Post-Liver Transplant Acute Kidney Injury

Acute kidney injury in patients with cirrhosis: Acute Disease Quality Initiative (ADQI) and International Club of Ascites (ICA) joint multidisciplinary consensus meeting

Patients with cirrhosis are prone to developing acute kidney injury (AKI), a complication associated with a markedly increased in-hospital morbidity and mortality, along with a risk of progression to chronic kidney disease. Whereas patients with cirrhosis are at increased risk of developing any phenotype of AKI, hepatorenal syndrome (HRS), a specific form of AKI (HRS-AKI) in patients with advanced cirrhosis and ascites, carries an especially high mortality risk. Early recognition of HRS-AKI is crucial since administration of splanchnic vasoconstrictors may reverse the AKI and serve as a bridge to liver transplantation, the only curative option. In 2023, a joint meeting of the International Club of Ascites (ICA) and the Acute Disease Quality Initiative (ADQI) was convened to develop new diagnostic criteria for HRS-AKI, to provide graded recommendations for the work-up, management and post-discharge follow-up of patients with cirrhosis and AKI, and to highlight priorities for further research.

Low preoperative serum uric acid is associated with early acute kidney injury after living donor liver transplantation

BACKGROUND

Liver transplantation is treatment option for patients with end-stage liver disease and hepatocellular carcinoma. Renal function deterioration significantly impacts the survival rates of liver recipients, and serum uric acid (SUA) is associated with both acute and chronic renal function disorders. Thus, our study aimed to assess the relationship and predictive value of preoperative SUA level and postoperative acute kidney injury (AKI) in living donor liver transplantation (LDLT).

METHODS

We conducted a prospective observational study on 87 patients undergoing LDLT. Blood samples were collected immediately before LDLT, and renal function status was followed up for 3 consecutive days postoperatively.

RESULTS

Low SUA levels (cutoff value 4.15 mg/dL) were associated with a high risk of early posttransplantation AKI. The area under the curve was 0.73 (sensitivity, 79.2%; specificity, 59.4%). Although not statistically significant, there were no deaths in the non-AKI group but two in the early AKI group secondary to liver graft dysfunction in addition to early AKI within the first month after LDLT.

CONCLUSION

AKI after liver transplantation may lead to a deterioration of patient status and increased mortality rates. We determined low preoperative SUA levels as a possible risk factor for early postoperative AKI.

Post Liver Transplant Renal Dysfunction-Evaluation, Management and Immunosuppressive Practice

Liver transplantation (LT) is an effective and lifesaving treatment for patients with end-stage liver disease and hepatocellular carcinoma. Significant improvement in intermediate and long-term survival has been possible due to advancements in immunosuppressive therapy, perioperative care, and surgical techniques. Despite these advances, metabolic complications, including diabetes mellitus, cardiovascular diseases, malignancies, and renal dysfunction, are challenging issues after LT. Acute kidney injury (AKI) and chronic kidney disease (CKD) after LT are common and result in significant morbidity and mortality. Early diagnosis of kidney injury after LT is challenging, and no technique has yet proven effective in prediction of renal dysfunction. The methods for assessing renal function range from formulas that predict glomerular filtration rate to non-invasive biomarkers. The universal adoption of the model for end-stage liver disease has a direct impact on the incidence of peri-transplant AKI and development of CKD in the long-term. Post-LT renal dysfunction is multifactorial and is usually a result of pre-transplantation comorbidities, occurrence of renal dysfunction on the waiting list, perioperative events, and post-transplant nephrotoxic immunosuppressive medication use. Early identification of patients at risk for renal dysfunction and adoption of preventive measures are crucial in the pre-transplant period. No data are currently available to suggest a surgical technique that reliably demonstrates renal protection. Nephroprotective strategies during LT follow accepted surgical practice guidelines, such as maintenance of intravascular volume and mean arterial pressure. The management of kidney disease following LT is challenging, as by the time the serum creatinine is significantly elevated, few interventions impact the course of progression. Early nephroprotective measures are strongly advised and they mostly center on delaying the administration of calcineurin inhibitors (CNIs) during the initial postoperative period, lowering CNI dosage and combining CNI with mycophenolate mofetil and everolimus. The reasons for renal failure following LT, the techniques used to diagnose it, and the therapies designed to preserve renal function both immediately and late after LT are all critically evaluated in this review.

