Liver transplantation in the context of organ shortage: toward extension and restriction of indications considering recent clinical data and ethical framework

Long-Term Outcomes of Recipients of Liver Transplants from Living Donors Treated with a Very Low-Calorie Diet

The increasing prevalence of steatotic liver disease (SLD) in potential living donors is concerning, as it limits donor's availability amid rising demand. OPTIFAST very low-calorie diet (VLCD), a meal replacement product, effectively reduces weight and hepatic steatosis before transplantation. However, data on the outcomes of recipients of VLCD-treated donors are lacking. We conducted a single-center, retrospective study on 199 living donor liver transplant recipients at Toronto General Hospital, Canada, between January 2015 and January 2020. We compared the 1-year posttransplant outcomes between recipients who received organs from donors treated with VLCD (N = 34) for either weight loss or steatosis reduction, with those who did not require treatment (N = 165). Our analysis revealed no statistically significant differences in the rates of postoperative complications (23% vs 32.4%, p=0.3) or intensive care unit stays (70.9% vs 70.6%, p=1) between recipients of non-VLCD and VLCD grafts. Following adjusted multivariate logistic regression, receipt of VLCD grafts was not associated with increased hospital length of stay. In addition, one-year mortality did not differ between the two groups (4.2% non-VLCD recipients vs 2.9% VLCD recipients, p=0.6). OPTIFAST VLCD treatment for liver donors demonstrates positive and safe outcomes in recipients, expanding the pool of potential living donors for increased organ availability.

Cirrosis hepática o falla hepática crónica agudizada: definición y clasificación

La cirrosis se considera el estadio crónico e irreversible de la lesión hepática. Su etiología es diversa y abarca causas como las infecciones víricas, tóxicos como el alcohol, medicamentos, patologías autoinmunes y otras. La descompensación de la cirrosis hepática es consecuencia de cambios fisiopatológicos que se dan con el tiempo como ascitis, peritonitis bacteriana espontánea, hemorragia del tubo digestivo, síndrome hepatorrenal, encefalopatía hepática o hipertensión portopulmonar, mientras que la falla hepática crónica agudizada debe considerarse como una entidad que debe diferenciarse de la anterior, ya que es una falla multiorgánica de curso rápido, por lo regular en pacientes hospitalizados en unidad de cuidado intensivo, a menudo secundaria a desencadenantes como estados de choque. El clínico debe identificarlas para su abordaje y evaluación. El método actual adecuado para estadificar esta entidad es el puntaje CLIFF SOFA, que evalúa la mortalidad a 28 y 90 días, permitiendo intervenciones adecuadas en cada caso.

Oncofetal Protein CRIPTO Is Involved in Wound Healing and Fibrogenesis in the Regenerating Liver and Is Associated with the Initial Stages of Cardiac Fibrosis

