Development of a liver graft assessment expert machine-learning system: when the artificial intelligence helps liver transplant surgeons.

Background: The complex process of liver graft assessment is one point for improvement in liver transplantation. The main objective of this study is to develop a tool that supports the surgeon who is responsible for liver donation in the decision-making process whether to accept a graft or not using the initial variables available to it. Material and method: Liver graft samples candidate for liver transplantation after donor brain death were studied. All of them were evaluated "in situ" for transplantation, and those discarded after the "in situ" evaluation were considered as no transplantable liver grafts, while those grafts transplanted after "in situ" evaluation were considered as transplantable liver grafts. First, a single-center, retrospective and cohort study identifying the risk factors associated with the no transplantable group was performed. Then, a prediction model decision support system based on machine learning, and using a tree ensemble boosting classifier that is capable of helping to decide whether to accept or decline a donor liver graft, was developed. Results: A total of 350 liver grafts that were evaluated for liver transplantation were studied. Steatosis was the most frequent reason for classifying grafts as no transplantable, and the main risk factors identified in the univariant study were age, dyslipidemia, personal medical history, personal surgical history, bilirubinemia, and the result of previous liver ultrasound (p < 0.05). When studying the developed model, we observe that the best performance reordering in terms of accuracy corresponds to 76.29% with an area under the curve of 0.79. Furthermore, the model provides a classification together with a confidence index of reliability, for most cases in our data, with the probability of success in the prediction being above 0.85. Conclusion: The tool presented in this study obtains a high accuracy in predicting whether a liver graft will be transplanted or deemed non-transplantable based on the initial variables assigned to it. The inherent capacity for improvement in the system causes the rate of correct predictions to increase as new data are entered. Therefore, we believe it is a tool that can help optimize the graft pool for liver transplantation.

Quantification and Characterization of CTCs and Clusters in Pancreatic Cancer by Means of the Hough Transform Algorithm.

Circulating Tumor Cells (CTCs) are considered a prognostic marker in pancreatic cancer. In this study we present a new approach for counting CTCs and CTC clusters in patients with pancreatic cancer using the IsofluxTM System with the Hough transform algorithm (Hough-IsofluxTM). The Hough-IsofluxTM approach is based on the counting of an array of pixels with a nucleus and cytokeratin expression excluding the CD45 signal. Total CTCs including free and CTC clusters were evaluated in healthy donor samples mixed with pancreatic cancer cells (PCCs) and in samples from patients with pancreatic ductal adenocarcinoma (PDAC). The IsofluxTM System with manual counting was used in a blinded manner by three technicians who used Manual-IsofluxTM as a reference. The accuracy of the Hough-IsofluxTM approach for detecting PCC based on counted events was 91.00% [84.50, 93.50] with a PCC recovery rate of 80.75 ± 16.41%. A high correlation between the Hough-IsofluxTM and Manual-IsofluxTM was observed for both free CTCs and for clusters in experimental PCC (R2 = 0.993 and R2 = 0.902 respectively). However, the correlation rate was better for free CTCs than for clusters in PDAC patient samples (R2 = 0.974 and R2 = 0.790 respectively). In conclusion, the Hough-IsofluxTM approach showed high accuracy for the detection of circulating pancreatic cancer cells. A better correlation rate was observed between Hough-IsofluxTM approach and with the Manual-IsofluxTM for isolated CTCs than for clusters in PDAC patient samples.

Impact of a Donor Age >75 Years on the Survival of Liver Transplant Recipients.

