Factors associated with low graft regeneration in the early phase after living donor liver transplantation

Scoring models and test indexes for diagnosis and prognosis of hepatitis B virus-related acute-on-chronic liver failure

Hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) is a common type of liver failure, which can occur in the context of chronic hepatitis B or cirrhosis compensatory period or decompensated period. HBV-ACLF progresses rapidly, is often complicated with multiple organ failure syndrome involving the liver, brain, heart, kidney, etc., and is associated with an extremely high short-term mortality rate. The American College of Gastroenterology (ACG) defines HBV-ACLF as a potentially reversible disease, and early diagnosis and standardized treatment will affect its prognosis. In recent years, the clinical application of some new scoring models and biomarkers has effectively improved the diagnosis and prognosis of HBV-ACLF. This article reviews some scoring models and test indexes recently used in the clinical treatment and explores their value in the diagnosis and prognosis of HBV-ACLF.

PLT Counts as a Predictive Marker after Plasma Exchange in Patients with Hepatitis B Virus-Related Acute-on-Chronic Liver Failure

BACKGROUND AND OBJECTIVES

The platelet (PLT) value in hepatitis B-related acute-on-chronic liver failure (HBV-ACLF) is not sufficiently understood. The present study aimed to evaluate the prognostic effect of PLT on the prediction of HBV-ACLF outcomes after plasma exchange (PE).

METHODS

HBV-ACLF patients treated with PE between January 2017 and August 2021 were followed up for at least 6 months. Cox regression was performed to develop the predictive model, and the model's performance was analyzed using the receiver operating characteristic curve (ROC).

RESULTS

A total of 170 patients were included. The overall survival rate within 180 days was 75.88%. Age, PLT, total bilirubin (TBil), and the iMELD scores were independent risk factors affecting the prognosis of HBV-ACLF patients after PE. According to the Cox regression results, the new model was calculated: R = 0.142 × iMELD-0.009 × PLT. The area under the curve (AUC) of the receiver operating characteristic curve (ROC) was 0.758 (95% CI 0.678-0.838), and patients with lower PLT-iMELD scores (<4.50) had a better prognosis (p < 0.001).

CONCLUSION

PLT is a valuable prognostic biomarker for HBV-ACLF patients after PE. The modified iMELD model incorporating PLT has a better sensitivity and efficacy in predicting the prognosis of patients.

Dualistic role of platelets in living donor liver transplantation: Are they harmful?

Platelets are anucleate fragments mainly involved in hemostasis and thrombosis, and there is emerging evidence that platelets have other nonhemostatic potentials in inflammation, angiogenesis, regeneration and ischemia/reperfusion injury (I/R injury), which are involved in the physiological and pathological processes during living donor liver transplantation (LDLT). LDLT is sometimes associated with impaired regeneration and severe I/R injury, leading to postoperative complications and decreased patient survival. Recent studies have suggested that perioperative thrombocytopenia is associated with poor graft regeneration and postoperative morbidity in the short and long term after LDLT. Although it is not fully understood whether thrombocytopenia is the cause or result, increasing platelet counts are frequently suggested to improve posttransplant outcomes in clinical studies. Based on rodent experiments, previous studies have identified that platelets stimulate liver regeneration after partial hepatectomy. However, the role of platelets in LDLT is controversial, as platelets are supposed to aggravate I/R injury in the liver. Recently, a rat model of partial liver transplantation (LT) was used to demonstrate that thrombopoietin-induced thrombocytosis prior to surgery accelerated graft regeneration and improved the survival rate after transplantation. It was clarified that platelet-derived liver regeneration outweighed the associated risk of I/R injury after partial LT. Clinical strategies to increase perioperative platelet counts, such as thrombopoietin, thrombopoietin receptor agonist and platelet transfusion, may improve graft regeneration and survival after LDLT.

