Portal hypertension

The polymorphic variant of SerpinB3 (SerpinB3-PD) is associated with faster cirrhosis decompensation

BACKGROUND

SerpinB3 is a cysteine protease inhibitor involved in liver disease progression due to its proinflammatory and profibrogenic properties. The polymorphic variant SerpinB3-PD (SB3-PD), presents a substitution in its reactive centre loop, determining the gain of function.

AIMS

To disclose the clinical characteristics of a cohort of patients with cirrhosis in relation to the presence of SB3-PD and to assess the effect of this genetic variant on fibrogenic and inflammatory cytokines in vitro.

METHODS

We assessed SB3 polymorphism in 90 patients with cirrhosis, prospectively followed up in our referral centre. We used HepG2 and HuH-7 cells transfected to overexpress either wild-type SB3 (SB3-WT) or SB3-PD to assess their endogenous effect, while LX2 and THP-1 cells were treated with exogenous SB3-WT or SB3-PD proteins.

RESULTS

Patients carrying SB3-PD had more severe portal hypertension and higher MELD scores, than patients carrying SB3-WT. In multivariate analysis, SB3-PD was an independent predictor of cirrhosis complications. Patients with SB3-PD polymorphism presented with more severe liver fibrosis and inflammatory features. Hepatoma cells overexpressing SB3-PD showed higher TGF-β1 expression than controls. The addition of recombinant SB3-PD induced an up-regulation of TGF-β1 in LX2 cells and a more prominent inflammatory profile in THP-1 cells, compared to the effect of SB3-WT protein.

CONCLUSIONS

The polymorphic variant SB3-PD is highly effective in determining activation of TGF-β1 and inflammation in vitro. Patients with cirrhosis who carry SB3-PD polymorphism may be more prone to develop severe liver disease progression. However, further validation studies are warranted to support the in vivo relevance of this polymorphism.

Distinct structural and dynamic components of portal hypertension in different animal models and human liver disease etiologies

BACKGROUND AND AIMS

Liver fibrosis is the static and main (70%-80%) component of portal hypertension (PH). We investigated dynamic components of PH by a three-dimensional analysis based on correlation of hepatic collagen proportionate area (CPA) with portal pressure (PP) in animals or HVPG in patients.

APPROACH AND RESULTS

Different animal models (bile duct ligation: n = 31, carbon tetrachloride: n = 12, thioacetamide: n = 12, choline-deficient high-fat diet: n = 12) and patients with a confirmed single etiology of cholestatic (primary biliary cholangitis/primary sclerosing cholangitis: n = 16), alcohol-associated (n = 22), and metabolic (NASH: n = 19) liver disease underwent CPA quantification on liver specimens/biopsies. Based on CPA-to-PP/HVPG correlation, potential dynamic components were identified in subgroups of animals/patients with lower-than-expected and higher-than-expected PP/HVPG. Dynamic PH components were validated in a patient cohort (n = 245) using liver stiffness measurement (LSM) instead of CPA. CPA significantly correlated with PP in animal models (Rho = 0.531; p < 0.001) and HVPG in patients (Rho = 0.439; p < 0.001). Correlation of CPA with PP/HVPG varied across different animal models and etiologies in patients. In models, severity of hyperdynamic circulation and specific fibrosis pattern (portal fibrosis: p = 0.02; septa width: p = 0.03) were associated with PH severity. In patients, hyperdynamic circulation (p = 0.04), vascular dysfunction/angiogenesis (VWF-Ag: p = 0.03; soluble vascular endothelial growth factor receptor 1: p = 0.03), and bile acids (p = 0.04) were dynamic modulators of PH. The LSM-HVPG validation cohort confirmed these and also indicated IL-6 (p = 0.008) and hyaluronic acid (HA: p < 0.001) as dynamic PH components.

CONCLUSIONS

The relative contribution of "static" fibrosis on PH severity varies by type of liver injury. Next to hyperdynamic circulation, increased bile acids, VWF-Ag, IL-6, and HA seem to indicate a pronounced dynamic component of PH in patients.

Dual-energy CT quantification of fractional extracellular space in cirrhotic patients: comparison between early and delayed equilibrium phases and correlation with oesophageal varices

OBJECTIVE

Fractional extracellular space has been validated as a marker of hepatic fibrotic in cirrhotic patients at CT-scan as well as on dual-energy CT, which takes advantage from iodine uptake. Since no consensus still exists between equilibrium phases performed at 3 or 10 min, the first aim of this work is to evaluate performances at the two different time points. Moreover, correlation between fractional extracellular space and oesophageal varices, directly related to liver fibrosis, has been assessed.

MATERIALS AND METHODS

Dual-Energy equilibrium phases at 3 and 10 min were performed within a follow-up CT-protocol scan in cirrhotic patients. Oesophageal varices were endoscopically assessed according to their size. At the two different time points, correlation between iodine density of the right and left liver lobes and correlation between the fractional extracellular space values were assessed. Correlation between fractional extracellular space and endoscopic grade of oesophageal varices was calculated.

