FXR-FGF19 signaling in the gut-liver axis is dysregulated in patients with cirrhosis and correlates with impaired intestinal defence.

BACKGROUND AND AIMS: Experimental studies linked dysfunctional Farnesoid X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling to liver disease. This study investigated key intersections of the FXR-FGF19 pathway along the gut-liver axis and their link to disease severity in patients with cirrhosis. METHODS: Patients with cirrhosis undergoing hepatic venous pressure gradient measurement (cohort-I n = 107, including n = 53 with concomitant liver biopsy; n = 5 healthy controls) or colonoscopy with ileum biopsy (cohort-II n = 37; n = 6 controls) were included. Hepatic and intestinal gene expression reflecting FXR activation and intestinal barrier integrity was assessed. Systemic bile acid (BA) and FGF19 levels were measured. RESULTS: Systemic BA and FGF19 levels correlated significantly (r = 0.461; p < 0.001) and increased with cirrhosis severity. Hepatic SHP expression decreased in patients with cirrhosis (vs. controls; p < 0.001), indicating reduced FXR activation in the liver. Systemic FGF19 (r = -0.512, p < 0.001) and BA (r = -0.487, p < 0.001) levels correlated negatively with hepatic CYP7A1, but not SHP or CYP8B1 expression, suggesting impaired feedback signaling in the liver. In the ileum, expression of FXR, SHP and FGF19 decreased in patients with cirrhosis, and interestingly, intestinal FGF19 expression was not linked to systemic FGF19 levels. Intestinal zonula occludens-1, occludin, and alpha-5-defensin expression in the ileum correlated with SHP and decreased in patients with decompensated cirrhosis as compared to controls. CONCLUSIONS: FXR-FGF19 signaling is dysregulated at essential molecular intersections along the gut-liver axis in patients with cirrhosis. Decreased FXR activation in the ileum mucosa was linked to reduced expression of intestinal barrier proteins. These human data call for further mechanistic research on interventions targeting the FXR-FGF19 pathway in patients with cirrhosis. CLINICAL TRIAL NUMBER: NCT03267615.

Peripheral versus central venous blood sampling does not influence the assessment of platelet activation in cirrhosis.

Cirrhotic patients have an increased risk of bleeding and thromboembolic events, with platelets being involved as key players in both situations. The impact of peripheral versus central blood sampling on platelet activation remains unclear. In 33 cirrhotic patients, we thus analyzed platelet function in peripheral (P) and central (C) blood samples. Platelet surface expression of P-selectin, activated glycoprotein (GP) IIb/IIIa, and leukocyte-platelet aggregate formation were measured by flow cytometry in response to different agonists: thrombin receptor-activating peptide-6, adenosine diphosphate, collagen-related peptide (CrP), epinephrine, AYPGKF, Pam3CSK4, and lipopolysaccharide. Unstimulated platelet surface expression of P-selectin (p = .850) and activated GPIIb/IIIa (p = .625) were similar in peripheral and central blood samples. Stimulation with various agonists yielded similar results of platelet surface expression of P-selectin and activated GPIIb/IIIa in peripheral and central samples, except for CrP-inducible expression of activated GPIIb/IIIa (median fluorescence intensity, MFI in P: 7.61 [0.00-24.66] vs. C: 4.12 [0.00-19.04], p < .001). The formation of leukocyte-platelet aggregate was similar in central and peripheral blood samples, both unstimulated and after stimulation with all above-mentioned agonists. In conclusion, peripheral vs. central venous blood sampling does not influence the assessment of platelet activation by flow cytometry in cirrhosis.Abbreviations: ACLD: advanced chronic liver disease; ADP: adenosine diphosphate; ALD: alcoholic liver disease; AYPGKF: PAR-4 agonist AYPGKF; CrP: collagen related protein; EPI: epinephrine; FACS: fluorescence-activated cell sorting; GP: glycoprotein; HVPG: hepatic venous pressure gradient; IQR: interquartile range; LPS: lipopolysaccharide; LSM: liver stiffness measurement; MFI: median fluorescence intensity; NAFLD: nonalcoholic fatty liver disease; PAM: lipopeptide Pam3CSK4; PAR: protease-activated receptor; PBS: phosphate-buffered saline; PH: portal hypertension; TIPS: transjugular intrahepatic portosystemic stent shunt; TLR: toll-like receptor; TRAP-6: thrombin receptor-activator peptide-6; vWF: von Willebrand factor.