The Lactate-to-Platelet Ratio: A Novel Predictor for Short-Term Early Allograft Failure After Liver Transplantation

BACKGROUND

Early allograft dysfunction (EAD) is a criterion to evaluate initial graft dysfunction associated with inferior graft survival and postoperative complications after liver transplantation (LT). This study defined the lactate-to-platelet ratio (LPR) as lactate level immediately post-LT/platelet count on postoperative day 1 and evaluated its association with EAD and short-term graft failure.

MATERIALS AND METHODS

This study reviewed 434 deceased-donor LTs from individuals with confirmed brain death between January 2008 and December 2014. The area under the curve (AUC) was used to compare the predictive capacity for 3-month graft survival between EAD and the LPR. Along with LPR, the risk factors for 3-month graft failure were analyzed by multivariate analysis.

RESULTS

EAD was reported in 127 patients (31%). The LPR in patients with EAD was significantly higher than that in patients without EAD (9.8 vs 5.9, P < .001). In the multivariate analysis, both the LPR (per 1.0 increase) and EAD were independent risk factors for 3-month graft failure (hazard ratio [HR] =1.03, P = .03; and HR = 9.14, P = .001). The comparison of the AUCs between the LPR and EAD showed no significant difference (0.79 vs 0.78, P = .84), whereas the combination of EAD and LPR had a better predictive capacity than EAD alone (0.86 vs 0.78, P < .001). The LPR showed an inverse relationship for predicting 3-month graft survival.

CONCLUSIONS

The LPR is a continuous parameter that enables prediction of initial graft function and estimation of the 3-month graft failure rate with the advantages of early availability and simple calculations.

Platelets Stimulate Liver Regeneration in a Rat Model of Partial Liver Transplantation

Living donor liver transplantation (LDLT) is sometimes associated with impaired regeneration and severe ischemia/reperfusion injury (IRI) in the graft, resulting in small-for-size syndrome (SFSS). Platelets were previously reported to stimulate liver regeneration in models of hepatectomy, but the evidence in partial liver transplantation (LT) is lacking. In this study, a rat model of partial LT was used, and the impact of thrombopoietin (TPO)-induced perioperative thrombocytosis on graft regeneration, IRI, and survival was investigated. In experiment 1, a 30% partial LT was performed. Under thrombocytosis, SFSS was attenuated, as shown by decreased levels of serum aminotransferases, bilirubin, and ascites. Serum hepatocyte regeneration-related cytokines, including insulin-like growth factor-1, hepatocyte growth factor, interleukin 6 (IL6), and tumor necrosis factor α (TNF-α), were elevated. In addition, the proliferative signaling pathways, Ki-67-labeling index, proliferating cell nuclear antigen (PCNA)-labeling index, mitotic index, and liver/body weight ratio were increased under thrombocytosis. The platelet-induced regeneration was independent of TPO because increases in the Ki-67-labeling and PCNA-labeling indexes were eliminated after reducing platelet counts by antiplatelet serum in rats administered with TPO. For IRI, thrombocytosis did not aggravate oxidative stress or downstream signaling pathways, necrosis, or apoptosis in the graft. After Kupffer cell (KC) depletion, the platelet-induced attenuation of serum aminotransferases, increased serum levels of IL6 and TNF-α, and proliferation-related signaling pathways were eliminated. Moreover, platelet accumulation in the graft decreased substantially. In experiment 2, a 20% partial LT was performed, and thrombocytosis improved postoperative survival. In conclusion, our results suggested that thrombocytosis stimulated graft regeneration and prolonged survival without aggregating IRI after partial LT, and KCs vitally contributed to platelet-derived regeneration. Platelet therapies to increase perioperative platelet counts may improve the outcomes after LDLT.

The dynamic of platelet count as a novel and valuable predictor for 90-day survival of hepatitis B virus-related acute-on-chronic liver failure patients

BACKGROUND

The prognosis of hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is extremely poor due to multiple organ dysfunction.

OBJECTIVES

To investigate the prognostic risk factors and create a 90-day prognostic predictive model for the patients with HBV-ACLF.

