Elevated alanine aminotransferase (ALT) in the deceased donor: impact on early post-transplant liver allograft function

Donor Liver Blood Tests and Liver Transplant Outcomes: UK Registry Cohort Study

BACKGROUND

Safely increasing organ utilization is a global priority. Donor serum transaminase levels are often used to decline livers, despite minimal evidence to support such decisions. This study aimed to investigate the impact of donor "liver blood tests" on transplant outcomes.

METHODS

This retrospective cohort study used the National Health Service registry on adult liver transplantation (2016-2019); adjusted regressions models were used to assess the effect of donor "liver blood tests" on outcomes.

RESULTS

A total of 3299 adult liver transplant recipients were included (2530 following brain stem death, 769 following circulatory death). Peak alanine transaminase (ALT) ranged from 6 to 5927 U/L (median = 45). Donor cause of death significantly predicted donor ALT; 4.2-fold increase in peak ALT with hypoxic brain injury versus intracranial hemorrhage (adjusted P  < 0.001). On multivariable analysis, adjusting for a wide range of factors, transaminase level (ALT or aspartate aminotransferase) failed to predict graft survival, primary nonfunction, 90-d graft loss, or mortality. This held true in all examined subgroups, that is, steatotic grafts, donation following circulatory death, hypoxic brain injury donors, and donors, in which ALT was still rising at the time of retrieval. Even grafts from donors with extremely deranged ALT (>1000 U/L) displayed excellent posttransplant outcomes. In contrast, donor peak alkaline phosphatase was a significant predictor of graft loss (adjusted hazard ratio = 1.808; 1.016-3.216; P  = 0.044).

CONCLUSIONS

Donor transaminases do not predict posttransplant outcomes. When other factors are favorable, livers from donors with raised transaminases can be accepted and transplanted with confidence. Such knowledge should improve organ utilization decision-making and prevent future unnecessary organ discard. This provides a safe, simple, and immediate option to expand the donor pool.

Normothermic Machine Perfusion—Improving the Supply of Transplantable Livers for High-Risk Recipients

The effectiveness of liver transplantation to cure numerous diseases, alleviate suffering, and improve patient survival has led to an ever increasing demand. Improvements in preoperative management, surgical technique, and postoperative care have allowed increasingly complicated and high-risk patients to be safely transplanted. As a result, many patients are safely transplanted in the modern era that would have been considered untransplantable in times gone by. Despite this, more gains are possible as the science behind transplantation is increasingly understood. Normothermic machine perfusion of liver grafts builds on these gains further by increasing the safe use of grafts with suboptimal features, through objective assessment of both hepatocyte and cholangiocyte function. This technology can minimize cold ischemia, but prolong total preservation time, with particular benefits for suboptimal grafts and surgically challenging recipients. In addition to more physiological and favorable preservation conditions for grafts with risk factors for poor outcome, the extended preservation time benefits operative logistics by allowing a careful explant and complicated vascular reconstruction when presented with challenging surgical scenarios. This technology represents a significant advancement in graft preservation techniques and the transplant community must continue to incorporate this technology to ensure the benefits of liver transplant are maximized.

Design, Analysis, and Pitfalls of Clinical Trials Using Ex Situ Liver Machine Perfusion: The International Liver Transplantation Society Consensus Guidelines

BACKGROUND

Recent trials in liver machine perfusion (MP) have revealed unique challenges beyond those seen in most clinical studies. Correct trial design and interpretation of data are essential to avoid drawing conclusions that may compromise patient safety and increase costs.

METHODS

The International Liver Transplantation Society, through the Special Interest Group "DCD, Preservation and Machine Perfusion," established a working group to write consensus statements and guidelines on how future clinical trials in liver perfusion should be designed, with particular focus on relevant clinical endpoints and how different techniques of liver perfusion should be compared. Protocols, abstracts, and full published papers of clinical trials using liver MP were reviewed. The use of a simplified Grading of Recommendations Assessment, Development, and Evaluation working group (GRADE) system was attempted to assess the level of evidence. The working group presented its conclusions at the International Liver Transplantation Society consensus conference "DCD, Liver Preservation, and Machine Perfusion" held in Venice, Italy, on January 31, 2020.

RESULTS

Twelve recommendations were proposed with the main conclusions that clinical trials investigating the effect of MP in liver transplantation should (1) make the protocol publicly available before the start of the trial, (2) be adequately powered, and (3) carefully consider timing of randomization in function of the primary outcome.

