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2.
Clin Transplant ; 23(5): 660-5, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19674013

RESUMO

BACKGROUND: The HLA-B8, DR3 haplotype has been associated with high immune reactivity. In this study, we have tested whether this haplotype has differential effect on graft survival in patients with IgAN compared with control patients. METHODS: From the Eurotransplant Registry we analyzed graft survival of 1207 recipients with IgAN and 7935 control patients with non-glomerular diseases. Death-censored graft loss according to the HLA-B8, DR3 haplotype was calculated with Kaplan-Meier analysis and Cox-regression model was used to correct for various risk factors. RESULTS: The frequency of the HLA-B8, DR3 haplotype was significantly lower in IgAN patients compared with controls (10.3% vs. 15.4%, p < 0.001). Ten-year graft survival was identical in the control group with and without the HLA-B8, DR3 haplotype (71.1% and 70.2%, respectively), but significantly worse in IgAN patients carrying the HLA-B8, DR3 haplotype compared with patients without it (52.5% vs. 69.1%, respectively, p = 0.009). The risk of graft loss was increased by 66% (HR 1.6, 95% CI 1.14, 2.29) in IgAN with the HLA-B8, DR3 haplotype and independent of well-known risk factors. CONCLUSIONS: We have identified a new risk factor for graft loss unique to patients with IgAN. This finding emphasizes the exclusive immune characteristics of IgAN patients after transplantation.


Assuntos
Glomerulonefrite por IGA/genética , Rejeição de Enxerto/genética , Antígeno HLA-B8/genética , Haplótipos/genética , Transplante de Rim , Membro 25 de Receptores de Fatores de Necrose Tumoral/genética , Feminino , Genótipo , Glomerulonefrite por IGA/cirurgia , Rejeição de Enxerto/imunologia , Antígeno HLA-B8/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Membro 25 de Receptores de Fatores de Necrose Tumoral/imunologia , Sistema de Registros , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento
3.
Transplantation ; 83(9): 1207-13, 2007 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-17496537

RESUMO

BACKGROUND: The introduction of human leukocyte antigen (HLA)-matching in nonliving kidney transplantation has resulted into a better graft outcome, but also in an increase of waiting time, especially for patients with rare HLA phenotypes. We addressed the question of the differential influence of HLA-DR-matching versus HLA-A,B in clinical kidney transplantation. METHODS: We used Kaplan-Meier product limit method to estimate survival rates, and Cox proportional hazard regression for the estimation of relative risks (Hazard-ratios) for different variables. RESULTS: A single center study (n=456 transplants, performed between 1985 and 1999) showed that full HLA-DR compatibility leads to a lower incidence of biopsy confirmed acute rejections in the first 180 posttransplantation days. These results were substantiated using the Eurotransplant database (n=39,205 transplants performed between 1985 and 2005) where graft survival in the full HLA-DR compatible group was significantly better than in the incompatible. An additional positive effect of HLA-A,B matching was only found in the full HLA-DR compatible group. In both studies, the introduction of a single HLA-DR incompatibility eliminates the HLA-A,B matching effect. CONCLUSIONS: We propose to allocate postmortem kidneys only to patients with full HLA-DR compatibility, and use HLA-A,B compatibility as an additional selection criterion. All patients, irrespective of their ethnic origin, will profit since the polymorphism of HLA-DR is by far lower than that of HLA-A,B. Excessive kidney travel and cold ischemia time will be significantly reduced.


Assuntos
Antígenos HLA-DR/sangue , Alocação de Recursos para a Atenção à Saúde , Histocompatibilidade , Transplante de Rim , Doadores de Tecidos , Obtenção de Tecidos e Órgãos , Doença Aguda , Cadáver , Bases de Dados Factuais , Feminino , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto , Antígenos HLA-A/sangue , Antígenos HLA-B/sangue , Teste de Histocompatibilidade , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Risco , Fatores de Tempo
4.
Transpl Int ; 19(1): 54-66, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16359377

RESUMO

The prospects of patients on the thoracic waiting list are governed by the chance of receiving an organ in time and by the outcome of the transplantation. The former probability is determined by a triad of disease severity, resource size and allocation rules. The aim of this study was to provide an objective description of the distributional effects of the thoracic allocation system in Eurotransplant. It appears that the interpretation of waiting-list outflow indicators is not straightforward and that it is difficult to assess the fairness of an organ allocation system in the framework of changing donor-organ availability. The timing of listing for heart transplantation can substantially be improved; whether this is also true for lung transplantation cannot be determined from the available data. Allocation schemes cannot solve the problem of organ shortage; a shift of attention toward collaboration with procurement professionals is needed.


