:
Non-cholestasis
Summary:
Rationale: Bile salts are potent signalling molecules influencing various metabolic and
functional processes. Bile salts exert these functions by activating nuclear (e.g. FXR )
and plasma cell membrane-bound receptors (e.g. TGR5) which are expressed in several
tissues (e.g. liver, small intestine, colon, kidney and gallbladder). Bile salts regulate
their own biosynthesis by controlling the transcription of the hepatic bile salt
synthetic enzyme CYP7A1. Two pathways are involved in the negative feedback control of
bile salt synthesis: i) the hepatic FXR-SHP pathway and ii) the ileal FXR-FGF19 pathway.
Studies showed that the latter is more prominent in controlling CYP7A1 transcript levels
(viz. bile salt synthesis). Thus, bile salts are synthesized in the liver, excreted in
bile and expelled by the gallbladder into the proximal intestine (to aid in lipid
absorption and digestion) and reabsorbed in the terminal ileum to recycle back to the
liver via portal blood. Bile salts reclaimed from the intestinal lumen by the ileocyte,
activate FXR. This induces the expression of an enterokine, FGF19, which signals via
portal blood to the liver to activate its receptor which initiates downstream signalling
to repress bile salt synthesis. The FXR/FGF19 signalling pathway is the subject of the
present study.
Patients with obstructive cholestasis (=accumulation of bile) caused by malignancies
(e.g. pancreatic cancer, cholangiocarcinoma) have a perturbed enterohepatic cycle.
Obstructive cholestasis is associated with i) gut barrier dysfunction, ii) endotoxemia,
iii) bacterial overgrowth and iv) liver injury. Previous study showed that FGF19 is
expressed in the liver of patients with obstructive cholestasis. However, knowledge about
the contribution of FGF19 protein by the gut in obstructive cholestasis has thus far been
unexplored. Preliminary findings revealed that FGF19 is produced by the portal drained
viscera (viz. intestine) of non-cholestatic patients undergoing liver surgery. The
inter-organ signalling of FGF19 in an obstructed entero-hepatic cycle has not yet been
characterized and likewise the metabolic and other functional effects of inflicted FGF19
signalling during cholestasis have not been clarified.
The hypothesis is that the FXR-FGF19 pathway is disturbed in patients with obstructive
cholestasis, and this is associated with organ injury and metabolic dysfunction. The
investigators postulate that FGF19 is not produced by the terminal ileum under conditions
of obstructive cholestatic, but production is shifted to the liver and this affects
metabolic processes.
The aim of this study is to investigate FGF19 signalling in patients with cholestasis
compared to non-cholestatic patients or post-cholestatic patients (drained patients) by
calculating fluxes across the portal drained organs. Secondly, the investigators aim to
investigate the metabolic and functional consequences (glucose, lipid homeostasis,
cholestatic itch, gut barrier function) of a disturbed FXR-FGF19 pathway in humans. This
study will provide insights that may lead to potential therapeutic strategies for
patients with a disturbed enterohepatic cycle (e.g. cholestatic liver diseases).
Study population: Adult (>18 years old) cholestatic (cholestasis group), drained
(restored enterohepatic cycle) and non-cholestatic patients (controls, normal
enterohepatic circulation) undergoing pancreaticoduodenectomy (Whipple procedure) for
hepatopancreaticobiliary malignancies (e.g. pancreatic cancer, cholangiocarcinoma) or
liver resection for hepatic malignancies (e.g. cholangiocarcinoma, colorectal liver
metastases) are eligible for this study.
Study period: inclusion is planned from 1.12.2017 until 1.12.2024
Detailed description:
Because bile salts are biological emulsifiers, they play an essential role in digestion
and absorption of dietary lipids and fat soluble vitamins. Bile salts also act as potent
signaling molecules targeting bile salt sensing nuclear and plasma cell membrane bound
receptors. Several metabolic and biological processes are influenced by activation of
these receptors, including bile salt and glucose homeostasis, thermogenesis, intestinal
barrier function and liver regeneration.
Bile salts are synthesized in the liver, and efficiently returned to the liver via the
intestinal lumen and portal blood (enterohepatic circulation = EHC). Hepatic bile salt
content is tightly regulated at multiple levels to maintain non-toxic levels. The
transcription factor Farnesoid X Receptor (FXR) plays a key role in bile salt homeostasis
by regulating synthesis, biliary excretion, intestinal reuptake and metabolism of bile
salts. Genetic deficiency of FXR in mice results in impaired gut barrier function,
dysregulated hepatic metabolism and impaired recovery from cholestatic liver injury. Bile
salts repress their own biosynthesis, and this encompasses activation of FXR by bile
salts in the enterohepatic tissue and controlling the transcription of Cyp7a1 in the
liver (rate limiting enzyme of bile salt synthesis). Activated hepatic FXR represses the
bile salt synthetic enzyme Cyp7a1 by inducing the expression of Shp. On the other hand,
activated FXR in the ileum induces the expression of FGF19 which signals to the liver to
repress the expression of Cyp7a1. The liver is considered to be the primary target of
FGF19 as it expresses both components of the FGF19 -receptor complex (FGFR4-βklotho).