BACKGROUND: An organ shortage is the reason why it is necessary to expand the pool of donors, which can be achieved by using elderly donors. The main goal of this study is to analyze the outcomes of liver transplant (LT) when it is performed with donors older than 75 years. METHODS: We carried out a retrospective case-control study (N = 212) that included LTs with donors older than 75 years (group A, n = 106 cases) that were performed in our center between the years 2010 and 2020. This cohort has been paired off with a similar control group (group B, n = 106) whose donors were significantly younger. A survival analysis using the Kaplan-Meier model was performed. RESULTS: Average (SD) age of donors in group A was statistically greater than group B (A, 79.1 [3.0] years vs B, 54.4 [15.3], P < .001). There were no differences either in the average age of the recipients or in the Model for End-Stage Liver Disease score of both groups. Indications for LT were distributed equally in both groups: the most common was cellular hepatocarcinoma followed by alcohol-related cirrhosis. Survival rates for group A were 81%, 78%, and 67%, in 1, 3, and 5 years, respectively, while in group B they were 85%, 76%, and 71%, respectively, without differences found between the groups (P = .57). CONCLUSIONS: Using elderly liver donors is safe, achieving good outcomes in terms of short- and midterm rates of survival.

Radiofrequency-assisted transection of the pancreas versus stapler in distal pancreatectomy: study protocol for a multicentric randomised clinical trial (TRANSPAIRE).

INTRODUCTION: To date, no pancreatic stump closure technique has been shown to be superior to any other in distal pancreatectomy. Although several studies have shown a trend towards better results in transection using a radiofrequency device (radiofrequency-assisted transection (RFT)), no randomised trial for this purpose has been performed to date. Therefore, we designed a randomised clinical trial, with the hypothesis that this technique used in distal pancreatectomies is superior in reducing clinically relevant postoperative pancreatic fistula (CR-POPF) than mechanical closures. METHODS AND ANALYSIS: TRANSPAIRE is a multicentre randomised controlled trial conducted in seven Spanish pancreatic centres that includes 112 patients undergoing elective distal pancreatectomy for any indication who will be randomly assigned to RFT or classic stapler transections (control group) in a ratio of 1:1. The primary outcome is the CR-POPF percentage. Sample size is calculated with the following assumptions: 5% one-sided significance level (α), 80% power (1-ß), expected POPF in control group of 32%, expected POPF in RFT group of 10% and a clinically relevant difference of 22%. Secondary outcomes include postoperative results, complications, radiological evaluation of the pancreatic stump, metabolomic profile of postoperative peritoneal fluid, survival and quality of life. Follow-ups will be carried out in the external consultation at 1, 6 and 12 months postoperatively. ETHICS AND DISSEMINATION: TRANSPAIRE has been approved by the CEIM-PSMAR Ethics Committee. This project is being carried out in accordance with national and international guidelines, the basic principles of protection of human rights and dignity established in the Declaration of Helsinki (64th General Assembly, Fortaleza, Brazil, October 2013), and in accordance with regulations in studies with biological samples, Law 14/2007 on Biomedical Research will be followed. We have defined a dissemination strategy, whose main objective is the participation of stakeholders and the transfer of knowledge to support the exploitation of activities. REGISTRATION DETAILS: ClinicalTrials.gov Registry (NCT04402346).

Liver Resuscitation With Hypothermic Oxygenated Perfusion After Donation in Asystolic Type Iii With Regional Perfusion in Normothermia: A Case Report About First Experience in Spain.

BACKGROUND: Extended criteria donor livers are increasingly being accepted for transplant in an attempt to bridge the gap between the number of patients on the waiting list and the number of available donor livers. Our objective was to describe our first case of hepatic resuscitation by means of an ex situ perfusion machine in hypothermia with oxygen insufflation of a liver graft extracted from a donor in type 3 asystole after regional perfusion in normothermia. METHODS: A 53-year-old woman with disabling polycystic liver disease was included on the liver transplant waiting list. Donation was offered in type 3 asystole with regional perfusion in normothermia. Given that it was an elderly donor with a low-weight graft, hepatic resuscitation was decided by means of an ex situ perfusion machine in hypothermia with oxygen insufflation. RESULTS: After performing the bench work, the injector is selectively cannulated via the portal to connect it to the hypothermic perfusion machine. The average temperature of the perfusate (3 L modified Belzer) was 10°C for 120 minutes at 250 mL/min. The implant was completed without the need for transfusion of blood products, postreperfusion Sd, or vasoactive support. Peak of GOT/GPT was 803/276 at 24 hours posttransplant.