Assuntos
Alocação de Recursos para a Atenção à Saúde , Transplante de Coração/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/organização & administração , Obtenção de Tecidos e Órgãos/tendências , Adulto , Europa (Continente) , Humanos , Fatores de Tempo , Doadores de Tecidos/estatística & dados numéricos , Doadores de Tecidos/provisão & distribuição , Listas de Espera
6.
Transplantation ; 80(8): 1012-8, 2005 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-16278579

RESUMO

BACKGROUND: Some studies have claimed that patients with immunoglobulin A (IgA) nephropathy have better graft survival than other renal graft recipients, whereas others have rejected this statement. We have addressed this paradox in the present study. METHODS: In all, 1,207 patients with IgA nephropathy who received a primary cadaveric renal graft from 1990 to 2002 were identified in the Eurotransplant database. For comparison, we analyzed 7,935 patients with nonglomerular diseases. Death-censored graft survival was calculated using Kaplan Meier estimates and a multivariable Cox regression analysis was used for risk calculations. RESULTS: Death-censored graft survival was superior in patients with IgA nephropathy in the first period after transplantation. After 3 years posttransplant, however, there was an accelerated decline in graft survival in recipients with IgA nephropathy. The fully adjusted risk of graft loss in the first year was increased by 40% in the control group compared to IgA nephropathy (hazard ratio [HR] 1.40, 95% CI 1.12-1.75), whereas the risk was significantly lower in the control group after the first year posttransplant (HR 0.75, 95% CI 0.63-0.88). Cold ischemia time, immunization and HLA-DR mismatch were risk factors for graft loss in the control group but not for IgA nephropathy, whereas HLA-AB mismatch was an independent risk factor, exclusively for the IgA nephropathy group. CONCLUSIONS: Recipients with IgA nephropathy have better 1-year graft survival, presumably due to favorable immunological behavior. This benefit was however abolished in the long-term by increased graft loss with time. Studies are needed to explain the difference in graft survival and the reason why different risk factors are involved in graft failure.


Assuntos
Glomerulonefrite por IGA/cirurgia , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto , Transplante de Rim , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Glomerulonefrite por IGA/imunologia , Glomerulonefrite por IGA/mortalidade , Rejeição de Enxerto/mortalidade , Humanos , Imunoglobulina A/imunologia , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Fatores de Risco , Resultado do Tratamento
8.
Nephrol Dial Transplant ; 20(1): 34-41, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15522904

RESUMO

INTRODUCTION: The goal of the Eurotransplant renal allocation scheme is to provide every patient on the waiting list with a reasonably balanced opportunity for a donor offer. New initiatives were taken in order to maximize donor usage while maintaining a successful transplant outcome. METHODS: Two Eurotransplant projects were launched in order to accommodate changes in donor and recipient profiles. A re-addressing of the non-heart-beating donor pool was undertaken and an allocation scheme in which organs from donors aged >65 are allocated to recipients aged >65 [the Eurotransplant Senior Programme (ESP)] was introduced. RESULTS: Especially in The Netherlands, an enormous increase in the number of non-heart-beating donor kidneys has been observed, however with a pace-keeping reduction in heart-beating donors. The organization-wide implementation of the ESP has been successful. The 3 year graft survival rates for these age-matched transplants were as good as the human leukocyte antigen (HLA)-matched transplants (64 vs 67%) (P = 0.4). CONCLUSION: Within the framework of sound research, the utmost flexibility and creativity is needed to keep or even increase the number of renal transplants when faced with a quantitatively stagnating but qualitatively deteriorating donor pool. Both the non-heart-beating donor protocol and the ESP have proven to be quite successful in achieving this goal without compromising the outcome for the individual end-stage renal disease patient.