CONCLUSIONS

There are issues with using accepted primary outcomes of liver transplantation trials in the context of MP trials, and no ideal endpoint could be defined by the working group. The setup of an international registry was considered vital by the working group.

Finger Citron Extract Ameliorates Glycolipid Metabolism and Inflammation by Regulating GLP-1 Secretion via TGR5 Receptors in Obese Rats

Finger citron (FC) is one of many traditional Chinese herbs that have been used to treat obesity. The aim of this study was to elucidate the pharmacological effects and mechanisms of FC on obese rats. Rats were fed with a high-fat diet as a model of obesity and treated with FC at three different dosages for 6 weeks. Pathology in liver tissue was observed. Glucose levels, lipids levels, and inflammatory indicators in serum were evaluated by enzyme‐linked immunosorbent assay. Furthermore, the expression of G protein-coupled receptor 5 (TGR5) pathway genes in rat colon tissue was detected by reverse transcription-polymerase chain reaction analysis (RT-PCR). Our result revealed that FC alleviates obesity by reducing body weight (BW) and waist circumference, managing inflammation and improving glycolipid metabolism, liver function, and liver lipid peroxidation in vivo. In addition, the mechanism of FC on obesity is possibly the stimulation of glucagon-like peptide-1 (GLP-1) secretion by activating the TGR5 pathway in intestinal endocrine cells. Our studies highlight the obesity reduction effects of FC and one of the mechanisms may be the activation of the TGR5 pathway in intestinal endocrine cells.

Effect of Donor Transaminase Levels on Graft Survival Following Liver Transplant: An Analysis of the Organ Procurement and Transplantation Network Database

OBJECTIVES

Despite data showing equivalent outcomes between grafts from marginal versus standard criteria deceased liver donors, elevated donor transaminases constitute a frequent reason to decline potential livers. We assessed the effect of donor transaminase levels and other characteristics on graft survival.

MATERIALS AND METHODS

We performed a retrospective cohort analysis of adult first deceased donor liver transplant recipients with available transaminase levels registered in the Organ Procurement and Transplantation Network database (2008-2018). We used Cox proportional hazards regression to determine the effects of donor characteristics on graft survival.

RESULTS

Of 53 913 liver transplants, 52 158 were allografts from donors with low transaminases (≤ 500 U/L; group A) and 1755 were from donors with elevated transaminases (> 500 U/L; group B). Group A recipients were more likely to be hospitalized (P = .01) or in intensive care (P < .001) or to have mechanical assistance (P < .001), portal vein thrombosis (P = .01), diabetes mellitus (P = .003), or dialysis the week before liver transplant (P = .004). Multivariable analysis (controlling for recipient characteristics) showed donor risk factors of graft failure included diabetes mellitus (P < .001), donation after cardiac death (P < .001), total bilirubin > 3.5 mg/dL (P < .001), serum creatinine > 1.5 mg/dL (P = .01), and cold ischemia time > 6 hours (P < .001). Regional organ sharing showed lower risk of graft failure (P = .02). Donor transaminases > 500 U/L were not associated with graft failure (relative risk, 1.02; 95% CI, 0.91-1.14; P = .74).

CONCLUSIONS

Donor transaminases > 500 U/L should not preclude the use of liver grafts. Instead, donor total bilirubin > 3.5 mg/dL and serum creatinine > 1.5 mg/dL appear to be associated with higher likelihood of graft failure after liver transplant.

Impact of donor preprocurement cardiac arrest on clinical outcomes in pediatric deceased donor liver transplantation

PPCA has historically been considered detrimental to donor quality in LT, but transplantation of grafts from this group of donors is now routine. Our study aims to evaluate the outcomes associated with use of donors with a history of PPCA in the pediatric population. This study is a single-center retrospective analysis of all pediatric LTs performed over an 18-year period. Donors and recipients were stratified by the presence and length of donor PPCA time. Preprocurement donor and post-transplant recipient laboratory values were collected to assess the degree of ischemic liver injury associated with each donor group. Cox regression analysis was used to compare survival. The records for 130 deceased pediatric LT donors and corresponding recipients were reviewed. There were 73 (56%) non-PPCA donors and 57 (44%) PPCA donors. Donors that experienced a PPCA event demonstrated a higher median, pretransplant peak alanine aminotransferase (ALT) level (P < .001). When comparing post-transplant recipient median ALT levels, donors with any PPCA had lower median peak ALT (P = .15) and day 3 ALT (P = .43) levels than the non-PPCA group. Rates of early graft loss did not differ. The PPCA group with >40 minutes of ischemia had markedly lower survival at 10 years, but this finding did not reach statistical significance. Liver grafts from donors with or without PPCA demonstrated no statistically significant differences in function or survival. A history of donor PPCA alone should not be used as an exclusionary criterion in pediatric liver transplantation.

