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1.
Updates Surg ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037684

RESUMO

With the increasing incidence of hepatocellular carcinoma (HCC) in both the United States and globally, the role of liver transplantation in management continues to be an area of active conversation as it is often considered the gold standard in the treatment of HCC. The use of living donor liver transplantation (LDLT) and the indications in the setting of malignancy, both generally and in HCC specifically, are frequently debated. In terms of both overall survival and recurrence-free survival, LDLT is at least equivalent to DDLT, especially when performed for disease within Milan criteria. Emerging and compelling evidence suggests that LDLT is superior to DDLT in treating HCC as there is a significant decrease in waitlist mortality. As the oncologic indications for liver transplantation continue to expand and the gap between organ demand and organ availability continues to worsen, high volumes centers should consider using LDLT to shrink the ever-expanding waitlist.

2.
Ann Surg ; 276(5): 854-859, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35920562

RESUMO

OBJECTIVE: We herein advocate for more extensive utilization of ex vivo resection techniques for otherwise unresectable liver tumors by presenting the largest collective American experience. BACKGROUND: Advanced in situ resection and vascular reconstruction techniques have made R0 resection possible for otherwise unresectable liver tumors. Ex vivo liver resection may further expand the limits of resectability but remains underutilized due to concerns about technical complexity and vascular thrombosis. However, we believe that the skillset required for ex vivo liver resection is more widespread and the complications less severe than widely assumed, making ex vivo resection a more attractive option in selected case. METHODS: We retrospectively analyzed 35 cases performed by surgical teams experienced with ex vivo liver resections (at least 4 cases) between 1997 and 2021. RESULTS: We categorized malignancies as highly aggressive (n=18), moderately aggressive (n=14), and low grade (n=3). All patients underwent total hepatectomy, vascular reconstruction and resection in hypothermia on the backtable, and partial liver autotransplantation. Overall survival was 67%/39%/28%, at 1/3/5 years, respectively, with a median survival of 710 days (range: 22-4824). Patient survival for highly aggressive, moderately aggressive, and low-grade tumors was 61%/33%/23%, 67%/40%/22%, and 100%/100%/100% at 1/3/5 years, respectively, with median survival 577 days (range: 22-3873), 444 days (range: 22-4824), and 1825 days (range: 868-3549). CONCLUSIONS: Ex vivo resection utilizes techniques commonly practiced in partial liver transplantation, and we demonstrate relatively favorable outcomes in our large collective experience. Therefore, we propose that more liberal use of this technique may benefit selected patients in centers experienced with partial liver transplantation.


Assuntos
Hepatectomia , Neoplasias Hepáticas , Hepatectomia/métodos , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Estudos Retrospectivos , Transplante Autólogo
3.
Cancer Immunol Res ; 10(10): 1190-1209, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-35895745

RESUMO

Assessment of immune-cell subsets within the tumor immune microenvironment is a powerful approach to better understand cancer immunotherapy responses. However, the use of biopsies to assess the tumor immune microenvironment poses challenges, including the potential for sampling error, restricted sampling over time, and inaccessibility of some tissues/organs, as well as the fact that single biopsy analyses do not reflect discordance across multiple intrapatient tumor lesions. Immuno-positron emission tomography (PET) presents a promising translational imaging approach to address the limitations and assess changes in the tumor microenvironment. We have developed 89Zr-DFO-REGN5054, a fully human CD8A-specific antibody conjugate, to assess CD8+ tumor-infiltrating lymphocytes (TIL) pre- and posttherapy. We used multiple assays, including in vitro T-cell activation, proliferation, and cytokine production, and in vivo viral clearance and CD8 receptor occupancy, to demonstrate that REGN5054 has minimal impact on T-cell activity. Preclinical immuno-PET studies demonstrated that 89Zr-DFO-REGN5054 specifically detected CD8+ T cells in lymphoid tissues of CD8-genetically humanized immunocompetent mice (VelociT mice) and discerned therapy-induced changes in CD8+ TILs in two models of response to a CD20xCD3 T-cell activating bispecific antibody (REGN1979, odronextamab). Toxicology studies in cynomolgus monkeys showed no overt toxicity, and immuno-PET imaging in cynomolgus monkeys demonstrated dose-dependent clearance and specific targeting to lymphoid tissues. This work supports the clinical investigation of 89Zr-DFO-REGN5054 to monitor T-cell responses in patients undergoing cancer immunotherapy.


