Portal vein thrombosis and chronic liver disease progression: The closer you look the more you see

Systemic inflammation and portal vein thrombosis in cirrhotic patients with gastroesophageal varices

BACKGROUND AND AIM

Cirrhotic patients with gastroesophageal varices and non-tumoral portal vein thrombosis have a higher risk of re-bleeding and poor prognosis. This study aimed to analyze inflammatory biomarkers and thromboelastography in cirrhotic patients with portal vein thrombosis.

METHODS

A total of 385 consecutive cirrhotic patients with gastroesophageal varices were prospectively enrolled between 1 December 2016, and 31 August 2017. Of these, 231 were eligible for analysis and were divided into portal vein thrombosis (n = 103) and non-portal vein thrombosis (n = 128) groups based on computerized tomography angiography findings.

RESULTS

Patients with portal vein thrombosis generally had higher Child-Pugh scores than those without portal vein thrombosis (6.38 ± 0.12 vs. 5.81 ± 0.09, P < 0.001). The serum albumin levels were significantly lower in patients with portal vein thrombosis (35.90 ± 0.52 vs. 38.52 ± 0.43, P < 0.001). The portal vein thrombosis group had significant higher serum levels of interleukin 6 [4.85 (3.15-6.99) vs. 3.09 (2.06-5.20) pg/ml, P < 0.001] and tumor necrosis factor alpha [10.70 (7.60-15.20) vs. 9.07 (7.03-11.60) pg/ml, P = 0.020]. The interleukin 6 level was 2.5-fold higher in patients with portal vein thrombosis (adjusted odds ratio: 2.574; 95% confidential interval: 1.248-5.310). Thromboelastography showed that TEG-R, the reaction time, was significantly lower in the portal vein thrombosis group [5.20 (4.80-6.30) vs. 6.00 (5.20-6.95), P = 0.009], indicating enhanced coagulation activity.

CONCLUSION

This study confirmed the important role of systemic inflammation in portal vein thrombosis. Interleukin 6, an important inflammatory cytokine, is independently associated with portal vein thrombosis. The correlation between the interleukin 6 level and portal vein thrombosis requires further investigation.

Gut-derived endotoxin stimulates factor VIII secretion from endothelial cells. Implications for hypercoagulability in cirrhosis

BACKGROUND & AIMS

Patients with cirrhosis display enhanced blood levels of factor VIII, which may result in harmful activation of the clotting system; however, the underlying mechanism is unknown.

METHODS

We performed a cross-sectional study in patients with cirrhosis (n=61) and matched controls (n=61) comparing blood levels of factor VIII, von Willebrand factor (vWf), lipopolysaccharide (LPS) and positivity for Escherichia coli DNA. Furthermore, we performed an in vitro study to investigate if LPS, in a concentration range similar to that found in the peripheral circulation of cirrhotic patients, was able to elicit factor VIII secretion from human umbilical vein endothelial cells (HUVEC).

RESULTS

Patients with cirrhosis displayed higher serum levels of LPS (55.8 [42.2-79.9] vs. 23.0 [7.0-34.0]pg/ml, p<0.001), factor VIII (172.0 [130.0-278.0] vs. 39.0 [26.0-47.0]U/dl, p<0.0001), vWf (265.0 [185.0-366.0] vs. 57.0 [48.0-65.0]U/dl, p<0.001) and positivity for Escherichia coli DNA (88% vs. 3%, p<0.001, n=34) compared to controls. Serum LPS correlated significantly with factor VIII (r=0.80, p<0.001) and vWf (r=0.63, p<0.001). Only LPS (beta-coefficient=0.70, p<0.0001) independently predicted factor VIII levels. The in vitro study showed that LPS provoked factor VIII and vWf release from HUVEC via formation and secretion of Weibel-Palade bodies, a phenomenon blunted by pre-treating HUVEC with an inhibitor of Toll-like receptor 4.

