RESUMO
BACKGROUND: Patients undergoing heart transplants are at risk of rejection which can have significant morbidity and mortality. Induction immunosuppression at the time of transplant reduces the early risk and has additional benefits. The induction agent of choice within our program was changed from rabbit antithymocyte-globulin (rATG) to basiliximab, so it was necessary to evaluate whether this had any impact on patient outcomes. OBJECTIVES: Our primary objective was to describe rejection, infection, and other outcomes in adult heart transplant patients at the University of Alberta Hospital in Edmonton, Canada. METHODS: This study was a nonrandomized, retrospective cohort study. RESULTS: Sixty-three patients were included with median ages 50 years versus 54 years. More female patients received rATG (20% vs. 42.4%). The most common indication for transplant in both cohorts was ICM (63.3% vs. 57.6%). Patients who received rATG had significantly higher PRA (0% vs. 43%, p < .001). Acute rejection episodes were similar between basiliximab and rATG at 3 months (16.7% vs. 15.1%; p = 1.0) and 6-months (30.0% vs. 18.1%; p = .376). Infections were not statistically different with basiliximab compared to rATG at 3-months, 43.3% vs. 63.6% and at 6-months 60.0% vs. 66.7%). There were no fatalities in either group. CONCLUSIONS: Our study did not demonstrate differences in rejection with basiliximab compared to rATG. Mortality did not differ, but basiliximab-treated patients had fewer infections and infection-related hospitalizations than those treated with rATG. Larger studies with longer durations are needed to more completely describe the differences in rejection and infectious outcomes.
Assuntos
Anticorpos Monoclonais , Soro Antilinfocitário , Basiliximab , Rejeição de Enxerto , Transplante de Coração , Imunossupressores , Proteínas Recombinantes de Fusão , Humanos , Basiliximab/uso terapêutico , Feminino , Masculino , Transplante de Coração/efeitos adversos , Pessoa de Meia-Idade , Estudos Retrospectivos , Proteínas Recombinantes de Fusão/uso terapêutico , Rejeição de Enxerto/prevenção & controle , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/imunologia , Soro Antilinfocitário/uso terapêutico , Imunossupressores/uso terapêutico , Adulto , Seguimentos , Anticorpos Monoclonais/uso terapêutico , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/imunologia , Prognóstico , Fatores de Risco , Complicações Pós-Operatórias , Idoso , Terapia de Imunossupressão/métodosRESUMO
The purpose of this review is to encourage a new perspective on the question of donor-recipient compatibility and post-transplant assessment of graft health based on functional measures. The premise is that we should be better sighted on what (and how) the immune system responds toward rather than what is merely there. Continuance of the pursuit of further and better definition of antigens and antibodies is not however discouraged but seen as necessary to improved understanding of the structural correlates of functional immunity. There currently exists, in the opinion of the authors, an opportunity for histocompatibility and immunogenetics laboratories to develop and widen their scope of involvement into these new areas of laboratory activity in support and to the benefit of the transplant programmes they serve.
Assuntos
Aloenxertos , Doadores de Tecidos , Humanos , Aloenxertos/imunologia , Teste de Histocompatibilidade/métodos , Transplante Homólogo , Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Antígenos HLA/genética , Histocompatibilidade/imunologia , Sobrevivência de Enxerto/imunologiaRESUMO
Organ shortage is a major challenge in kidney transplantation but the use of older donors, often with co-morbidities, is hampered by inconsistent outcomes. Methods of accurately stratifying marginal donor organs by clinical and histological assessment are lacking. To better understand organ variability, we profiled the transcriptomes of 271 kidneys from deceased donors at retrieval. Following correction for biopsy composition, we assessed molecular pathways that associated with delayed, and sub-optimal one-year graft function. Analysis of cortical biopsies identified an adaptive immune gene-rich module that significantly associated with increasing age and worse outcomes. Cellular deconvolution using human kidney reference single cell transcriptomes confirmed an increase in kidney-specific B and T cell signatures, as well as kidney macrophage, myofibroblast and fibroblast gene sets in this module. Surprisingly, innate immune pathway and neutrophil gene signature enrichment was associated with better outcomes. Thus, our work uncovers cellular molecular features of pathological organ ageing, identifiable at kidney retrieval, with translational potential.
