High Prevalence of ITPA Alleles Associated with Ribavirin-Induced Hemolytic Anemia Among Mexican Population

Meta-analysis and systematic review: Prevalence, graft failure, mortality, and post-operative thrombosis in liver transplant recipients with pre-operative portal vein thrombosis

AIMS

This study seeks to evaluate the association between pre-transplant portal vein thrombosis (PVT) and overall survival, graft failure, waitlist mortality, and post-operative PVT after liver transplantation.

METHODS

A conventional pairwise meta-analysis between patients with and without pre-transplant PVT was conducted using hazard ratios or odds ratios where appropriate.

RESULTS

Prevalence of preoperative PVT was 11.6% (CI 9.70-13.7%). Pre-operative PVT was associated with increased overall mortality (HR 1.45, 95% CI 1.27-1.65) and graft loss (HR 1.58, 95% CI 1.34-1.85). In particular, grade 3 (HR 1.59, 95% CI 1.00-2.51) and 4 (HR 2.24, 95% CI 1.45-3.45) PVT significantly increased mortality, but not grade 1 or 2 PVT. Patients with PVT receiving living donor (HR 1.54, 95% CI 1.24-1.91) and deceased donor (HR 1.52, 95% CI 1.21-1.92) liver transplantation had increased mortality, with no significant difference between transplant types (P = .13). Furthermore, pre-transplant PVT was associated with higher occurrence of post-transplant PVT (OR 5.06, 95% CI 3.89-6.57). Waitlist mortality was not significantly increased in patients with pre-transplant PVT.

CONCLUSION

Graft failure, mortality, and post-operative PVT are more common in pre-transplant PVT patients, especially in grade 3 or 4 PVT. Prophylactic anticoagulation can be considered to reduce re-thrombosis and improve survival.

Up to 50% of portal vein thrombosis remains undiagnosed until liver transplantation

BACKGROUND

Impact of portal vein thrombosis (PVT) on the clinical course in liver transplant candidates remains unclear. This study aims to identify prevalence and risk factors for PVT, assess outcome after liver transplantation (LT) in patients with PVT and study the effect of anticoagulation.

METHODS

This single-center retrospective cohort study was performed from January 2006 until June 2016. Patients were stratified according to presence of PVT. Risk factors and outcome were assessed using logistic regression and survival analysis.

RESULTS

Among 390 adults who underwent orthotopic LT, PVT occurred in 40 (10.3%). In, respectively, 10 (25%), 7 (17.5%), and 23 (57.5%) patients, PVT was identified at time of evaluation for transplantation, on the waiting list and during transplantation. A beneficial trend was present favoring the use of anticoagulation for PVT resolution (n = 3/7 vs 0/9; p = .062). Patient and graft survival were similar between the groups after a median follow-up of 5 years. However, 1-year patient survival was significantly lower (p = .031) in patients with PVT.

CONCLUSION

Portal vein thrombosis occurred in 10% of patients awaiting LT was undiagnosed in 50% until moment of LT and had a deleterious effect on 1-year survival. Anticoagulation showed a beneficial trend on recanalization of PVT and survival rate.

Risk factors and impact of portal vein thrombosis in liver transplantation

INTRODUCTION

portal vein thrombosis is a relatively common complication of advanced cirrhosis that increases perioperative risk in liver transplant recipients. This condition was characterized in a cohort of patients, including risk factors and their influence on survival.

MATERIAL AND METHODS

a retrospective study of liver transplant recipients at the Clínica Universidad de Navarra was performed between 2000 and 2015. Differences in clinical and biological characteristics and survival were analyzed in subjects with and without portal vein thrombosis. A predictive index was also developed.

RESULTS

a total of 288 patients were included in the study, portal vein thrombosis was recorded in 46 (16%) cases and seven (15.2%) had stage 3/4 disease according to Yerdel's classification. Factors associated with the presence of esophageal/gastric varices (OR = 3.7; p = 0.03) included variceal ligation or sclerotherapy (OR = 2.3; p = 0.01), being overweight/obesity (OR = 2.1; p = 0.04) and thrombocytopenia (OR = 3.6; p = 0.04). There were no significant differences between the groups with and without portal vein thrombosis in terms of survival according to Kaplan-Meier curve analysis (p = 0.7). However, the mortality rate was higher for Yerdel stages 3-4 (p < 0.01). A predictive index was developed that included varices, body mass index (BMI), thrombocytopenia and activated partial thromboplastin time (APTT). This index had a sensitivity of 76.1% and a specificity of 53.7% for the development of portal thrombosis.