Assuntos
Falência Renal Crônica/cirurgia , Transplante de Rim/estatística & dados numéricos , Doadores de Tecidos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/organização & administração , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Europa (Continente) , Feminino , Alemanha , Humanos , Incidência , Falência Renal Crônica/diagnóstico , Transplante de Rim/métodos , Doadores Vivos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Países Baixos , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Fatores de Risco
9.
Transplantation ; 78(2): 190-3, 2004 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-15280676

RESUMO

There are many highly sensitized patients on the kidney waiting lists of organ exchange organizations because it is difficult to find a crossmatch negative cadaver kidney for these patients. Recently, several protocols have been developed to remove the donor-specific human leukocyte antigen (HLA) antibodies from the serum of these patients before transplantation. These approaches, including the use of intravenous immunoglobulins, plasmapheresis and immunoglobulins (plasmapheresis-cytomegalovirus-immunoglobulin), and immunoabsorption, seem to lead to a certain success rate, although the additional immunosuppression necessary to remove and control the production of donor-specific alloantibodies may have its impact on the short-term (infections) and long-term (incidence of cancer) immune surveillance. Furthermore, some of these therapies represent a considerable financial burden for patients and society. In the present report, we advocate selection of crossmatch negative donors on the basis of the Acceptable Mismatch Program, as the first and best option for highly sensitized patients to undergo transplantations. No additional immunosuppression is necessary, and graft survival in this group of "difficult" patients is identical to that of nonsensitized recipients. Because the nature of the HLA polymorphism does not allow all patients to profit from this approach, removal of circulating HLA antibodies can be considered as a rescue therapy for those patients for whom the Acceptable Mismatch Program does not give a solution.


Assuntos
Sobrevivência de Enxerto/imunologia , Teste de Histocompatibilidade/métodos , Transplante de Rim/imunologia , Cadáver , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Antígenos HLA-DR/imunologia , Humanos , Imunização , Fatores de Tempo , Doadores de Tecidos , Resultado do Tratamento , Listas de Espera
10.
Transplantation ; 77(4): 615-7, 2004 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-15084947

RESUMO

In March 1996, a new allocation point system for cadaver kidneys, the Eurotransplant (ET) Kidney Allocation System (KAS), was introduced in ET, the first multinational organ exchange organization. The aims of ETKAS were to reduce average and maximum waiting time, to allow patients with rare human leukocyte antigen (HLA) phenotypes or combinations to receive an "optimal" offer, to keep the exchange rates between the participating countries balanced, and finally to keep optimal graft survival, by means of HLA matching. Elderly patients and highly sensitized patients profit in addition from special programs, the ET Senior Program and the Acceptable Mismatch Program, respectively. All kidneys are offered to the pool and are allocated according to the degree of HLA matching, mismatch probability, waiting time, distance from the donor center, and balance between the countries participating in ET. A summary of 6 years' experience with the ETKAS is presented in this article.


Assuntos
Transplante de Rim , Rim , Alocação de Recursos , Cadáver , Europa (Continente) , Teste de Histocompatibilidade/métodos , Teste de Histocompatibilidade/tendências , Humanos , Listas de Espera
11.
Transplantation ; 77(8): 1191-4, 2004 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-15114083

RESUMO

BACKGROUND: To study the effect of donor age on kidney function, the authors investigated matched pairs from the same kidney donor given to a pediatric or an adult recipient. METHODS: Fifteen matched pairs of an adult and a pediatric patient, selected from the Eurotransplant registry, receiving the renal graft from the same cadaveric donor were selected for analysis of graft function over 7 years. Nine matched pairs were from adult donors (mean age, 40 years; range, 23-60 years) and six from pediatric donors (mean age, 11 years; range, 4-15 years). All recipients had comparable immunosuppression with cyclosporine A, prednisolone, and azathioprine and comparable numbers of acute rejection, cytomegalovirus reactivation, and antihypertensive therapy. Mean age of pediatric and adult recipients at transplantation was 5 years (range, 1-9 years) and 38 years (range, 25-60 years), respectively. RESULTS: The calculated glomerular filtration rate (GFR) corrected to body surface area was not different in adult and pediatric recipients. Initial absolute GFR was significantly lower in pediatric recipients (27 mL/ min; range, 17-38 mL/min) than in adult recipients (54 mL/min; range, 25-74 mL/min) (P <0.05) and remained lower in the following years. Initially, pediatric donor kidneys transplanted into pediatric recipients showed a lower absolute GFR than those transplanted into adults, however, approaching the GFR in adult recipients later. Adult donor kidneys transplanted into pediatric recipients showed a persistently lower absolute GFR in children compared with those transplanted into adult recipients. CONCLUSIONS: The authors conclude that adult donor kidneys in pediatric recipients decrease GFR in the early stages and lack an increase in GFR with growth of the child.


