Miriam Cortés

Metabolomics discloses donor liver biomarkers associated with early allograft dysfunction

BACKGROUND & AIMS Early allograft dysfunction (EAD) dramatically influences graft and patient outcome after orthotopic liver transplantation and its incidence is strongly determined by donor liver quality. Nevertheless, objective biomarkers, which can assess graft quality and anticipate organ function, are still lacking. This study aims to investigate whether there is a preoperative donor liver metabolomic biosignature associated with EAD. METHODS A comprehensive metabolomic profiling of 124 donor liver biopsies collected before transplantation was performed by mass spectrometry coupled to liquid chromatography. Donor liver grafts were classified into two groups: showing EAD and immediate graft function (IGF). Multivariate data analysis was used to search for the relationship between the metabolomic profiles present in donor livers before transplantation and their function in recipients. RESULTS A set of liver graft dysfunction-associated biomarkers was identified. Key changes include significantly increased levels of bile acids, lysophospholipids, phospholipids, sphingomyelins and histidine metabolism products, all suggestive of disrupted lipid homeostasis and altered histidine pathway. Based on these biomarkers, a predictive EAD model was built and further evaluated by assessing 24 independent donor livers, yielding 91% sensitivity and 82% specificity. The model was also successfully challenged by evaluating donor livers showing primary non-function (n=4). CONCLUSIONS A metabolomic biosignature that accurately differentiates donor livers, which later showed EAD or IGF, has been deciphered. The remarkable metabolomic differences between donor livers before transplant can relate to their different quality. The proposed metabolomic approach may become a clinical tool for donor liver quality assessment and for anticipating graft function before transplant.

Hepatocyte transplantation program: Lessons learned and future strategies

This review aims to share the lessons we learned over time during the setting of the hepatocyte transplantation (HT) program at the Hepatic Cell Therapy Unit at Hospital La Fe in Valencia. New sources of liver tissue for hepatocyte isolation have been explored. The hepatocyte isolation and cryopreservation procedures have been optimized and quality criteria for assessment of functionality of hepatocyte preparations and suitability for HT have been established. The results indicate that: (1) Only highly viable and functional hepatocytes allow to recover those functions lacking in the native liver; (2) Organs with steatosis (≥ 40%) and from elderly donors are declined since low hepatocyte yields, viability and cell survival after cryopreservation, are obtained; (3) Neonatal hepatocytes are cryopreserved without significant loss of viability or function representing high-quality cells to improve human HT; (4) Cryopreservation has the advantage of providing hepatocytes constantly available and of allowing the quality evaluation and suitability for transplantation; and (5) Our results from 5 adults with acute liver failure and 4 from children with inborn metabolic diseases, indicate that HT could be a very useful and safe cell therapy, as long as viable and metabolically functional human hepatocytes are used.

Trasplante celular hepático. Aspectos técnicos y metodológicos

Hepatic cell transplantation consists of grafting already differentiated cells such as hepatocytes. Human hepatocytes are viable and functionally active. Liver cell transplantation is carried out by means of a 3-step method: isolation of hepatocytes from donor liver rejected for orthotopic transplantation, preparing a cell suspension for infusion and, finally, hepatocytes are implanted into the recipient. There are established protocols for the isolation of human hepatocytes from unused segments of donor livers, based on collagenase digestion of cannulated liver tissue at 37 degrees C. The hepatocytes can be used fresh or cryopreserved. Cryopreservation of isolated human hepatocytes would then be available for planned use. In cell transplant, the important aspects are: infusion route, number of cells, number of infusions and viability of the cells. The cells are infused into the patient through a catheter inserted via portal vein or splenic artery. Liver cell transplantation allows liver tissue to be used that would, otherwise, be discarded, enabling multiple patients to be treated with hepatocytes from a single tissue donor.

Is size the only determinant of delayed abdominal closure in pediatric liver transplant

The aim was to determine the factors associated with the use of delayed abdominal closure in pediatric liver transplantation (LT) and whether this affected outcome. From a prospectively maintained database, transplants performed in children (≤18 years) were identified (October 2010 to March 2015). Primary abdominal closure was defined as mass closure performed at time of transplant. Delayed abdominal closure was defined as mass closure not initially performed at the same time as transplant; 230 children underwent LT. Of these, 176 (76.5%) had primary closure. Age was similar between the primary and delayed groups (5.0 ± 4.9 versus 3.9 ± 5.0 years; P = 0.13). There was no difference in the graft‐to‐recipient weight ratio (GRWR) in the primary and delayed groups (3.4 ± 2.8 versus 4.1 ± 2.1; P = 0.12). Children with acute liver failure (ALF) were more likely to experience delayed closure then those with chronic liver disease (CLD; P < 0.001). GRWR was similar between the ALF and CLD (3.4 ± 2.4 versus 3.6 ± 2.7; P = 0.68). Primary closure children had a shorter hospital stay (P < 0.001), spent fewer days in pediatric intensive care unit (PICU; P = 0.001), and required a shorter duration of ventilation (P < 0.001). Vascular complications (arterial and venous) were similar (primary 8.2% versus delayed 5.6%; P = 0.52). Graft (P = 0.42) and child survival (P = 0.65) in the primary and delayed groups were similar. Considering timing of mass closure after transplant, patients in the early delayed closure group (<6 weeks) were found to experience a shorter time of ventilation (P = 0.03) and in PICU (P = 0.003). In conclusion, ALF was the main determinant of delayed abdominal closure rather than GRWR. The optimal time for delayed closure is within 6 weeks. The use of delayed abdominal closure does not adversely affect graft/child survival. Liver Transplantation 23 352–360 2017 AASLD.