Donor-Specific Cell-Free DNA qPCR Quantification as a Noninvasive Accurate Biomarker for Early Rejection Detection in Liver Transplantation.

(1) Background: Graft-cell-free DNA (cfDNA) in the circulation of liver transplant recipients has been proposed as a noninvasive biomarker of organ rejection. The aim of this study was to detect donor-specific cfDNA (ds-cfDNA) in the recipient's serum after either liver damage or rejection using a qPCR-based method. (2) Methods: We proposed a qPCR method based on the amplification of 10 specific insertion-deletion (InDel) polymorphisms to detect donor-specific circulating DNA diluted in the recipient cfDNA. ds-cfDNA from 67 patients was evaluated during the first month post-transplantation. (3) Results: Graft rejection in the first month post-transplantation was reported in 13 patients. Patients without liver complications showed a transitory increase in ds-cfDNA levels at transplantation. Patients with rejection showed significant differences in ds-cfDNA increase over basal levels at both the rejection time point and several days before rejection. Receiver operator characteristic (ROC) analysis showed that ds-cfDNA levels discriminated rejection, with an AUC of 0.96. Maximizing both sensitivity and specificity, a threshold cutoff of 8.6% provided an estimated positive and negative predictive value of 99% and 60%, respectively. (4) Conclusions: These results suggest that ds-cfDNA may be a useful marker of graft integrity in liver transplant patients to screen for rejection and liver damage.

Hepatic Artery Thrombosis After Orthotopic Liver Transplant: Experience in the Last 10 Years.

BACKGROUND: Hepatic artery thrombosis (HAT) is the second cause of graft failure, after primary disfunction. It has a significant morbidity, with a retransplant and mortality rate in early hepatic artery thrombosis of 50%. The incidence of this event goes from 2% to 9% in the adult population. METHODS: The objective is to assess the incidence of HAT in a third-level hospital. The study design is an observational retrospective study, collecting data of the transplant recipient from 2010 to 2020. RESULTS: Incidence of HAT was 5.33% (39/732). A statistical difference was found with the blood intraoperative administration (P = .002) and with the presence of anatomic abnormalities in the hepatic artery between the HAT and the non-HAT group. We did not find any statistical difference with portal thrombosis (P = .73) between the groups. CONCLUSIONS: HAT is a fatal complication after an orthotopic liver transplant, which can lead to graft loss and even recipient death. For these reasons, we should early identify risk factors associated with this event early and try to minimize them to avoid the devastating consequences.

Factores de riesgo para injertos hepáticos no válidos. Estudio multivariante a partir de las variables recogidas en el protocolo de donación de la Organización Nacional de Trasplantes / Risk Factors for No Valid Liver Graft. Multivariate Study Based on the Variables Included in the Donation Protocol of the National Trasplant Organisation

INTRODUCCIÓN: Entre las estrategias diseñadas para optimizar el número de injertos hepáticos existentes para trasplante, la implementación del proceso de valoración de injertos constituye una de las menos exploradas. El objetivo principal es identificar los factores de riesgo que presentan los donantes hepáticos para la «NO validez». Secundariamente analizamos la coincidencia entre la valoración del cirujano y la del anatomopatólogo en los donantes NO válidos. MATERIAL Y MÉTODO: Estudio retrospectivo realizado a partir de una base de datos prospectiva que analiza 190 donantes hepáticos, 95 válidos y 95 NO válidos. Se estudian las variables de cada uno de ellos correspondientes al protocolo de donación de la Organización Nacional de Trasplantes. Mediante el estudio multivariante determinamos los factores de riesgo independientes de NO validez. Cotejamos las causas de NO validez argumentadas con los hallazgos histopatológicos de dichos injertos. RESULTADOS: Los factores de riesgo independientes de NO validez en el estudio multivariante (p < 0,05) fueron: dislipemia, antecedentes personales médicos distintos a factores de riesgo cardiovascular y quirúrgicos abdominales, GGT, BrT, y el resultado de la ecografía hepática previa. Las dos causas más frecuentes de NO validez fueron: esteatosis y fibrosis. El 78% de las biopsias confirmaron la NO validez del injerto (en 57,9% del total coincidían los hallazgos histológicos con los descritos por el cirujano). El 22% restante de las biopsias no presentaban hallazgos patológicos. CONCLUSIONES: La determinación de los factores de riesgo de NO validez contribuirá al diseño de futuros scores de valoración que constituyan herramientas útiles en el proceso de valoración de injertos hepáticos