Assuntos
Anticorpos Biespecíficos , Neoplasias , Animais , Linfócitos T CD8-Positivos , Citocinas/uso terapêutico , Humanos , Linfócitos do Interstício Tumoral , Macaca fascicularis , Camundongos , Tomografia por Emissão de Pósitrons/métodos , Radioisótopos , Microambiente Tumoral , Zircônio
5.
Pediatr Transplant ; 26(3): e14209, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34907641

RESUMO

BACKGROUND: Immunotherapy, specifically immune checkpoint inhibitors (ICIs), including anti-programmed cell death 1 (anti-PD1), has recently received clinical approval for the treatment of adult hepatocellular carcinoma (HCC). However, the safety and efficacy of ICIs prior to solid organ transplant are unknown, especially in pediatrics. Safety reports are variable in adults, with some series describing subsequent allograft rejection and loss while others report successful transplants without allograft rejection.As ICIs stimulate the immune system by blocking the interaction between PD1 and the ligand-receptor pair programmed cell death-ligand 1 (PDL1), the downstream effects of T-cell activation increase the risk of graft rejection. METHODS: Here, we present a case of an adolescent with moderately differentiated non-fibrolamellar HCC treated with pembrolizumab, an anti-PD1 therapy, who subsequently underwent successful orthotopic liver transplantation (OLT). RESULTS: Our patient received an OLT 138 days from the last pembrolizumab dose with graft preservation. The patient has no evidence of recurrent disease or any episode of allograft rejection 48 months post OLT. Staining of tumor and normal tissues from longitudinal specimens finds PDL1 positive Kupffer cells present in normal liver and peritumoral areas with no changes post anti-PD1 therapy. In contrast, tumor cells were negative for PDL1. CONCLUSION: This case represents a basis for optimism in potential use of anti-PD1 therapy in liver transplant candidates and supports further investigation of immune checkpoint inhibitors use in this unique patient population.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Transplante de Fígado , Adolescente , Adulto , Carcinoma Hepatocelular/cirurgia , Criança , Humanos , Inibidores de Checkpoint Imunológico , Ligantes , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/cirurgia
6.
J Gastrointest Surg ; 25(11): 2851-2858, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33825121

RESUMO

BACKGROUND: Hepatic resections are uncommon in children. Most studies reporting complications of these procedures and risk factors associated with unplanned readmissions are limited to retrospective data from single centers. We investigated risk factors for 30-day unplanned readmission after hepatectomy in children using the American College of Surgeons National Surgical Quality Improvement-Pediatric database. METHODS: The database was queried for patients aged 0-18 years who underwent hepatectomy for the treatment of liver lesions from 2012 to 2018. Chi-squared tests were performed to evaluate for potential risk factors for unplanned readmissions. A multivariate regression analysis was performed to identify independent predictors for unplanned 30-day readmissions. RESULTS: Among 438 children undergoing hepatectomy, 64 (14.6%) had unplanned readmissions. The median age of the hepatectomy cohort was 1 year (0-17); 55.5% were male. Patients readmitted had significantly higher rates of esophageal/gastric/intestinal disease (26.56% vs. 14.97%; p=0.022), current cancer (85.94% vs. 75.67%; p=0.012), and enteral and parenteral nutritional support (31.25% vs. 17.65%; p=0.011). Readmitted patients had significantly higher rates of perioperative blood transfusion (67.19% vs. 52.41%; p=0.028), organ/space surgical site infection (10.94% vs. 1.07%; p<.001), sepsis (15.63% vs. 3.74%; p<.001), and total parenteral nutrition at discharge (9.09% vs. 2.66%; p=0.041). Organ/space surgical site infection was an independent risk factor for unplanned readmission (OR=9.598, CI [2.070-44.513], p=0.004) by multivariable analysis. CONCLUSION: Unplanned readmissions after liver resection are frequent in pediatric patients. Organ/space surgical site infections may identify patients at increased risk for unplanned readmission. Strategies to reduce these complications may decrease morbidity and costs associated with unplanned readmissions.