Soluble guanylyl cyclase stimulation and phosphodiesterase-5 inhibition improve portal hypertension and reduce liver fibrosis in bile duct-ligated rats.

BACKGROUND: In cirrhosis, the nitric oxide-soluble guanylyl cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway is impaired, which contributes to increased intrahepatic vascular resistance (IHVR) and fibrogenesis. We investigated if sGC stimulation (riociguat (RIO)), sGC activation (cinaciguat (CINA)) or phosphodiesterase (PDE)-5 inhibition (tadalafil (TADA)) improves portal hypertension (PHT) and liver fibrosis. METHODS: Fifty male Sprague-Dawley rats underwent bile-duct ligation (BDL) or sham operation. RIO (0.5 mg/kg), CINA (1 mg/kg), TADA (1.5 mg/kg) or vehicle (VEH) was administered from weeks 2 to 4 after BDL. At week 4, invasive haemodynamic measurements were performed, and liver fibrosis was assessed by histology (chromotrope-aniline blue (CAB), Picro-Sirius red (PSR)) and hepatic hydroxyproline content. RESULTS: Cirrhotic bile duct-ligated rats presented with PHT (13.1 ± 1.0 mmHg) and increased IHVR (4.9 ± 0.5 mmHg⋅min/mL). Both RIO (10.0 ± 0.7 mmHg, p = 0.021) and TADA (10.3 ± 0.9 mmHg, p = 0.050) decreased portal pressure by reducing IHVR (RIO: -41%, p = 0.005; TADA: -21%, p = 0.199) while not impacting heart rate, mean arterial pressure and portosystemic shunting. Hepatic cGMP levels increased upon RIO (+239%, p = 0.006) and TADA (+32%, p = 0.073) therapy. In contrast, CINA dosed at 1 mg/kg caused weight loss, arterial hypotension and hyperlactataemia in bile duct-ligated rats. Liver fibrosis area was significantly decreased by RIO (CAB: -48%, p = 0.011; PSR: -27%, p = 0.121) and TADA (CAB: -21%, p = 0.342; PSR: -52%, p = 0.013) compared to VEH-treated bile duct-ligated rats. Hepatic hydroxyproline content was reduced by RIO (from 503 ± 20 to 350 ± 30 µg/g, p = 0.003) and TADA (282 ± 50 µg/g, p = 0.003), in line with a reduction of the hepatic stellate cell activation markers smooth-muscle actin and phosphorylated moesin. Liver transaminases decreased under RIO (AST: -36%; ALT: -32%) and TADA (AST: -24%; ALT: -27%) treatment. Hepatic interleukin 6 gene expression was reduced in the RIO group (-56%, p = 0.053). CONCLUSION: In a rodent model of biliary cirrhosis, the sGC stimulator RIO and the PDE-5 inhibitor TADA improved PHT. The decrease of sinusoidal vascular resistance was paralleled by a reduction in liver fibrosis and hepatic inflammation, while systemic haemodynamics were not affected.

Point Shear Wave Elastography for Non-invasive Assessment of Liver Fibrosis in Patients with Viral Hepatitis.

Elastography point quantification (ElastPQ) is a new ultrasound-based shear wave elastography method for non-invasive assessment of liver fibrosis. We evaluated the diagnostic accuracy of ElastPQ in patients with chronic viral hepatitis. Fibrosis stage (F) was determined by transient elastography (F0/F1: <7.1 kPa, F2: 7.1-9.4 kPa, F3: 9.5-12.4 kPa, F4: ≥12.5 kPa). Area under the receiver operator characteristics curve (AUROC) analysis was performed to assess ElastPQ cutoffs for significant fibrosis (≥F2) and cirrhosis (F4). Paired transient elastography and ElastPQ measurements were obtained from 217 patients (mean age ± SEM: 49 ± 0.79 years, 68.2% male, F0/F1: n = 98 [45.0%], F2: 47 [21.6%], F3: 22 [10.1%], F4: 50 [22.9%]). AUROC for ≥F2 was 0.843 (95% confidence interval: 0.791-0.895), and for F4, 0.933 (95% confidence interval: 0.894-0.972). The optimal ElastPQ cutoff for F2 was 6.68 kPa (sensitivity: 80.7%, specificity: 70.4%, positive predictive value: 78.5%, negative predictive value: 72.3%), and for F4 11.28 kPa (sensitivity: 86.0%, specificity: 85.6%, positive predictive value: 60.52%, negative predictive value: 97.16%). In conclusion, ElastPQ represents an accurate tool for non-invasive staging of liver fibrosis in patients with viral hepatitis.