Adequate cumulative exposure to tacrolimus and low tacrolimus variability decrease the incidence of biliary complications after liver transplantation

BACKGROUND

Nonearly biliary complications (BCs) after liver transplantation (LT) are highly associated with immunological status. Tacrolimus is the main immunosuppressant. Whether and how tacrolimus bioavailability affects BCs is unclear.

METHODS

LT recipients receiving tacrolimus-free immunosuppressants or developing BCs within 3 months after LT were excluded. Tacrolimus-related variables included trough concentration (C0), variability and cumulative exposure to tacrolimus (CET). Receiver operating characteristic (ROC) curves defined cutoff values of CET and variability. The values divided patients into adequate and low CET groups, also high and low-variability groups. Inverse probability of treatment weighting (IPTW) was used to reduce bias. Logistic regression identified risk factors. Kaplan-Meier curves were generated for survival comparison.

RESULTS

409 patients were enrolled, and 39 (9.5 %) suffered from BCs. The mean C0 values were 6.9 and 7.2 ng/mL in the BCs and BCs-free groups, respectively. CET within 3 postoperative months was 550.0 and 608.6 ng.day/mL, while the tacrolimus variability was 0.4 and 0.3, respectively. The cutoff values for CET within 3 months and variability predicting BCs were 660.5 and 0.54, respectively. Multivariable logistic regression revealed that low CET within 3 months (p = 0.005, p = 0.002) and high variability (p < 0.001, p < 0.001) were associated with BCs before and after IPTW. Appropriate CET and low variability were associated with better overall survival (p = 0.009 and 0.029). Subgroup analysis indicated that long cold ischemia time (CIT), high bilirubin and low CET had a higher relative risk and raised the incidence of BCs.

CONCLUSIONS

Adequate CET and low variability of tacrolimus ameliorated nonearly BCs incidence and improved survival.

Global Scientific Trends in Continuous Renal Replacement Therapy from 2000 to 2023: A Bibliometric and Visual Analysis

INTRODUCTION

Continuous renal replacement therapy (CRRT) is one of the most widely used blood purification and organ support methods in the ICU. However, the development process, the current status, hotspots, and future trends of CRRT remain unclear.

METHOD

The WoSCC database was used to analyze CRRT research evolution and theme trends. VOSviewer was used to construct coauthorship, co-occurrence, co-citation, and network visualizations. CiteSpace is used to detect bursts for co-occurrence items. Several important subtopics were reviewed and discussed in more detail.

RESULTS

Global publications increased from 56 in 2000 to 398 in 2023, a 710.71% increase. Blood Purification published the most manuscripts, followed by the International Journal of Artificial Organs. The USA, the San Bortolo Hospital, and Bellomo were the most productive and impactful institution, country, and author, respectively. Based on co-occurrence cluster analysis, five clusters emerged: (1) clinical applications and management of CRRT; (2) sepsis and CRRT; (3) CRRT anticoagulant management; (4) CRRT and antibiotic pharmacokinetics and pharmacodynamics; and (5) comparison of CRRT and intermittent hemodialysis. COVID-19, initiation, ECOMO, cefepime, guidelines, cardiogenic shock, biomarker, and outcome were the latest high-frequency keywords or strongest bursts, indicating the emerging frontiers of CRRT.

CONCLUSIONS

There has been widespread publication and citation of CRRT research in the past 2 decades. We provide an overview of current trends, global collaboration patterns, basic knowledge, research hotspots, and emerging frontiers.

Liver Transplant as a Treatment of Primary and Secondary Liver Neoplasms

Importance

Liver malignancies are an increasing global health concern with a high mortality. We review outcomes following liver transplant for primary and secondary hepatic malignancies.

Observations

Transplant may be a suitable treatment option for primary and secondary hepatic malignancies in well-selected patient populations.