Assuntos
Perfilação da Expressão Gênica , Transplante de Rim , Rim , Transcriptoma , Humanos , Transplante de Rim/efeitos adversos , Rim/patologia , Rim/imunologia , Biópsia , Pessoa de Meia-Idade , Masculino , Adulto , Feminino , Perfilação da Expressão Gênica/métodos , Idoso , Fatores Etários , Doadores de Tecidos , Envelhecimento/patologia , Envelhecimento/genética , Envelhecimento/imunologia , Patologia Molecular/métodos , Imunidade Inata , Imunidade Adaptativa/genética , Adulto Jovem , Análise de Célula Única , Sobrevivência de Enxerto/imunologiaRESUMO
HLA matching improves long-term outcomes of kidney transplantation, yet implementation challenges persist, particularly within the African American (Black) patient demographic due to donor scarcity. Consequently, kidney survival rates among Black patients significantly lag behind those of other racial groups. A refined matching scheme holds promise for improving kidney survival, with prioritized matching for Black patients potentially bolstering rates of HLA-matched transplants. To facilitate quantity, quality and equity in kidney transplants, we propose two matching algorithms based on quantification of HLA immunogenicity using the hydrophobic mismatch score (HMS) for prospective transplants. We mined the national transplant patient database (SRTR) for a diverse group of donors and recipients with known racial backgrounds. Additionally, we use novel methods to infer survival assessment in the simulated transplants generated by our matching algorithms, in the absence of actual target outcomes, utilizing modified unsupervised clustering techniques. Our allocation algorithms demonstrated the ability to match 87.7% of Black and 86.1% of White recipients under the HLA immunogenicity threshold of 10. Notably, at the lowest HMS threshold of 0, 4.4% of Black and 12.1% of White recipients were matched, a marked increase from the 1.8% and 6.6% matched under the prevailing allocation scheme. Furthermore, our allocation algorithms yielded similar or improved survival rates, as illustrated by Kaplan-Meier (KM) curves, and enhanced survival prediction accuracy, evidenced by C-indices and Integrated Brier Scores.
Assuntos
Algoritmos , Antígenos HLA , Teste de Histocompatibilidade , Transplante de Rim , Feminino , Humanos , Masculino , Negro ou Afro-Americano , Sobrevivência de Enxerto/imunologia , Teste de Histocompatibilidade/métodos , Antígenos HLA/imunologia , BrancosRESUMO
Despite its recent decline in volumes, intestinal transplantation remains an important option for patients with irreversible intestinal failures. The long-term outcome of an intestinal transplant has stagnated. The major cause of graft loss is rejection, resulting from mismatches in human leukocyte antigens (HLA) and the presence of antibodies to mismatched donor-specific HLA antigens (DSA). Literature has reported that DSAs, either preformed before transplantation or developed de novo after transplantation, are harmful to intestinal grafts, especially for those without combined liver grafts. A comprehensive assessment of DSA by the histocompatibility laboratory is critical for successful intestinal transplantation and its long-term survival. This paper briefly reviews the history and current status of different methods for detecting DSA and their clinical applications in intestinal transplantation. The focus is on applying different antibody assays to manage immunologically challenging intestinal transplant patients before and after transplantation. A clinical case is presented to illustrate the complexity of HLA tests and the necessity of multiple assays. The review of risk assessment by the histocompatibility laboratory also highlights the need for close interaction between the laboratory and the intestinal transplant program.
Assuntos
Rejeição de Enxerto , Antígenos HLA , Teste de Histocompatibilidade , Intestinos , Humanos , Antígenos HLA/imunologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/diagnóstico , Intestinos/transplante , Intestinos/imunologia , Medição de Risco , Teste de Histocompatibilidade/métodos , Isoanticorpos/imunologia , Isoanticorpos/sangue , Histocompatibilidade , Transplante de Órgãos/efeitos adversos , Sobrevivência de Enxerto/imunologiaRESUMO
The EuroTransplant Kidney Allocation System (ETKAS) aims at allocating organs to patients on the waiting list fairly whilst optimizing HLA match grades. ETKAS currently considers the number of HLA-A, -B, -DR mismatches. Evidently, epitope matching is biologically and clinically more relevant. We here executed ETKAS-based computer simulations to evaluate the impact of epitope matching on allocation and compared the strategies. A virtual population of 400,000 individuals was generated using the National Marrow Donor Program (NMDP) haplotype frequency dataset of 2011. Using this population, a waiting list of 10,400 patients was constructed and maintained during simulation, matching the 2015 Eurotransplant Annual Report characteristics. Unacceptable antigens were assigned randomly relative to their frequency using HLAMatchmaker. Over 22,600 kidneys were allocated in 10 years in triplicate using Markov Chain Monte Carlo simulations on 32-CPU-core cloud-computing instances. T-cell epitopes were calculated using the www.pirche.com portal. Waiting list effects were evaluated against ETKAS for five epitope matching scenarios. Baseline simulations of ETKAS slightly overestimated reported average HLA match grades. The best balanced scenario maintained prioritisation of HLA A-B-DR fully matched donors while replacing the HLA match grade by PIRCHE-II score and exchanging the HLA mismatch probability (MMP) by epitope MMP. This setup showed no considerable impact on kidney exchange rates and waiting time. PIRCHE-II scores improved, whereas the average HLA match grade diminishes slightly, yet leading to an improved estimated graft survival. We conclude that epitope-based matching in deceased donor kidney allocation is feasible while maintaining equal balances on the waiting list.
