Arterial Lactate Concentration at the End of Liver Transplantation Is an Early Predictor of Primary Graft Dysfunction

Validation and performance of three scoring systems for predicting primary non-function and early allograft failure after liver transplantation

BACKGROUND

Primary non-function (PNF) and early allograft failure (EAF) after liver transplantation (LT) seriously affect patient outcomes. In clinical practice, effective prognostic tools for early identifying recipients at high risk of PNF and EAF were urgently needed. Recently, the Model for Early Allograft Function (MEAF), PNF score by King's College (King-PNF) and Balance-and-Risk-Lactate (BAR-Lac) score were developed to assess the risks of PNF and EAF. This study aimed to externally validate and compare the prognostic performance of these three scores for predicting PNF and EAF.

METHODS

A retrospective study included 720 patients with primary LT between January 2015 and December 2020. MEAF, King-PNF and BAR-Lac scores were compared using receiver operating characteristic (ROC) and the net reclassification improvement (NRI) and integrated discrimination improvement (IDI) analyses.

RESULTS

Of all 720 patients, 28 (3.9%) developed PNF and 67 (9.3%) developed EAF in 3 months. The overall early allograft dysfunction (EAD) rate was 39.0%. The 3-month patient mortality was 8.6% while 1-year graft-failure-free survival was 89.2%. The median MEAF, King-PNF and BAR-Lac scores were 5.0 (3.5-6.3), -2.1 (-2.6 to -1.2), and 5.0 (2.0-11.0), respectively. For predicting PNF, MEAF and King-PNF scores had excellent area under curves (AUCs) of 0.872 and 0.891, superior to BAR-Lac (AUC = 0.830). The NRI and IDI analyses confirmed that King-PNF score had the best performance in predicting PNF while MEAF served as a better predictor of EAD. The EAF risk curve and 1-year graft-failure-free survival curve showed that King-PNF was superior to MEAF and BAR-Lac scores for stratifying the risk of EAF.

CONCLUSIONS

MEAF, King-PNF and BAR-Lac were validated as practical and effective risk assessment tools of PNF. King-PNF score outperformed MEAF and BAR-Lac in predicting PNF and EAF within 6 months. BAR-Lac score had a huge advantage in the prediction for PNF without post-transplant variables. Proper use of these scores will help early identify PNF, standardize grading of EAF and reasonably select clinical endpoints in relative studies.

Serum Lactate Clearance as a Predictive Biomarker for Optimal Graft Perfusion in Living Donor Liver Transplantation

BACKGROUND

The optimal balance between the graft volume (GV) and portal venous flow (PVF) in living donor liver transplantation (LDLT) is unclear. As lactate is mainly metabolized in the liver, perioperative lactate levels are reportedly a useful biomarker for early graft dysfunction (EGD). The present study analyzed perioperative lactate levels according to the PVF.

METHODS

The PVF/GV (mL/min per 100 g GV) of 97 recipients from 1996 to 2022 was retrospectively classified as low (LPVF; PVF/GV ≤ 100, N = 29), moderate (MPVF; PVF/GV 100-250, N = 40), or high (HPVF; PVF/GV > 250, N = 28). Lactate levels were obtained preoperatively (L0), immediately after graft reperfusion (L1), 4 h after reperfusion (L2), and on postoperative day 3 (L3). The lactate clearances were then calculated.

RESULTS

The lower the PVF/GV ratio, the younger the age at LDLT and the higher the graft-to-recipient weight ratio. The median L2 and L3 in the HPVF group were significantly higher than those in the other groups (p = 0.019 and p = 0.003, respectively). The median ΔL1 in the HPVF group was lower than that in the LPVF and MPVF groups (0.23 vs. 0.50, p < 0.0001 and 0.23 vs. 0.41, p = 0.011, respectively). ΔL1 was negatively correlated with the PVF/GV. Although no patient had EGD, three patients with HPVF with low ΔL1 developed small-for-size syndrome.

CONCLUSIONS

Graft hyperperfusion may delay the recovery of the graft function and result in poor lactate clearance. The combination of the PVF/GV and lactate clearance may be useful as a prognostic marker for optimal graft perfusion in LDLT.

LEVEL OF EVIDENCE

IV.

Advancements in Predictive Tools for Primary Graft Dysfunction in Liver Transplantation: A Comprehensive Review

Orthotopic liver transplantation stands as the sole curative solution for end-stage liver disease. Nevertheless, the discrepancy between the demand and supply of grafts in transplant medicine greatly limits the success of this treatment. The increasing global shortage of organs necessitates the utilization of extended criteria donors (ECD) for liver transplantation, thereby increasing the risk of primary graft dysfunction (PGD). Primary graft dysfunction (PGD) encompasses early allograft dysfunction (EAD) and the more severe primary nonfunction (PNF), both of which stem from ischemia-reperfusion injury (IRI) and mitochondrial damage. Currently, the only effective treatment for PNF is secondary transplantation within the initial post-transplant week, and the occurrence of EAD suggests an elevated, albeit still uncertain, likelihood of retransplantation urgency. Nonetheless, the ongoing exploration of novel IRI mitigation strategies offers hope for future improvements in PGD outcomes. Establishing an intuitive and reliable tool to predict upcoming graft dysfunction is vital for early identification of high-risk patients and for making informed retransplantation decisions. Accurate diagnostics for PNF and EAD constitute essential initial steps in implementing future mitigation strategies. Recently, novel methods for PNF prediction have been developed, and several models for EAD assessments have been introduced. Here, we provide an overview of the currently scrutinized predictive tools for PNF and EAD evaluation strategies, accompanied by recommendations for future studies.

Lactate concentration at the end of liver transplant: Early predictor of graft function or just one piece of the puzzle?

BACKGROUND

The post-operative course after Liver Transplantation (LT) can be complicated by early allograft dysfunction (EAD), primary nonfunction (PNF) and death. A lactate concentration at the end of transplant of ≥5 mmol/L was recently proposed as a predictive marker of PNF, EAD, and mortality; this study aimed to validate these previous reports in a large single center cohort.

METHODS

This retrospective cohort study included adult liver transplant recipients who received grafts from deceased donors at our center between June 2012 and May 2021. Receiver operating characteristic (ROC) curves for the lactate concentration at the end of transplantation were computed to determine the AUC for PNF, EAD and mortality at 90 days.