INTRODUCTION: Among the strategies designed to optimize the number of existing liver grafts for transplantation, the implementation of the graft assessment process is one of the least explored. The main objective is to identify the risk factors presented by liver donors for «NO validity». Secondly, we analyzed the coincidence between the surgeon's assessment and that of the anatomo-pathologist in the invalid donors. MATERIAL AND METHOD: Retrospective study conducted from a prospective database that analyzes 190 liver donors, 95 valid and 95 NOT valid. The variables of each of them corresponding to the donation protocol of the National Transplant Organization are studied. Through a multivariate study we determine the independent risk factors of NO validity. We checked the causes of NO validity argued with the histopathological findings of these grafts. RESULTS: The independent risk factors of non-validity in the multivariate study (P < .05) were: dyslipidemia, personal medical history other than cardiovascular and abdominal surgical risk factors, GGT, BrT, and the result of previous liver ultrasound. The 3 most frequent causes of NO validity were: steatosis, fibrosis and macroscopic appearance of the organ. 78% of the biopsies confirmed the NO validity of the graft (in 57.9% of the cases the histological findings coincided with those described by the surgeon). The 22.1% of the biopsies hadńt pathological findings. CONCLUSIONS: The determination of the risk factors of NO validity will contribute to the design of future assessment scores that are useful tools in the process of liver graft assessment)

Risk Factors for No Valid Liver Graft. Multivariate Study Based on the Variables Included in the Donation Protocol of the National Trasplant Organisation. / Factores de riesgo para injertos hepáticos no válidos. Estudio multivariante a partir de las variables recogidas en el protocolo de donación de la Organización Nacional de Trasplantes.

INTRODUCTION: Among the strategies designed to optimize the number of existing liver grafts for transplantation, the implementation of the graft assessment process is one of the least explored. The main objective is to identify the risk factors presented by liver donors for «NO validity¼. Secondly, we analyzed the coincidence between the surgeon's assessment and that of the anatomo-pathologist in the invalid donors. MATERIAL AND METHOD: Retrospective study conducted from a prospective database that analyzes 190 liver donors, 95 valid and 95 NOT valid. The variables of each of them corresponding to the donation protocol of the National Transplant Organization are studied. Through a multivariate study we determine the independent risk factors of NO validity. We checked the causes of NO validity argued with the histopathological findings of these grafts. RESULTS: The independent risk factors of non-validity in the multivariate study (P < .05) were: dyslipidemia, personal medical history other than cardiovascular and abdominal surgical risk factors, GGT, BrT, and the result of previous liver ultrasound. The 3 most frequent causes of NO validity were: steatosis, fibrosis and macroscopic appearance of the organ. 78% of the biopsies confirmed the NO validity of the graft (in 57.9% of the cases the histological findings coincided with those described by the surgeon). The 22.1% of the biopsies hadnt pathological findings. CONCLUSIONS: The determination of the risk factors of NO validity will contribute to the design of future assessment scores that are useful tools in the process of liver graft assessment.).