Assuntos
Hepatectomia , Readmissão do Paciente , Criança , Bases de Dados Factuais , Hepatectomia/efeitos adversos , Humanos , Masculino , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fatores de Risco , Infecção da Ferida Cirúrgica , Fatores de Tempo
7.
J Clin Invest ; 131(8)2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33630757

RESUMO

In humans receiving intestinal transplantation (ITx), long-term multilineage blood chimerism often develops. Donor T cell macrochimerism (≥4%) frequently occurs without graft-versus-host disease (GVHD) and is associated with reduced rejection. Here we demonstrate that patients with macrochimerism had high graft-versus-host (GvH) to host-versus-graft (HvG) T cell clonal ratios in their allografts. These GvH clones entered the circulation, where their peak levels were associated with declines in HvG clones early after transplant, suggesting that GvH reactions may contribute to chimerism and control HvG responses without causing GVHD. Consistently, donor-derived T cells, including GvH clones, and CD34+ hematopoietic stem and progenitor cells (HSPCs) were simultaneously detected in the recipients' BM more than 100 days after transplant. Individual GvH clones appeared in ileal mucosa or PBMCs before detection in recipient BM, consistent with an intestinal mucosal origin, where donor GvH-reactive T cells expanded early upon entry of recipient APCs into the graft. These results, combined with cytotoxic single-cell transcriptional profiles of donor T cells in recipient BM, suggest that tissue-resident GvH-reactive donor T cells migrated into the recipient circulation and BM, where they destroyed recipient hematopoietic cells through cytolytic effector functions and promoted engraftment of graft-derived HSPCs that maintain chimerism. These mechanisms suggest an approach to achieving intestinal allograft tolerance.


Assuntos
Doença Enxerto-Hospedeiro/imunologia , Intestinos/transplante , Linfopoese/imunologia , Transplante de Órgãos , Linfócitos T/imunologia , Quimeras de Transplante/imunologia , Aloenxertos , Feminino , Doença Enxerto-Hospedeiro/patologia , Humanos , Intestinos/imunologia , Intestinos/patologia , Masculino , Linfócitos T/patologia
9.
Transplantation ; 104(8): 1580-1590, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32732835

RESUMO

BACKGROUND: Although short-term outcomes for liver transplantation have improved, patient and graft survival are limited by infection, cancer, and other complications of immunosuppression. Rapid induction of tolerance after liver transplantation would decrease these complications, improving survival and quality of life. Tolerance to kidneys, but not thoracic organs or islets, has been achieved in nonhuman primates and humans through the induction of transient donor chimerism. Since the liver is considered to be tolerogenic, we tested the hypothesis that the renal transplant transient chimerism protocol would induce liver tolerance. METHODS: Seven cynomolgus macaques received immune conditioning followed by simultaneous donor bone marrow and liver transplantation. The more extensive liver surgery required minor adaptations of the kidney protocol to decrease complications. All immunosuppression was discontinued on postoperative day (POD) 28. Peripheral blood chimerism, recipient immune reconstitution, liver function tests, and graft survival were determined. RESULTS: The level and duration of chimerism in liver recipients were comparable to those previously reported in renal transplant recipients. However, unlike in the kidney model, the liver was rejected soon after immunosuppression withdrawal. Rejection was associated with proliferation of recipient CD8 T effector cells in the periphery and liver, increased serum interleukin (IL)-6 and IL-2, but peripheral regulatory T cell (Treg) numbers did not increase. Antidonor antibody was also detected. CONCLUSIONS: These data show the transient chimerism protocol does not induce tolerance to livers, likely due to greater CD8 T cell responses than in the kidney model. Successful tolerance induction may depend on greater control or deletion of CD8 T cells in this model.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Rejeição de Enxerto/prevenção & controle , Transplante de Fígado/efeitos adversos , Quimeras de Transplante/imunologia , Condicionamento Pré-Transplante/métodos , Aloenxertos/imunologia , Animais , Medula Óssea/imunologia , Transplante de Medula Óssea/métodos , Modelos Animais de Doenças , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Humanos , Fígado/imunologia , Transplante de Fígado/métodos , Macaca fascicularis , Linfócitos T Citotóxicos/imunologia , Tolerância ao Transplante , Transplante Homólogo/efeitos adversos
10.
Ann Surg ; 272(5): 766-772, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32833756