RESULTS

In our cohort of 1137 cases, the AUCs for lactate to predict EAD, PNF and mortality were respectively .56 (95% confidence interval [CI]: .53-.60), .69 (95% CI: .52-.85), and .74 (95% CI: .63-.84).

CONCLUSION

The clinical value of lactate concentration at the end of transplantation to predict PNF, EAD and mortality at 90 days was, at best, modest, as shown by the relatively low AUCs. Our findings cannot validate previous reports that the lactate level alone is a good predictor of poor outcomes after liver transplantation.

Early allograft dysfunction after living donor liver transplantation-current concepts and future directions

Early allograft dysfunction (EAD) after liver transplantation is a significant clinical problem that negatively impacts graft and patient outcomes. The rising incidence of EAD and what it means concerning living donor liver transplantation (LDLT) is an area of great interest. However, EAD after LDLT is a complex research topic yet to be reviewed comprehensively. Most of the literature on EAD is based on experience in deceased donor liver transplantation, and limited information is available in the context of LDLT. Thus, in this review, we present an overview of EAD after LDLT and have attempted to present balanced points of view on all its aspects, such as definitions, pathogenesis, risk factors, predictive markers, and management. The review aims to broadly overview the nature and extent of ongoing research evidence on this complex topic and inform practice in the field by identifying key concepts and knowledge gaps and highlighting areas that require further inquiry.

Serum neutrophil gelatinase-associated lipocalin and lactate level during surgery predict acute kidney injury and early allograft dysfunction after liver transplantation

Early allograft dysfunction (EAD) and acute kidney injury (AKI) are common and clinically important complications after liver transplantation. Serum lactate level at the end of surgery could predict EAD and neutrophil gelatinase-associated lipocalin (NGAL) is known as a biomarker for AKI after liver transplantation. The authors investigated whether the combination of these two laboratory tests could be used as an early predictor of these two complications of EAD and AKI. We reviewed cases undergoing living donor liver transplantation (n = 353). Lactate-adjusted NGAL level, a combination of these two predictors, was calculated as the sum of each value multiplied by the odds ratio for EAD or AKI. We evaluated whether this combined predictor at the end of surgery is significantly associated with both postoperative AKI or EAD. We compared the area under the receiver operating characteristic curve (AUC) between our multivariable regression models with and without NGAL, lactate, or lactate-adjusted NGAL. NGAL, lactate and lactate-adjusted NGAL are significant predictors for EAD and AKI. The regression model for EAD or AKI including lactate-adjusted NGAL showed a greater AUC (for EAD: odds ratio [OR] 0.88, 95% confidence interval [CI] 0.84-0.91; for AKI: OR 0.89, 95% CI 0.85-0.92) compared to the AUC of the models including lactate (for EAD: OR 0.84, 95% CI 0.81-0.88; for AKI: OR 0.79, 95% CI 0.74-0.83) or NGAL alone (for EAD: OR 0.82, 95% CI 0.77-0.86; for AKI: OR 0.84, 95% CI 0.80-0.88) or the model without lactate or NGAL (for EAD: OR 0.64, 95% CI 0.58-0.69, for AKI: OR 0.75, 95% CI 0.70-0.79). In conclusion, lactate-adjusted NGAL level at the end of surgery could be a reliable combined laboratory predictor for postoperative EAD or AKI after liver transplantation with a greater discriminative ability than lactate or NGAL alone.

Forced-air prewarming prevents hypothermia during living donor liver transplantation: a randomized controlled trial

Despite various intraoperative thermal strategies, core heat loss is considerable during liver transplantation and hypothermia is common. We tested whether forced-air prewarming prevents hypothermia during liver transplantation. Adult patients undergoing living donor liver transplantation were randomly assigned to non-prewarming group (n = 20) or prewarming group (n = 20). Patients in prewarming group underwent 30-min forced-air warming before anesthetic induction. During surgery, core temperature was measured in the pulmonary artery. The primary outcome was intraoperative hypothermia (< 36.0 °C). The secondary outcomes included plasma lactate concentration. Intraoperative hypothermia risk was significantly lower in prewarming group than in non-prewarming group (60.0% vs. 95.0%, P = 0.020). The difference in hypothermia incidence between groups was greater in the post-induction phase (20.0% vs. 85.0%, P < 0.001) than in the anhepatic or post-reperfusion phase, suggesting that prewarming mainly acts on preventing post-induction core-to-peripheral heat redistribution. Hypothermia duration was significantly shorter in prewarming group (60 [0-221] min vs. 383 [108-426] min, P = 0.001). Lactate concentration decreased during 3 h after graft reperfusion in prewarming group, whereas it continuously increased in non-prewarming group (- 0.19 [- 0.48 to 0.13] mmol/L vs. 1.17 [3.31-0.77] mmol/L, P = 0.034). In conclusion, forced-air prewarming decreases the incidence and duration of intraoperative hypothermia with potential clinical benefit while mainly acting by preventing the core-to-peripheral heat redistribution.Clinical trial registration: Registered at the Clinical Research Information Service ( https://cris.nih.go.kr , [KCT0003230]) on 01/10/2018.

Arterial Lactate Concentration at the End of Liver Transplantation is Independently Associated With One-Year Mortality

BACKGROUND

Liver transplant patients who develop hyperlactatemia are at increased risk of postoperative morbidity and short-term mortality, but there are few data on longer-term outcomes. We therefore investigated if arterial lactate concentration obtained immediately after surgery, at the time of admission to the intensive care unit (ICU), was associated with 1-year mortality.

METHODS

In this retrospective cohort study, all patients who underwent liver transplant surgery from a deceased donor between September 2013 and December 2019 were screened for inclusion. Patients who underwent combined transplantation surgery and those with a history of previous liver transplantation (ie, redo surgery) were not included. Logistic regression modeling included univariate and multivariate analyses. Receiver operating characteristic curves and areas under the curves were calculated. Lactate thresholds and association with outcome were analyzed for specificity, sensitivity, and Youden's index.

RESULTS

Of 226 patients included, 18.4% died within 1 year of liver transplantation. Immediate postoperative lactate concentration was independently associated with 1-year mortality with an adjusted odds ratio of 1.35 (95% CI 1.16-1.59; P < .001) per mmol/L increase in lactate and an area under the curve of 0.80 (95% CI 0.72-0.87; P < .001). A lactate concentration of 2.25 mmol/L (cutoff determined using Youden's index) was associated with increased 1-year mortality with a sensitivity of 0.71 and a specificity of 0.72.

