Higher Bilirubin Levels of Healthy Living Liver Donors Are Associated With Lower Posttransplant Hepatocellular Carcinoma Recurrence

PREDICTIVE BIOMARKERS OF LIVING DONOR LIVER TRANSPLANTATION

Objective: Liver transplantation using a living donor (LDLT) is currently the most popular method used in the worldwide. Appropriate biomarkers that predict graft status should be used to detect early post-transplant complications that may lead to a rejection reaction. Material and Method: The study involved a total of 44 liver recipients and 44 liver donors, from whom preoperative blood samples were taken and immunoassay and spectrophotometric studies were carried out. The levels of serum neopterin, interferon-gamma (IFN- y), indoleamine-2,3 dioxygenase (IDO), and -glutathione S transferase (a-GST) were assessed using an enzyme-linked immunosorbent test. The activity of glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) in erythrocytes was measured using spectrophotometry. Result and Discussion: “Neopterin, IDO, and G6PD levels were significantly higher in the recipient group than in the donor group. The differences in gender and blood groups were statistically insignificant. The rejection reaction developed in 25% of patients and none survived. These findings may facilitate the identification of novel predictive biomarkers for the diagnosis of acute rejection reactions after LDLT. The clinical use of novel non-invasive biomarkers may provide time and cost advantages.

The Protective Role of the Heme Catabolic Pathway in Hepatic Disorders

Significance: As the central metabolic organ, the liver is exposed to a variety of potentially cytotoxic, proinflammatory, profibrotic, and carcinogenic stimuli. To protect the organism from these deleterious effects, the liver has evolved a number of defense systems, which include antioxidant substrates and enzymes, anti-inflammatory tools, enzymatic biotransformation systems, and metabolic pathways. Recent Advances: One of the pivotal systems that evolved during phylogenesis was the heme catabolic pathway. Comprising the important enzymes heme oxygenase and biliverdin reductase, this complex pathway has a number of key functions including enzymatic activities, but also cell signaling, and DNA transcription. It further generates two important bile pigments, biliverdin and bilirubin, as well as the gaseous molecule carbon monoxide. These heme degradation products have potent antioxidant, immunosuppressive, and cytoprotective effects. Recent data suggest that the pathway participates in the regulation of metabolic and hormonal processes implicated in the pathogenesis of hepatic and other diseases. Critical Issues: This review discusses the impact of the heme catabolic pathway on major liver diseases, with particular focus on the involvement of cellular targeting and signaling in the pathogenesis of these conditions. Future Directions: To utilize the biological consequences of the heme catabolic pathway, several unique therapeutic strategies have been developed. Research indicates that pharmaceutical, nutraceutical, and lifestyle modifications positively affect the pathway, delivering potentially long-term clinical benefits. However, further well-designed studies are needed to confirm the clinical benefits of these approaches. Antioxid. Redox Signal. 35, 734-752.

Decrease in the Risk of Posttransplant Hepatocellular Carcinoma Recurrence After the Conversion to Prestorage Leukoreduction for Transfused Red Blood Cells

BACKGROUND

Prestorage leukoreduction has the advantage over poststorage leukoreduction in reducing leukocyte-derived molecules in red blood cells (RBC) unit, which induce immunomodulation. Our institution newly introduced prestorage leukoreduction, instead of conventional poststorage leukoreduction, for liver transplant recipients since March 2012. In this study, we aimed to evaluate the risk of posttransplant hepatocellular carcinoma (HCC) recurrence after the conversion of poststorage leukoreduction into prestorage leukoreduction for transfused allogeneic RBCs.

METHODS

Among 220 patients who underwent living-donor liver transplantation for HCC, 83 of 113 who received only poststorage-leukoreduced RBCs were matched with 83 of 107 who received only prestorage-leukoreduced RBCs using 1:1 propensity score matching based on factors like tumor biology. The primary outcome was overall HCC recurrence. Survival analysis was performed with death as a competing risk event.

RESULTS

In the matched cohort, recurrence probability at 1, 2, and 5 years posttransplant was 9.6%, 15.6%, and 18.1% in prestorage group and 15.6%, 21.6%, and 33.7% in poststorage group (hazard ratio [HR], 0.52; 0.28-0.97; P = 0.040). Multivariable analysis confirmed a significance of prestorage leukoreduction (HR, 0.29; 0.15-0.59; P < 0.001). Overall death risk was also lower with prestorage leukoreduction (HR, 0.51; 0.26-0.99; P = 0.049). In subgroup analysis for the unmatched cohort, recurrence risk was significantly lower in prestorage group within the patients who underwent surgery 2 years (HR, 0.24; 0.10-0.61; P = 0.002), 1 year (HR, 0.16; 0.03-0.92; P = 0.040), and 6 months (HR, 0.13; 0.02-0.85; P = 0.034), respectively, before and after the conversion to prestorage leukoreduction.

CONCLUSIONS

Our findings suggest a potential benefit of prestorage leukoreduction in reducing the risk of HCC recurrence in liver transplant recipients who received allogeneic RBCs during the perioperative period.