Conclusions and Relevance

Many patients with primary or secondary liver tumors are not eligible for liver resection because of advanced underlying liver disease or high tumor burden, precluding complete tumor clearance. Although liver transplant has been a long-standing treatment modality for patients with hepatocellular carcinoma, recently transplant has been considered for patients with other malignant diagnoses. In particular, while well-established for hepatocellular carcinoma and select patients with perihilar cholangiocarcinoma, transplant has been increasingly used to treat patients with intrahepatic cholangiocarcinoma, as well as metastatic disease from colorectal liver and neuroendocrine primary tumors. Because of the limited availability of grafts and the number of patients on the waiting list, optimal selection criteria must be further defined. The ethics of organ allocation to individuals who may benefit from prolonged survival after transplant yet have a high incidence of recurrence, as well as the role of living donation, need to be further discerned in the setting of transplant oncology.

Role of the immune system in liver transplantation and its implications for therapeutic interventions

Liver transplantation (LT) stands as the gold standard for treating end-stage liver disease and hepatocellular carcinoma, yet postoperative complications continue to impact survival rates. The liver's unique immune system, governed by a microenvironment of diverse immune cells, is disrupted during processes like ischemia-reperfusion injury posttransplantation, leading to immune imbalance, inflammation, and subsequent complications. In the posttransplantation period, immune cells within the liver collaboratively foster a tolerant environment, crucial for immune tolerance and liver regeneration. While clinical trials exploring cell therapy for LT complications exist, a comprehensive summary is lacking. This review provides an insight into the intricacies of the liver's immune microenvironment, with a specific focus on macrophages and T cells as primary immune players. Delving into the immunological dynamics at different stages of LT, we explore the disruptions after LT and subsequent immune responses. Focusing on immune cell targeting for treating liver transplant complications, we provide a comprehensive summary of ongoing clinical trials in this domain, especially cell therapies. Furthermore, we offer innovative treatment strategies that leverage the opportunities and prospects identified in the therapeutic landscape. This review seeks to advance our understanding of LT immunology and steer the development of precise therapies for postoperative complications.

Update on persistent acute kidney injury in critical illnesses

Acute kidney injury (AKI) affects about half of patients admitted to the intensive care unit (ICU), and worsens their short- and long-term outcomes. Apparently self-limiting AKI episodes initiate a progression toward chronic kidney disease (CKD) through cellular and molecular mechanisms that are yet to be explained. In particular, persistent AKI, defined in 2016 by the Acute Dialysis Quality Initiative as an AKI which lasts more than 48 h from its onset, has been correlated with higher morbidity and mortality, and with a higher progression to acute kidney disease (AKD) and CKD than transient AKI (i.e. AKI with a reversal within 48 h). This classification has been also used in the setting of solid organ transplantation, demonstrating similar outcomes. Due to its incidence and poor prognosis and because prompt interventions seem to change its course, persistent AKI should be recognized early and followed-up also after its recovery. However, while AKI and CKD are well-described syndromes, persistent AKI and AKD are relatively new entities. The purpose of this review is to highlight the key phases of persistent AKI in ICU patients in terms of both clinical and mechanistic features in order to offer to clinicians and researchers an updated basis from which to start improving patients' care and direct future research.

Development of a nomogram for the prediction of acute kidney injury after liver transplantation: a model based on clinical parameters and postoperative cystatin C level

BACKGROUND

Acute kidney injury (AKI) is common after liver transplantation (LT). We developed a nomogram model to predict post-LT AKI.

METHODS

A total of 120 patients were eligible for inclusion in the study. Clinical information was extracted from the institutional electronic medical record system. Blood samples were collected prior to surgery and immediately after surgery. Univariable and multivariate logistic regression were used to identify independent risk factors. Finally, a nomogram was developed based on the final multivariable logistic regression model.