CONCLUSIONS

Increased arterial lactate concentration on admission to the intensive care unit immediately after orthotopic liver transplantation is independently associated with increased 1-year mortality.

Intraoperative measurement of the respiratory exchange ratio predicts postoperative complications after liver transplantation

BACKGROUND

During surgery, any mismatch between oxygen delivery (DO₂) and consumption (VO₂) can promote the development of postoperative complications. The respiratory exchange ratio (RER), defined as the ratio of carbon dioxide (CO₂) production (VCO₂) to VO₂, may be a useful noninvasive tool for detecting inadequate DO₂. The primary objective of this study was to test the hypothesis that RER measured during liver transplantation may predict postoperative morbidity. Secondary objectives were to assess the ability of other variables used to assess the DO₂/VO₂ relationship, including arterial lactate, mixed venous oxygen saturation, and veno-arterial difference in the partial pressure of carbon dioxide (VAPCO₂gap), to predict postoperative complications.

METHODS

This retrospective study included consecutive adult patients who underwent liver transplantation for end stage liver disease from June 27th, 2020, to September 5th, 2021. Patients with acute liver failure were excluded. All patients were routinely equipped with a pulmonary artery catheter. The primary analysis was a receiver operating characteristic (ROC) curve constructed to investigate the discriminative ability of the mean RER measured during surgery to predict postoperative complications. RER was calculated at five standardized time points during the surgery, at the same time as measurement of blood lactate levels and arterial and mixed venous blood gases, which were compared as a secondary analysis.

RESULTS

Of the 115 patients included, 57 developed at least one postoperative complication. The mean RER (median [25-75] percentiles) during surgery was significantly higher in patients with complications than in those without (1.04[0.96-1.12] vs 0.88[0.84-0.94]; p < 0.001). The area under the ROC curve was 0.87 (95%CI: 0.80-0.93; p < 0.001) with a RER value (Youden index) of 0.92 giving a sensitivity of 91% and a specificity of 74% for predicting the occurrence of postoperative complications. The RER outperformed all other measured variables assessing the DO₂/VO₂ relationship (arterial lactate, SvO₂, and VAPCO₂gap) in predicting postoperative complications.

CONCLUSION

During liver transplantation, the RER can reliably predict postoperative complications. Implementing this measure intraoperatively may provide a warning for physicians of impending complications and justify more aggressive optimization of oxygen delivery. Further studies are required to determine whether correcting the RER is feasible and could reduce the incidence of complications.

Clinical Impact of Spontaneous Portosystemic Shunts in Liver Transplantation: A Comprehensive Assessment Through Total Shunt Area Measurement

BACKGROUND

The impact of spontaneous portosystemic shunts (SPSSs) on natural history of cirrhotic patients was recently evaluated through the measurement of total shunt area (TSA), a novel tool that allows a comprehensive assessment of SPSSs extension, identifying a direct correlation of higher TSA with lower patient survival. The role of SPSSs in liver transplant (LT) is still debated: we sought to investigate the clinical impact of TSA on the development of early allograft dysfunction (EAD), acute kidney injury (AKI), postoperative complications, and graft and patient survival following LT.

METHODS

Preoperative imaging of 346 cirrhotic patients undergoing primary LT between 2015 and 2020 were retrospectively revised, recording the size and anatomy of each SPSS to calculate TSA. The impact of TSA and selected patient and donor characteristics on the development of EAD, AKI, and clinically relevant complications was evaluated through univariate and multivariate logistic regression, whereas their effect on graft and patient survival was investigated through Cox regression analysis.

RESULTS

A TSA exceeding 78.54 mm 2 resulted as an independent risk factor for the development of EAD (odds ratio [OR]: 2.327; P = 0.003), grade 3 AKI (OR: 2.093; P = 0.041), and clinically relevant complications (OR: 1.962; P = 0.015). Moreover, higher TSA was significantly related to early graft and patient survivals, emerging as an independent risk factor for 12-mo graft loss (hazard ratio: 3.877; P = 0.007) and patient death (hazard ratio: 2.682; P = 0.018).

CONCLUSIONS

Higher TSA emerged as a significant risk factor for worse postoperative outcomes following LT, supporting the need for careful hemodynamic assessment and management of patients presenting multiple/larger shunts.

Postoperative serum myoglobin as a predictor of early allograft dysfunction after liver transplantation

Background

Early allograft dysfunction (EAD) is a common postliver transplant complication that has been associated with graft failure and risk for poor prognosis. There are many risk factors for the incidence of EAD after liver transplantation (LT). This study investigated whether elevated postoperative myoglobin (Mb) increases the incidence of EAD in liver transplanted recipients.

Methods

A total of 150 adult recipients who measured Mb within 3 days after liver transplantation between June 2019 and June 2021 were evaluated. Then, all patients were divided into two groups: the EAD group and the non-EAD group. Univariate and multivariate logistic regression analyses were performed, and receiver operating characteristic curves (ROCs) were constructed.

Results

The incidence of EAD was 53 out of 150 patients (35.3%) in our study. Based on the multivariate logistic analysis, the risk of EAD increased with elevated postoperative Mb (OR = 1.001, 95% CI 1.000–1.001, P = 0.002). The Mb AUC was 0.657, and it was 0.695 when combined with PCT. When the subgroup analysis was conducted, the AUC of serum Mb prediction was better in patients whose preoperative model for end-stage liver disease score  ≤ 15 or operative time ≥ 10 h (AUC = 0.751, 0.758, respectively, or 0.760, 0.800 when combined with PCT).

Conclusion

Elevated Mb significantly increased the risk of postoperative EAD, suggesting that postoperative Mb may be a novel predictor of EAD after liver transplantation.

The study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2100044257, URL: http://www.chictr.org.cn).

The Effects of sodium bicarbonate Ringer’s solution on acute kidney injury and the clinical outcomes after liver transplantation: A randomized controlled trial

Background: Acute kidney injury is the most common complication after liver transplantation. Sodium bicarbonate Ringer’s solution is a new type of crystalloid solution that has been recently used in the clinical setting. Whether sodium bicarbonate Ringer’s solution reduces the occurrence of postoperative AKI and improves the clinical outcomes of liver transplantation patients is not clear.

Objective: To compare the effects of sodium bicarbonate Ringer’s solution versus normal saline on acute kidney injury and clinical outcomes following classic orthotopic liver transplantation.