Expanding the donor pool for liver transplantation with marginal donors

The current supply of acceptable donor livers is not sufficient to meet the demands of listed patients awaiting transplantation resulting in thousands of deaths each year. Increased utilization of marginal livers may help alleviate this supply/demand mismatch by expanding the donor liver pool. The current status of liver transplantation using marginal donor grafts and efforts to optimize usage are discussed with attention to elderly donors, steatotic livers, donors after circulatory death, and split liver grafts.

Trends in deceased donor liver enzymes prior to transplant: The impact on graft selection and outcomes

We sought to characterize the trend in alanine aminotransferase elevations prior to transplant and the impact on the pattern of enzyme elevations on organ utilization and graft function. We performed a retrospective cohort study of UNOS data on all deceased donors between 2007 and 2016. Serum alanine aminotransferase (ALT) was categorized into six study groups with peak ALT < 499, 500-749, 750-999, 1000-1999, 2000-2999, and >3000 IU/L. The change from peak ALT to terminal ALT prior to transplant was categorized as no change/increasing at time transplant, 0.1-9.9%, 10-24.9%, 25-49.9%, 50-74.9% and >75% change. In multivariable models evaluating liver utilization, the interaction between peak ALT and percent change in ALT was most pronounced at the highest peak ALT levels, where liver utilization varied markedly as a function of percentage drop from peak to terminal ALT. There was no increased risk of graft failure based on peak ALT. Markers of ischemic liver injury and recovery are significantly associated with liver utilization, yet among transplanted livers they were not associated with graft outcomes and may represent an area to expand the donor pool.

Impact of Donor Pre-Procurement Cardiac Arrest (PPCA) on Clinical Outcomes in Liver Transplantation

Background

Transplantation of liver grafts from deceased donors who experienced cardiac arrest prior to liver procurement is now common. This single-center study analyzed the impact of pre-donation arrest time on clinical outcomes in liver transplantation.

Material/Methods

Records of all orthotopic liver transplants performed at a single center over a 15-year period were reviewed. Donor records were reviewed and total arrest time was calculated as cumulative minutes. Post-transplant liver graft function was assessed using laboratory values. Graft survival was assessed with Cox regression analysis.

Results

Records for 1830 deceased donor transplants were reviewed, and 521 donors experienced pre-procurement cardiac arrest (28%). Median arrest time was 21 min (mean 25 min, range 1–120 min). After transplant, the peak alanine aminotransferase and bilirubin levels for liver grafts from donors with arrest were lower compared to those for donors without arrest (p<0.001). Early allograft dysfunction occurred in 25% (arrest) and 28% (no arrest) of patients (p=0.22). There were no differences in risk of early graft loss (3% vs. 3%, p=0.84), length of hospital stay (10 vs. 10 days, p=0.76), and 1-year graft survival (89% vs. 89%, p=0.94). Cox regression analysis comparing 4 groups (no arrest, <20 min, 20–40 min, and >40 min arrest) demonstrated no statistically significant difference in survival at 10 years. Subgroup analysis of 93 donation after cardiac death grafts showed no significant difference for these same outcomes.

Conclusions

These results support the use of select deceased liver donors who experience pre-donation cardiac arrest. Pre-donation arrest may be associated with less early allograft dysfunction, but had no impact on long-term clinical outcomes. The results for donation after cardiac death donors were similar.

Comparison of simplified and traditional pericardial devascularisation combined with splenectomy for the treatment of portal hypertension

AIM

To compare the clinical outcomes of patients with portal hypertension (PH) who underwent treatment with splenectomy plus simplified pericardial devascularisation (SSPD) or splenectomy plus traditional pericardial devascularisation (STPD).

METHODS

We conducted a single-centre retrospective study of 1045 PH patients treated with either SSPD (S Group, 357 patients) or STPD (T Group, 688 patients) between January 2002 and February 2017. In all, 37 clinical indicators were compared to evaluate the efficacy of SSPD.