Hepatic cell transplantation. Technical and methodological aspects

Abstract Hepatic cell transplantation consists of grafting already differentiated cells such as hepatocytes. Human hepatocytes are viable and functionally active. Liver cell transplantation is carried out by means of a 3-step method: isolation of hepatocytes from donor liver rejected for orthotopic transplantation, preparing a cell suspension for infusion and, finally, hepatocytes are implanted into the recipient. There are established protocols for the isolation of human hepatocytes from unused segments of donor livers, based on collagenase digestion of cannulated liver tissue at 37°C. The hepatocytes can be used fresh or cryopreserved. Cryopreservation of isolated human hepatocytes would then be available for planned use. In cell transplant, the important aspects are: infusion route, number of cells, number of infusions and viability of the cells. The cells are infused into the patient through a catheter inserted via portal vein or splenic artery. Liver cell transplantation allows liver tissue to be used that would, otherwise, be discarded, enabling multiple patients to be treated with hepatocytes from a single tissue donor.

Liver transplantation in children: state of the art and future perspectives

In this review, we provide a state of the art of liver transplantation in children, as the procedure is now carried out for more than 30 years and most of our paediatric colleagues are managing these patients jointly with liver transplant centres. Our goal for this article is to enhance the understanding of the liver transplant process that a child and his family goes through while explaining the surgical advances and the associated complications that could happen in the immediate or long-term follow-up. We have deliberately introduced the theme that ‘liver transplant is a disease’ and ‘not a cure’, to emphasise the need for adherence with immunosuppression, a healthy lifestyle and lifelong medical follow-up.

Estado actual y perspectivas futuras del trasplante de hepatocitos

The imbalance between the number of potential beneficiaries and available organs, originates the search for new therapeutic alternatives, such as Hepatocyte transplantation (HT).Even though this is a treatment option for these patients, the lack of unanimity of criteria regarding indications and technique, different cryopreservation protocols, as well as the different methodology to assess the response to this therapy, highlights the need of a Consensus Conference to standardize criteria and consider future strategies to improve the technique and optimize the results.Our aim is to review and update the current state of hepatocyte transplantation, emphasizing the future research attempting to solve the problems and improve the results of this treatment.

Trasplante celular hepático: un nuevo tratamiento en las enfermedades hepáticas

Liver transplantation has been remarkably effective in the treatment in patients with end-stage liver disease. However, disparity between solid-organ supply and increased demand is the greatest limitation, resulting in longer waiting times and increase in mortality of transplant recipients. This situation creates the need to seek alternatives to orthotopic liver transplantation.Hepatocyte transplantation or liver cell transplantation has been proposed as the best method to support patients. The procedure consists of transplanting individual cells to a recipient organ in sufficient quantity to survive and restore the function. The capacity of hepatic regeneration is the biological basis of hepatocyte transplantation. This therapeutic option is an experimental procedure in some patients with inborn errors of metabolism, fulminant hepatic failure and acute and chronic liver failure, as a bridge to orthotopic liver transplantation. In the Hospital La Fe of Valencia, we performed the first hepatocyte transplantation in Spain creating a new research work on transplant program.

Nuevas alternativas al trasplante hepático: trasplante de hepatocitos

La reciente irrupción del concepto de medicina regenerativa abre un nuevo marco de actuación terapéutica en aquellas enfermedades cuya causa es el deterioro celular de un órgano, y para las que no es factible el trasplante del órgano entero. Existe un gran número de enfermedades hepáticas en las que el único tratamiento efectivo en la actualidad es el trasplante hepático ortotópico (THO). Sin embargo, su principal limitación se encuentra en la falta de órganos disponibles, lo que genera un desequilibrio entre pacientes y receptores y una significativa lista de espera, que conlleva un aumento de la mortalidad. Esto plantea la urgente necesidad de buscar nuevas alternativas terapéuticas. El tratamiento celular se considera hoy una estrategia terapéutica de vanguardia complementaria al trasplante de órgano sólido. Las ventajas objetivas que presenta el trasplante de hepatocitos frente al trasplante de órgano lo convierten en una alternativa muy atractiva. El trasplante celular hepático (TCH) permitirı́a mantener las funciones hepáticas durante el perı́odo puente hasta la obtención de un órgano adecuado, o incluso en casos de fallo hepático fulminante tratarı́a de conseguir la regeneración hepática, lo que implicarı́a la recuperación de la función del órgano. Los resultados de este tratamiento indican que puede ser una técnica muy útil en la medida en que dispongamos de hepatocitos humanos de calidad, viables y metabólicamente funcionantes. Por otra parte, se trata de un método poco invasivo, que gracias la posibilidad de criopreservación celular se puede realizar de forma semiprogramada, y posibilita el tratamiento de varios receptores a partir de un único donante.

Hemangioendotelioma epitelioide: un tumor hepatico infrecuente

We report the case of a female patient who was referred to our unit because of a solid liver tumor, suggestive of metastasis. After biopsy, the patient was diagnosed with epithelioid hemangioendothelioma of the liver. Epithelioid hemangioendothelioma is a rare entity with an unpredictable, potentially fatal, clinical course and outcome. Due to its rarity, this entity should be considered when a solitary hepatic lesion is detected and should be included in the differential diagnosis with liver metastases. We highlight the infrequency of this tumor, its presentation as a solitary hepatic lesion and the indication of surgical treatment. We describe the clinical and pathological characteristics of epithelioid hemangioendothelioma of the liver and report a new case of this entity. The distinct therapeutic options are discussed.