Oncofetal protein, CRIPTO, is silenced during homeostatic postnatal life and often re-expressed in different neoplastic processes, such as hepatocellular carcinoma. Given the reactivation of CRIPTO in pathological conditions reported in various adult tissues, the aim of this study was to explore whether CRIPTO is expressed during liver fibrogenesis and whether this is related to the disease severity and pathogenesis of fibrogenesis. Furthermore, we aimed to identify the impact of CRIPTO expression on fibrogenesis in organs with high versus low regenerative capacity, represented by murine liver fibrogenesis and adult murine heart fibrogenesis. Circulating CRIPTO levels were measured in plasma samples of patients with cirrhosis registered at the waitlist for liver transplantation (LT) and 1 year after LT. The expression of CRIPTO and fibrotic markers (αSMA, collagen type I) was determined in human liver tissues of patients with cirrhosis (on a basis of viral hepatitis or alcoholic disease), in cardiac tissue samples of patients with end-stage heart failure, and in mice with experimental liver and heart fibrosis using immuno-histochemical stainings and qPCR. Mouse models with experimental chronic liver fibrosis, induced with multiple shots of carbon tetrachloride (CCl4) and acute liver fibrosis (one shot of CCl4), were evaluated for CRIPTO expression and fibrotic markers. CRIPTO was overexpressed in vivo (Adenoviral delivery) or functionally sequestered by ALK4Fc ligand trap in the acute liver fibrosis mouse model. Murine heart tissues were evaluated for CRIPTO and fibrotic markers in three models of heart injury following myocardial infarction, pressure overload, and ex vivo induced fibrosis. Patients with end-stage liver cirrhosis showed elevated CRIPTO levels in plasma, which decreased 1 year after LT. Cripto expression was observed in fibrotic tissues of patients with end-stage liver cirrhosis and in patients with heart failure. The expression of CRIPTO in the liver was found specifically in the hepatocytes and was positively correlated with the Model for End-stage Liver Disease (MELD) score for end-stage liver disease. CRIPTO expression in the samples of cardiac fibrosis was limited and mostly observed in the interstitial cells. In the chronic and acute mouse models of liver fibrosis, CRIPTO-positive cells were observed in damaged liver areas around the central vein, which preceded the expression of αSMA-positive stellate cells, i.e., mediators of fibrosis. In the chronic mouse models, the fibrosis and CRIPTO expression were still present after 11 weeks, whereas in the acute model the liver regenerated and the fibrosis and CRIPTO expression resolved. In vivo overexpression of CRIPTO in this model led to an increase in fibrotic markers, while blockage of CRIPTO secreted function inhibited the extent of fibrotic areas and marker expression (αSMA, Collagen type I and III) and induced higher proliferation of residual healthy hepatocytes. CRIPTO expression was also upregulated in several mouse models of cardiac fibrosis. During myocardial infarction CRIPTO is upregulated initially in cardiac interstitial cells, followed by expression in αSMA-positive myofibroblasts throughout the infarct area. After the scar formation, CRIPTO expression decreased concomitantly with the αSMA expression. Temporal expression of CRIPTO in αSMA-positive myofibroblasts was also observed surrounding the coronary arteries in the pressure overload model of cardiac fibrosis. Furthermore, CRIPTO expression was upregulated in interstitial myofibroblasts in hearts cultured in an ex vivo model for cardiac fibrosis. Our results are indicative for a functional role of CRIPTO in the induction of fibrogenesis as well as a potential target in the antifibrotic treatments and stimulation of tissue regeneration.

Systematic Assessment of Safety Threshold for Donor Age in Cadaveric Liver Transplantation

Background: Donor age affects allograft quality and the prognosis of recipients after liver transplantation (LT). Clinicians have assessed the quality of grafts from older donors based on their appearance and texture, with no reliable quantitative evidence. Our study aimed to assess the quantitative impact of donor age on post-transplant outcomes and its safety threshold for LT, based on the published literature.

Methods: Relevant studies were retrieved from the Embase, PubMed, and ISI Web of Science databases. Pooled dichotomous relative risks (RRs) were calculated using metan. Continuous RRs were calculated using a two-stage random-effects model.

Results: Eleven studies including 30,691 LT cases were included for further analysis. For categorical comparison, the RR of death within the first post-transplant year was significantly higher among patients who received grafts from older donors. Similarly, the RR of graft failure (GF) was increased within the 3 years after transplantation. For continuous comparison, advanced donor age affected transplant outcomes in a linear manner (P > 0.05). A 10-year increment in donor age was associated with RRs 1.10, 1.12, 1.15, 1.10, and 1.08 for 90-day, 180-day, 1-year, 3-year, and 5-year patient mortality and 1.08, 1.06, 1.10, 1.11, and 1.12, for 90-day, 180-day, 1-year, 2-year, and 3-year GF, respectively (all P < 0.05). A spline model showed that transplants using grafts from donors <43 years old were not associated with age-related risks (P > 0.05). The risk of GF was increased in subgroups with fewer LT cases, longer cold ischemic time, fewer male donors, and recipients with viral hepatitis (P < 0.05).