Assuntos
Epitopos de Linfócito T/imunologia , Teste de Histocompatibilidade/métodos , Transplante de Rim/métodos , Obtenção de Tecidos e Órgãos/métodos , Algoritmos , Computação em Nuvem , Biologia Computacional , Simulação por Computador , Europa (Continente) , Estudos de Viabilidade , Sobrevivência de Enxerto/imunologia , Teste de Histocompatibilidade/estatística & dados numéricos , Humanos , Transplante de Rim/estatística & dados numéricos , Cadeias de Markov , Método de Monte Carlo , Fatores de Tempo , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Interface Usuário-Computador , Listas de EsperaRESUMO
Donor organ shortage, growing waiting lists and substantial organ discard rates are key problems in transplantation. The critical importance of organ quality in determining long-term function is becoming increasingly clear. However, organ quality is difficult to predict. The lack of good measures of organ quality is a serious challenge in terms of acceptance and allocation of an organ. The underlying review summarizes currently available methods used to assess donor organ quality such as histopathology, clinical scores and machine perfusion characteristics with special focus on molecular analyses of kidney quality. The majority of studies testing molecular markers of organ quality focused on identifying organs at risk for delayed graft function, yet without prediction of long-term graft outcome. Recently, interest has emerged in looking for molecular markers associated with biological age to predict organ quality. However, molecular gene sets have not entered the clinical routine or impacted discard rates so far. The current review critically discusses the potential reasons why clinically applicable molecular quality assessment using early kidney biopsies might not have been achieved yet. Besides a critical analysis of the inherent limitations of surrogate markers used for organ quality, i.e., delayed graft function, the intrinsic methodological limitations of studies assessing organ quality will be discussed. These comprise the multitude of unpredictable hits as well as lack of markers of nephron mass, functional reserve and regenerative capacity.
Assuntos
Transplante de Rim/métodos , Rim/imunologia , Transplantes/imunologia , Biópsia , Função Retardada do Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Humanos , Rim/patologia , Preservação de Órgãos/métodos , Perfusão/métodosRESUMO
Short-term allograft survival has improved among solid organ transplant (SOT) patients. An increasing number of SOT patients are prepared for re-transplantation because of chronic allograft failure. Lack of HLA typing or incomplete HLA typing of previous donors complicates pretransplant risk assessment, as repeated HLA mismatches may be missed. In addition, a complete HLA type of the donor is essential in the diagnosis of antibody-mediated rejection. We aimed to determine donor HLA types from allograft biopsies from kidney, heart and liver grafts. Graft biopsies were obtained from 13 kidney, heart and liver transplanted patients. HLA typing was performed using q-PCR. Alleles of both donor and recipient origin were detected, and donor HLA type was concluded by deducting known HLA types of the recipient. For all 13 patients, we were able to determine mismatched donor HLA alleles from graft material. These results are promising, because they enable better individualized risk assessment.
Assuntos
Aloenxertos/imunologia , Antígenos HLA/genética , Teste de Histocompatibilidade/métodos , Transplante de Órgãos , Doadores de Tecidos , Adulto , Idoso , Alelos , Aloenxertos/patologia , Biópsia , Feminino , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Medição de Risco , Transplante HomólogoRESUMO
BACKGROUND: Monoclonal immunoglobulin (MIg)-associated renal disease (MIgARD) comprises a group of disorders caused by direct deposition of paraproteins in the kidney. Allograft MIgARD is infrequently encountered and poorly characterized. METHODS: First, we assessed our allograft biopsies diagnosed with MIgARD between 2007 and 2018. The cohort included the following 26 patients: proliferative glomerulonephritis with MIg deposits (PGNMID) (n = 13), AL amyloidosis (n = 5), light chain deposition disease (n = 5), light chain proximal tubulopathy (n = 2), and light chain cast nephropathy (n = 1). Second, we conducted a literature review to evaluate the rare non-PGNMID entities. We identified 20 studies describing 29 patients that were added to our cohort (total n = 42). RESULTS: Part 1: Patients' median age was 55 years; 31% were women, and 19% were blacks. Twelve patients (46%) lost their grafts at a median of 8 months after diagnosis. Compared to non-PGNMID, PGNMID patients had lower frequency of detectable paraproteins (31% versus 92%, P = 0.004) and hematologic neoplasms (23% versus 77%, P = 0.02). Within PGNMID group, 6 patients changed their apparent immunofluorescence phenotype between monotypic and polytypic, while all 3 patients with hematologic neoplasms had substructure on electron microscopy. Part 2: Whereas light chain cast nephropathy occurred the earliest and had the worst graft survival, AL amyloidosis occurred the latest and had the best graft survival. CONCLUSIONS: MIgARD in the kidney allograft is associated with poor prognosis. While posttransplant PGNMID can change its apparent clonality by immunofluorescence supporting oligoclonal immune responses, the presence of deposit substructure is an important indicator of underlying hematologic neoplasm. Non-PGNMID are often associated with hematologic neoplasms and varied prognosis.