RESUMO

BACKGROUND AND AIMS: Ex vivo surgery may provide a chance at R0 resection for conventionally unresectable tumors. However, long-term outcomes have not been well documented. In this study, we analyze our 11-year outcomes to define its role. STUDY DESIGN: We retrospectively analyzed 46 consecutive patients who underwent ex vivo surgery at our institution 2008-2019. RESULTS: The types of tumors were: carcinoma (n = 20), sarcoma (n = 20) and benign to low grade tumor (n = 6). The type of ex vivo surgery was chosen based on tumor location and vascular involvement. The most commonly performed procedure was ex vivo hepatectomy (n = 18), followed by ex vivo resection and intestinal autotransplantation (n = 12), ex vivo Whipple procedure and liver autotransplantation (n = 8) and multivisceral ex vivo procedure (n = 7). Twenty-three patients (50%) are currently alive with median follow-up of 4.0-years (11 months-11.8 years). The overall survival was 70%/59%/52%, at 1-/3-/5-years, respectively. Patient survival for benign to low grade tumors, sarcoma, and carcinoma was 100%/100%/100%, 65%/60%/50%, and 65%/45%/40%, at 1-/3-/5-years, respectively. Ninety-one percent patients had R0 resection, and 57% had no recurrence to date with median follow-up of 3.1-years. Two patients (4.3%) died within 30 days due to sepsis and gastroduodenal artety (GDA) stump blowout. Two additional patients died between 30 and 90 days due to sepsis. Perioperative mortality in the last 23 consecutive cases was limited to 1 patient who died of sepsis between 30 and 90 days. CONCLUSIONS: For a selected group of patients with conventionally unresectable tumors, ex vivo surgery can offer effective surgical removal with a reasonably low perioperative mortality at experienced centers.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/métodos , Neoplasias Gastrointestinais/cirurgia , Transplante Autólogo , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Estudos Retrospectivos , Taxa de Sobrevida
11.
Arch Pathol Lab Med ; 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32302212

RESUMO

We present a case of COVID-19 hepatitis in a living donor liver allograft recipient whose donor subsequently tested positive for COVID-19. The patient is a female infant with biliary atresia (failed Kasai procedure). She recovered well, with improving liver function tests for 4 days. On post-operative day (POD) 4 the patient developed respiratory distress and fever. COVID-19 testing (polymerase chain reaction) was positive. Liver function tests increased approximately 5-fold. Liver biopsy showed moderate acute hepatitis with prominent clusters of apoptotic hepatocytes and associated cellular debris. Lobular lymphohistiocytic inflammation was noted. Typical portal features of mild to moderate acute cellular rejection were also noted.

12.
Transplantation ; 104(2): 270-279, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31385931

RESUMO

BACKGROUND: Cytomegalovirus (CMV) infection is a serious complication in immunosuppressed patients, specifically transplant recipients. Here, we describe the development and use of an assay to monitor the incidence and treatment of CMV viremia in a Cynomolgus macaque model of bone marrow transplantation (BMT) for tolerance induction. We address the correlation between the course of viremia and immune reconstitution. METHODS: Twenty-one animals received a nonmyeloablative conditioning regimen. Seven received cyclosporine A for 28 days and 14 received rapamycin. A CMV polymerase chain reaction assay was developed and run twice per week to monitor viremia. Nineteen recipients were CMV seropositive before BMT. Immune reconstitution was monitored through flow cytometry and CMV viremia was tracked via quantitative polymerase chain reaction. RESULTS: Recipients developed CMV viremia during the first month post-BMT. Two animals developed uncontrollable CMV disease. CMV reactivation occurred earlier in cyclosporine A-treated animals compared with those receiving rapamycin. Post-BMT, T-cell counts remained significantly lower compared with pretransplant levels until CMV reactivation, at which point they increased during the viremic phase and approached pretransplant levels 3 months post-BMT. Management of CMV required treatment before viremia reached 10 000 copies/mL; otherwise clinical symptoms were observed. High doses of ganciclovir resolved the viremia, which could subsequently be controlled with valganciclovir. CONCLUSIONS: We developed an assay to monitor CMV in Cynomolgus macaques. CMV reactivation occurred in 100% of seropositive animals in this model. Rapamycin delayed CMV reactivation and ganciclovir treatment was effective at high doses. As in humans, CD8 T cells proliferated during CMV viremia.