RESULTS

In total, 58 (48.3%) patients developed AKI. Multivariable logistic regression revealed four independent risk factors for post-LT AKI: operation duration [odds ratio (OR) = 1.728, 95% confidence interval (CI) = 1.121-2.663, p = 0.013], intraoperative hypotension (OR = 3.235, 95% CI = 1.316-7.952, p = 0.011), postoperative cystatin C level (OR = 1.002, 95% CI = 1.001-1.004, p = 0.005) and shock (OR = 4.002, 95% CI = 0.893-17.945, p = 0.070). Receiver operating characteristic curve analysis was used to evaluate model discrimination. The area under the curve value was 0.815 (95% CI = 0.737-0.894).

CONCLUSION

The model based on combinations of clinical parameters and postoperative cystatin C levels had a higher predictive performance for post-LT AKI than the model based on clinical parameters or postoperative cystatin C level alone. Additionally, we developed an easy-to-use nomogram based on the final model, which could aid in the early detection of AKI and improve the prognosis of patients after LT.

Impact of Sirolimus versus Mycophenolate Mofetil on Kidney Function after Calcineurin Inhibitor Dose Reduction in Liver Transplant Recipients

Impaired kidney function is associated with increased morbidity and mortality in patients undergoing liver transplantation. Although immunosuppressants are essential in these patients, they impair kidney function. This study aimed to compare adverse kidney outcomes between patients treated with a reduced dose of tacrolimus (calcineurin inhibitor) plus sirolimus or mycophenolate mofetil (MMF) in the liver transplant center at Kaohsiung Chang Gung Memorial Hospital between April 2011 and December 2017. Propensity score matching was used to identify 232 patients. The risk of adverse kidney outcomes was estimated using Cox proportional hazards regression, and changes in kidney function over time were analyzed using linear mixed modeling. Acute kidney disease risks in this study cohort were not significantly different for the two immunosuppressants (aHR 1.04; 95% CI: 0.70-1.55, p = 0.8328). However, sirolimus use was significantly associated with a higher risk of estimated glomerular filtration rate decline > 30% than MMF (aHR, 2.09; 95% CI: 1.33-3.28; p = 0.0014). Our results demonstrate that sirolimus use may have worsened long-term kidney outcomes compared to MMF. Close monitoring of kidney function, dose adjustment, and timely transition to MMF is necessary for LT patients receiving sirolimus.

Artificial intelligence, machine learning, and deep learning in liver transplantation

Liver transplantation (LT) is a life-saving treatment for individuals with end-stage liver disease. The management of LT recipients is complex, predominantly because of the need to consider demographic, clinical, laboratory, pathology, imaging, and omics data in the development of an appropriate treatment plan. Current methods to collate clinical information are susceptible to some degree of subjectivity; thus, clinical decision-making in LT could benefit from the data-driven approach offered by artificial intelligence (AI). Machine learning and deep learning could be applied in both the pre- and post-LT settings. Some examples of AI applications pre-transplant include optimising transplant candidacy decision-making and donor-recipient matching to reduce waitlist mortality and improve post-transplant outcomes. In the post-LT setting, AI could help guide the management of LT recipients, particularly by predicting patient and graft survival, along with identifying risk factors for disease recurrence and other associated complications. Although AI shows promise in medicine, there are limitations to its clinical deployment which include dataset imbalances for model training, data privacy issues, and a lack of available research practices to benchmark model performance in the real world. Overall, AI tools have the potential to enhance personalised clinical decision-making, especially in the context of liver transplant medicine.

Risk factors for and prognostic values of postoperative acute kidney injury after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma: A retrospective, propensity score‐matched cohort study of 1312 patients

BACKGROUND

While an association between postoperative acute kidney injury (AKI) and adverse events exists, the incidence and impact of postoperative AKI after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma remain unclear. This study aimed to diagnose AKI and investigate the risk factors for and prognostic value of postoperative AKI.

METHODS

Clinical characteristics of patients who underwent pancreaticoduodenectomy between 2013 and 2020 at a high-volume centre were collected retrospectively. The Kidney Disease Improving Global Outcomes criteria were used to diagnose AKI. A 1:2 propensity score matching (PSM) was used to minimise bias between the AKI and non-AKI groups. Short-term surgical and long-term survival outcomes were compared between groups. Multivariate logistic regression analysis assessed the independent risk factors for AKI development, major complications, and 30-day mortality.