Trasplante hepático dominó con injerto procedente de donante en muerte circulatoria (Maastricht III) / Successful domino liver transplantation using a graft from a controlled donation after circulatory death (Maastricht III)

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Does the Artery-first Approach Improve the Rate of R0 Resection in Pancreatoduodenectomy?: A Multicenter, Randomized, Controlled Trial.

OBJECTIVE: To compare the rates of R0 resection in pancreatoduodenectomy (PD) for pancreatic and periampullary malignant tumors by means of standard (ST-PD) versus artery-first approach (AFA-PD). BACKGROUND: Standardized histological examination of PD specimens has shown that most pancreatic resections thought to be R0 resections are R1. "Artery-first approach" is a surgical technique characterized by meticulous dissection of arterial planes and clearing of retropancreatic tissue in an attempt to achieve a higher rate of R0. To date, studies comparing AFA-PD versus ST-PD are retrospective cohort or case-control studies. METHODS: A multicenter, randomized, controlled trial was conducted in 10 University Hospitals (NCT02803814, ClinicalTrials.gov). Eligible patients were those who presented with pancreatic head adenocarcinoma and periampullary tumors (ampulloma, distal cholangiocarcinoma, duodenal adenocarcinoma). Assignment to each group (ST-PD or AFA-PD) was randomized by blocks and stratified by centers. The primary end-point was the rate of tumor-free resection margins (R0); secondary end-points were postoperative complications and mortality. RESULTS: One hundred seventy-nine patients were assessed for eligibility and 176 randomized. After exclusions, the final analysis included 75 ST-PD and 78 AFA-PD. R0 resection rates were 77.3% (95% CI: 68.4-87.4) with ST-PD and 67.9% (95% CI: 58.3-79.1) with AFA-PD, P=0.194. There were no significant differences in postoperative complication rates, overall 73.3% versus 67.9%, and perioperative mortality 4% versus 6.4%. CONCLUSIONS: Despite theoretical oncological advantages associated with AFA-PD and evidence coming from low-level studies, this multicenter, randomized, controlled trial has found no difference neither in R0 resection rates nor in postoperative complications in patients undergoing ST-PD versus AFA-PD for pancreatic head adenocarcinoma and other periampullary tumors.

Incidencia y supervivencia de los tumores de novo en el trasplante hepático / Incidence and survival rate of de novo tumors in liver transplants

INTRODUCCIÓN: La mayor supervivencia del paciente trasplantado viene acompañada del aumento en la tasa de tumores de novo (TN) que representan la complicación tardía más frecuente. Podemos distinguir entre tumores de piel no melanoma (TPNM), síndrome linfoproliferativo postrasplante (SLPT) y tumores de órgano sólido (TOS). Nuestro objetivo es determinar la incidencia de los distintos TN, el tiempo trascurrido hasta su diagnóstico y su supervivencia en nuestro medio. MATERIAL Y MÉTODO: Realizamos un estudio retrospectivo de 1.071 trasplantados hepáticos desde 1990 hasta 2015 en nuestro centro. Analizamos las variables demográficas, la incidencia de TN y la supervivencia. RESULTADOS: Se desarrollaron 184 TN en 1.071 pacientes trasplantados (17%), en el 19% de los varones y en el 13% de las mujeres (p = 0,004). Los TN más frecuentes fueron los TPNM (29%), pulmón (18%), cabeza y cuello (16%), SLPT (10%) y gastrointestinales (8%). La mediana del tiempo de diagnóstico fue de 7,9 años en los TPNM, 3,9 años en SLPT y de 9,8 años en TOS. Los pacientes con TPNM tuvieron significativamente mejor supervivencia que aquellos con SLPT o TOS. La incidencia de los tumores de novo (excluidos TPNM) fue 1.889/100.000 trasplantados/año. Por género, el cáncer de pulmón fue el TOS más común en varones y el cáncer de mama en mujeres. CONCLUSIÓN: En nuestro medio, excluidos los TPNM, la incidencia es 8,8 veces la estimada para la población general, con una alta tasa de cáncer de pulmón por lo que deberíamos implementar estrategias preventivas y diagnósticas