RESULTS

Perioperative indicators in the S Group were significantly better than those in the T Group (P < 0.05). In both groups, the postoperative long-term portal vein diameter and Model for End-Stage Liver Disease score were significantly lower than those in the preoperative and postoperative short-term groups (P < 0.05). The incidence of complications in the S Group was significantly lower than that in the T Group (P < 0.05). Compared to the T Group, postoperative short-term WBC (white blood cell) and platelet counts were significantly lower and the short-term Hb (haemoglobin) level was significantly higher in the S Group (P < 0.05). In the S Group, postoperative long-term total bilirubin, direct bilirubin, alanine transaminase, and aspartate transaminase and postoperative serum creatinine and cystatin C levels were significantly lower than those in the T Group (P < 0.05), and postoperative albumin was significantly higher than that in the T Group (P < 0.05).

CONCLUSION

Compared to STPD, SSPD is a simple and easy procedure resulting in less tissue damage. Patients recovered smoothly and steadily with fewer complications. Short-term liver and kidney function damage was less severe, and long-term liver function recovery was better. Therefore, SSPD is worthy of clinical promotion and application for the treatment of PH.

Acute and sub-acute oral toxicity studies of the aqueous extract from radix, radix with cortex and cortex of Psammosilene tunicoides in mice and rats

ETHNOPHARMACOLOGICAL RELEVANCE

Psammosilene tunicoides is one of the important ingredients of a famous Chinese traditional medicine formulation "Yunnan Baiyao". Also, this plant is commonly used as an anodyne and hemostatic agent in southwest China. Currently, little toxicological information is available on its safety following prolonged use.

AIM OF THE STUDY

In this study, we sought to evaluate the toxicity of the three different parts of Psammosilene tunicoides: Psammosilenes Radix (PR), Psammosilenes Radix with Cortex (PRC) and Psammosilenes Cortex (PC) by acute and sub-acute toxicity studies.

MATERIALS AND METHODS

In the acute toxicity study, mice were orally administrated with different doses of PR, PRC and PC. General behavior and mortality were observed up to 14 days. In sub-acute toxicity study, these aqueous extracts were given orally as a single administration to rats at doses of 0.3, 0.6 and 1.2g/kg/day, respectively, for 28 days. General behavior, body weight, biochemical, hematological, organ coefficients and pathological morphology parameters were detected.

RESULTS

In acute study, single oral administration of the aqueous extract of PR, PRC and PC caused dose-dependent general behavior adverse effects and mortality. The LD50 values of PR, PRC and PC were 4.64g/kg, 4.85g/kg and 6.40g/kg, respectively. In sub-acute study, the administration of the extract of PR, PRC and PC during 28 days at all doses reduced spontaneous activities with both genders. Occasional nasal secretion with blood at high doses (1.2g/kg) of PR, PRC and PC were observed. Daily single oral administration provoked varying degrees of growth retardation in female rats. The relative heart and spleen weight in the female rats were reduced after the administration. On the hematological and biochemical analyses, the administration of the extract of PR, PRC and PC during 28 days mainly caused variation of indexes in female rats. Histopathological analysis has shown vascular congestion in heart, thickened alveolar wall and emphysema in lung, and vascular congestion in kidney of rats after sub-acute oral administrations.

CONCLUSIONS

As shown in the results, Psammosilene tunicoides has a toxic potential in acute and sub-acute oral administrations. However, there is no direct relationship between toxicity and the cortex. Daily oral administration of three different parts from Psammosilene tunicoides (PR, PRC and PC) may cause damages to heart, lung and kidney in rats. Thus these extracts should be used with caution.

Antidiabetic effects of Morus alba fruit polysaccharides on high-fat diet- and streptozotocin-induced type 2 diabetes in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Type 2 diabetes mellitus (T2DM) is becoming a serious threat to human health. The fruit of Morus alba L. is widely used as a traditional Chinese medicine for the treatment of DM, dizziness, tinnitus, insomnia, and premature graying, as well as to protect the liver and kidneys. Several studies have demonstrated that the aqueous extracts of the roots bark, leaves, and ramuli of mulberry, which are known to contain polyphenols and polysaccharides, have antihyperglycemic and antihyperlipidemic activities. The aim of the present study was to further investigate the active polysaccharides from M. alba fruit by evaluating the antidiabetic activities of different fractions on T2DM rats and elucidate the mechanism underlying these activities.