Methods: Sixty-four participants were randomly assigned to the sodium bicarbonate Ringers (BRS) group or the normal saline (NS) group. The primary outcomes were the incidence and severity of acute kidney injury after liver transplantation. The secondary outcomes included the rate of renal replacement therapy, length of mechanical ventilation, stay in the ICU, stay in the hospital after surgery and 30-day mortality. Other outcomes included the concentration of sodium, chloride, bicarbonate, anion gap, lactate concentration and changes in chloride preoperatively and postoperatively.

Result: Sixty-two patients completed the trial and were analyzed, with 31 patients in each group. There was a significantly lower rate of postoperative acute kidney injury in the BRS group (14/31, 45.2%) than in the NS group (24/31, 77.4%), with a relative risk of 0.58 (95% CI, 0.38–0.90; p = 0.009). The severity of AKI in the BRS group was lower than that in the NS group (Z = -2.932, p = 0.003). There was no significant difference observed in the secondary outcomes. For other outcomes, the concentration of preoperative sodium was lower than postoperative sodium in the NS group (137.2 vs. 140.4, p = 0.009). The concentration of preoperative chloride was lower than that of postoperative chloride in the NS group (102.9 vs. 106.2, p < 0.001). The change in the concentration of chloride in the BRS group was lower than that in the NS group (1.6 vs. 4.7, p = 0.006).

Conclusion: Sodium bicarbonate Ringer’s solution reduced the incidence and severity of acute kidney injury after classic orthotopic liver transplantation.

Biomarkers and predictive models of early allograft dysfunction in liver transplantation - A systematic review of the literature, meta-analysis, and expert panel recommendations

BACKGROUND

Prompt identification of early allograft dysfunction (EAD) is critical to reduce morbidity and mortality in liver transplant (LT) recipients.

OBJECTIVES

Evaluate the evidence supporting biomarkers that can provide diagnostic and predictive value for EAD.

DATA SOURCES

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

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach was derived from an international expert panel. Studies that investigated biomarkers or models for predicting EAD in adult LT recipients were included for in-depth evaluation and meta-analysis. Olthoff's criteria were used as the standard reference for the diagnostic accuracy evaluation.

PROSPERO ID

CRD42021293838 RESULTS: Ten studies were included for the systematic review. Lactate, lactate clearance, uric acid, Factor V, HMGB-1, CRP to ALB ratio, phosphocholine, total cholesterol, and metabolomic predictive model were identified as potential early EAD predictive biomarkers. The sensitivity ranged between .39 and .92, while the specificity ranged from .63 to .90. Elevated lactate level was most indicative of EAD after adult LT (pooled diagnostic odds ratio of 7.15 (95%CI: 2.38-21.46)). The quality of evidence (QOE) for lactate as indicator was moderate according to the GRADE approach, whereas the QOE for other biomarkers was very low to low likely as consequence of study design characteristics such as single study, small sample size, and large ranges of sensitivity or specificity.

CONCLUSIONS

Lactate is an early indicator to predict EAD after LT (Quality of Evidence: Moderate | Grade of Recommendation: Strong). Further multicenter studies and the use of machine perfusion setting should be implemented for validation.

Targeting the Hepatic Microenvironment to Improve Ischemia/Reperfusion Injury: New Insights into the Immune and Metabolic Compartments

Hepatic ischemia/reperfusion injury (IRI) is mainly characterized by high activation of immune inflammatory responses and metabolic responses. Understanding the molecular and metabolic mechanisms underlying development of hepatic IRI is critical for developing effective therapies for hepatic IRI. Recent advances in research have improved our understanding of the pathogenesis of IRI. During IRI, hepatocyte injury and inflammatory responses are mediated by crosstalk between the immune cells and metabolic components. This crosstalk can be targeted to treat or reverse hepatic IRI. Thus, a deep understanding of hepatic microenvironment, especially the immune and metabolic responses, can reveal new therapeutic opportunities for hepatic IRI. In this review, we describe important cells in the liver microenvironment (especially non-parenchymal cells) that regulate immune inflammatory responses. The role of metabolic components in the diagnosis and prevention of hepatic IRI are discussed. Furthermore, recent updated therapeutic strategies based on the hepatic microenvironment, including immune cells and metabolic components, are highlighted.

Liver Ischemia and Reperfusion Induce Periportal Expression of Necroptosis Executor pMLKL Which Is Associated With Early Allograft Dysfunction After Transplantation

Background

Early allograft dysfunction (EAD) following liver transplantation (LT) remains a major threat to the survival of liver grafts and recipients. In animal models, it is shown that hepatic ischemia-reperfusion injury (IRI) triggers phosphorylation of Mixed Lineage Kinase domain-like protein (pMLKL) inducing necroptotic cell death. However, the clinical implication of pMLKL-mediated cell death in human hepatic IRI remains largely unexplored. In this study, we aimed to investigate the expression of pMLKL in human liver grafts and its association with EAD after LT.

Methods

The expression of pMLKL was determined by immunohistochemistry in liver biopsies obtained from both human and rat LT. Human liver biopsies were obtained at the end of preservation (T0) and ~1 hour after reperfusion (T1). The positivity of pMLKL was quantified electronically and compared in rat and human livers and post-LT outcomes. Multiplex immunofluorescence staining was performed to characterize the pMLKL-expressing cells.

Results

In the rat LT model, significant pMLKL expression was observed in livers after IRI as compared to livers of sham-operation animals. Similarly, the pMLKL score was highest after IRI in human liver grafts (in T1 biopsies). Both in rats and humans, the pMLKL expression is mostly observed in the portal triads. In grafts who developed EAD after LT (n=24), the pMLKL score at T1 was significantly higher as compared to non-EAD grafts (n=40). ROC curve revealed a high predictive value of pMLKL score at T1 (AUC 0.70) and the ratio of pMLKL score at T1 and T0 (pMLKL-index, AUC 0.82) for EAD. Liver grafts with a high pMLKL index (>1.64) had significantly higher levels of serum ALT, AST, and LDH 24 hours after LT compared to grafts with a low pMLKL index. Multivariate logistical regression analysis identified the pMLKL-index (Odds ratio=1.3, 95% CI 1.1-1.7) as a predictor of EAD development. Immunohistochemistry on serial sections and multiplex staining identified the periportal pMLKL-positive cells as portal fibroblasts, fibrocytes, and a minority of cholangiocytes.