Conclusion: Donor age might affect post-LT outcomes in a dose-dependent manner. The safety threshold for donor age in terms of GF should be lowered to 43 years as an early warning for the guarantee of satisfactory outcomes. Clinicians should weigh the benefits against the risks carefully for patients receiving grafts from older donors. Further studies are warranted to investigate the mechanisms responsible for the relationship between donor age and graft quality.

Treatment stage migration and treatment sequences in patients with hepatocellular carcinoma: drawbacks and opportunities

Purpose

This retrospective analysis focuses on treatment stage migration in patients with hepatocellular carcinoma (HCC) to identify successful treatment sequences in a large cohort of real-world patients.

Methods

1369 HCC patients referred from January 1993 to January 2020 to the tertiary center of the Heidelberg University Hospital, Germany were analyzed for initial and subsequent treatment patterns, and overall survival.

Results

The most common initial treatment was transarterial chemoembolization (TACE, n = 455, 39.3%) followed by hepatic resection (n = 303, 26.1%) and systemic therapy (n = 200, 17.3%), whereas the most common 2nd treatment modality was liver transplantation (n = 215, 33.2%) followed by systemic therapy (n = 177, 27.3%) and TACE (n = 85, 13.1%). Kaplan–Meier analysis revealed by far the best prognosis for liver transplantation recipients (median overall survival not reached), followed by patients with hepatic resection (11.1 years). Patients receiving systemic therapy as their first treatment had the shortest median overall survival (1.7 years; P < 0.0001). When three or more treatment sequences preceded liver transplantation, patients had a significant shorter median overall survival (1st seq.: not reached; 2nd seq.: 12.4 years; 3rd seq.: 11.1 years; beyond 3 sequences: 5.5 years; P = 0.01).

Conclusion

TACE was the most common initial intervention, whereas liver transplantation was the most frequent 2nd treatment. While liver transplantation and hepatic resection were associated with the best median overall survival, the timing of liver transplantation within the treatment sequence strongly affected median survival.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03528-3.

EVALUATION AND SELECTION OF CANDIDATES FOR LIVER TRANSPLANTATION: AN ECONOMIC PERSPECTIVE

BACKGROUND

Over the next 20 years, the number of patients on the waiting list for liver transplantation (LTx) is expected to increase by 23%, while pre-LTx costs should raise by 83%.

OBJECTIVE

To evaluate direct medical costs of the pre-LTx period from the perspective of a tertiary care center.

METHODS

The study included 104 adult patients wait-listed for deceased donor LTx between October 2012 and May 2016 whose treatment was fully provided at the study transplant center. Clinical and economic data were obtained from electronic medical records and from a hospital management software. Outcomes of interest and costs of patients on the waiting list were compared through the Kruskal-Wallis test. A generalized linear model with logit link function was used for multivariate analysis. P-values <0.05 were considered statistically significant.

RESULTS

The costs of patients who underwent LTx ($8,879.83; 95% CI 6,735.24-11,707.27; P<0.001) or who died while waiting ($6,464.73; 95% CI 3,845.75-10,867.28; P=0.04) were higher than those of patients who were excluded from the list for any reason except death ($4,647.78; 95% CI 2,469.35-8,748.04; P=0.254) or those who remained on the waiting list at the end of follow-up.

CONCLUSION

Although protocols of inclusion on the waiting list vary among transplant centers, similar approaches exist and common problems should be addressed. The results of this study may help centers with similar socioeconomic realities adjust their transplant policies.

Unfavorable prognosis of patients with acute liver injury due to drug-induced liver injury and acute exacerbation of hepatitis B virus infection

AIM

Acute liver injury (ALI) has a favorable prognosis, whereas acute liver failure (ALF) leads to organ failure and thus has an unfavorable prognosis. The effect of each etiology on the clinical course of ALI remains unclear. This study aimed to determine how each etiology and glucocorticoid on the unfavorable etiology affects the clinical course of ALI.

METHODS

This prospective observational study enrolled 522 patients with ALI/ALF from 2004 and 2017. To evaluate the influence of etiology on prognosis, decision tree analysis was carried out using age, disease type, etiology, and the presence of hepatic encephalopathy.