RESULTS

No statistical differences were found between the iodine density values from the two liver lobes at the two time points (p = 0.8 at 3'; p = 0.5 at 10'). No statistical difference about fractional extracellular space estimation was found between the two time points (p = 0.17). Correlation between fractional extracellular space values and oesophageal varices was moderate (ρ = 0.45, IC 0.08-0.71, p < 0.05).

CONCLUSION

Fractional extracellular space assessed on dual-energy CT at equilibrium phases with different timing was substantially similar. The moderate correlation found between fractional extracellular space and endoscopic grade of oesophageal varices confirms that CT-scan is not currently reliable as endoscopy.

Non-selective β-blockers improve the correlation of liver stiffness and portal pressure in advanced cirrhosis

BACKGROUND

Liver stiffness (LS) correlates with portal pressure (hepatic venous pressure gradient, HVPG). However, the dynamic components of portal hypertension (PHT) in advanced cirrhosis may not be adequately assessed by TE. The influence of treatment with non-selective β-blockers (NSBB) on the correlation of HVPG and LS has not been investigated.

METHODS

One hundred and twenty-two patients with esophageal varices were included. LS, hemodynamic parameters, and HVPG were recorded at baseline (BL) and after 6 weeks of treatment with NSBB (FU). The correlation of LS and HVPG was compared to control patients with HVPG ≤ 12 mmHg.

RESULTS

Patients with higher Child-Pugh stages (A:88/B:25/C:9) had higher levels of liver stiffness (47.4 ± 16.5 vs. 70.3 ± 7.9 vs. 73.7 ± 2.1 kPa) and HVPG (21 ± 5 vs. 26 ± 5 vs. 26 ± 4 mmHg). The correlation of LS and HVPG was stronger in controls with HVPG ≤ 12 mmHg (R = 0.951; P < 0.0001) than in patients with HVPG > 12 mmHg (R = 0.538; P = 0.0004). The association of HVPG with LS became stronger under treatment with NSBB, which finally restored the linear correlation of HVPG and LS (R = 0.930; P < 0.0001). Forty-three percent (53/122) of patients were hemodynamic responders to NSBB. The improvement in the correlation of LS and HVPG under NSBB was mainly noted in hemodynamic responders (R = 0.864), but not in nonresponders (R = 0.535), whereas changes in LS, heart rate, and MAP were similar in responders and nonresponders.

CONCLUSIONS

Targeting the hyperdynamic circulation and the increased splanchnic blood inflow by treatment with NSBB unmasks the linear (mechanical) correlation of HVPG and LS in patients with HVPG > 12 mmHg. Measurement of LS by TE is not a feasible method to assess the dynamic components of PHT.

Pre- and postoperative systemic hemodynamic evaluation in patients subjected to esophagogastric devascularization plus splenectomy and distal splenorenal shunt: A comparative study in schistomomal portal hypertension

AIM: To investigate the systemic hemodynamic effects of two surgical procedures largely employed for treatment of schistosomal portal hypertension.

METHODS: Thirty-six patients undergoing elective surgical treatment of portal hypertension due to hepatosplenic mansonic schistosomiasis were prospectively evaluated. All patients were subjected to preoperative pulmonary artery catheterization; 17 were submitted to esophagogastric devascularization and splenectomy (EGDS) and 19 to distal splenorenal shunt (DSRS). The systemic hemodynamic assessment was repeated 4 d after the surgical procedure.

RESULTS: Preoperative evaluation revealed (mean ± SD) an increased cardiac index (4.78 ± 1.13 L/min per m²), associated with a reduction in systemic vascular resistance index (1457 ± 380.7 dynes.s/cm⁵.m²). The mean pulmonary artery pressure (18 ± 5.1 mmHg) as well as the right atrial pressure (7.9 ± 2.5 mmHg) were increased, while the pulmonary vascular resistance index (133 ± 62 dynes.s/cm⁵.m²) was decreased. Four days after EGDS, a significant reduction in cardiac index (3.80 ± 0.4 L/min per m², P < 0.001) and increase in systemic vascular resistance index (1901.4 ± 330.2 dynes.s/cm⁵.m², P < 0.001) toward normal levels were observed. There was also a significant reduction in pulmonary artery pressure (12.65 ± 4.7 mmHg, P < 0.001) and no significant changes in the pulmonary vascular resistance index (141.6 ± 102.9 dynes.s/cm⁵.m²). Four days after DSRS, a non-significant increase in cardiac index (5.2 ± 0.76 L/min per m²) and systemic vascular resistance index (1389 ± 311 dynes.s/cm⁵.m²) was observed. There was also a non-significant increase in pulmonary artery pressure (19.84 ± 5.2 mmHg), right cardiac work index (1.38 ± 0.4 kg.m/m²) and right ventricular systolic work index (16.3 ± 6.3 g.m/m²), without significant changes in the pulmonary vascular resistance index (139.7 ± 67.8 dynes.s/cm⁵.m²).