Animal experiments demonstrated a crucial role of intestinal FXR in preventing bacterial
overgrowth and maintaining intestinal integrity in a mouse model of obstructive
cholestasis. Moreover, intestinal FXR activation ameliorated cholestatic liver injury in
bile duct-ligated mice. This emphasizes that an intact EHC is crucial to maintain tissue
homeostasis in the small intestine and the liver.
Intraluminal bacterial overgrowth, translocation of microbial endotoxins, increased
intestinal permeability, activation of intestinal and hepatic inflammatory cascades and
endotoxemia occurs frequently in patients with obstructive cholestasis (e.g. pancreatic
cancer and cholangiocarcinoma). Absence of bile in the intestinal tract is associated
with these anomalies. The investigators postulate that normal bile flow in patients with
obstructive cholestasis is impaired and therefore bile salt signaling is impaired leading
to dysregulation in enterohepatic tissues. To further improve our understanding of bile
salt-FGF19 signaling across different abdominal organs, the investigators will obtain
blood samples not only from the radial artery, the portal and the hepatic vein, but also
from the superior mesenteric vein, inferior mesenteric vein, the splenic vein and the
renal vein. By including these blood vessels, the investigators will be able to obtain
information about the contribution of the small intestine, the colon, the spleen and the
kidneys, separately in the production or extraction of FGF19 in humans. Namely,
arteriovenous differences (ΔAV) and net organ fluxes (flow x ΔAV) serve as a quantitative
measure of metabolite exchange across the portal drained viscera (PDV), the splanchnic
area and the small intestine, colon, spleen and kidneys.
The hypothesis is that FGF19 inter-organ flux shifts during obstructive cholestasis
towards production or release of FGF19 by other abdominal organs rather than the small
intestine. Serum FGF19 elevation and FGF19 mRNA expression in the liver of patients with
obstructive cholestasis support this concept.
The aim of this study is to investigate FGF19 signalling in patients with cholestasis
compared to non-cholestatic patients by calculating fluxes across the portal drained
organs. Secondly, the investigators will investigate the metabolic and functional
consequences (glucose, lipid homeostasis, cholestatic itch, gut barrier function, bile
salt composition) of a disturbed FXR-FGF19 pathway in humans. Findings from this study
will provide novel insights into enterohepatic bile salt-FGF19 signaling in humans and
may lead to potential therapeutic strategies in cholestatic liver diseases.
Primary objective
• Determine in vivo inter-organ fluxes of FGF19 in patients with obstructive cholestasis
compared with non-cholestatic patients and drained patients
Secondary objectives
- Determine organ fluxes of bile salts (species) in patients with obstructive
cholestasis compared with non-cholestatic patients (control group) and drained
patients (restored EHC group)
- Determine gene expression of genes implicated in bile salt and FGF19 signaling in
enterohepatic tissues (liver, jejunum, gallbladder, common bile duct, white adipose
tissues), and skeletal muscle tissue of patients with obstructive cholestasis
compared with non-cholestatic patients (control group) and drained patients
(restored EHC group).
- Determine microbiota of patients with obstructive cholestasis compared with
non-cholestatic patients (control group) and drained patients (restored EHC group)
in preoperative stool and intraoperative intraluminal fecal content.
- Determine bile salt composition in patients with non-cholestatic patients (control
group) and drained patients (restored EHC group) in plasma, urine and bile.
- Determine whether fluxes of metabolites (e.g. bile salts, FGF19) are related to
cholestatic itch
From the patients participating in the study i) blood, ii) tissue from resected material,
iii) bile, iv) stool, v) urine, vi) jejunal content and vii) information on the itch
severity will be collected. Since the blood vessels indicated below are easily accessible
in patients undergoing pylorus-preserving pancreaticoduodenectomy (pp Whipple) or liver
resection, these patients are eligible for the study and will be included. Prior to blood
sampling, the blood flow of the portal vein and hepatic artery will be measured
immediately with the Transonic blood flow meter. Blood will be sampled from the following
vessels:
portal vein, hepatic vein, superior mesenteric vein, inferior mesenteric vein, splenic
vein, renal vein, radial artery
Arteriovenous differences (ΔAV) and net organ fluxes (flow x ΔAV) are a quantitative
measure of the role of the liver, PDV, the splanchnic area, small intestine, colon,
spleen and the kidneys in producing or extracting FGF19 and bile salts. The fluxes will
be calculated by measuring plasma levels of metabolites and determining blood flow in
these vessels.