Assuntos
Aloenxertos/patologia , Nefropatias/diagnóstico , Transplante de Rim/efeitos adversos , Rim/patologia , Paraproteinemias/diagnóstico , Complicações Pós-Operatórias/diagnóstico , Aloenxertos/imunologia , Biópsia , Feminino , Sobrevivência de Enxerto/imunologia , Humanos , Rim/imunologia , Nefropatias/imunologia , Nefropatias/mortalidade , Nefropatias/patologia , Masculino , Pessoa de Meia-Idade , Paraproteinemias/imunologia , Paraproteinemias/mortalidade , Paraproteinemias/patologia , Paraproteínas/imunologia , Paraproteínas/metabolismo , Complicações Pós-Operatórias/imunologia , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/patologia , Prognóstico , Estudos RetrospectivosRESUMO
BACKGROUND: There is concern in the transplant community that outcomes for the most highly sensitized recipients might be poor under Kidney Allocation System (KAS) high prioritization. METHODS: To study this, we compared posttransplant outcomes of 525 pre-KAS (December 4, 2009, to December 3, 2014) calculated panel-reactive antibodies (cPRA)-100% recipients to 3026 post-KAS (December 4, 2014, to December 3, 2017) cPRA-100% recipients using SRTR data. We compared mortality and death-censored graft survival using Cox regression, acute rejection, and delayed graft function (DGF) using logistic regression, and length of stay (LOS) using negative binomial regression. RESULTS: Compared with pre-KAS recipients, post-KAS recipients were allocated kidneys with lower Kidney Donor Profile Index (median 30% versus 35%, P < 0.001) but longer cold ischemic time (CIT) (median 21.0 h versus 18.6 h, P < 0.001). Compared with pre-KAS cPRA-100% recipients, those post-KAS had higher 3-year patient survival (93.6% versus 91.4%, P = 0.04) and 3-year death-censored graft survival (93.7% versus 90.6%, P = 0.005). The incidence of DGF (29.3% versus 29.2%, P = 0.9), acute rejection (11.2% versus 11.7%, P = 0.8), and median LOS (5 d versus 5d, P = 0.2) were similar between pre-KAS and post-KAS recipients. After accounting for secular trends and adjusting for recipient characteristics, post-KAS recipients had no difference in mortality (adjusted hazard ratio [aHR]: 0.861.623.06, P = 0.1), death-censored graft failure (aHR: 0.521.001.91, P > 0.9), DGF (adjusted odds ratio [aOR]: 0.580.861.27, P = 0.4), acute rejection (aOR: 0.610.941.43, P = 0.8), and LOS (adjusted LOS ratio: 0.981.161.36, P = 0.08). CONCLUSIONS: We did not find any statistically significant worsening of outcomes for cPRA-100% recipients under KAS, although longer-term monitoring of posttransplant mortality is warranted.