Conclusion

Periportal pMLKL expression increased significantly after IRI in both rat and human LT. The histological score of pMLKL is predictive of post-transplant EAD and is associated with early liver injury after LT. Periportal non-parenchymal cells (i.e. fibroblasts) appear most susceptible to pMLKL-mediated cell death during hepatic IRI.

Transplantation of Extended Criteria Donor Livers Following Continuous Normothermic Machine Perfusion Without Recooling

BACKGROUND

Traditional liver transplant strategies with cold preservation usually result in ischemia-reperfusion injury (IRI) to the donor liver. Regular normothermic machine perfusion (NMP) donor livers suffer IRI twice. Here, we aimed to introduce a novel technique called continuous NMP without recooling to avoid a second IRI and its application in livers from extended criteria donors.

METHODS

Seven donor livers transplanted following continuous NMP without recooling, 7 donor livers transplanted following standard NMP, and 14 livers under static cold storage (SCS) were included in this study. Perioperative outcomes were recorded and analyzed between groups.

RESULTS

During the NMP without a recooling procedure, all livers cleared lactate quickly to normal levels in a median time of 100 min (interquartile range, 60-180) and remained stable until the end of perfusion. In the NMP without recooling and standard NMP groups, posttransplant peak aspartate aminotransferase and alanine aminotransferase levels were both significantly lower than those in the SCS group (P = 0.0015 and 0.016, respectively). The occurrence rate of early allograft dysfunction was significantly lower in the NMP without recooling group than in the SCS group (P = 0.022), whereas there was no difference in the NMP group with or without recooling (P = 0.462).

CONCLUSIONS

Our pilot study revealed a novel technique designed to avoid secondary IRI. This novel technique is shown to have at least a comparable effect on the standard NMP, although more data are needed to show its superiority in the future.

Reassessment of Relevance and Predictive Value of Parameters Indicating Early Graft Dysfunction in Liver Transplantation: AST Is a Weak, but Bilirubin and INR Strong Predictors of Mortality

Introduction: Early graft dysfunction (EAD) complicates liver transplantation (LT). The aim of this analysis was to discriminate between the weight of each variable as for its predictive value toward patient and graft survival. Methods: We reviewed all LT performed at the Medical University of Innsbruck between 2007 and 2018. EAD was recorded when one of the following criteria was present: (i) aspartate aminotransferase (AST) levels >2,000 IU/L within the first 7 days, (ii) bilirubin levels ≥10mg/dL or (iii) international normalized ratio (INR) ≥1.6 on postoperative day 7. Results: Of 616 LT, 30.7% developed EAD. Patient survival did not differ significantly (P = 0.092; log rank-test = 2.87), graft survival was significantly higher in non-EAD patients (P = 0.008; log rank-test = 7.13). Bilirubin and INR on postoperative day 7 were identified as strong mortality predictors (Bilirubin HR = 1.71 [1.34, 2.16]; INR HR = 2.69 [0.51, 14.31]), in contrast to AST (HR = 0.91 [0.75, 1.10]). Similar results were achieved for graft loss estimation. A comparison with the Model for Early Allograft Function (MEAF) and the Liver Graft Assessment Following Transplantation (L-GrAFT) score identified a superior discrimination potential but lower specificity. Conclusion: Contrarily to AST, bilirubin and INR have strong predictive capacity for patient and graft survival. This fits well with the understanding, that bile duct injury and deprivation of synthetic function rather than hepatocyte injury are key factors in LT.

Early postoperative arterial lactate concentrations to stratify risk of post-hepatectomy liver failure

BACKGROUND

Post-hepatectomy liver failure (PHLF) represents the major determinant for death after liver resection. Early recognition is essential. Perioperative lactate dynamics for risk assessment of PHLF and associated morbidity were evaluated.

METHODS

This was a multicentre observational study of patients undergoing hepatectomy with validation in international high-volume units. Receiver operating characteristics analysis and cut-off calculation for the predictive value of lactate for clinically relevant International Study Group of Liver Surgery grade B/C PHLF (clinically relevant PHLF (CR-PHLF)) were performed. Lactate and other perioperative factors were assessed in a multivariable CR-PHLF regression model.

RESULTS

The exploratory cohort comprised 509 patients. CR-PHLF, death, overall morbidity and severe morbidity occurred in 7.7, 3.3, 40.9 and 29.3 per cent of patients respectively. The areas under the curve (AUCs) regarding CR-PHLF were 0.829 (95 per cent c.i. 0.770 to 0.888) for maximum lactate within 24 h (Lactate_Max) and 0.870 (95 per cent c.i. 0.818 to 0.922) for postoperative day 1 levels (Lactate_POD1). The respective AUCs in the validation cohort (482 patients) were 0.812 and 0.751 and optimal Lactate_Max cut-offs were identical in both cohorts. Exploration cohort patients with Lactate_Max 50 mg/dl or greater more often developed CR-PHLF (50.0 per cent) than those with Lactate_Max between 20 and 49.9 mg/dl (7.4 per cent) or less than 20 mg/dl (0.5 per cent; P < 0.001). This also applied to death (18.4, 2.7 and 1.4 per cent), severe morbidity (71.1, 35.7 and 14.1 per cent) and associated complications such as acute kidney injury (26.3, 3.1 and 2.3 per cent) and haemorrhage (15.8, 3.1 and 1.4 per cent). These results were confirmed in the validation group. Combining Lactate_Max with Lactate_POD1 further increased AUC (ΔAUC = 0.053) utilizing lactate dynamics for risk assessment. Lactate_Max, major resections, age, cirrhosis and chronic kidney disease were independent risk factors for CR-PHLF. A freely available calculator facilitates clinical risk stratification (www.liver-calculator.com).

CONCLUSION

Early postoperative lactate values are powerful, readily available markers for CR-PHLF and associated complications after hepatectomy with potential for guiding postoperative care.Presented in part as an oral video abstract at the 2020 online Congress of the European Society for Surgical Research and the 2021 Congress of the Austrian Surgical Society.

Blood Lactate During Double-Lung Transplantation: A Predictor of Grade-3 Primary Graft Dysfunction

OBJECTIVE

Many prognostic factors of grade-3 primary graft dysfunction at postoperative day 3 (PGD3-T72) have been reported, but intraoperative blood lactate level has not been studied. The present retrospective study was done to test the hypothesis that intraoperative blood lactate level (BLL) could be a predictor of PGD3-T72 after double-lung transplantation.