Postoperative adjuvant TACE-associated nomogram for predicting the prognosis of resectable Hepatocellular Carcinoma with portal vein Tumor Thrombus after Liver Resection

Background: To explore the effects of postoperative adjuvant transarterial chemoembolization (PA-TACE) on the prognosis of HCC patients with Portal Vein Tumor Thrombus (PVTT) undergoing resection, and to develop a PA-TACE-related nomogram for predicting survival individually. Patients and Methods: Two hundred and ninety-three consecutive HCC patients with PVTT under R0 hepatectomy were recruited. Forty-seven cases had recurrence within one month after surgery. The remaining 246 cases consisted of 90 PA-TACE and 156 non-PA-TACE cases. COX regression analysis was performed for overall survival (OS) or recurrence-free survival (RFS) of these 246 cases, allowing the derivation of independent factors that were integrated into the nomogram. C-index, calibration curves, and risk stratification were performed to evaluate the performance and discriminative power of the nomograms. Results: In 246 patients without recurrence within one month after surgery, the OS and RFS for the PA-TACE group were significantly better than those for the non-PA-TACE group (P<0.0001, P<0.0001, respectively). After Cox regression analysis of OS or RFS, PA-TACE-related nomogram models were constructed. The C-index of the PA-TACE-related nomogram for OS and RFS was 0.72 and 0.73, respectively. Calibration curves revealed a good agreement between predictions and observations for the nomograms. Based on the nomogram-related risk stratification, Kaplan-Meier curves showed powerful discriminative ability. Conclusions: PA-TACE therapy improved the survival of HCC patients with PVTT undergoing hepatectomy. Accurate nomogram models were developed for predicting the individual survival and recurrence of these patients.

Biliverdin reductase and bilirubin in hepatic disease

The buildup of fat in the liver (hepatic steatosis) is the first step in a series of incidents that may drive hepatic disease. Obesity is the leading cause of nonalcoholic fatty liver disease (NAFLD), in which hepatic steatosis progresses to liver disease. Chronic alcohol exposure also induces fat accumulation in the liver and shares numerous similarities to obesity-induced NAFLD. Regardless of whether hepatic steatosis is due to obesity or long-term alcohol use, it still may lead to hepatic fibrosis, cirrhosis, or possibly hepatocellular carcinoma. The antioxidant bilirubin and the enzyme that generates it, biliverdin reductase A (BVRA), are components of the heme catabolic pathway that have been shown to reduce hepatic steatosis. This review discusses the roles for bilirubin and BVRA in the prevention of steatosis, their functions in the later stages of liver disease, and their potential therapeutic application.

Lowered expression of microRNA-125a-5p in human hepatocellular carcinoma and up-regulation of its oncogenic targets sirtuin-7, matrix metalloproteinase-11, and c-Raf

Human microRNA-125a-5p (miR-125a) is expressed in most tissues where it downregulates the expression of membrane receptors or intracellular transductors of mitogenic signals, thus limiting cell proliferation. Expression of this miRNA generally increases with cell differentiation whereas it is downregulated in several types of tumors, such as breast, lung, ovarian, gastric, colon, and cervical cancers, neuroblastoma, medulloblastoma, glioblastoma, and retinoblastoma. In this study, we focused on hepatocellular carcinoma and used real-time quantitative PCR to measure miR-125a expression in 55 tumor biopsies and in matched adjacent non-tumor liver tissues. This analysis showed a downregulation of miR-125a in 80 % of patients, with a mean decrease of 4.7-fold. Comparison of miRNA downregulation with clinicopathological parameters of patients didn't yield significant correlations except for serum bilirubin. We then evaluated the expression of known targets of miR-125a and found that sirtuin-7, matrix metalloproteinase-11, and c-Raf were up-regulated in tumor tissue by 2.2-, 3-, and 1.7-fold, respectively. Overall, these data support a tumor suppressor role for miR-125a and encourage further studies aimed at the comprehension of the molecular mechanisms governing its expression, eventually leading to treatments to restore its expression in tumor cells.

Risk of posttransplant hepatocellular carcinoma recurrence is greater in recipients with higher platelet counts in living donor liver transplantation

Platelets interact with tumor cells and promote metastasis. The importance of platelets in posttransplant hepatocellular carcinoma (HCC) recurrence is unclear. Thus, we aimed to evaluate the association between preoperative platelet count (PLT) and HCC recurrence after living donor liver transplantation. Of 359 recipients of livers from living donors for HCC, 209 of 240 patients who had preoperative PLT ≤75 × 10⁹ /L were matched with 97 of 119 patients who had preoperative PLT >75 × 10⁹ /L using propensity score matching, with an unfixed matching ratio based on factors such as tumor biology. The cutoff value of 75 × 10⁹ /L was set based on optimum stratification analysis. Survival analysis was performed with death as a competing risk event. The primary outcome was overall HCC recurrence. The median follow-up time was 59 months. Before matching, recurrence probability at 1, 2, and 5 years after transplantation was 4.7%, 9.2%, and 11.3% for the low platelet group and 14.5%, 23.0%, and 30.5% for the high platelet group. Recurrence risk was significantly greater in the high platelet group in both univariate (hazard ratio [HR] = 3.09; 95% confidence interval [CI], 1.86-5.14; P < 0.001) and multivariate analyses (HR = 2.10; 95% CI, 1.23-3.60; P =  0.007). In the matched analysis, recurrence risk was also greater in the high platelet group in both univariate (HR = 2.33; 95% CI, 1.36-4.01; P =  0.002) and multivariate analyses (HR = 1.90; 95% CI, 1.02-3.54; P =  0.04). Preoperative PLT had no interaction with the Milan criteria, alpha-fetoprotein level, Edmonson grade, microvascular invasion, or intrahepatic metastasis. Incorporation of preoperative PLT into the Milan criteria significantly improved predictive power. Inflammation-based scores including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and the inflammation-based index did not show superiority to preoperative PLT in predicting HCC recurrence. In conclusion, preoperative PLT appears to be an important host factor affecting HCC recurrence after living donor liver transplantation. Liver Transplantation 24 44-55 2018 AASLD.