Assuntos
Transplante de Medula Óssea/métodos , Infecções por Citomegalovirus/terapia , Rejeição de Enxerto/imunologia , Reconstituição Imune/fisiologia , Tolerância Imunológica , Sirolimo/farmacologia , Ativação Viral , Animais , Antifúngicos/farmacologia , Citomegalovirus/imunologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Modelos Animais de Doenças , Rejeição de Enxerto/prevenção & controle , Macaca fascicularis , Transplantados
13.
Scand J Immunol ; 91(1): e12839, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31630416

RESUMO

The humanized IgG1κ monoclonal antibody siplizumab and its rat parent monoclonal IgG2b antibody BTI-322 are directed against the CD2 antigen. Siplizumab is species-specific, reacting with human and chimpanzee cells but not with cells from any other species, including other non-human primates. Because siplizumab treatment has recently shown great potential in clinical transplantation, we now present the results of our previous pharmacokinetic, pharmacodynamic and safety studies of both antibodies. Fourteen chimpanzees received 1-3 doses of 0.143 to 5.0 mg/kg iv The effects were followed with flow cytometry on peripheral lymphocytes and staining of lymph nodes. Side effects were recorded. Serum antibody concentrations were followed. Across the doses, a rapid, transient depletion of CD2, CD3, CD4 and CD8 lymphocytes and NK cells was observed for both antibodies. Immune reconstitution was more rapid for BTI-322 compared to siplizumab. Paracortical lymph node T cell depletion was moderate, estimated at 45% with doses of >0.6 mg/kg. Restoration of lymph node architecture was seen after two weeks to two months for all animals. All four subjects receiving BTI-322 experienced AEs on the first dosing day, while the eight subjects dosed with siplizumab experienced few mild, transient AEs. Infusion with siplizumab and BTI-322 resulted in rapid depletion of CD2+ cells in circulation and tissue. Siplizumab had a longer t1/2 and fewer AEs compared to BTI-322.


Assuntos
Anticorpos Monoclonais/farmacocinética , Antígenos CD2/antagonistas & inibidores , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/farmacocinética , Anticorpos Monoclonais Humanizados/uso terapêutico , Biomarcadores , Biópsia , Citocinas/sangue , Feminino , Imunoglobulina G/administração & dosagem , Imunoglobulina G/farmacologia , Imunofenotipagem , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Depleção Linfocítica , Linfócitos/imunologia , Linfócitos/metabolismo , Masculino , Pan troglodytes , Ratos
14.
J Surg Educ ; 77(2): 329-336, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31753606

RESUMO

OBJECTIVE: We evaluated the medical student experience with a deceased-donor multiorgan procurement program at a single center. The program provided the opportunity to assist with organ procurement, but no formal curriculum was offered. DESIGN, SETTING, PARTICIPANTS: In 2018, medical students who registered for the program between 2014 and 2017 completed a voluntary survey about the experience and its impact on surgery interest and organ donation knowledge and advocacy. RESULTS: Of 139 respondents, 53.3% (N = 74) of students participated in at least one procurement. The experience was resoundingly positive: 81.7% (N = 58) believed it exceeded expectations, with less than one-third missing class and only 4.3% (N = 3) reporting a negative impact on academics. Although 60.6% (N = 43) students studied prior to procurement, 57.8% (N = 41) expressed the need for increased preparation. Preferred learning modalities included videos, discussion with the transplant fellows, and focused anatomy overview. Following participation, 53.5% (N = 38) of students had increased interest in pursuing an acting internship and career in surgery. However, participation was not associated with improved familiarity with organ donation concepts or advocacy. CONCLUSIONS: Adding a structured curriculum may turn medical students from passive observers into active learners, maximizing the educational value of procurement and better equipping future providers to promote organ donation.