All patients undergoing pp Whipple or liver resection have an arterial catheter during
surgery from which the investigators can sample blood. The mentioned veins (6x) will be
punctured directly using 25G needles. 10 ml of arterial blood and 10 ml intra-abdominal
blood from the different vessels separately will be sampled once during surgery resulting
in a total amount of sampled blood of maximally 70 ml. All blood samples will be
collected in both pre-chilled EDTA and heparinized vacuum tubes and centrifuged at 3500
rpm at 4°C for 10 minutes. Plasma will be stored in Eppendorf cups at -80°C until further
analysis. Blood flow will be measured using intra-operative Duplex ultrasonography.
Tissues will be explored by histology (histochemistry, immunohistochemistry/fluorescent),
and for detailed analysis of genes implicated in bile salt-FGF19 signaling and metabolic
processes (e.g. glucose homeostasis, lipid homeostasis). The following tissues (from
resected material) during surgery will be collected allowing detailed study of genes
implicated in bile salt-FGF19 signaling in enterohepatic tissues:
liver specimen (in case of liver resection), gallbladder specimen, common bile duct
specimen, proximal jejunal specimen (in case of hepaticojejunostomy during surgical
procedure), white adipose tissue (WAT) [subcutaneous, omental, visceral], rectus
abdominis muscle
Previous study showed that human bile contains high levels of FGF19. However, the exact
functional role of FGF19 in bile is not known. Therefore, bile will be collected
intra-operatively to investigate the effect of obstructive cholestasis on FGF19 levels in
bile. Bile will be collected by puncture of the gallbladder after removal or from the
hepatic bile duct in case the gallbladder is not in situ.
The gut microbiota plays a major role in bile salt homeostasis by secondary modification
and deconjugation of primary bile salts. The microbial composition (e.g. shift in bile
salt hydrolase producing bacteria) of preoperative stool and proximal jejunal content
during surgery will be analyzed. Plasma from the three patient groups (control, drained
and cholestatic) will be analyzed for markers of enterocyte function (e.g. citrulline)
and enterocyte damage (e.g. IFABP), transmural damage (SM22), endotoxins (LBP),
pro-inflammatory cytokines (IL-6 and TNF-alpha) and novel markers for hepatic
inflammation (Cathepsin).
Cholestatic pruritis (itch) is common in patients with obstructive cholestasis. The
source of itch is currently unknown, and bile salts are implicated in the development of
cholestatic itch. Therefore the investigators would like to ask the patients to score
their itch intensity on the day before surgery by means of a Visual Analogue Scale (VAS,
a scale from 0 (no itch) to 10 (worst itch possible)). In addition, the investigators
will ask them to fill in a short questionnaire, the 5D itch scale. Metabolites implicated
in itch (e.g. bile salts) will be analyzed in the blood samples to calculate fluxes and
these will be correlated with the preoperative VAS scores and 5D itch scale.
Urine will also be collected preoperatively of all patients to investigate whether
cholestasis influences the route of bile salt excretion (from biliary excretion to renal
excretion). Bile salt composition will be analyzed in urine with liquid chromatography
mass spectrometry (LC-MS).
Main study parameters/endpoints: The main study parameter is the net organ flux of FGF19
across abdominal organs calculated by measuring FGF19 levels in human plasma using an
enzyme-linked immuno-sorbent assay (ELISA) in cholestatic versus non-cholestatic patients
and drained patients. Human plasma will be obtained during surgery from 7 vessels i)
radial artery, ii) mesenteric superior vein, iii) mesenteric inferior vein, iv) renal
vein, v) splenic vein, vi) hepatic vein and vii) portal vein to calculate net organ
fluxes. Secondary parameters are expression of genes related to bile salt and FGF19
signaling in enterohepatic tissues (liver, jejunum, gallbladder, common bile duct, white
adipose tissue and skeletal muscle tissue), genes implicated in glucose and lipid
homeostasis, FGF19 levels in bile, gut microbiota, cholestatic itch and bile salt
composition in urine.
Nature and extent of the burden and risks associated with participation, benefit and
group relatedness: Patients planned for a Whipple procedure or liver resection are
included. Informed consent will be obtained either at the outpatient ward or at the day
of admission, with one week time to decide. Patients will then also have time to ask
questions.