CONCLUSIONS

The study provides the first evidence that LPS derived from gut microbiota increases the systemic levels of factor VIII via stimulating its release by endothelial cells. Lay summary: Cirrhosis is associated with thrombosis in portal and systemic circulation. Enhanced levels of factor VIII have been suggested to play a role but the underlying mechanism is still unclear. Here we show that patients with cirrhosis display a concomitant increase of factor VIII and lipopolysaccharide (LPS) from Escherichia coli and suggest that LPS contributes to the release of factor VIII from endothelial cells.

Low-grade endotoxemia and platelet activation in cirrhosis

Patients with cirrhosis may display impaired or enhanced platelet activation, but the reasons for these equivocal findings are unclear. We investigated if bacterial lipopolysaccharide (LPS) is implicated in platelet activation. In a cross-sectional study, conducted in an ambulatory care clinic and hospital, comparing 69 cirrhosis patients and 30 controls matched for sex, age, and atherosclerotic risk factors, serum levels of LPS, soluble cluster of differentiation 40 ligand and p-selectin (two markers of platelet activation), and zonulin (a marker of gut permeability) were investigated. Ex vivo and in vitro studies were also performed to explore the effect of LPS on platelet activation. Compared to controls, cirrhosis patients displayed higher serum levels of LPS (6.0 [4.0-17.5] versus 57.4 [43.4-87.2] pg/mL, P < 0.0001), soluble cluster of differentiation 40 ligand (7.0 ± 2.2 versus 24.4 ± 13.3 ng/mL, P < 0.0001), soluble p-selectin (14.2 ± 4.05 versus 33.2 ± 15.2 ng/mL, P < 0.0001), and zonulin (1.87 ± 0.84 versus 2.54 ± 0.94 ng/mL, P < 0.006). LPS significantly correlated with zonulin (r = 0.45, P < 0.001). Ex vivo studies showed that platelets from cirrhosis patients were more responsive to the agonists independently from platelet count; this phenomenon was blunted by incubation with an inhibitor of Toll-like receptor 4. In vitro study by normal platelets showed that LPS alone (50-150 pg/mL) did not stimulate platelets but amplified platelet response to the agonists; Toll-like receptor 4 inhibitor blunted this effect.

CONCLUSION

LPS may be responsible for platelet activation and potentially contributes to thrombotic complications occurring in cirrhosis. (Hepatology 2017;65:571-581).

Portal vein thrombosis relevance on liver cirrhosis: Italian Venous Thrombotic Events Registry

Portal vein thrombosis may occur in cirrhosis; nevertheless, its prevalence, and predictors are still elusive. To investigate this issue, the Italian Society of Internal Medicine undertook the "Portal vein thrombosis Relevance On Liver cirrhosis: Italian Venous thrombotic Events Registry" (PRO-LIVER). This prospective multicenter study includes consecutive cirrhotic patients undergoing Doppler ultrasound examination of the portal area to evaluate the prevalence and incidence of portal vein thrombosis over a 2-year scheduled follow-up. Seven hundred and fifty-three (68 % men; 64 ± 12 years) patients were included in the present analysis. Fifty percent of the cases were cirrhotic outpatients. Viral (44 %) etiology was predominant. Around half of the patients had a mild-severity disease according to the Child-Pugh score; hepatocellular carcinoma was present in 20 %. The prevalence of ultrasound-detected portal vein thrombosis was 17 % (n = 126); it was asymptomatic in 43 % of the cases. Notably, more than half of the portal vein thrombosis patients (n = 81) were not treated with anticoagulant therapy. Logistic step-forward multivariate analysis demonstrated that previous portal vein thrombosis (p < 0.001), Child-Pugh Class B + C (p < 0.001), hepatocellular carcinoma (p = 0.01), previous upper gastrointestinal bleeding (p = 0.030) and older age (p = 0.012) were independently associated with portal vein thrombosis. Portal vein thrombosis is a frequent complication of cirrhosis, particularly in patients with moderate-severe liver failure. The apparent undertreatment of patients with portal vein thrombosis is a matter of concern and debate, which should be addressed by planning interventional trials especially with newer oral anticoagulants. Clinicaltrials.gov identifier NCT01470547.