RESULTS

Postoperative AKI occurred in 10.7% of 1312 patients. Total bilirubin level > 250 μmol/L (odds ratio [OR]: 3.24; p < 0.001), estimated glomerular filtration rate < 60 ml/min/1.73 m² (OR: 2.30; p = 0.048), and intraoperative estimated blood loss >1000 ml (OR: 2.96; p = 0.001) were independent risk factors for postoperative AKI. After PSM, higher incidences of major complications (p < 0.001) and 30-day mortality (p < 0.001) were observed in the AKI group than in the non-AKI group. There was no difference in long-term overall survival outcomes between both groups (p = 0.535). AKI was an independent predictor of major complications (OR: 3.06; p < 0.001) and 30-day mortality (OR: 2.87; p = 0.034).

CONCLUSIONS

Postoperative AKI is common after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma and has a predictive effect on major complications and 30-day mortality. Therefore, prevention and proper management of postoperative AKI are required in clinical practice.

Highly pathogenic coronaviruses and the kidney

Since the end of 2019, the outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has triggered a pneumonia epidemic, posing a significant public health challenge in 236 countries, territories, and regions worldwide. Clinically, in addition to the symptoms of pulmonary infection, many patients with SARS-CoV-2 infections, especially those with a critical illness, eventually develop multiple organ failure in which damage to the kidney function is common, ultimately leading to severe consequences such as increased mortality and morbidity. To date, three coronaviruses have set off major global public health security incidents: Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and SARS-CoV-2. Among the diseases caused by the coronaviruses, the coronavirus disease 2019 (COVID-19) has been the most impactful and harmful. Similar to with SARS-CoV-2 infections, previous studies have shown that kidney injury is also common and prominent in patients with the two other highly pathogenic coronaviruses. Therefore, in this review, we aimed to comprehensively summarize the epidemiological and clinical characteristics of these three pandemic-level infections, provide a deep analysis of the potential mechanism of COVID-19 in various types of kidney diseases, and explore the causes of secondary kidney diseases of SARS-CoV-2, so as to provide a reference for further research and the clinical prevention of kidney damage caused by coronaviruses.

Are short-term complications associated with poor allograft and patient survival after liver transplantation? A systematic review of the literature and expert panel recommendations

BACKGROUND

Maximizing patient and allograft survival after liver transplant (LT) is important from both a patient care and organ utilization perspective. Although individual studies have addressed the effects of short-term post-LT complications on a limited scale, there has not been a systematic review of the literature formally assessing the potential effects of early complications on long-term outcomes.

OBJECTIVES

To identify whether short-term complications after LT affect allograft and overall survival, to identify short-term complications of particular clinical interest and significance, and to provide recommendations to improve post-LT graft and patient survival.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

A systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel.

RESULTS

The literature review and analysis provided show that short-term complications have a large impact on allograft and patient survival after LT. The complications with the strongest effect on survival are acute kidney injury (AKI), biliary complications, and early allograft dysfunction (EAD).

CONCLUSION

This panel recommends taking measures to reduce the risk and incidence of short-term complications post-LT. Clinicians should pay particular attention to preventing or ameliorating AKI, biliary complications, and EAD (Quality of evidence; Moderate | Grade of Recommendation; Strong).

Association between Gut Colonization of Vancomycin-resistant Enterococci and Liver Transplant Outcomes

BACKGROUND

Vancomycin-resistant enterococci (VRE) colonization is common in liver transplant recipients and has been associated with worse post-transplant outcomes.

METHODS

We conducted a retrospective cohort study at the University of Alberta Hospital including patients who underwent a liver transplant between September 2014 and December 2017.