DESIGN

Retrospective monocentric cohort study.

SETTING

Foch University Hospital, Suresnes, France.

PARTICIPANTS

Patients having received a double-lung transplantation between 2012 and 2019. Patients transplanted twice during the study period, having undergone a multiorgan transplantation, or cardiopulmonary bypass, and those under preoperative extracorporeal membrane oxygenation, were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Analysis was performed on a cohort of 449 patients. Seventy-two (16%) patients had a PGD3-T72. Blood lactate level increased throughout surgery to reach a median value of 2.2 (1.6-3.2) mmol/L in the No-PGD3-T72 group and 3.4 (2.3-5.0) mmol/L in the PGD3-T72 group after second lung implantation. The best predictive model for PGD3-T72 was obtained adding a lactate threshold of 2.6 mmol/L at the end of surgery to the clinical model, and the area under the curve was 0.867, with a sensitivity = 76.9% and specificity = 85.4%. Repeated-measures mixed model of BLL during surgery remained significant after adjustment for covariates (F ratio= 4.22, p < 0.001 for interaction).

CONCLUSIONS

Blood lactate level increases during surgery and reaches a maximum after the second lung implantation. A value below the threshold of 2.6 mmol/L at the end of surgery has a high negative predictive value for the occurrence of a grade-3 primary graft dysfunction at postoperative day 3.

Combination of arterial lactate levels and Cv-aCO2/Da-vO2 ratio to predict early allograft dysfunction after liver transplantation

PURPOSE

We examined the ability of the P(v-a)CO2/Da-vO2 ratio combined with elevated lactate levels to predict early allograft dysfunction (EAD).

MATERIALS AND METHODS

Patients were classified into four groups according to lactate levels and P(v-a)CO2/Da-vO2 ratio: Group 1; lactate >2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio >1.0; Group 2; lactate >2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio <1.0; group 3; lactate<2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio >1.0; group 4; lactate<2.0 mmol/L and P(v-a)CO2/Da-vO2 ratio <1.0. We defined EAD according to Olthoff criteria.

RESULTS

One-hundred and fifty patients were included. EAD occurred in 41 patients (27.3%), and was associated with worse graft survival at 1 year (92% vs. 73%; P = ,003) as well as a higher re-transplantation rate (4,6% vs. 17,1%; P = ,019). The multivariate analysis revealed that P(v-a)CO2/Da-vO2 ratio at T6 [OR 7.05(CI95% 2.77-19.01, P<.001)] was an independent predictor for EAD. Belonging to group 1 at 6 h was associated with worse clinical outcomes but no association was found with 1-year graft survival or 1-year patient survival.

CONCLUSIONS

In this single center, prospective, observational study in patients who received an OLT, we found that elevated lactate levels combined with a high Cv-aCO2/Da-vO2 after 6 h was associated with the development of EAD and worse clinical outcomes in the early postoperative period.

A Novel Oxygen Carrier (M101) Attenuates Ischemia-Reperfusion Injuries during Static Cold Storage in Steatotic Livers

The combined impact of an increasing demand for liver transplantation and a growing incidence of nonalcoholic liver disease has provided the impetus for the development of innovative strategies to preserve steatotic livers. A natural oxygen carrier, HEMO2life^®, which contains M101 that is extracted from a marine invertebrate, has been used for static cold storage (SCS) and has shown superior results in organ preservation. A total of 36 livers were procured from obese Zucker rats and randomly divided into three groups, i.e., control, SCS-24H and SCS-24H + M101 (M101 at 1 g/L), mimicking the gold standard of organ preservation. Ex situ machine perfusion for 2 h was used to evaluate the quality of the livers. Perfusates were sampled for functional assessment, biochemical analysis and subsequent biopsies were performed for assessment of ischemia-reperfusion markers. Transaminases, GDH and lactate levels at the end of reperfusion were significantly lower in the group preserved with M101 (p < 0.05). Protection from reactive oxygen species (low MDA and higher production of NO2-NO3) and less inflammation (HMGB1) were also observed in this group (p < 0.05). Bcl-1 and caspase-3 were higher in the SCS-24H group (p < 0.05) and presented more histological damage than those preserved with HEMO2life^®. These data demonstrate, for the first time, that the addition of HEMO2life^® to the preservation solution significantly protects steatotic livers during SCS by decreasing reperfusion injury and improving graft function.

Lactated Ringer's solution versus normal saline in pediatric living-donor liver transplantation: A matched retrospective cohort study

BACKGROUND

In pediatric living-donor liver transplantation, lactated Ringer's solution and normal saline are commonly used for intraoperative fluid management, but the comparative clinical outcomes remain uncertain.

AIMS

To compare the effect between lactated Ringer's solution and normal saline for intraoperative volume replacement on clinical outcomes among pediatric living-donor liver transplantation patients.

METHODS

This single-center, retrospective trial study enrolled children who received either lactated Ringer's solution or normal saline during living-donor liver transplantation between January 2010 and August 2016. The groups with comparable clinical characteristics were balanced by propensity score matching. The primary outcome was 90-day all-cause mortality, and the secondary outcomes included early allograft dysfunction, primary nonfunction, acute renal injury, and hospital-free days (days alive postdischarge within 30 days of liver transplantation).

RESULTS

We included 333 pediatric patients who met the entry criteria for analysis. Propensity score matching identified 61 patients in each group. After matching, the lactated Ringer's solution group had a higher 90-day mortality rate than the normal saline group (11.5% vs. 0.0%). Early allograft dysfunction and primary nonfunction incidences were also more frequent in the lactated Ringer's solution group (19.7% and 11.5%, respectively) than in the normal saline group (3.3% and 0.0%, respectively). In the lactated Ringer's solution group, four (6.6%) recipients developed acute renal injury within 7 days postoperatively compared with three (4.9%) recipients in the normal saline group. Hospital-free days did not differ between groups (9 days [1-13] vs. 9 days [0-12]).

CONCLUSIONS

For intraoperative fluid management in pediatric living-donor liver transplantation patients, lactated Ringer's solution administration was associated with a higher 90-day mortality rate than normal saline. This finding has important implications for selecting crystalloid in pediatric living-donor liver transplantation. Further randomized clinical trials in larger cohort are necessary to confirm this finding.