Assuntos
Função Retardada do Enxerto/epidemiologia , Rejeição de Enxerto/epidemiologia , Falência Renal Crônica/cirurgia , Transplante de Rim/normas , Alocação de Recursos/normas , Obtenção de Tecidos e Órgãos/normas , Adulto , Aloenxertos/imunologia , Aloenxertos/provisão & distribuição , Isquemia Fria/estatística & dados numéricos , Função Retardada do Enxerto/imunologia , Feminino , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA/análise , Antígenos HLA/imunologia , Implementação de Plano de Saúde/estatística & dados numéricos , Teste de Histocompatibilidade/normas , Teste de Histocompatibilidade/estatística & dados numéricos , Humanos , Incidência , Falência Renal Crônica/mortalidade , Transplante de Rim/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Avaliação de Programas e Projetos de Saúde/estatística & dados numéricos , Sistema de Registros/estatística & dados numéricos , Alocação de Recursos/organização & administração , Alocação de Recursos/estatística & dados numéricos , Fatores de Risco , Obtenção de Tecidos e Órgãos/organização & administração , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Resultado do Tratamento , Estados Unidos/epidemiologia , Listas de Espera , Adulto JovemRESUMO
BACKGROUND: The 2013 Banff meeting updated the requirements for the diagnosis of acute/active antibody-mediated rejection (AAMR) in kidney allografts. There has been speculation that the changes lower the threshold for diagnosing AAMR, and may lead to possible unnecessary and expensive treatment. METHODS: We compared the 2013 Banff classification for AAMR to the previous 2007 Banff to determine if there was an increase in the number of patients receiving a diagnosis of AAMR and if the diagnosis affected allograft survival and post-biopsy 3-month and 6-month creatinine and eGFR values. RESULTS: A total of 212 renal allograft biopsies were compared to both 2007 and 2013 Banff classification requirements for AAMR. Ten patients (11 biopsies) met the 2007 criteria. An additional 15 patients (20 biopsies) met the 2013 criteria. These 2 groups showed no statistically significant demographic differences. By applying the 2013 Banff classification, we observed a 2.5-fold increase in the number of AAMR cases. One-year post-transplant allograft survival was higher in the 2013 group (.85 vs .55) and the 3-month and 6-month post-biopsy creatinine values were significantly lower for the 2013 group (1.6 ± .6 vs 3.3 ± 2.2, P value .01, and 1.7 ± .6 vs 3.4 ± 2.8, P value .03). The 3-month and 6-month eGFR values were higher in the 2013 group, although not statistically significant. CONCLUSIONS: These results suggest that use of Banff 2013 criteria in place of Banff 2007 may result in diagnosing milder and earlier cases of AAMR with the possibility of initiating earlier treatment and improving graft outcomes.
Assuntos
Anticorpos/análise , Rejeição de Enxerto/diagnóstico , Transplante de Rim/efeitos adversos , Escores de Disfunção Orgânica , Adulto , Aloenxertos/imunologia , Aloenxertos/patologia , Anticorpos/imunologia , Biópsia , Creatinina/análise , Feminino , Taxa de Filtração Glomerular , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto/imunologia , Humanos , Rim/imunologia , Rim/patologia , Masculino , Pessoa de Meia-Idade , Transplante Homólogo , Resultado do TratamentoRESUMO
Mass cytometry, or Cytometry by Time-Of-Flight, is a powerful new platform for high-dimensional single-cell analysis of the immune system. It enables the simultaneous measurement of over 40 markers on individual cells through the use of monoclonal antibodies conjugated to rare-earth heavy-metal isotopes. In contrast to the fluorochromes used in conventional flow cytometry, metal isotopes display minimal signal overlap when resolved by single-cell mass spectrometry. This review focuses on the potential of mass cytometry as a novel technology for studying immune reconstitution in allogeneic hematopoietic stem cell transplant (HSCT) recipients. Reconstitution of a healthy donor-derived immune system after HSCT involves the coordinated regeneration of innate and adaptive immune cell subsets in the recipient. Mass cytometry presents an opportunity to investigate immune reconstitution post-HSCT from a systems-level perspective, by allowing the phenotypic and functional features of multiple cell populations to be assessed simultaneously. This review explores the current knowledge of immune reconstitution in HSCT recipients and highlights recent mass cytometry studies contributing to the field.
Assuntos
Citometria de Fluxo , Sobrevivência de Enxerto/imunologia , Reconstituição Imune , Animais , Citometria de Fluxo/métodos , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunofenotipagem/métodosRESUMO
The development of de novo donor-specific HLA antibody (dnDSA) is a critical feature contributing to late allograft failure. The complexity of the issue is further complicated by organ-specific differences, detection techniques, reliance of tissue histopathology and changing diagnostic criteria, ineffective therapies, and lack of consensus. To tackle these issues, the Sensitization in Transplantation Assessment of Risk (STAR) 2017 was initiated as a collaboration of the American Society of Transplantation and American Society of Histocompatibility and Immunogenetics consisting of 8 working groups with the goal to provide guidelines on how to assess risk and risk stratify patients based on their potential alloimmune and DSA status. Herein is a summary of discussions by the Naïve Abdominal Working Group, highlighting currently available data and identifying gaps in our knowledge on the development and impact of dnDSA following kidney transplantation.