Assuntos
Estudantes de Medicina , Obtenção de Tecidos e Órgãos , Currículo , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Percepção , Inquéritos e Questionários
15.
J Pediatr Gastroenterol Nutr ; 68(6): 793-798, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30908386

RESUMO

OBJECTIVE: There are multiple approaches to manage the clinical complications of portal hypertension (PHTN) to treat/prevent spontaneous hemorrhage by mitigating thrombocytopenia. No single approach is ideal for all patients given the heterogeneity of this population. Our goal was to determine whether partial splenic embolization (PSE) was safe and effective in the pediatric population. METHODS: This is a retrospective review of our single-center experience for all patients ages 0 to 21 who underwent PSE between January 2010 and August 2017. The embolized splenic volume targeted was 60% to 70%. RESULTS: Twenty-six patients underwent PSE due to thrombocytopenia and/or recurrent variceal bleeding. Patients ranged in age from 18 months to 20 years (mean 13.1 years). The median platelet count before PSE was 53.0 (×10/L). The platelet count improved after PSE with values >100,000 in 21 patients (80.8%). Children with prior esophageal varices showed improvement after PSE with only 9 (34.6%) requiring further endoscopic therapy. After PSE, patients developed transient abdominal pain, distention, fever, and perisplenic fluid collections. Serious complications such as splenic abscess, splenic rupture, bleeding, pancreatic infarction, opportunistic infection, or death were not observed. One patient experienced thrombotic complications after PSE and was later diagnosed with myelodysplastic syndrome. CONCLUSIONS: PSE is a safe and effective alternative in the management of pediatric PHTN in select populations. PSE may be a favorable alternative to splenectomy and portal systemic shunting because it preserves functional spleen mass and avoids postprocedure accelerated liver disease or encephalopathy.


Assuntos
Embolização Terapêutica/métodos , Varizes Esofágicas e Gástricas/prevenção & controle , Hemorragia Gastrointestinal/prevenção & controle , Hipertensão Portal/complicações , Trombocitopenia/terapia , Adolescente , Criança , Pré-Escolar , Varizes Esofágicas e Gástricas/etiologia , Feminino , Hemorragia Gastrointestinal/etiologia , Humanos , Hipertensão Portal/fisiopatologia , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Veia Esplênica/fisiopatologia , Trombocitopenia/etiologia , Resultado do Tratamento , Adulto Jovem
16.
Cell Stem Cell ; 24(2): 227-239.e8, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30503142

RESUMO

Human intestinal transplantation often results in long-term mixed chimerism of donor and recipient blood in transplant patients. We followed the phenotypes of chimeric peripheral blood cells in 21 patients receiving intestinal allografts over 5 years. Donor lymphocyte phenotypes suggested a contribution of hematopoietic stem and progenitor cells (HSPCs) from the graft. Surprisingly, we detected donor-derived HSPCs in intestinal mucosa, Peyer's patches, mesenteric lymph nodes, and liver. Human gut HSPCs are phenotypically similar to bone marrow HSPCs and have multilineage differentiation potential in vitro and in vivo. Analysis of circulating post-transplant donor T cells suggests that they undergo selection in recipient lymphoid organs to acquire immune tolerance. Our longitudinal study of human HSPCs carried in intestinal allografts demonstrates their turnover kinetics and gradual replacement of donor-derived HSPCs from a circulating pool. Thus, we have demonstrated the existence of functioning HSPCs in human intestines with implications for promoting tolerance in transplant recipients.