CONCLUSION: The hyperdynamic circulatory state observed in mansonic schistosomiasis was corrected by EGDS, but was maintained in patients who underwent DSRS. Similarly, the elevated mean pulmonary artery pressure was corrected after EGDS and maintained after DSRS. EGDS seems to be the most physiologic surgery for patients with schistosomal portal hypertension.

The clinical outcome of small (<20 mm) arterially enhancing nodules on MRI in the cirrhotic liver

OBJECTIVES

To evaluate the outcome of arterially enhancing nodules (AENs) measuring <20 mm detected on MRI in patients with cirrhosis.

METHODS

Prospective analysis of 54 patients with a total of 161 AENs <20 mm on MRI. Inclusion criteria included a minimum of 12 months of MRI follow-up or histological evaluation of the AEN. Key exclusions were patients with an AEN >20 mm or prior diagnosis of HCC. Two radiologists blinded to the clinical and pathological data reviewed serial MRIs and classified the AENs as no longer visible, stable, increasing, or decreasing in size.

RESULTS

A total of 161 AENs were identified and were followed by serial MRI for a mean of 24 months. Eighty (50%) AENs were no longer visible on repeat imaging, 42 (26%) remained stable, 1 of which was diagnosed as HCC on short-term follow-up, 8 (5%) increased in size and were subsequently diagnosed as HCC, and 24 (15%) decreased in size. In addition, 7 AENs (4%) were diagnosed on biopsy immediately following the initial MRI. Overall MR characteristics diagnostic of HCC were growth > or =2 mm and peripheral rim enhancement on initial MRI.

CONCLUSIONS

The majority (90%) of AENs <20 mm in cirrhosis are benign. The presence of rim enhancement or interval growth of an AEN are suggestive of HCC.

Effect of vardenafil, an inhibitor of phosphodiesterase-5, on portal haemodynamics in normal and cirrhotic liver -- results of a pilot study

BACKGROUND

Dysregulation of the cyclic guanosine 3',5' monophosphate-nitric oxide system is in part responsible for portal hypertension in cirrhosis.

AIM

To test the effects of inhibitors of phosphodiesterase-5 on portal haemodynamics.

METHODS

To 18 healthy subjects and 18 patients with Child A liver cirrhosis, 10 mg of vardenafil, an inhibitor of phosphodiesterase-5, were administered orally. Doppler sonographic measurements of hepatic and splanchnic blood flow, systemic blood pressure and heart rate were recorded before, 1 h after, and 48 h after the application. Vardenafil plasma levels were determined after 1 h. In five patients, invasive registration of free and wedged hepatic vein pressure was performed.

RESULTS

Portal venous flow increased in patients from 0.82 +/- 0.30 L/min (mean +/- s.d.) by 26% (CI: 16-37%, P = 0.0004) and in healthy subjects from 0.75 +/- 0.20 L/min (mean +/- s.d.) by 19% (CI: 9-28%; P = 0.0010). Celiac and hepatic artery resistivity indices rose significantly. Systemic blood pressure decreased slightly in patients. The wedged hepatic venous pressure gradient decreased in four of five patients with liver cirrhosis. Vardenafil plasma levels were higher in patients (14 +/- 10 microg/L) than in healthy subjects (9 +/- 6 microg/L; n.s.).

CONCLUSIONS

Inhibition of phosphodiesterase-5 increases portal flow and lowers portal pressure by a decrease in sinusoidal resistance and may be a novel therapeutic strategy for portal hypertension.

Losartan in cardiovascular disease

Hypertension is a major risk factor for the development of cardiovascular disease. Numerous placebo-controlled trials have demonstrated that treatment of hypertension results in substantial reduction of hypertension-related vascular events. The benefit of specific therapies beyond their effect on blood pressure is well established. Losartan is an orally-active, selective, nonpeptide, angiotensin II type 1-receptor antagonist (ARB), and it was the first in this class to be marketed. Several large-scale clinical trials have demonstrated that losartan and other ARBs have benefits in preventing cardiovascular disease. The Losartan Intervention For End point reduction in hypertension (LIFE) study demonstrated improved outcomes with losartan as compared with atenolol-based therapies in hypertensive patients with left ventricular hypertrophy, mainly because of stroke prevention. The Reduction of End points in Non-insulin-dependent diabetes mellitus with the Angiotensin II Antagonist Losartan (RENAAL) study demonstrated that losartan prevented the progression of diabetic nephropathy. In this review, evidence from these and other clinical trials with losartan shall be discussed. The pharmacodynamic and pharmacokinetic properties of losartan are described to explain its mechanisms of action. Among the ARB class, losartan possesses certain unique properties, which may enhance its cardiovascular protective effects. These include an increase of urinary uric acid excretion and antiatherothrombotic properties. Potential future roles for losartan and other ARBs shall be discussed, in addition to emphasizing areas in which evidence is currently lacking or indecisive, including head-to-head comparisons of ARBs and the effects of combining an ARB with angiotensin-converting-enzyme inhibitors.