Severity of early allograft dysfunction following donation after circulatory death liver transplantation: a multicentre study

Background

Early allograft dysfunction (EAD) is associated with decreased graft and patient survival rates. This study aimed to identify the severity of EAD and develop a predictive model for EAD after donation after circulatory death (DCD) liver transplantation (LT). Furthermore, the influence of operative time on EAD incidence was also evaluated.

Methods

In this retrospective, multicentre cohort study, nomograms were established based on a single-centre training cohort (n=321) and validated in a 3-center validation cohort (n=501).

Results

The incidence rate of EAD was 46.4% (149/321) in the training cohort and 40.5% (203/501) in the validation cohort. Of the 149 EAD patients in the training cohort, 77 patients with either elevated alanine aminotransferase (ALT) or aspartate aminotransferase (AST) were classified as having EAD type A, and the rest of the EAD patients were classified as having EAD type B. Recipients with EAD type B had lower graft and patient survival rates than recipients with EAD type A (P=0.043 and 0.044, respectively). We further developed a nomogram to predict EAD (graft weight, cold ischemia time, donor age, model for end-stage liver disease (MELD) score) and another nomogram to predict EAD type B (graft weight, cold ischemia time, MELD score). The nomograms for the prediction of EAD and EAD type B had good discrimination [concordance index (C-index) =0.712 (0.666-0.758), 0.707 (0.641-0.773)] and calibration [Hosmer-Lemeshow (HL) P=0.384, P=0.425] in the validation cohort. An increased operative time (>6 h) was associated with increased EAD and EAD type B incidence in the high-risk group (P=0.005, P=0.020, respectively).

Conclusions

EAD type B was associated with decreased graft and patient survival rates. The novel nomograms effectively predicted the incidence of EAD and EAD type B in DCD LT patients.

Indocyanine Green Fluorescence Imaging to Predict Graft Survival After Orthotopic Liver Transplantation: A Pilot Study

The incidence of primary nonfunction (PNF) after liver transplantation (LT) remains a major concern with the increasing use of marginal grafts. Indocyanine green (ICG) fluorescence is an imaging technique used in hepatobiliary surgery and LT. Because few early predictors are available, we aimed to quantify in real time the fluorescence of grafts during LT to predict 3-month survival. After graft revascularization, ICG was intravenously injected, and then the fluorescence of the graft was captured with a near infrared camera and postoperatively quantified. A multiparametric modeling of the parenchymal fluorescence intensity (FI) curve was proposed, and a predictive model of graft survival was tested. Between July 2017 and May 2019, 76 LTs were performed, among which 6 recipients underwent retransplantation. No adverse effects of ICG injection were observed. The parameter a₁₅₀ (temporal course of FI) was significantly higher in the re-LT group (0.022 seconds^-1 (0.0011-0.059) versus 0.012 seconds^-1 (0.0001-0.054); P = 0.01). This parameter was the only independent predictive factor of graft survival at 3 months (OR, 2.4; 95% CI, 1.05-5.50; P = 0.04). The best cutoff for the parameter a₁₅₀ (0.0155 seconds^-1 ) predicted the graft survival at 3 months with a sensitivity (Se) of 83.3% and a specificity (Spe) of 78.6% (area under the curve, 0.82; 95% CI, 0.67-0.98; P = 0.01). Quantitative assessment of intraoperative ICG fluorescence on the graft was feasible to predict graft survival at 3 months with a good Se and Spe. Further prospective studies should be undertaken to validate these results over larger cohorts and evaluate the clinical impact of this tool.

Graft factors as determinants of postoperative delirium after liver transplantation

Post-operative delirium (POD) is a frequent complication after surgery, occurring in 15-20% of patients. POD is associated with a higher complications rate and mortality. Literature on POD after liver transplantation (LT) is limited, with the few available studies reporting an incidence of 10-47%. The aim of this study was analyzing pattern, risk factors and clinical impact of POD after LT. Data on donor and recipient characteristics, postoperative course and POD of consecutive adult LT recipients from March 2016 to May 2018 were prospectively collected and retrospectively analyzed. Risk factors for POD were analyzed using univariable logistic regression and Lasso regression. Kaplan-Meier method was used for survival analysis. 309 patients underwent LT during study period; 3 were excluded due to perioperative death. Incidence of POD was 13.4% (n = 41). The median day of onset was 5th (IQR [4-7]) with a median duration of 4 days (IQR [3-7]). Several risk factors, related to the severity of liver disease and graft characteristics, were identified. Graft macrovesicular steatosis was the only factor independently associated with POD at multivariable analysis (OR 1.27, CI 1.09-1.51, p = 0.003). POD was associated with a higher rate of severe postoperative complications and longer intensive care unit and hospital stay, but did not significantly impact on patient and graft survival. Incidence of POD after LT is comparable to that observed after general surgery and graft factors are strongly associated with its onset. These results help identifying a subset of patients to be considered for preventive interventions.

Metabonomic Profile of Macrosteatotic Allografts for Orthotopic Liver Transplantation in Patients With Initial Poor Function: Mechanistic Investigation and Prognostic Prediction

BACKGROUND

Our previous study revealled amplified hazardous effects of macrosteatosis (MaS) on graft failure (GF) in recipients with severe liver damage in short post-operative days, with vague mechanism inside.

AIM

We aimed to uncover the molecular mechanism of donor MaS on GF, and construct the predictive model to monitor post-transplant prognosis based on "omics" perspective.

METHODS

Ultra-performance liquid chromatography coupled to mass spectrometry metabolomic analysis was performed in allograft tissues from 82 patients with initial poor function (IPF) from multi-liver transplant (LT) centers. Pathway analysis was performed by on-line toolkit Metaboanalyst (v 3.0). Predictive model was constructed based on combinative metabonomic and clinical data extracted by stepwised cox proportional analysis.

RESULTS

Principle component analysis (PCA) analysis revealled stratification on metabolic feature in organs classified by MaS status. Differential metabolits both associated with MaS and GF were significantly enriched on pathway of glycerophospholipid metabolism (P < 0.05). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) involved in glycerophospholipid metabolism was significantly decreased in cases with MaS donors and GF (P < 0.05). Better prediction was observed on graft survival by combinative model (area under the curve = 0.91) and confirmed by internal validation.