Assuntos
Movimento Celular , Células-Tronco Hematopoéticas/citologia , Intestinos/citologia , Intestinos/transplante , Animais , Diferenciação Celular , Linhagem Celular , Linhagem da Célula , Quimerismo , Doença Enxerto-Hospedeiro/imunologia , Humanos , Tolerância Imunológica , Mucosa Intestinal/citologia , Fígado/citologia , Linfonodos/citologia , Camundongos , Nódulos Linfáticos Agregados/citologia , Fenótipo , Linfócitos T/citologia , Doadores de Tecidos , Transplante Homólogo
17.
Ann Surg ; 268(4): 602-609, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30102634

RESUMO

OBJECTIVE: In order to minimize the impact of donation, fully laparoscopic donor hepatectomy (LDH) is being investigated at a few centers throughout the world. We report here our experience with 51 living donor pure laparoscopic hepatectomies. BACKGROUND: Adoption of minimal access techniques to living donor liver transplantation (LDLT) has been slowed by concerns about donor safety and the quality of the grafts. METHODS: Of 344 donor hepatectomies (DHs) for living donor liver transplantation (LDLT) since 1998, 51 pure LDH have been performed since 2009. We report here our experience with 51 living donor pure laparoscopic hepatectomy (LH), based on prospectively collected data. There were 31 left lateral sectionectomy and 20 full lobectomies LH. We matched full lobe LH to open DH prior to introduction of LH. RESULTS: LH increased from 21% of all DH in first 5 years of performing LH to 45% of DH in the most recent 3 years. Laparoscopic donors were more likely female, had lower body mass index, smaller total livers, and smaller allografts but longer operating room times. In the total LD experience, total 5 donors were converted to open surgery (10%), 2 donors required transfusion (4%), and there was 2 donor bile leaks (4%). Recipient patient and graft 1-year survival was 98% and 94%. CONCLUSIONS: Our experience indicates that LDH for LDLT can be safely used with appropriate attention to learning curve and progression from left lateral sectionectomy to right hepatectomy.


Assuntos
Hepatectomia/métodos , Laparoscopia/métodos , Transplante de Fígado , Doadores Vivos , Adulto , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Duração da Cirurgia , Complicações Pós-Operatórias , Estudos Prospectivos , Taxa de Sobrevida
18.
Liver Transpl ; 24(7): 881-887, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29377486

RESUMO

The goal of the study is to characterize the relationship between portal vein thrombosis (PVT) and hepatic atrophy in patients without cirrhosis and the effect of various types of surgical shunts on liver regeneration and splenomegaly. Patients without cirrhosis with PVT suffer from presinusoidal portal hypertension, and often hepatic atrophy is a topic that has received little attention. We hypothesized that patients with PVT have decreased liver volumes, and shunts that preserve intrahepatic portal flow enhance liver regeneration. Sixty-four adult and pediatric patients with PVT who underwent surgical shunt placement between 1998 and 2011 were included in a retrospective study. Baseline liver volumes from adult patients were compared with standard liver volume (SLV) as well as a group of healthy controls undergoing evaluation for liver donation. Clinical assessment, liver function tests, and liver and spleen volumes from cross-sectional imaging were compared before and after surgery. A total of 40 patients received portal flow-preserving shunts (32 mesoportal and 8 selective splenorenal), whereas 24 received portal flow-diverting shunts (16 nonselective splenorenal and 8 mesocaval). Baseline adult liver volumes were 26% smaller than SLV (1248 versus 1624 cm3 ; P = 0.02) and 20% smaller than the control volumes (1248 versus 1552 cm3 ; P = 0.02). Baseline adult spleen volumes were larger compared with controls (1258 versus 229 cm3 ; P < 0.001). Preserving shunts were associated with significant increase in liver volumes (886 versus 1131 cm3 ; P = 0.01), whereas diverting shunts were not. Diverting shunts significantly improved splenomegaly. In conclusion, we have demonstrated that patients without cirrhosis with PVT have significant liver atrophy and splenomegaly. Significant liver regeneration was achieved after portal flow-preserving shunts. Liver Transplantation 24 881-887 2018 AASLD.