INTRODUCTION: The greater survival of transplanted patients is accompanied by an increase in the rate of de novo malignancies (NM), which are the most frequent late-onset complication. We can distinguish between non-melanoma skin cancers (NMSC), post-transplant lymphoproliferative disorders (PTLD) and solid organ cancers (SOC). Our objective is to determine the incidence of the different types of NM, the time elapsed until diagnosis and survival rates in our setting. METHODS: We conducted a retrospective study of 1071 liver transplant patients from 1990 to 2015 at our center. We analyzed the demographic variables, incidence of NM and survival. RESULTS: 184 NM developed in 1071 transplant patients (17%), specifically 19% of the males and 13% of the females (P=.004). The most frequent NM were NMSC (29%), lung (18%), head and neck (16%), PTLD (10%) and gastrointestinal (8%). The median time of diagnosis was 7.9 years in NMSC, 3.9 years in PTLD and 9.8 years in SOC. Patients with NMSC had significantly better survival than those with PTLD or SOC. The incidence of de novo tumors (excluding NMSC) was 1889/100,000 transplants/year. By gender, lung cancer was the most common TOS in men and breast cancer in women. CONCLUSION: In our setting, excluding NMSC, the incidence is 8.8 times greater than estimations for the general population, with a high rate of lung cancer, so we should implement preventive and diagnostic strategies

Incidence and survival rate of de novo tumors in liver transplants. / Incidencia y supervivencia de los tumores de novo en el trasplante hepático.

INTRODUCTION: The greater survival of transplanted patients is accompanied by an increase in the rate of de novo malignancies (NM), which are the most frequent late-onset complication. We can distinguish between non-melanoma skin cancers (NMSC), post-transplant lymphoproliferative disorders (PTLD) and solid organ cancers (SOC). Our objective is to determine the incidence of the different types of NM, the time elapsed until diagnosis and survival rates in our setting. METHODS: We conducted a retrospective study of 1071 liver transplant patients from 1990 to 2015 at our center. We analyzed the demographic variables, incidence of NM and survival. RESULTS: 184 NM developed in 1071 transplant patients (17%), specifically 19% of the males and 13% of the females (P=.004). The most frequent NM were NMSC (29%), lung (18%), head and neck (16%), PTLD (10%) and gastrointestinal (8%). The median time of diagnosis was 7.9 years in NMSC, 3.9 years in PTLD and 9.8 years in SOC. Patients with NMSC had significantly better survival than those with PTLD or SOC. The incidence of de novo tumors (excluding NMSC) was 1889/100,000 transplants/year. By gender, lung cancer was the most common TOS in men and breast cancer in women. CONCLUSION: In our setting, excluding NMSC, the incidence is 8.8 times greater than estimations for the general population, with a high rate of lung cancer, so we should implement preventive and diagnostic strategies.

1000 trasplantes hepáticos consecutivos. Análisis descriptivo y evolución de un centro / 1000 consecutive liver transplants. Descriptive analysis and evolution of a single center

Desde 1991 a 2013 se realizaron en el Hospital Virgen del Rocío 1.000 trasplantes hepáticos. Se realizó un estudio retrospectivo, en el que se analizaron las características de los donantes y los receptores, las indicaciones, la técnica quirúrgica, las complicaciones y la supervivencia en 2 etapas diferentes (1991-2002 vs. 2003-2013), coincidiendo con la implantación del MELD como modelo de priorización. La indicación más frecuente fue la hepatopatía de origen hepatocelular en 48,8%. Hubo un incremento significativo en las indicaciones por hepatocarcinoma (8,6% y 24,1% p = 0,03), y de la tasa retrasplantes (5,9% Vs 9,6%, p = 0,04). Se apreció un cambio en la edad de donación, pasando de 27,7 años en 1990 a 62,9 años en 2012 (p = 0,001). El porcentaje de pacientes que no precisaron transfusión de hemoderivados se duplicó (6,16 vs. 14,31%, p = 0,001). La supervivencia de todos los pacientes a uno, 5 y 10 años fue del 77, 63,5 y 51,3%, respectivamente