Assuntos
Transplante de Rim/fisiologia , Doadores de Tecidos , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Europa (Continente) , Feminino , Taxa de Filtração Glomerular , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Obtenção de Tecidos e Órgãos
12.
Transplantation ; 77(8): 1236-9, 2004 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-15114091

RESUMO

BACKGROUND: The correlation between antibody production against mismatched donor human leukocyte antigens (HLA) and the number of amino acid sequence mismatches was analyzed in patients who rejected a kidney transplant (n=146). METHODS: A similar analysis was performed for the antibody production of women against the paternal HLA antigens of their child (n=1,397). The amino acid sequence (triplet) differences were analyzed using the HLAMatchmaker algorithm. RESULTS: In both groups, a positive correlation was found between the number of triplet mismatches and the percentage of individuals producing antibodies (P <0.0001). If zero triplet mismatches were present, no antibodies were formed in all cases. When 11 or 12 triplet mismatches were present, 94% of the transplant patients produced antibodies against the donor. In pregnancy, 11 or 12 triplet mismatches led to 27% of the women producing specific antibodies. CONCLUSIONS: These results indicate that the immunogenicity of the fetus is lower than that of a rejected kidney and that analysis of the number of triplet mismatches can predict the antibody reactivity against the mismatched HLA antigens.


Assuntos
Antígenos HLA/genética , Isoanticorpos/biossíntese , Transplante de Rim/imunologia , Sequência de Aminoácidos , Feminino , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Teste de Histocompatibilidade , Humanos , Transplante de Rim/efeitos adversos , Masculino , Troca Materno-Fetal/genética , Troca Materno-Fetal/imunologia , Gravidez , Doadores de Tecidos
13.
Hum Immunol ; 65(1): 13-9, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14700591

RESUMO

Recent studies suggest that the immunogenicity of an human leukocyte antigen (HLA) incompatibility should be considered in the context of the HLA phenotype of the recipient. The HLA-DR phenotype of the responder is thought to be predictive for the strength of the alloimmune response. In order to analyze the humoral response against HLA class I antigens in the context of the HLA-DR phenotype of the responder, we selected all HLA-DR homozygous Dutch patients that were present on the Eurotransplant waiting list between 1967 and 2000 (n=1,317 patients). By logistic regression it was determined whether antibody production against a specific HLA class I antigen is associated with a particular HLA-DR antigen in the patient. Furthermore, it was analyzed whether a patient, expressing a particular HLA-DR antigen, preferentially produces antibodies against particular HLA class I antigens. The results demonstrate that patients, homozygous for a certain HLA-DR antigen, cannot be considered high or low responders when analyzing the antibody response in terms of panel reactive antibody (PRA) value. However, a correlation can be found between the HLA-DR phenotype of the patient and the specific antibody response against HLA class I antigens. For example, antibodies against HLA-A10, -A11, -A19, and -B35 are produced more frequently by HLA-DR6 positive individuals, whereas antibodies against HLA-A3, -B5, -B7, -B8, and -B12 are produced more frequently by HLA-DR4 positive individuals. These data confirm that the HLA-DR phenotype of the responder plays a determinative role in the immunogenicity of mismatched HLA antigens. The results indicate that selection of HLA class I mismatches of the donor in the context of the HLA-DR phenotype of the responder might reduce the incidence of humoral graft rejection and minimize the sensitization grade of retransplant candidates.