RESULTS

Of 522 patients, 398 patients satisfied the ALI criteria at registration in this study. The ALI etiologies were as follows: viral hepatitis through oral infection (n = 54), acute hepatitis B virus (HBV) infection (n = 24), acute exacerbation of HBV infection (n = 30), de novo hepatitis due to HBV (n = 5), autoimmune hepatitis (n = 59), drug-induced liver injury (DILI; n = 85), other viruses (n = 12), and undetermined (n = 129). ALI in 46 patients progressed to ALF after registration. Of 11 patients (age >52 years) with ALF due to acute exacerbation of HBV infection or DILI, seven patients (63.6%) died. Whether glucocorticoid affected the clinical course of ALI due to acute exacerbation of HBV infection or DILI was evaluated using propensity score matching (age, sex, alanine aminotransferase, total bilirubin, and prothrombin time-international normalized ratio). Glucocorticoid did not improve the prognosis of ALI patients due to the two etiologies.

CONCLUSIONS

Progression of ALI due to DILI or acute exacerbation of HBV infection to ALF showed a poor prognosis.

Local but not systemic administration of mesenchymal stromal cells ameliorates fibrogenesis in regenerating livers

Chronic liver injury leads to the accumulation of myofibroblasts resulting in increased collagen deposition and hepatic fibrogenesis. Treatments specifically targeting fibrogenesis are not yet available. Mesenchymal stromal cells (MSCs) are fibroblast-like stromal (stem) cells, which stimulate tissue regeneration and modulate immune responses. In the present study we assessed whether liver fibrosis and cirrhosis can be reversed by treatment with MSCs or fibroblasts concomitant to partial hepatectomy (pHx)-induced liver regeneration. After carbon tetrachloride-induced fibrosis and cirrhosis, mice underwent a pHx and received either systemically or locally MSCs in one of the two remaining fibrotic/cirrhotic liver lobes. Eight days after treatment, liver fibrogenesis was evaluated by Sirius-red staining for collagen deposition. A significant reduction of collagen content in the locally treated lobes of the regenerated fibrotic and cirrhotic livers was observed in mice that received high dose MSCs. In the non-MSC-treated counterpart liver lobes no changes in collagen deposition were observed. Local fibroblast administration or intravenous administration of MSCs did not ameliorate fibrosis. To conclude, local administration of MSCs after pHx, in contrast to fibroblasts, results in a dose-dependent on-site reduction of collagen deposition in mouse models for liver fibrosis and cirrhosis.

Systematic Evaluation of the Safety Threshold for Allograft Macrovesicular Steatosis in Cadaveric Liver Transplantation

Background: Currently, 30% macrovesicular steatosis (MaS) content is usually assigned empirically as the boundary between “use” and “refuse” a donor liver for liver transplantation (LT); however, this cut-off is questionable due to the lack of systemic evidence of the efficiency relative to prognosis prediction. Clinicians have tried to identify the threshold for optimized utilization of marginal steatotic allografts, but controversy exists among different studies.

Aim: Our study aimed to systematically determine an acceptable donor MaS content cut-off without incurring extra risk in liver transplantation, using meta-analysis.

Methods: The relevant literature reporting the relationship between MaS content and post-transplant mortality/morbidity was searched and retrieved in Pubmed, Embase, and ISI Web of Science.

Results: Nine studies were enrolled into the final analysis. A categorical comparison revealed that patients who received allografts with moderate steatosis (MaS content >30%) had significantly higher risks of graft failure/dysfunction, but not of mortality. Dose-response analysis showed that donor MaS content affected the graft failure/dysfunction in a non-linear relationship. Risks associated with MaS content in terms of poorer outcomes were independent of other risk covariates for liver transplantation. A non-significant increase in risk of inferior post-transplant outcomes was observed in patients who received allografts with a MaS content <35%. The risks of post-transplant graft failure and dysfunction increased with severe donor MaS content infiltration, without a consistent relationship.

Conclusions: The threshold of allograft MaS content can be safely extended to 35% without additional risk burden on post-transplant inferior outcomes. Clarification on “the effects of stratification” for MaS content can provide theoretical evidence for further optimal utilization of marginal steatotic allografts in liver transplantation.