Assuntos
Rejeição de Enxerto/diagnóstico , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Histocompatibilidade/imunologia , Isoanticorpos/sangue , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Rejeição de Enxerto/sangue , Rejeição de Enxerto/etiologia , Humanos , Isoanticorpos/imunologia , Relatório de Pesquisa , Medição de Risco , Sociedades MédicasRESUMO
The development of de novo donor-specific HLA antibodies (dnDSA) after transplantation is associated with graft failure, mortality, and cost. There is no effective therapeutic intervention to prevent dnDSA or ameliorate associated injury. The aims of this study were to identify specific HLA factors associated with dnDSA development and to propose primary prevention strategies that could reduce the incidence of dnDSA without prohibitively limiting access to transplant. The investigation cohort included heart transplant recipients from 2008 to 2015 (n = 265). HLA typing was performed and HLA antibody testing was undertaken before and after transplantation. HLAMatchmaker analysis was performed for persistent dnDSA to identify potentially more immunogenic eplet differences. Validation was performed in recipients of lung transplants from 2008 to 2013 (n = 433). The majority of recipients with dnDSA had antibodies to identical eplet positions on DQ2 and DQ7. A high-risk epitope mismatch (found in DQA1*05 + DQB1*02/DQB1*03:01(7)) was associated with a 4.2- and 4.9-fold increased risk of dnDSA in heart and lung recipients respectively. HLA electrostatic potential modeling provided a plausible explanation for this observed immunogenicity. A theoretical allocation algorithm avoiding high-risk epitope mismatches was generated and predicted to reduce dnDSA by up to 72% without additional testing, eplet analysis, or cost.
Assuntos
Epitopos/imunologia , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Coração/efeitos adversos , Isoanticorpos/efeitos adversos , Transplante de Pulmão/efeitos adversos , Estudos de Coortes , Seguimentos , Teste de Histocompatibilidade , Humanos , Complicações Pós-Operatórias , Prognóstico , Alocação de Recursos , Fatores de Risco , Doadores de TecidosRESUMO
The presence of preexisting (memory) or de novo donor-specific HLA antibodies (DSAs) is a known barrier to successful long-term organ transplantation. Yet, despite the fact that laboratory tools and our understanding of histocompatibility have advanced significantly in recent years, the criteria to define presence of a DSA and assign a level of risk for a given DSA vary markedly between centers. A collaborative effort between the American Society for Histocompatibility and Immunogenetics and the American Society of Transplantation provided the logistical support for generating a dedicated multidisciplinary working group, which included experts in histocompatibility as well as kidney, liver, heart, and lung transplantation. The goals were to perform a critical review of biologically driven, state-of-the-art, clinical diagnostics literature and to provide clinical practice recommendations based on expert assessment of quality and strength of evidence. The results of the Sensitization in Transplantation: Assessment of Risk (STAR) meeting are summarized here, providing recommendations on the definition and utilization of HLA diagnostic testing, and a framework for clinical assessment of risk for a memory or a primary alloimmune response. The definitions, recommendations, risk framework, and highlighted gaps in knowledge are intended to spur research that will inform the next STAR Working Group meeting in 2019.
Assuntos
Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Histocompatibilidade/imunologia , Isoanticorpos/imunologia , Transplante de Órgãos , Guias de Prática Clínica como Assunto/normas , Medição de Risco/métodos , Doadores de Tecidos , Humanos , Relatório de PesquisaRESUMO
Extending the functional integrity of renal allografts is the primary goal of transplant medicine. The development of donor-specific antibodies (DSAs) posttransplantation leads to chronic active antibody-mediated rejection (cAMR) and transplant glomerulopathy (TG), resulting in the majority of graft losses that occur in the United States. This reduces the quality and length of life for patients and increases cost. There are no approved treatments for cAMR. Evidence suggests the proinflammatory cytokine interleukin 6 (IL-6) may play an important role in DSA generation and cAMR. We identified 36 renal transplant patients with cAMR plus DSAs and TG who failed standard of care treatment with IVIg plus rituximab with or without plasma exchange. Patients were offered rescue therapy with the anti-IL-6 receptor monoclonal tocilizumab with monthly infusions and monitored for DSAs and long-term outcomes. Tocilizumab-treated patients demonstrated graft survival and patient survival rates of 80% and 91% at 6 years, respectively. Significant reductions in DSAs and stabilization of renal function were seen at 2 years. No significant adverse events or severe adverse events were seen. Tocilizumab provides good long-term outcomes for patients with cAMR and TG, especially compared with historical published treatments. Inhibition of the IL-6-IL-6 receptor pathway may represent a novel approach to stabilize allograft function and extend patient lives.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Antígenos HLA/imunologia , Isoanticorpos/efeitos adversos , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Receptores de Interleucina-6/antagonistas & inibidores , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/imunologia , Humanos , Imunossupressores/uso terapêutico , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Prognóstico , Receptores de Interleucina-6/imunologia , Fatores de Risco , Transplante HomólogoRESUMO