Impact of IL28B genotype on the early and sustained virologic response in treatment-naïve patients with chronic hepatitis C.

BACKGROUND & AIMS: Single nucleotide polymorphisms (SNPs) in the gene that encodes interleukin (IL)-28B predict response of patients with chronic hepatitis C to antiviral therapy. We investigated the roles of polymorphisms rs12979860 and rs8099917 on the early virologic response of treatment-naïve patients. METHODS: SNPs were identified by real-time polymerase chain reaction analysis of samples from 682 patients (genotype [GT]1=372, GT2/3=208, GT4=102) who were treated with 180 µg pegylated interferon-α2a and 400 or 800 mg (GT2/3, depending on the protocol) or 1000-1200 mg (GT1/4) ribavirin/day. The duration of treatment was 24 (GT2/3) or 24-72 weeks (GT1/4). RESULTS: Patients with C/C also had higher rates of rapid virologic response (RVR) (GT1, 38.3% vs 11.6%; GT4, 76.5% vs 23.5%; both P<.001) and sustained virologic responses (SVRs) (GT1, 79.1% vs 43.2%; GT4, 85.3% vs 44.1%; both P<.001). In patients with GT2/3, the RVR was more frequent in carriers of C/C (75.3% vs 52.6%, P<.01), but SVR rates were similar between those with C/C and T (80.5% vs 74.4%, P=.31). Results for rs8099917 were comparable. The positive predictive value of rs12979860 C/C for SVR was higher than that of rs8099917 T/T (80.5% vs 71.6%). Overall, RVR was the best predictor of SVR. In patients who did not have GT1, IL28B polymorphisms did not affect the SVR if RVR data were included in the multivariate analysis. CONCLUSIONS: An early virologic response to pegylated interferon and ribavirin is more likely among carriers of rs12979860 C/C and rs8099917 T/T, which might underlie their high rates of SVR. Determination of the IL28B genotype and whether patients have an RVR might be used in future studies of patients with hepatitis C virus genotype 1 or 4.

Common NOD2/CARD15 variants are not associated with susceptibility or the clinicopathologic characteristics of sporadic colorectal cancer in Hungarian patients.

BACKGROUND: Epidemiological observations suggest that cancer arises from chronically inflamed tissues. Inflammatory bowel disease (IBD) is a typical example as patients with longstanding IBD are at an increased risk for developing colorectal cancer (CRC) and mutations of the NOD2/CARD15 gene increase the risk for Crohn's disease (CD). Recently, NOD2/CARD15 has been associated with a risk for CRC in some studies, which stemmed from ethnically diverse populations. Our aim was to identify common NOD2/CARD15 mutations in Hungarian patients with sporadic CRC. METHODS: A total of 194 sporadic CRC patients (m/f: 108/86, age at diagnosis of CRC: 63.2 +/- 9.1 years old) and 200 healthy subjects were included. DNA was screened for SNP8, SNP12 and SNP13 NOD2/CARD15 mutations by denaturing-HPLC and confirmed by direct sequencing. RESULTS: NOD2/CARD15 mutations were found in 28 patients (14.4%) and in 23 controls (11.5%, p = NS). Allele frequencies for SNP8/R702W (1.8% vs. 1.5%) SNP12/G908R (1.8% vs. 1.8%) and SNP13/3020insC (3.6% vs. 2.5%) were also not statistically different between patients and controls. The clinicopathologic characteristics of CRC patients with or without NOD2/CARD15 mutations were not significantly different. CONCLUSION: Our results suggest that common NOD2/CARD15 mutations alone do not contribute to CRC risk in the Hungarian population.