Assuntos
Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Antígenos HLA-DR/análise , Teste de Histocompatibilidade , Isoanticorpos/biossíntese , Transplante de Rim/imunologia , Formação de Anticorpos , Estudos de Coortes , Genótipo , Antígenos HLA-DR/imunologia , Humanos , Isoanticorpos/sangue , Valor Preditivo dos Testes
14.
Clin Transpl ; : 83-90, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-16704140

RESUMO

Eurotransplant introduced a new allocation policy in January 2003 to increase the number of liver transplants by offering centers an incentive to split deceased donor livers for 2 recipients. Centers were granted the option of choosing a suitable recipient for the second portion of the split liver from their own waiting list and, to increase the awareness for liver splitting, centers were asked by the Eurotransplant duty officer whether they would consider splitting whenever a liver that met the 50/50 rule (donor age <50 and weight >50 kg) was available. During the first year after implementing this policy, split-liver transplants increased by 67% and again by 10% during the second year (a total of 288 transplants in the 2-year period). The number of pediatric recipients of a split liver increased from 44 in 2002 to 76 in 2004 and the pediatric waiting list decreased by 36% (73 to 47) one year after implementation of the new policy. More than 95% of the 288 split liver transplants involved one adult and one pediatric recipient. Nearly three-quarters of the split liver transplants were performed at 3 centers with both a pediatric and adult waiting list and with surgeons experienced in the procedure. We conclude that Eurotransplant's liver allocation policy has increased the number of liver transplants, particularly among children, by rewarding centers that split livers for transplantation to 2 recipients without prolonging cold ischemia time. The number of centers that could benefit from this policy will increase as more surgeons are trained in the splitting procedure.


Assuntos
Transplante de Fígado/métodos , Obtenção de Tecidos e Órgãos/organização & administração , Adolescente , Adulto , Criança , Pré-Escolar , Europa (Continente) , Feminino , Humanos , Lactente , Recém-Nascido , Transplante de Fígado/estatística & dados numéricos , Masculino , Fatores de Tempo , Coleta de Tecidos e Órgãos , Obtenção de Tecidos e Órgãos/legislação & jurisprudência , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Listas de Espera
15.
Transplantation ; 76(10): 1492-7, 2003 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-14657692

RESUMO

BACKGROUND: Numerous studies have investigated prognostic factors for the survival of transplant candidates waiting for a donor organ, but little is known about the impact of allocation policies on waiting list outcome. Simulation models would allow a comparison of different policies for allocating donor hearts on pretransplant outcome. METHODS: A model was built for the Eurotransplant waiting list for heart transplantation. Survival and delisting distributions were estimated from the Eurotransplant transplant candidate inflow between 1995 and 2000 (n=7,142). Other characteristics were obtained directly from the transplant candidate inflow of 1999 and 2000 (n=2,097) and the donor organs of 1998 and 1999 (n=1,520). Overall and subgroup waiting list mortality were estimated for allocation policies differing by ABO blood group, border, and clinical profile rules. RESULTS: The model estimated that international organ exchange reduces waiting list mortality in the different countries by 1.9% to 12.4%. An allocation policy incorporating the initial clinical profile of the transplant candidates further reduced waiting list mortality by 1.7%. Changing ABO rules toward identical matching yielded a slightly more equitable survival for the different groups, without an overall effect on mortality. The best possible allocation policy is the policy where organs are allocated to patients that are at highest risk of dying, and withholding organs from patients that would eventually delist because of improvement. CONCLUSIONS: Patients benefit from international organ exchange and by a heart allocation scheme based on clinical profiles. Timely delisting of patients who are-temporarily-too well for transplantation is the best waiting list policy.


Assuntos
Transplante de Coração/estatística & dados numéricos , Coração , Alocação de Recursos/métodos , Doadores de Tecidos/provisão & distribuição , Obtenção de Tecidos e Órgãos/métodos , Simulação por Computador , Europa (Continente) , Transplante de Coração/mortalidade , Humanos , Valor Preditivo dos Testes , Obtenção de Tecidos e Órgãos/organização & administração , Listas de Espera
16.
Transplantation ; 76(8): 1185-9, 2003 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-14578751