Challenging the principle of utility as a barrier for wider use of liver transplantation for hepatocellular cancer

Background

Although transplant benefit appears superior for patients with advanced hepatocellular cancer (HCC), liver transplantation remains limited to selected low-risk HCC patients to keep their outcomes similar to heterogeneous group of non-HCC patients. The purpose of this study was to assess the rationale for current policy of restricting access to liver transplantation to minority of HCC patients based on utility principle.

Methods

This retrospective cohort study comprised 1246 liver transplant recipients, including 206 HCC and 1040 non-HCC patients. Patient survival was the primary outcome measure. Patients with HCC and benign diseases were divided into low-, moderate-, and high-risk subgroups basing on independent risk factors for disease-free survival and model for end-stage liver disease (MELD) score (<30, 30–40, >40), respectively.

Results

MELD (p < 0.001) and presence of HCC (p = 0.008) were independent risk factors for early and late mortality, respectively. Total tumor volume (p = 0.008) and alpha-fetoprotein (p = 0.013) were independent predictors of recurrence and mortality used for division of HCC patients into low-, moderate-, and high-risk subgroups, with disease-free survival rates of 74.9% (5 years), 51.7% (5 years), and 8.0% (3 years), respectively (p < 0.001). There were no differences in 5-year overall survival between low-risk HCC (74.9%) and non-HCC (81.9%) patients (p = 0.210), moderate-risk HCC (63.3%) and non-HCC (68.0%) patients (p = 0.372), and high-risk HCC (55.0%) and non-HCC (56.0%) patients (p = 0.559).

Conclusions

The principle of utility is unequally applied for restriction of access to liver transplantation for HCC patients. The results provide rationale for discussion on reinitiation of liver transplantation for advanced HCCs.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-017-5989-x) contains supplementary material, which is available to authorized users.

High-throughput Functional Genomics Identifies Regulators of Primary Human Beta Cell Proliferation

The expansion of cells for regenerative therapy will require the genetic dissection of complex regulatory mechanisms governing the proliferation of non-transformed human cells. Here, we report the development of a high-throughput RNAi screening strategy specifically for use in primary cells and demonstrate that silencing the cell cycle-dependent kinase inhibitors CDKN2C/p18 or CDKN1A/p21 facilitates cell cycle entry of quiescent adult human pancreatic beta cells. This work identifies p18 and p21 as novel targets for promoting proliferation of human beta cells and demonstrates the promise of functional genetic screens for dissecting therapeutically relevant state changes in primary human cells.

Identifying candidates with favorable prognosis following liver transplantation for hepatocellular carcinoma: Data mining analysis

BACKGROUND AND OBJECTIVES

The optimal cutoff of each value in configuring selection criteria for pre-transplant assessment of hepatocellular carcinoma (HCC) remains uncertain.

METHODS

To build a predictive model for recurrent HCC, we performed data mining analysis on patients who underwent LT for HCC at University Health Network (n = 246). The model was externally validated using a cohort from the Scientific Registry of Transplant Recipients (SRTR) database (n = 9,769).

RESULTS

Among 246 patients, 14.6% (n = 36) experienced recurrent HCC within 2.5 years post-LT. The risk prediction model for recurrent HCC identified two subgroups with low-risk (total tumor diameter [TTD] <4 cm and serum alpha-fetoprotein [AFP] <73 ng/ml, n = 135) and with high-risk (TTD >4 cm and/or AFP >73 ng/ml, n = 111). The reproducibility of the model was validated through the SRTR database; overall patient survival rate was significantly better in low-risk group than high-risk group (P < 0.0001). Using Cox regression model, this yardstick, not Milan criteria, was revealed to efficiently predict post-transplant survival independent of underlying characteristics (P < 0.0001).

CONCLUSIONS

Grouping LT candidates with pre-LT HCC by the cutoffs of TTD 4 cm and AFP 73 ng/ml which were unearthed by data mining analysis efficiently classify patients according by the post-transplant prognosis.