CONCLUSIONS

the presence of esophageal/gastric varices, variceal ligation/sclerotherapy, thrombocytopenia and being overweight/obesity was associated with a higher rate of portal vein thrombosis. Advanced stages had an impact on survival.

Portal vein thrombosis: yes or no on anticoagulation therapy

PURPOSE OF REVIEW

To describe portal vein thrombosis (PVT) in the setting of cirrhosis especially in relation to its potential impact on liver transplantation. In addition, the safety and efficacy of anticoagulation is reviewed.

RECENT FINDINGS

PVT in cirrhosis occurs in up to 26% of patients awaiting liver transplantation. Different studies have suggested that PVT impacts negatively post-liver transplantation survival, particularly in first year post-liver transplantation and when PVT is complete involving the porto-mesenteric confluence and not allowing physiological anastomosis. Anticoagulation is effective in preventing PVT progression and may achieve partial or complete PVT recanalization. Its use in patients with cirrhosis seems not to be associated with increased bleeding risk.

SUMMARY

The goal of anticoagulation is to prevent thrombus extension to the superior mesenteric vein and/or favor recanalization if previously affected, allowing physiological anastomosis during liver transplantation and therefore improving outcome. Low-molecular-weight heparin and vitamin K antagonist have a similar safety profile without specific data in favor of any of them. Treatment with direct anticoagulants cannot be recommended yet because of limited experience in cirrhosis. Transjugular intrahepatic portosystemic shunt could be an alternative particularly if thrombosis progresses despite satisfactory anticoagulation and/or when PVT is associated with severe portal hypertension complications. However, careful consideration of potential risks and benefits of anticoagulation is recommended until further studies are conducted.

Impact of Nonmalignant Portal Vein Thrombosis in Transplant Recipients With Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease is an increasingly prevalent condition, and its more severe progressive state, nonalcoholic steatohepatitis (NASH), is currently the second most common indication for wait-listed adults in the United States. The association of portal vein thrombosis (PVT) prior to or at transplant and poor graft and patient outcomes is not well established, particularly among NASH patients who inherently have an increased hypercoagulable profile. Using the United Network for Organ Sharing data set, we analyzed graft and patient outcomes of patients transplanted for the indication of NASH with and without PVT. Of 3689 NASH transplant recipients, the prevalence of PVT was 12% (450 with PVT and 3239 without PVT). NASH transplant recipients with PVT had inferior graft and patient survival compared with NASH transplant recipients without PVT, even after adjusting for recipient and donor demographic characteristics, body mass index, synthetic dysfunction, and presence of diabetes. In a multivariate Cox regression model, NASH transplant recipients with PVT had a 37% increased risk of graft failure (hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.15-1.63; P < 0.001) and 31% increased risk of overall death (HR, 1.31; 95% CI, 1.09-1.58; P < 0.001) compared with NASH transplant recipients without PVT at transplant. This difference in graft and patient survival was most pronounced in the early posttransplant period. These results demonstrate that NASH patients with PVT have decreased graft and patient survival independent of recipient and donor factors.

Portal vein thrombosis in patients with liver cirrhosis and its impact on early and long-term outcomes after liver transplantation

AIM

Portal vein thrombosis (PVT) is a common complication amongst patients with liver cirrhosis. The PVT risk factors and its impact on post liver transplant outcome has not been well defined, yet. This study aimed to investigate PVT prevalence, its risk factors and influence on early and long-term outcomes after liver transplantation.

METHODS

Adult (>18 years) patients with liver cirrhosis undergoing liver transplantation between March 2013 to March 2015 were included. Presence or absence of PVT was recorded at transplant. PVT risk factors in patients with liver cirrhosis and its impact on early and long-term outcomes were analysed.