Blood from these patients will be sampled during surgery under general anesthesia from
the portal vein, hepatic vein, superior mesenteric vein, inferior mesenteric vein,
splenic vein, renal vein and the radial artery. The experimental set-up consists of 1
time arterial blood sampling (10ml) and 1 time intra-abdominal blood sampling (6x10ml)
which is maximal 70 ml in total. During surgery blood flow will be measured of the portal
vein and hepatic artery to precisely calculate organ fluxes. The portal vein and hepatic
artery are easy accessible for flow measurement with the Transonic flow meter. This
device is CE-certified and used routinely to measure actual blood flow. No risks are
associated with measuring of these blood flows.
Additionally, bile will be sampled during surgery (4 ml) from the gallbladder or hepatic
duct during surgery, and biopsies will be taken from the liver (1, in case of liver
resection), gallbladder (1), jejunum (1, in case of hepaticojejunostomy), common bile
duct (CBD, 1). white adipose tissue (WAT, from three sites; subcutaneous, omental and
visceral adipose tissue) and rectus abdominis muscle for gene expression studies of
genes. Moreover, perioperative stool and urine, and jejunal content during surgery (in
case of hepaticojejunostomy) will be collected for detailed analysis of microbiota/bile
salt composition to investigate the effect of obstructive cholestasis on these
parameters. Patients will be assessed for severity of itch by a questionnaire (visual
analog scale and 5D itch scale) on the day before surgery to correlate fluxes to
cholestatic itch.
The methods applied, i.e. arterial and intra-abdominal blood sampling and collecting
liver/jejunal biopsies as part of planned resection, have been used previously without
any consequences for the surgical procedures or the patients. In comparison to previously
ethical approved protocols, bile (4 ml) will be sampled from the gallbladder or hepatic
duct during surgery, and biopsies of the gallbladder (1x), CBD (1x) and WAT (3x), as well
as stool will be collected one time preoperatively. There are no additional risks related
to the collection of bile and tissues since these are part of the resected tissues. The
biopsy of the small intestine, white adipose tissue, and rectus abdominis muscle will be
taken from parts that will be resected during the surgery or from the surgical incision
site, thus preventing the risk for permanent complications. Potential peroperative
bleeding of the tissue will be electrocoagulated by the surgeon. Abdominal biopsies will
be taken by skilled hepatopancreaticobiliary surgeons. No further risk is associated with
the collection of preoperative stool and urine. Although the results of this project have
no direct positive effects for the patients involved, they do contribute to the
understanding of the role of bile salts and FGF19 signaling under cholestatic conditions.
Insights from this study would provide novelty and substantial knowledge in possible
effects of FGF19 therapy in cholestatic liver injury.
Criteria for eligibility:
Study pop:
Patients with obstructive jaundice undergoing pp Whipple or liver resection are eligible
for this study. Controls are non-jaundiced and drained patients undergoing pp Whipple or
liver resection. The rationale for including patients undergoing pp Whipple or liver
resection is that the nature of the surgical procedure in the abdomen allows sampling of
blood from the portal drained organs, and tissue sampling. Patients will be recruited at
the surgical outpatient clinic of Maastricht University Medical Center (MUMC+) and
University Hospital RWTH Aachen (Germany). Patients in the cholestasis group (group III),
will be included largely at the University Hospital RWTH Aachen. Ten to twenty percent of
the cholestasis group can be included in MUMC+.
Sampling method:
Non-Probability Sample
Criteria:
Inclusion Criteria:
- Patients undergoing pp Whipple or liver resection
- Age >18 and <75 years
Exclusion Criteria:
- Jejunostomy
- Lactation, pregnancy and planning of pregnancy
- Inflammatory bowel disease
- Alcohol or drug abuse within 1 year
- Inborn errors of bile salt synthesis
- Failure to give informed consent or refusal to store patient data for fifteen years
Gender:
All
Minimum age:
18 Years
Maximum age:
75 Years
Healthy volunteers:
No
Locations:
Facility:
Name:
RWTH Aachen
Address:
City:
Aachen
Country:
Germany
Status:
Recruiting
Contact:
Last name:
Jan Bednarsch, MD, PhD
Email:
jbednarsch@ukaachen.de
Start date:
January 1, 2017
Completion date:
June 1, 2025
Lead sponsor:
Agency:
Nicole Hildebrand
Agency class:
Other
Collaborator:
Agency:
RWTH Aachen University
Agency class:
Other
Source:
Academisch Ziekenhuis Maastricht
Record processing date:
ClinicalTrials.gov processed this data on November 12, 2024
Source: ClinicalTrials.gov page:
https://clinicaltrials.gov/ct2/show/NCT05718349