The wide range of immunosuppressive therapies and protocols permits tailored planning of the initial regimen according to the immunological risk status of individual patients. Pre-transplant risk assessment can include many factors, but there is no clear consensus on which parameters to take into account, and their relative importance. In general younger patients are known to be at higher risk for acute rejection, compounded by higher rates of non-adherence in adolescents. Donor age and recipient gender do not appear to exert a meaningful effect on risk of rejection per se, but black recipient ethnicity remains a well-established risk factor even under modern immunosuppression regimens. Little difference in risk is now observed between deceased- and living-donor recipients. Immunological risk assessment has developed substantially in recent years. Cross-match testing with cytotoxic analysis has long been supplemented by flow cytometry, but development of solid-phase single-bead antigen testing of solubilized human leukocyte antigens (HLA) to detect donor-specific antibodies (DSA) permits a far more nuanced stratification of immunological risk status, including the different classes and intensities of HLA antibodies Class I and/or II, including HLA-DSA. Immunologic risk evaluation is now often based on a combination of these tests, but other assessments are becoming more widely introduced, such as measurement of non-HLA antibodies against angiotensin type 1 (AT1) receptors or T-cell ELISPOT assay of alloantigen-specific donor. Targeted densensitization protocols can improve immunological risk, notably for DSA-positive patients with negative cytotoxicity and flow cross-match. HLA mismatch remains an important and undisputed risk factor for rejection. Delayed graft function also increases the risk of subsequent acute rejection, and the early regimen can be modified in such cases. Overall, there is a shift towards planning the immunosuppressive regimen based on pre-transplant immunology testing although certain conventional risk factors retain their importance.
Assuntos
Função Retardada do Enxerto/tratamento farmacológico , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Terapia de Imunossupressão/métodos , Imunossupressores/uso terapêutico , Transplante de Rim , Medição de Risco , Função Retardada do Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Teste de Histocompatibilidade , Humanos , Doadores Vivos , Fatores de RiscoRESUMO
The importance of the innate immune system, including complement, in causing transplant injury and augmenting adaptive immune responses is increasingly recognized. Therefore variability in graft outcome may in part be due to genetic polymorphism in genes encoding proteins of the immune system. This study assessed the relationship between single nucleotide polymorphisms (SNPs) in complement genes and outcome after transplantation. Analysis was performed on two patient cohorts of 650 and 520 transplant recipients. 505 tagged SNPs in 47 genes were typed in both donor and recipient. The relationships between SNPs and graft survival, serum creatinine, delayed graft function and acute rejection were analyzed. One recipient SNP in the gene encoding mannose binding lectin was associated with graft outcome after correction for analysis of multiple SNPs (p=6.41 × 10(-5)). When further correction was applied to account for analysis of the effect of SNPs in both donor and recipient this lost significance. Despite association p values of <0.001 no SNP was significantly associated with clinical phenotypes after Bonferroni correction. In conclusion, the variability seen in transplant outcome in this patient cohort cannot be explained by variation in complement genes. If causal genetic effects exist in these genes, they are too small to be detected by this study.
Assuntos
Proteínas do Sistema Complemento/genética , Rejeição de Enxerto/genética , Transplante de Rim , Lectina de Ligação a Manose/genética , Polimorfismo de Nucleotídeo Único , Insuficiência Renal Crônica/genética , Estudos de Coortes , Creatinina/sangue , Expressão Gênica , Estudo de Associação Genômica Ampla , Genótipo , Rejeição de Enxerto/sangue , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Humanos , Rim/imunologia , Rim/metabolismo , Rim/patologia , Rim/cirurgia , Lectina de Ligação a Manose/imunologia , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/imunologia , Insuficiência Renal Crônica/cirurgia , Doadores de Tecidos , Transplantados , Resultado do TratamentoRESUMO
Across the world, the proportions of senior citizens (i.e. those ≥65years) increase rapidly and are predicted to constitute over 25% of the general population by 2050. In 2012 already 48% of the population with end stage renal disease (ESRD) was aged 65years or older. Transplantation is considered the preferred treatment option for ESRD offering survival advantage over long-term dialysis in the majority of patients. Indeed, acceptable outcomes have been documented for selected patients over the age of 70years or even cases over 80years. The reality of organ scarcity and prolonged waiting times for a deceased donor kidney transplantation, however, indicate that at best 50% of the selected elderly may have realistic expectations to receive a timely transplant offer. By choice or medical selection, access to transplantation also decreases with increasing age. In order to expedite the chance for elderly to receive a kidney transplant dedicated allocation systems have been developed. These allocation systems, like the Eurotransplant Senior Program (ESP), support preferential local allocation of kidneys from older donors to older patients in order to match recipient and graft life while disregarding histocompatibility for HLA antigens. The consequence has been more acute rejection episodes and an increase in immunosuppressive load. In the elderly, the most common cause of graft loss is death with functioning graft and death from infectious diseases is one of the dominant causes. The Eurotransplant Senior DR-compatible Program (ESDP) was designed to further improve the perspective of successful transplantation in the elderly in terms of life and quality of life by re-introducing matching criteria for HLA-DR in the old-for-old algorithm.