RESULTS

Of 343 patients, 68 (19.8%) had pre-transplant VRE colonization and 27 (27/275, 9.8%) acquired VRE post-transplant, 67% were males and the median age was 56.5 years. VRE colonized patients at baseline had higher MELD scores and required longer post-transplant hospitalization. VRE colonization was associated with increased risk of early acute kidney injury (AKI) (64% vs 52%, p = 0. 044), clinically significant bacterial/fungal infection (29% vs 17%, p = 0. 012) and invasive VRE infection (5% vs 1%, p = 0. 017). Mortality at 2-years was 13% in VRE-colonized versus 7% in non-colonized (p = 0.085). On multivariate analysis, VRE colonization increased the risk of post-transplant AKI (HR 1.504, 95% CI: 1.077-2.100, p = 0.017) and clinically significant bacterial or fungal infection at 6 months (HR 2.038, 95%CI: 1.222-3.399, p = 0.006), and was associated with non-significant trend towards increased risk of mortality at 2-years post-transplant (HR 1.974 95% CI 0.890-4.378; p = 0.094).

CONCLUSIONS

VRE colonization in liver transplant patients is associated with increased risk of early AKI, clinically significant infections, and a trend towards increased mortality at 2-years. This article is protected by copyright. All rights reserved.

Predictive Role of the D-Dimer Level in Acute Kidney Injury in Living Donor Liver Transplantation: A Retrospective Observational Cohort Study

This study aimed to determine the association between serum D-dimer levels and the risk of acute kidney injury (AKI) in patients undergoing living donor liver transplantation (LDLT). Clinical data of 675 patients undergoing LDLT were retrospectively analyzed. The exclusion criteria included a history of kidney dysfunction, emergency cases, and missing data. The final study population of 617 patients was divided into the normal and high D-dimer groups (cutoff: 0.5 mg/L). After LDLT, 145 patients (23.5%) developed AKI. A high D-dimer level (>0.5 mg/L) was an independent predictor of postoperative development of AKI in the multivariate analysis when combined with diabetes mellitus [DM], platelet count, and hourly urine output. AKI was significantly higher in the high D-dimer group than in the normal D-dimer group (odds ratio [OR], 2.792; 95% confidence interval [CI], 1.227-6.353). Patients with a high D-dimer exhibited a higher incidence of early allograft dysfunction, longer intensive care unit stay, and a higher mortality rate. These results could improve the risk stratification of postoperative AKI development by encouraging the determination of preoperative D-dimer levels in patients undergoing LDLT.

Acute Kidney Injury After Liver Transplant: Incidence, Risk Factors, and Impact on Patient Outcomes

OBJECTIVES

Acute kidney injury is a frequent complication of liver transplant. Here, we assessed the rate and contributing factors of acute kidney injury and need for renal replacement therapy in patients undergoing liver transplant at a transplant center in Tehran, Iran.

MATERIAL AND METHODS

We identified all patients who underwent liver transplant at the Imam Khomeini Hospital Complex from March 2018 to March 2019 and who were followed for 3 months after transplant. Acute kidney injury was defined based on the Acute Kidney Injury Network criteria. We collected demographic and pretransplant, intraoperative, and posttransplant data. Univariable and multivariable models were applied to explore independent risk factors for acute kidney injury incidence and need for renal replacement therapy.

RESULTS

Our study included 173 deceased donor liver transplant recipients. Rates of incidence of acute kidney injury and need for renal replacement therapy were 68.2% and 14.5%, respectively. The 3-month mortality rate among those with severe and mild or moderate acute kidney injury was 44.0% (14/25) and 9.7% (9/ 93), respectively (P < .001). Multivariable analyses indicated that serum albumin (relative risk of 0.55; 95% confidence interval, 0.34-0.87; P = .021), baseline serum creatinine (relative risk of 2.11; 95% confidence interval, 1.56-2.90; P = .037), and intraoperative mean arterial pressure (relative risk of 0.76; 95% confidence interval, 0.63-0.82; P = .008) were independent factors for predicting posttransplant acute kidney injury. Independent risk factors for requiring renal replacement therapy were pretransplant serum creatinine (relative risk of 1.99; 95% confidence interval, 1.89-4.47; P = .044) and intraoperative vasopressor infusion (relative risk of 1.41; 95% confidence interval, 1.38-2.00; P = .021).

CONCLUSIONS

We found a high incidence of acute kidney injury among liver transplant recipients in our center. There was a significant association between severity of acute kidney injury and 3-month and in-hospital mortality.