Between 1991 and 2013, 1,000 liver transplantations were performed at Virgen del Rocio Hospital (Seville, Spain). A retrospective study was conducted, analyzing the characteristics of recipients and donors, indications, surgical technique, complications and survival in 2 different stages (1991-2002 vs. 2003-2013) coinciding with the implementation of the MELD scale as a prioritization model. The most frequent indication were of hepatopathy of hepatocellular origin in 48.8%. There was a significant increase in the indications for hepatocarcinoma (8.6% and 24.1% P = 0.03), and the rate of retransplantation (5.9% vs 9.6%, P = 0.04). There was a change in the age of donation, going from 27.7 years in 1990 to 62.9 years in 2012 (P = 0.001). The percentage of patients who did not require blood transfusion doubled (6.16 vs. 14.31%, P = .001). Survival of all patients after one, 5 and 10 years was 77, 63.5 and 51.3%, respectively

1000 consecutive liver transplants. Descriptive analysis and evolution of a single center. / 1000 trasplantes hepáticos consecutivos. Análisis descriptivo y evolución de un centro.

Between 1991 and 2013, 1,000 liver transplantations were performed at Virgen del Rocio Hospital (Seville, Spain). A retrospective study was conducted, analyzing the characteristics of recipients and donors, indications, surgical technique, complications and survival in 2 different stages (1991-2002 vs. 2003-2013) coinciding with the implementation of the MELD scale as a prioritization model. The most frequent indication were of hepatopathy of hepatocellular origin in 48.8%. There was a significant increase in the indications for hepatocarcinoma (8.6% and 24.1% P=0.03), and the rate of retransplantation (5.9% vs 9.6%, P=0.04). There was a change in the age of donation, going from 27.7 years in 1990 to 62.9 years in 2012 (P=0.001). The percentage of patients who did not require blood transfusion doubled (6.16 vs. 14.31%, P=.001). Survival of all patients after one, 5 and 10 years was 77, 63.5 and 51.3%, respectively.

CMV-specific T-cell immunity in solid organ transplant recipients at low risk of CMV infection. Chronology and applicability in preemptive therapy.

OBJECTIVES: To characterize whether the CMV-specific cellular immune response can be used as a predictor of the control of CMV infection and disease and determine thresholds in solid organ transplant (SOT) recipients seropositive for CMV (R+). METHODS: The CMV-specific T-cell response was characterized using intracellular cytokine staining and the evolution of clinical and virological parameters were recorded during the first year after transplantation. RESULTS: Besides having positive CMV serology, only 28.4% patients had positive immunity (CD8+CD69+IFN-γ+ ≥0.25%) at 2 weeks after transplantation. These patients had less indication of preemptive treatment (p = 0.025) and developed less high grade (≥2000 IU/ml) CMV replication episodes (p = 0.006) than patients with no immunity. Of the 49 patients with a pretransplant sample, only 22.4% had positive immunity, and had a detectable immune response early after transplantation (median of 3.7 weeks). However, only 50% of patients with negative pretransplant immunity acquired a positive immune response and it was significantly later, at a median of 11 weeks (p < 0.001). Patients that developed CMV disease had no CMV-specific immunity. CONCLUSIONS: Having CMV-specific CD8+IFN-γ+ cells ≥0.25% before transplant; 0.15% at two weeks or 0.25% at four weeks after transplantation, identifies patients that may spontaneously control CMV infection and may require less monitoring.