METHODS

Demographic information, clinical examination, and laboratory test results of the enrolled patients were collected to study the prognostic risk factors. Univariate and multivariate analysis and stepwise Logistic regression were performed to develop the predictive model. External validation was performed to verify the model.

RESULTS

A total of 333 HBV-ACLF patients and 86 HBV-non-ACLF patients were included in this study. Age, alpha-fetoprotein (AFP), total bilirubin (TBIL), platelet (PLT), and international normalized ratio (INR) were found to be independent risk factors for poor outcomes of HBV-ACLF patients. The formula identified for the linear predictor (LP) of the prognosis of HBV-ACLF patients is thus: LP_ACLF=-5.04-0.056×age-0.002×AFP-0.010×PLT+0.002×TBIL+0.877×INR. The area under curve (AUC) of the receiver operating characteristic curve (ROC) was 0.7835 (95% CI 0.7248-0.8423).

CONCLUSIONS

A predictive model with good calibration and discrimination for 90-day survival of HBV-ACLF patients, including 5 variables, namely age, AFP, PLT, TBIL, and INR was established. Platelet count was a sensitive and dynamic variable for the prognosis of HBV-ACLF.

Prediction of liver regeneration in recipients after living-donor liver transplantation in using preoperative CT texture analysis and clinical features

PURPOSE

The aim of the study is to predict the rate of liver regeneration in recipients after living-donor liver transplantation using preoperative CT texture and shape analysis of the future graft.

METHODS

102 donor-recipient pairs who underwent living-donor liver transplantation using right lobe grafts were retrospectively included. We semi-automatically segmented the future graft from preoperative CT. The volume of the future graft (LV_pre) was measured, and texture and shape analyses were performed. The graft liver was segmented from postoperative follow-up CT and the volume of the graft (LV_post) was measured. The regeneration index was defined by the following equation: [(LV_post-LV_pre)/LV_pre] × 100(%). We performed a stepwise, multivariate linear regression analysis to investigate the association between clinical, texture and shape parameters and the RI and to make the best-fit predictive model.

RESULTS

The mean regeneration index was 47.5 ± 38.6%. In univariate analysis, the volume of the future graft, energy, effective diameter, surface area, sphericity, roundness_m, compactness1, and grey-level co-occurrence matrix contrast as well as several clinical parameters were significantly associated with the regeneration index (p < 0.05). The best-fit predictive model for the regeneration index made by multivariate analysis was as follows: Regeneration index (%) = 127.020-0.367 × effective diameter - 1.827 × roundness_m + 47.371 × recipient body surface area (m²) + 12.041 × log(recipient white blood cell count) (× 10³/μL)+ 18.034 (if the donor was female).

CONCLUSION

The effective diameter and roundness_m of the future graft were associated with liver regeneration. Preoperative CT texture analysis of future grafts can be useful for predicting liver regeneration in recipients after living-donor liver transplantation.

Hallmarks of postoperative liver regeneration: An updated insight on the regulatory mechanisms

Performance and advances in liver surgery makes remarkable progress of the understanding of liver regeneration. Liver regeneration after liver resection has been widely researched, and the underlying mechanism mostly concerns proliferation of hepatocytes and the influence by inflammation through activation of Kupffer cells and the other parenchymal cells, the second regenerative pathway by hepatic progenitor cells (HPCs), inducing angiogenesis, remodeling of a extracellular matrix (ECM), and termination mechanisms. New clinical surgeries and the updated multiomics analysis are exploiting the remarkable progress, especially in immune regulation and metabolic process of two emerging hallmarks. This review briefly represents a systemic outline of eight hallmarks, including hepatocyte proliferation, contribution of hepatic progenitor cells, inducing angiogenesis, reprogramming of the extracellular matrix, apoptosis and termination of proliferation, inflammation, immune and metabolic regulation, which are set as organizing characteristics of postoperative liver regeneration and future directions of refining treatment targets.