CONCLUSION

Metabonomic features of allografts can be clearly distinguished by MaS status in patients with IPF. Dysfunction on glycerophospholipid metabolism was culprit to link donor MaS and final GF. Decrement on PC and PE exerted the fatal effects of MaS on organ failure. Metabonomic data might help for monitoring long-term graft survival after LT.

Is Lactic Acidosis After Lung Transplantation Associated With Worse Outcomes?

BACKGROUND

Elevated lactate levels may be caused by increased production suggestive of tissue ischemia; however, they may also occur without evidence of ischemia, by catecholamine activation of beta receptors. The purpose of this study was to determine the factors associated with increased lactate levels during and after lung transplantation and to evaluate whether lactate levels were associated with increased time to extubation and postoperative complications.

METHODS

This was a retrospective study of patients who underwent lung transplantation between January 2015 and May 2017 at the University of Michigan, Ann Arbor, MI. Multivariable linear regression was used to determine the factors associated with peak lactate levels and to find the associations between lactate levels and outcomes of nitric oxide time, intubation time, length of stay, and creatinine level. Logistic regression was used to determine the associations between lactate levels and acute kidney injury and atrial fibrillation.

RESULTS

A total of 86 patients underwent single-lung transplantation (n = 17; 20%) or double-lung transplantation (n = 69; 80%). All patients initially had normal lactate levels. On univariate analysis, lactate levels at several time points were correlated with subsequent acute kidney injury, increased time to extubation, and increased nitric oxide time. After adjustment, the study found that higher peak intensive care unit lactate levels (regression coefficient B = 0.046; interquartile range, 0.006, 0.086; P = .025) were associated with longer length of stay.

CONCLUSIONS

Cardiopulmonary bypass time, total ischemic time, and catecholamine use were associated with higher lactate levels, whereas nitric oxide and higher pulmonary artery pressures were associated with lower levels. Increased lactate levels were independently associated with longer intubation times, postoperative acute kidney injury, and longer length of stay.

Systematic review on peri-operative lactate measurements to predict outcomes in patients undergoing liver resection

Lactate measurements have proven utility as a triage tool, therapeutic guide, and prognostic indicator, with broad use in Acute Care and transplantation. Its value in guiding therapy and predicting outcomes following liver resection is less well‐defined. This systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines assessed the relationship between peri‐operative lactate levels and morbidity and mortality after liver resection. Seven relevant studies comprising 2573 patients in total were identified. Six studies assessed intra‐operative or early postoperative lactate levels, one publication examined pre‐operative levels. All studies demonstrated a significant association between peri‐operative lactate levels and adverse outcomes. The influence of pre‐operative diabetes and cirrhosis on postoperative lactate levels was shown in one study each, no study assessed the association of lactate with post‐hepatectomy liver failure according to defined criteria. The heterogeneity of study measurements and end‐points precluded a meta‐analysis from being performed. Early postoperative lactate >3‐3.7 mmol/L is associated with mortality but validation of clear cut‐off levels for outcome prediction is pending. Literature suggests lactate is a useful predictive marker for outcomes post liver surgery, especially when measured in the early postoperative phase. Further research is required to standardize the use of lactate measurements in a meaningful therapeutic manner.

Predictive Capacity of Risk Models in Liver Transplantation

Supplemental Digital Content is available in the text.

Several risk models to predict outcome after liver transplantation (LT) have been developed in the last decade. This study compares the predictive performance of 7 risk models.

Evaluation of bioenergetic and mitochondrial function in liver transplantation

BACKGROUND/AIMS

We measured changes in mitochondrial function and bioenergetics that occur during ischemia/ reperfusion in fresh liver samples of patients undergoing liver transplantation. These variations correlated with markers of liver function and clinical outcome. Ischemia/reperfusion injury related to liver transplantation affects mitochondrial function and bioenergetics. Experimental studies were conducted to identify the role of bioenergetics and mitochondrial dysfunction. To the best of our knowledge, no investigation of these two factors' impacts on liver transplantation has been performed.

METHODS

This was a prospective study of 28 patients who underwent liver transplantation. We measured parameters of mitochondrial function and bioenergetics in biopsies performed during the procedure.

RESULTS

We observed a statistically significant reduction in mitochondrial membrane potential, an increase in lag phase, and decreases in mitochondrial respiration and adenosine triphosphate content (P<0.010). Higher postoperative aminotransferase peaks correlated with worse mitochondrial function; mitochondrial respiration correlated with arterial lactate (P<0.010).

CONCLUSION

There is a relationship between mitochondrial function and ischemia/reperfusion injury. The future use of these clinical markers as prognostic factors may allow early identification of post-transplant liver failure and may indicate the need to perform a new transplant.

Extracellular histones are clinically associated with primary graft dysfunction in human liver transplantation

Extracellular histones have been involved in numerous inflammatory conditions such as ischemia/reperfusion (I/R) injury, trauma, and infection. There is growing evidence of I/R injury associated with primary graft dysfunction (PGD) following organ transplantation. Here we investigated whether extracellular histones are clinically involved with PGD in human liver transplantation. In total 58 patients undergoing liver transplantation were studied. We collected blood samples from the recipients before and serially after transplantation (24 h, 72 h). We measured extracellular histones, myeloperoxidase (MPO), S100A8/A9, and multiple inflammatory cytokines. Additionally, we exposed human L02 hepatocytes or U937 monocytic cells to the recipient's sera overnight, and assessed cellular viability and cytokine production respectively. Lastly, we assessed the effect of histone-targeted interventions by administration of heparin or an anti-histone antibody. It showed that extracellular histones increased immediately after transplantation, peaked within 24 hours and remained at high levels up to 72 hours (all p < 0.01). Notably, extracellular histone levels were significantly higher in recipients with PGD (n = 9) than recipients without PGD (n = 49, p = 0.004). Extracellular histones correlated positively with MPO, S100A8/A9 and most detected cytokines. Ex vivo analysis demonstrated that the patients' sera after graft markedly induced L02 cell death and caused profound cytokine production in cultured U937 cells, which could be abrogated by heparin or an anti-histone antibody. Collectively, extracellular histones were increased significantly after liver transplantation, which may contribute to the occurrence of PGD through direct cytotoxicity and enhancement of systemic inflammation. Targeting extracellular histones may provide a promising approach for preventing PGD or other complications in clinical practice.

Extracellular histones have been involved in numerous inflammatory conditions such as ischemia/reperfusion (I/R) injury, trauma, and infection.