MATERIALS AND METHODS

Diabetic rats were treated with two fractions of M. alba fruit polysaccharides (MFP50 and MFP90). The disease models were induced by a high-fat diet and low dose injection of streptozotocin and were compared to normal rats and metformin-treated diabetic rats. After seven weeks, the fasting blood glucose (FBG), oral glucose tolerance test (OGTT), fasting serum insulin (FINS) levels, homeostasis model of assessment-insulin resistance (HOMA-IR), glycated serum protein (GSP), and serum alanine transaminase (ALT) levels, as well as serum lipid profiles and histopathological changes in the pancreas were measured. Next, the expressions of the insulin signaling pathway were measured by western blot analysis to elucidate the potential mechanism underlying these antidiabetic activities.

RESULTS

After seven weeks of treatment, a significant reduction in the FBG levels, OGTT-area under the curve (OGTT-AUC), FINS, HOMA-IR, ALT, and triglyceride (TG) values of the MFP50 group was observed. On the other hand, in the MFP90 group, the FBG, OGTT-AUC, FINS, HOMA-IR, GSP, and TG levels were significantly reduced. The level of high-density lipoprotein cholesterol (HDL-c) and the proportion of HDL-c to total cholesterol (TC) significantly increased in the MFP50 group. Moreover, MFP50 and MFP90 induced repair of damaged pancreatic tissues of the diabetic rats. The hypoglycemic effect of MFP50 was more stable than MFP90, whereas the hypolipidemic effect of MFP90 was slightly better than MFP50. Moreover, the expression levels of InsR, IRS-2, Akt and GLUT4 in the MFP90 group significantly increased relative to that of the T2DM group.

CONCLUSIONS

MFP50 and MFP90 have markedly antihyperglycemic and antihyperlipidemic effects and can clearly relieve diabetes symptoms in the T2DM rat model. The M. alba fruit polysaccharides may potentially be utilized as an effective treatment for T2DM. Further research into the structures of active M. alba fruit polysaccharides and their mechanisms in promoting antidiabetic effects are underway.

Transplantation of Deceased Donor Livers With Elevated Levels of Serum Transaminases at Shiraz Transplant Center

BACKGROUND

The current organ shortage has prompted the use of marginal organs. We conducted this retrospective study to present our experience with transplanting deceased donor livers with elevated levels of serum transaminases and to explain whether elevated levels of serum transaminases in donors affect allograft function and survival of the recipients.

METHODS

Data of deceased donor livers and patients, who underwent liver transplantation from March 2013 to March 2015 at Shiraz center for organ transplantation, was reviewed. Liver donors with aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) level of more than 500 IU/l and their related recipients were considered as the case group (n = 24) and the others were considered as the control group (n = 834).

RESULTS

In the case group, the medians of levels of serum AST and ALT of donors were 834 ± 425 IU/L (range: 250 - 2285) and 507 ± 367 IU/L (range: 100 - 1600), respectively. Recipients were followed for a median of 13.6 ± 9 months (range: 7 - 28.4). Post-transplant complications were acute rejection (n = 5), infection (n = 3), portal vein thrombosis (n = 3), bile duct stricture (n = 1), and hepatic artery stenosis (n = 1). The one-year survival rate of the patients was 91.7%. Demographics, post-transplant complications and one-year survival rates were not significantly different between the two study groups.

CONCLUSIONS

Transplanting deceased donor livers with markedly elevated liver enzymes may be an acceptable choice for expanding the donor pool.

High peak alanine aminotransferase determines extra risk for nonanastomotic biliary strictures after liver transplantation with donation after circulatory death

Orthotopic liver transplantation (OLT) with donation after circulatory death (DCD) often leads to a higher first week peak alanine aminotransferase (ALT) and a higher rate of biliary nonanastomotic strictures (NAS) as compared to donation after brain death (DBD). This retrospective study was to evaluate whether an association exists between peak ALT and the development of NAS in OLT with livers from DBD (n = 399) or DCD (n = 97) from two transplantation centers. Optimal cutoff value of peak ALT for risk of development of NAS post-DCD-OLT was 1300 IU/l. The 4-year cumulative incidence of NAS after DCD-OLT was 49.5% in patients with a high ALT peak post-OLT, compared with 11.3% in patients with a low ALT peak. (P < 0.001). No relation between peak ALT and NAS was observed after DBD-OLT. Multivariate analysis revealed peak ALT ≥1300 IU/l [adjusted hazard ratio (aHR) = 3.71, confidence interval (CI) (1.26-10.91)] and donor age [aHR = 1.04, CI 1.00-1.07] to be independently associated with development of NAS post-DCD-OLT. A peak ALT of <1300 IU/l carries a risk for NAS similar to DBD-OLT. Thus, in DCD-OLT, but not in DBD-OLT, peak ALT discriminates patients at high or low risk for NAS.