RESUMO

BACKGROUND: Current trends in medical management of advanced heart failure and transplant medicine and the enactment of a national transplant law forced a change toward allocation driven by disease severity. OBJECTIVE: The aim of this study was to create a model for predicting waiting-list survival on the basis of simple clinical parameters. METHODS: The clinical profiles of all patients registered for heart transplantation in Germany in 1997 (n=889) were used as a derivation set, and the total German 1998 cohort (n=897) was used as a validation set. The model was validated by the c statistic and by comparison of risk stratified mortality rates. The validated model was fine tuned by the appropriate calibration procedures. The data were first classified into physiologic subscores: an urgency score, a left ventricular heart failure score, a right ventricular heart failure score, and a systemic heart failure score. A stepwise modeling procedure was undertaken using these subscores as factors as well as the recipient's age, ABO blood group, and body surface area. RESULTS: The urgency and the left ventricular subscore were found to be significantly associated with waiting-list mortality. A summary index termed German Transplant Society (GTS) score was then calculated on the basis of seven parameters contained in these two subscores. The GTS score was able to predict waiting-list mortality risks for the 1998 cohort: 1-year mortality before transplantation was 71%, 34%, 11% for the high, medium, and low risk groups, respectively. CONCLUSION: The use of this continuous disease severity index may improve the selection of cardiac transplant candidates.


Assuntos
Baixo Débito Cardíaco/mortalidade , Baixo Débito Cardíaco/cirurgia , Transplante de Coração , Modelos Teóricos , Listas de Espera , Adulto , Baixo Débito Cardíaco/etiologia , Estudos de Coortes , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Medição de Risco , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Direita/complicações
17.
Transplantation ; 75(6): 884-9, 2003 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-12660519

RESUMO

BACKGROUND: HLAMatchmaker is a recently developed computer-based algorithm to determine donor-recipient HLA compatibility at the molecular level. Originally designed for highly alloimmunized patients, this algorithm is based on the concept that immunogenic epitopes are represented by amino acid triplets on exposed parts of protein sequences of HLA-A, -B, and -C chains accessible to alloantibodies. Donor HLA compatibility is determined by intralocus and interlocus comparisons of triplets in polymorphic sequence positions. For most patients, HLAMatchmaker can identify certain mismatched HLA antigens that are zero-triplet mismatches to the patient's HLA phenotype and should, therefore, be considered fully histocompatible. The present study was designed to determine how class I HLA matching at the triplet level affects kidney transplant outcome. METHODS: We analyzed two multicenter databases of zero-HLA-DR-mismatched kidneys transplanted from 1987 to 1999. One database consisted of 31,879 primary allografts registered by U.S. transplant centers in the United Network for Organ Sharing database and the other consisted of 15,872 transplants in the Eurotransplant program. RESULTS: HLA-A,B mismatched kidneys that were compatible at the triplet level exhibited almost identical graft survival rates as the zero-HLA-A,B antigen mismatches defined by conventional criteria. This beneficial effect of triplet matching was seen for both nonsensitized and sensitized patients and also for white and nonwhite patients. CONCLUSIONS: These findings suggest that the application of HLAMatchmaker will increase the number of successful transplants, at least in the HLA-DR match combinations.


Assuntos
Antígenos HLA-A/análise , Antígenos HLA-B/análise , Teste de Histocompatibilidade/métodos , Transplante de Rim/imunologia , Transplante de Rim/mortalidade , Algoritmos , Sequência de Aminoácidos , Bases de Dados Factuais , Epitopos/análise , Epitopos/genética , Sobrevivência de Enxerto/imunologia , Antígenos HLA-A/química , Antígenos HLA-B/química , Humanos
18.
Transplantation ; 75(3): 418-20, 2003 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-12589169

RESUMO

The immunogenicity of human leukocyte antigen (HLA)-A2 versus HLA-A28 was analyzed by antibody production, cytotoxic T-lymphocyte (CTL) induction, and graft survival. We observed that an HLA-A2 mismatched child in HLA-A28 women leads to HLA-A2 specific antibodies in 32% of the women (n=31), whereas in the case of an HLA-A28 child and HLA-A2 women (n=30), no HLA-A28 specific antibodies were found ( P<0.002). Also, the CTL precursor frequencies were significantly lower against HLA-A28 compared with CTLp frequencies against HLA-A2 ( P=0.012). Finally, the kidney graft survival was slightly better in HLA-A2 positive recipients transplanted with HLA-A28 mismatches. We can conclude that single HLA-A28 mismatches are less immunogenic in HLA-A2 individuals compared with single HLA-A2 mismatches in HLA-A28 individuals, which is probably because the mismatched epitopes on the HLA-A2 molecule are unique epitopes, whereas the mismatched epitopes on HLA-A28 are shared by other HLA-A and HLA-B molecules.