Assuntos
Teste de Histocompatibilidade/estatística & dados numéricos , Falência Renal Crônica/cirurgia , Transplante de Rim/estatística & dados numéricos , Idoso , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Acessibilidade aos Serviços de Saúde , Humanos , Imunossupressores/imunologia , Incidência , Falência Renal Crônica/epidemiologia , Transplante de Rim/mortalidade , Seleção de Pacientes , Qualidade de Vida , Sistema de Registros , Fatores de Risco , Obtenção de Tecidos e Órgãos , Listas de EsperaRESUMO
AbstractObjective: to verify the correlation between the rates of hospitalization for primary care-sensitive cardiovascular diseases and the coverage by the Family Health Strategy of residents of the State of Paraná, by regional health divisions, from 2000 to 2011.Method: ecological study developed from data of the Hospital Information System of the Brazilian Unified Health System (SUS) and the Department of Primary Care of the Ministry of Health. The rates of hospitalization for cardiovascular diseases were correlated with the annual coverage by the Family Health Strategy using Pearson's and Spearman's correlation coefficients.Result: there was a strong and negative correlation in the State of Paraná (r=-0.91; p <0.001) and in most regional health divisions, with the highest correlations observed in the Metropolitan and Toledo (r =-0.93; p<0.001) and Paranaguá (r=-0.92, p<0.001) regional health divisions.Conclusion: the results suggest that the increase in the coverage by the Family Health Strategy was an important factor for decrease in the hospitalizations for cardiovascular conditions among residents of the State of Paraná and in most regional health divisions. Other studies should be performed to analyze the factors and causes in regional health divisions where there was no correlation with increase in the Family Health Strategy.
ResumoObjetivo:verificar a correlação entre taxas de internação por doenças cardiovasculares sensíveis à atenção primária e a cobertura da Estratégia Saúde da Família de residentes no estado do Paraná, por regionais de saúde, no período de 2000 a 2011.Método:estudo ecológico, desenvolvido a partir de dados do Sistema de Informações Hospitalares do Sistema Único de Saúde e do Departamento de Atenção Básica do Ministério da Saúde. Correlacionaram-se as taxas de internação por doenças cardiovasculares com as coberturas anuais da Estratégia Saúde da Família, utilizando-se os coeficientes de correlação de Pearson e Spearman.Resultado:houve correlação negativa e forte no estado do Paraná (r=-0,91; p<0,001) e na maioria das regionais de saúde, sendo maior na Metropolitana e Toledo (r=-0,93; p<0,001) e Paranaguá (r=-0,92; p<0,001).Conclusão:os resultados sugerem que o aumento da cobertura da Estratégia Saúde da Família foi fator importante para a diminuição das internações por condições cardiovasculares em residentes no estado do Paraná e na maioria das regionais de saúde. Outros estudos devem ser realizados para analisar fatores e causas nas regiões do estado onde não houve correlação com incremento da Estratégia Saúde da Família.
ResumenObjetivo:verificar la correlación entre tasas de internación por enfermedades cardiovasculares sensibles a la atención primaria y la cobertura de la Estrategia Salud de la Familia de residentes en el estado de Paraná, por regionales de salud, en el período de 2000 a 2011.Método:estudio ecológico, desarrollado a partir de datos del Sistema de Informaciones Hospitalarias del Sistema Único de Salud y del Departamento de Atención Básica del Ministerio de la Salud. Se correlacionaron las tasas de internación por enfermedades cardiovasculares con las coberturas anuales de la Estrategia Salud de la Familia, utilizando los coeficientes de correlación de Pearson y Spearman.Resultado:hubo correlación negativa y fuerte en el estado de Paraná (r=-0,91; p<0,001) y en la mayoría de las regionales de salud, siendo mayor en la Metropolitana y Toledo (r=-0,93; p<0,001) y Paranaguá (r=-0,92; p<0,001).Conclusión:los resultados sugieren que el aumento de la cobertura de la Estrategia Salud de la Familia fue un factor importante para la disminución de las internaciones por condiciones cardiovasculares en residentes en el estado de Paraná y en la mayoría de las regionales de salud. Otros estudios deben ser realizados para analizar factores y causas en las regiones del estado en donde no hubo correlación con incremento de la Estrategia Salud de la Familia.