Assuntos
Hipertensão Portal/cirurgia , Regeneração Hepática , Fígado/patologia , Veia Porta/patologia , Derivação Portossistêmica Cirúrgica/métodos , Adolescente , Adulto , Atrofia/cirurgia , Criança , Feminino , Humanos , Hipertensão Portal/etiologia , Hipertensão Portal/patologia , Fígado/irrigação sanguínea , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Veia Porta/cirurgia , Estudos Retrospectivos , Esplenomegalia/diagnóstico por imagem , Esplenomegalia/patologia , Esplenomegalia/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Trombose Venosa/complicações , Trombose Venosa/patologia , Adulto Jovem
19.
Transplantation ; 102(6): 953-960, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29369249

RESUMO

BACKGROUND: Despite high survival in pediatric living donor liver transplantation (LDLT), only 10% of liver transplants in children in the United States are from living donors, reflecting reluctance to embrace this approach. In addition to optimal timing and graft quality, LDLT may offer immunologic benefit because most donors are haploidentical parents. We sought to quantify the benefit of LDLT compared to deceased donor liver transplantation (DDLT) using granular clinical and immunologic outcomes over the long term. METHODS: A retrospective cohort of children (age <18 years) surviving 1 year or longer posttransplant was evaluated to determine the impact of donor type on graft survival and immunologic outcomes. RESULTS: Two hundred forty-one children (177 DDLT and 64 LDLT) were assessed. In multivariable analysis, LDLT was associated with a lower rate of acute cellular rejection (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.29-0.98; P = 0.04), a lower rate of chronic rejection (HR, 0.12; 95% CI, 0.03-0.56; P = 0.007), better graft survival on monotherapy immunosuppression at 3 years posttransplant (87.7% vs 46.7%; odds ratio, 7.41; 95% CI, 2.80-19.66; P < 0.001), and a lower rate of graft loss (HR, 0.29; 95% CI, 0.10-0.88; P = 0.03). Graft type was not an independent predictor of posttransplant mortality (LDLT HR, 0.57; 95% CI, 0.16-2.01; P = 0.38). Maternal graft LDLT was associated with a lower rate of acute cellular rejection (HR, 0.13; 95% CI, 0.03-0.64; P = 0.01) and posttransplant lymphoproliferative disorder (HR, 0.04; 95% CI, 0.004-0.44; P = 0.008) compared with paternal grafts. CONCLUSIONS: This study demonstrates the potential benefit of LDLT, particularly with maternal grafts, for pediatric liver transplant recipients on multiple clinical parameters over long-term follow-up.


Assuntos
Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/uso terapêutico , Transplante de Fígado/métodos , Doadores Vivos , Adolescente , Fatores Etários , Criança , Pré-Escolar , Pai , Feminino , Rejeição de Enxerto/imunologia , Histocompatibilidade , Humanos , Lactente , Transplante de Fígado/efeitos adversos , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/prevenção & controle , Masculino , Mães , Fatores de Proteção , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Transplante Haploidêntico , Resultado do Tratamento
20.
Oncol Lett ; 14(4): 4863-4865, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29085493

RESUMO

Ganglioneuromas are slow growing, clinically silent benign tumors for which surgery is considered to be the standard treatment. However, surgical excision in cases where surrounding structures are involved can be challenging. The present study reports a novel technique of ex vivo excision for the management of a retroperitoneal ganglioneuroma in a 21-year old patient, that appeared to be inoperable using standard surgical resection. Preoperative investigations revealed a large tumor with encasement of the origins of the superior mesenteric artery (SMA) and bilateral renal arteries. Initially, to prevent the need to explant the liver, the distal SMA (with takeoff of the replaced common hepatic artery) was anastomosed to the splenic artery. The bulk of the tumor along with the bilateral kidneys was mobilized from the retroperitoneum, and the aorta and inferior vena cava (IVC) were cross-clamped above and below the tumor and divided. The two kidneys were dissected free of the tumor at the back-table and were auto-transplanted in a standard technique following the reconstruction of the aorta and IVC. The patient tolerated surgery well and a one-year postoperative follow-up did not show any sign of tumor recurrence. Although technically demanding, ex vivo resection and auto-transplantation of the involved organs can be introduced as a final option for the treatment of tumors that are un-resectable using standard surgical techniques.

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