Assuntos
Epitopos/imunologia , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Antígeno HLA-A2/imunologia , Transplante de Rim/imunologia , Anticorpos/sangue , Feminino , Feto/imunologia , Antígenos HLA-A/imunologia , Teste de Histocompatibilidade , Humanos , Técnicas In Vitro , Gravidez , Linfócitos T Citotóxicos/imunologia
19.
Transplantation ; 76(11): 1604-8, 2003 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-14702532

RESUMO

BACKGROUND: Despite its reduced benefit for a single recipient, the transplantation of two single-lung allografts as opposed to one bilateral lung transplant has the indisputable advantage of maximizing the number of patients that benefit from a single donor. METHODS: In the period 1997 to 1999, 90 paired single-lung transplants (SLTx) from 45 donors were performed in 16 lung centers in Eurotransplant, with a complete follow-up of 1 year. RESULTS: No significant differences between left- and right-lung allograft recipients were observed regarding age, sex, primary disease, number of human leukocyte antigen mismatches, cold ischemic time, and donor-to-recipient cytomegalovirus match. Early posttransplant outcome, as assessed by oxygenation index at 12, 24, and 48 hr, also did not differ significantly, and there were no differences in time to extubation and time spent in the intensive care unit. In the first month, six left- and three right-lung allograft recipients died. Bronchiolitis obliterans syndrome developed in 5 of 39 left-lung and 10 of 42 right-lung allograft recipients. If the retrieval team was different from the transplanting team, a significantly worse 1-year posttransplant survival rate was seen in patients who underwent left SLTx compared with those who underwent right SLTx (62% vs. 92%, respectively; P=0.04). CONCLUSIONS: More fatal posttransplant complications occur in patients undergoing left SLTx compared with right SLTx. A less optimistic assessment of the left lung by the not-implanting retrieval team is warranted.


Assuntos
Transplante de Pulmão/fisiologia , Doadores de Tecidos , Adolescente , Adulto , Idoso , Infecções por Citomegalovirus/epidemiologia , Feminino , Seguimentos , Lateralidade Funcional , Teste de Histocompatibilidade , Humanos , Pulmão , Pneumopatias/classificação , Pneumopatias/cirurgia , Transplante de Pulmão/imunologia , Transplante de Pulmão/mortalidade , Masculino , Pessoa de Meia-Idade , Preservação de Órgãos/métodos , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento
20.
Clin Transpl ; : 89-100, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-15387100