Síndrome linfoproliferativo en el trasplante hepático / Post-transplant lymphoproliferative disease in liver transplant recipients

Introducción: el síndrome linfoproliferativo postrasplante (SLPT) es una complicación infrecuente que ensombrece el pronóstico de los pacientes sometidos a un trasplante hepático (TH). Su patogenia es multifactorial, siendo sus dos principales factores de riesgo la inmunodepresión y la infección del virus de Epstein- Barr (VEB); sin embargo, en actualidad se piensa que puede estar relacionada con otros factores. Métodos: estudio observacional en el que hemos analizado de forma retrospectiva 851 casos que fueron sometidos a un trasplante hepático, de los cuales diez casos han desarrollado un SLPT. Se han analizado sus características clinicopatológicas y el tratamiento recibido. Resultados: la incidencia del SLPT ha sido del 1,2% (10/851) y el tiempo medio de presentación desde el TH hasta el diagnóstico, de 36 meses (rango 1,2-144 meses). El lugar de presentación ha sido extranodal en todos los casos, siendo más frecuente la localización intestinal. Siete casos presentaron un SLPT monomorfo, todos ellos linfomas diferenciados de células B. El 50% de la serie presentó seronegatividad para el virus de Epstein-Barr. La supervivencia global ha sido del 50%. Entre estos pacientes, hemos observado tres casos de curación completa, un caso de estabilización de la enfermedad y otro caso de recurrencia. Conclusión: el SLPT es una complicación infrecuente que supone una amenaza para la vida del paciente. Para poder instaurar un diagnóstico precoz y un tratamiento que pueda modificar el curso de la enfermedad, es fundamental la identificación de los pacientes en riesgo (AU)

Introduction: Post-transplant lymphoproliferative syndrome (PTLD) is a rare and potentially life-threatening complication after liver transplantation. The aim of this study was to analyze the clinicopathologic features related to PTLD in a single institution after liver transplantation. Methods: Observational study where we have retrospectively analyzed 851 cases who underwent liver transplantation. Ten cases have developed PTLD. Their clinical-pathological characteristics and the treatment received have been analyzed. Results: PTLD incidence was 1.2% (10/851). The mean time from liver transplantation to PTLD diagnosis was 36 months (range 1.2 to 144 months). PTLD localization was extranodal in all cases, the most frequent location being intestinal. Seven cases showed a monomorphic lymphoma which in all cases was differentiated B cell lymphomas. Fifty per cent of the series were seropositive for Epstein-Barr virus. Five patients were alive at the time of the review. Among these patients, we observed three cases of complete remission and two cases of disease stabilization. The death rate was higher in the first year after diagnosis of PTLD. Conclusion: PTLD is a rare complication after liver transplantation, but it may pose a threat to the life of a liver transplant recipient. It is essential to identify patients at risk, to establish an early diagnosis and treatment that can change the outcome of the disease (AU)

Post-transplant lymphoproliferative disease in liver transplant recipients.

INTRODUCTION: Post-transplant lymphoproliferative syndrome (PTLD) is a rare and potentially life-threatening complication after liver transplantation. The aim of this study was to analyze the clinicopathologic features related to PTLD in a single institution after liver transplantation. METHODS: Observational study where we have retrospectively analyzed 851 cases who underwent liver transplantation. Ten cases have developed PTLD. Their clinical-pathological characteristics and the treatment received have been analyzed. RESULTS: PTLD incidence was 1.2% (10/851). The mean time from liver transplantation to PTLD diagnosis was 36 months (range 1.2 to 144 months). PTLD localization was extranodal in all cases, the most frequent location being intestinal. Seven cases showed a monomorphic lymphoma which in all cases was differentiated B cell lymphomas. Fifty per cent of the series were seropositive for Epstein-Barr virus. Five patients were alive at the time of the review. Among these patients, we observed three cases of complete remission and two cases of disease stabilization. The death rate was higher in the first year after diagnosis of PTLD. CONCLUSION: PTLD is a rare complication after liver transplantation, but it may pose a threat to the life of a liver transplant recipient. It is essential to identify patients at risk, to establish an early diagnosis and treatment that can change the outcome of the disease.