RESULTS

Portal vein thrombosis was diagnosed in 174 patients (17.3%). Large oesophageal varices (grade II and III vs grade I) (OR: 2.5; 95% CI: 1.46-4.26; P = 0.001), diabetes mellitus before transplantation (OR: 2.03; 95% CI: 1.13-3.64; P = 0.017) and cryptogenic-NASH (OR: 1.36; 95% CI: 1.08-1.72; P = 0.008) as a cause of underlying liver disease were the independent risk factors for PVT. PVT (OR: 2.05; 95% CI: 1.10-3.81; P = 0.023) was an independent predictor of early (within 90 days) posttransplant mortality, but did not influence long-term survival.

CONCLUSION

Portal vein thrombosis prevalence is high in pretransplant period. NASH related cirrhosis and diabetes mellitus might be risk factors for PVT. More intense screening of these patients for PVT is warranted.

Immunometabolic Effect of Cholesterol in Hepatitis C Infection: Implications in Clinical Management and Antiviral Therapy

Hepatitis C virus (HCV) is a lipid-enveloped virion particle that causes infection to the liver, and as part of its life cycle, it disrupts the host lipid metabolic machinery, particularly the cholesterol synthesis pathway. The innate immune response generated by liver resident immune cells is responsible for successful viral eradication. Unfortunately, most patients fail to eliminate HCV and progress to chronic infection. Chronic infection is associated with hepatic fat accumulation and inflammation that triggers fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Despite that the current direct-acting antiviral agents have increased the cure rate of HCV infection, viral genotype and the host genetic background influence both the immune response and lipid metabolism. In this context, recent evidence has shown that cholesterol and its derivatives such as oxysterols might modulate and potentialize the hepatic innate immune response generated against HCV. The impairment of the HCV life cycle modulated by serum cholesterol could be relevant for the clinical management of HCV-infected patients before and after treatment. Alongside, cholesterol levels are modulated either by genetic variations in IL28B, ApoE, and LDLR or by dietary components. Indeed, some nutrients such as unsaturated fatty acids have demonstrated to be effective against HCV replication. Thus, cholesterol modifications may be considered as a new adjuvant strategy for HCV infection therapy by providing a biochemical tool that guides treatment decisions, an improved treatment response and favoring viral clearance. Herein, the mechanisms by which cholesterol contributes to the immune response against HCV infection and how genetic and environmental factors may affect this role are reviewed.

The Editorial Challenges Faced by International Medical Journals in Latin America

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Stratifying Mortality in a Model for End-Stage Liver Disease Waiting List: A Brazilian Single-Center Study

BACKGROUND

The Model for End-Stage Liver Disease (MELD) system reliably predicts mortality in cirrhotic patients. However, the etiology of liver disease and presence of portal vein thrombosis are not directly taken into account in MELD score. Its impact on the outcomes of patients on the waiting list is still unclear. The aim of this study was to investigate mortality and access to transplantation regarding etiology of liver disease and portal vein thrombosis (PVT).

METHODS

A total of 465 adult patients on the liver waiting list from August 2015 to August 2016 were followed up until August 2017. Patients were divided into groups according to the etiology of liver disease and presence of PVT.

RESULTS

The most frequent etiologies were hepatitis C (26.88%), alcoholic cirrhosis (26.02%) and cryptogenic cirrhosis (10.75%). Death while on the waiting list occurred in 168 patients (36.1%) and was more frequent in nonalcoholic steatohepatitis (NASH, 65.4%) and alcoholic cirrhosis (41.3%). A total of 142 (30.5%) patients underwent transplantation and viral, autoimmune, and biliary diseases showed higher proportion of transplantation (36.3%, 53.8%, and 34%, respectively; P < .01). Mean delta-MELD at the study endpoint was higher in patients with autoimmune hepatitis, biliary diseases, and NASH (8.3 ± 7.2, 8.3 ± 9.1, and 7.5 ± 9.1, respectively; P < .01). A total 77 patients (16.7%) presented PVT. There was no significant difference in outcomes between patients with and without PVT.

CONCLUSIONS

Patients with NASH and alcoholic liver disease had higher mortality while on the waiting list, whereas patients with viral and autoimmune hepatitis had higher transplantation rate. Outcomes were not influenced by PVT.