RESUMO

The definition of proper patient selection criteria remains a prominent item in constant need of attention. While the concept of gathering evidence in order to determine practice continues to be hopelessly ambiguous, it can never be emphasized too much that these univariate results are just a first foray into analysing predictors of survival; all following results should be regarded and interpreted in this perspective. HEART TRANSPLANT SURVIVAL: The 3-year survival rate for heart transplant recipients under age 16 was 83% versus 72% for adult recipients. Acutely retransplanted adult heart recipients had a 3-year survival rate of 36% compared with 72% for recipients of a first heart allograft. Patients suffering from DCM had the best survival rates at 3 years (74%) compared with patients suffering from CAD (70%) or from another end-stage heart disease (67%). With advancing age of the adult recipient, the mortality risk increased. Patients aged 16-40 had a 3-year survival rate of 77%, compared with 74%, 70% and 61% for transplant recipients aged 41-55, 56-65 and over age 65, respectively. The 3-year survival rates for adult recipients transplanted with an heart allograft from a donor aged under 16 or between 16-44 were 78% and 74%, compared with 66% and 63% for donors aged 45-55 and over 55, respectively. The 3-year survival rates for recipients of hearts with cold ischemic times under 2 hours, 2-3, 3-4, 4-5, 5-6 and more than 6 hours were 74%, 75%, 70%, 65%, 54% and 40%, respectively. Transplanting a female donor heart into a male recipient was associated with the worst prognosis: the 3-year survival rates were 73%, 71%, 66% and 76%, respectively, for the donor/recipient groups male/male, male/female, female/male and female/female, respectively. When the donor-to-recipient body weight ratio was below 0.8, the 3-year survival rate was 64%, compared to 72% for weight-matched pairs and 74% for patients who received a heart from an oversized donor (p=0.004). Better survival rates were obtained for better HLA-matched transplants. The 3-year survival rates were 75%, 89%, 78%, 78%, 69%, 72%, and 71% for HLA-A,-B,-DR zero, 1, 2, 3, 4, 5 and 6 mismatched groups, respectively (p=0.04). Survival was significantly associated with the CMV serologic status of the donor and recipient; the 3-year survival rates were: D+/R+, 71%; D+/R-, 69%; D- R-, 76%; and D-/R+, 76% (p=0.04). Patients in an ICU had a 3-year survival rate of 62%, compared to 72% for patients in a general ward and 74% for outpatients (p<0.0001). Patients that were on a VAD and there-upon transplanted had a 3-year survival rate of 65%, compared to 73% for patients without a VAD (p=0.004). Being on a ventilator was a major risk factor for death after transplantation; patients on ventilator support at the time of the transplant had a 3-year survival rate of 52% compared to 73% for the other patients (p<0.0001). LUNG TRANSPLANT SURVIVAL: The 3-year survival rate for children (73%) appeared to be better than the adult rate (61%; p=0.8). Adult lung transplant survival was significantly worse in the case of a repeat lung transplant; a 3-year retransplant survival rate of 42% was obtained compared with 61% for first transplants (p=0.049). With respect to the underlying end-stage lung disease, no statistically significant difference in long-term survival could be detected in this cohort. The 3-year survival rates were: 62% for COPD/Emphysema, 70% for CF, 58% for IPF, 64% for Alpha-1 ATD and 56% for PPH (p=0.2). Our data demonstrated no effect of the recipient's age on long-term lung transplant survival, except for 2 senior patients in this cohort. At 3-years the survival rates for recipients aged 16-40, 41-55 and 56-65 were 65%, 60% and 62%, respectively (p=0.05). The 3-year survival rates for transplants performed with lungs from donors aged under 16, 16-44, 45-55 and over 55 was 57%, 64%, 55% and 62%, respectively (p=0.1) No association between the duration of cold ischemic time and 3-year survival was observed; under 3 hours, 3-4, 4-5, 5-6 and over 6 hours of ischemia resulted in 3-year survival rates of 53%, 59%, 64%, 68% and 57%, respectively (p=0.2). Early posttransplant outcome tended to be better for gender-matched transplants, while transplanting a female donor lung into a male recipient was associated with the worst prognosis. The 3-year survival rates were 65% for male/male, 63% for male/female, 48% for female/male and 61% for female/female (p=0.009). No effect of donor-to-recipient weight match was observed in this Eurotransplant cohort; when the donor-to-recipient weight ratio was below 0.8, the 3-year survival rate was 57%, compared with 59% for weight-matched pairs and 64% for patients who received a lung from an oversized donor (p=0.5). Long-term survival after lung transplantation was influenced by HLA matching. The 3-year survival rates were 100%, 68%, 70%, 65%, 54% and 55% for the HLA-A,-B,-DR 1, 2, 3, 4, 5 and 6 mismatched groups, respectively (p=0.06). A donor CMV+ and recipient CMV- match was a risk factor for long-term mortality, with 3-year survival rates of 56% for D+/R+, 55% for D+/R-, 71% for D-/R- and 62% for D-/R+ transplants (p=0.046). En-bloc transplantation of both lungs yielded worse early results, but the 3-year survival rates for patients who underwent single (60%), bilateral sequential double lung (63%) and en-bloc double lung transplantation (56%) were not different (p=0.2). Ventilator dependency was associated with a significantly reduced survival at 3 years. Patients on a ventilator support at the time of the transplant had a 3-year survival rate of 48% compared with 63% for other patients (p=0.006).


Assuntos
Transplante de Coração , Transplante de Pulmão , Adolescente , Adulto , Fatores Etários , Idoso , Peso Corporal , Estudos de Coortes , Criopreservação , Europa (Continente) , Feminino , Histocompatibilidade , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação , Análise de Sobrevida , Fatores de Tempo , Doadores de Tecidos
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