FGF19 in Obstructive Cholestasis: "Unveil the Signal"

Studien-Informationen Einschlusskriterien Studien-Rationale Studien-Arme Geprüfte Regime

Rekrutierend

NCT-Nummer:
NCT05718349

Studienbeginn:
Januar 2017

Letztes Update:
08.02.2023

Wirkstoff:
-

Indikation (Clinical Trials):
Cholangiocarcinoma, Pancreatic Neoplasms, Cholestasis

Geschlecht:
Alle

Altersgruppe:
Erwachsene (18+)

Phase:
-

Sponsor:
Nicole Hildebrand

Collaborator:
RWTH Aachen University

Studienleiter

Steven Olde Damink, MD, PhD
Principal Investigator
Academisch Ziekenhuis Maastricht

Kontakt

Steven Olde Damink, MD, PhD
Kontakt:
E-Mail: steven.oldedamink@maastrichtuniversity.nl» Kontaktdaten anzeigen

Jan Bednarsch, MD, PhD
Kontakt:
E-Mail: jbednarsch@ukaachen.de» Kontaktdaten anzeigen

Studienlocations
(1 von 1)

Leberkarzinomzentrum an der Uniklinik RWTH Aachen
Pauwelsstraße 30
52074 Aachen
(Nordrhein-Westfalen)
DeutschlandRekrutierend» Google-Maps
Ansprechpartner:
Jan Bednarsch, MD, PhD
E-Mail: jbednarsch@ukaachen.de» Ansprechpartner anzeigen

Studien-Informationen

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.

Ein-/Ausschlusskriterien

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

Studien-Rationale

Primary outcome:

1. plasma FGF19 levels (Time Frame - Intraoperatively):
A factor which signals to the liver to repress the expression of Cyp7a1 (rate limiting enzyme of bile salt synthesis)

2. plasma bile salt levels (Time Frame - Intraoperatively):
Bile salts are synthesized in the liver, and efficiently returned to the liver via the intestinal lumen and portal blood

3. Gene expression levels of genes implicated in bile salt homeostasis and FGF19 signaling (Time Frame - Intraoperatively):
in liver, proximal jejunum, gallbladder, common bile duct, subcutaneous adipose tissue, omental adipose tissue, visceral adipose tissue, and rectus abdominis muscle

4. Biliary FGF19 level (Time Frame - Intraoperatively):
A factor which signals to the liver to repress the expression of Cyp7a1 (rate limiting enzyme of bile salt synthesis)

5. itch intensity (Time Frame - Preoperatively):
by means of a Visual Analogue Scale (VAS, a scale from 0 (no itch) to 10 (worst itch possible))

6. Enterocyte damage (Time Frame - Intraoperatively):
Plasma IFABP

7. Enterocyte function (Time Frame - Intraoperatively):
Plasma Citrulline

8. Transmural intestinal damage (Time Frame - Intraoperatively):
Plasma SM22

9. Endotoxinemia (Time Frame - Intraoperatively):
Plasma LBP

10. Bile salt composition (Time Frame - Preoperatively):
In stool, jejunal content, plasma, and urine

11. Bile salt composition (Time Frame - Intraoperatively):
In stool, jejunal content, plasma, and urine

12. Microbial composition (Time Frame - Preoperatively):
In stool and jejunal content

13. Microbial composition (Time Frame - Intraoperatively):
In stool and jejunal content

Studien-Arme

Non-cholestasis
Patients planned for pancreaticoduodenectomy or liver resection (with or without hepaticojejunostomy) who do not have cholestasis preoperatively.
Drained
Patients planned for pancreaticoduodenectomy or liver resection (with or without hepaticojejunostomy) who had cholestasis and underwent ERCP (endoscopic retrograde choledochopancreatography) with stenting to normalize the enterohepatic circulation.
Cholestasis
Patients planned for pancreaticoduodenectomy or liver resection (with or without hepaticojejunostomy) who have cholestasis preoperatively and did not undergo drainage.

Geprüfte Regime

Biospecimen sampling:
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.

Quelle: ClinicalTrials.gov

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