RESUMO
BACKGROUND: The clinical significance of the flow cytometry crossmatch has been addressed in several retrospective studies, but the results have been controversial. There are no prospective studies in which patients known to be antibody positive underwent transplantation. METHODS: The flow cytometry crossmatch was performed prospectively in 1130 renal transplant recipients. A decision to perform transplantation was based on whether the positive results were on T or B cells, in the current or peak specimen, and taking into account the presence or absence of other immunological risk factors. One hundred antibody-positive patients received a transplant. Graft survival and rejection episodes were analyzed in this group and compared with 100 crossmatch-negative patients matched for age, sex, race, and time of transplantation. RESULTS: The incidence of rejection at 1 month was higher in antibody-positive patients (26%) than in antibody-negative patients (12%, P<0.01). Early rejection seemed to be more frequent in antibody-positive patients regardless of whether the antibodies were current or historic, or against T or B cells. There were more steroid-resistant rejections in antibody-positive than in antibody-negative patients. However, biopsy specimens showed that vascular lesions that can be associated with humoral rejection were not more frequent in the antibody-positive patients than in the controls. There were no differences in graft survival between the two groups. CONCLUSIONS: Low-level preformed alloantibodies detected by flow cytometry represent a risk of rejection even for patients purposely selected for having no additional immunological risk factors. The risk seems to be due to donor-specific memory rather than to a direct effect of the antibodies. The results indicate that flow cytometry provides useful information to assess donor-recipient compatibility.
Assuntos
Linfócitos B/imunologia , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Teste de Histocompatibilidade , Transplante de Rim/fisiologia , Linfócitos T/imunologia , Citometria de Fluxo/métodos , Seguimentos , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/epidemiologia , Antígenos HLA-D/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunossupressores/uso terapêutico , Isoanticorpos/sangue , Transplante de Rim/imunologia , Muromonab-CD3/uso terapêutico , Fatores de Tempo , Resultado do TratamentoRESUMO
Most studies of discordant xenograft rejection have focused on the roles of recipient xenoreactive antibody and complement as mediators of hyperacute rejection; there are essentially no data from in vivo studies as to the contribution of endothelial cell responses to the pathobiology of xenograft rejection. We hypothesized that the mechanism by which xenoreactive natural antibodies and complement of the recipient are involved in rejection of a discordant, immediately vascularized xenograft involves donor organ endothelial cell activation, with the consequences of such activation contributing significantly to the rejection process. We performed a kinetic analysis of rejection of guinea pig hearts by untreated Lewis rats or recipients depleted of complement activity that underwent delayed xenograft rejection. We report that in both hyperacute rejection and delayed xenograft rejection there is widespread evidence of endothelial cell activation, including expression of P-selectin and E-selectin, upregulation of tissue factor, and downregulation of thrombomodulin and antithrombin III expression. Many of these changes occur very early posttransplantation in grafts that are not completely rejected until approximately 3 days. In delayed xenograft rejection, an intense cellular infiltrate is seen that results from progressive accumulation of activated macrophages and natural killer cells. T cell receptor alpha/beta+T cells are present only at relatively low levels. This cellular infiltrate is associated with dense expression of pro-inflammatory cytokines, including interferon gamma, interleukin 1, and tumor necrosis factor-alpha. We conclude that both endothelial cell activation and infiltration by activated macrophages and natural killer cells may play an important role in xenograft rejection. These newly described features of the xenogeneic rejection response may require targeting by future therapeutic regimens aimed at prolonging xenograft survival.
Assuntos
Endotélio Vascular/metabolismo , Transplante Heterólogo/imunologia , Animais , Ativação do Complemento/fisiologia , Venenos Elapídicos/uso terapêutico , Endotélio Vascular/citologia , Rejeição de Enxerto , Sobrevivência de Enxerto/efeitos dos fármacos , Cobaias , Transplante de Coração/imunologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/fisiologia , Ativação de Macrófagos/fisiologia , Masculino , Ratos , Ratos Endogâmicos Lew , Transplante Heterólogo/patologiaRESUMO
Rapamycin (Rapa) monotherapy can promote renal allograft survival in dogs, but it is very toxic. To attempt to augment the effectiveness of Rapa and reduce its toxicity in a tolerance induction protocol, canine renal allograft recipients were treated briefly with antilymphocyte serum (ALS), donor bone marrow cells (BMC), and a limited course of cyclosporine (CsA). Rapa had little effect when CsA-treated recipients were given ALS on days -5 to -1 and BMC on day +1. When combined with CsA given days +13 to +42, ALS on days -5 to +7, and BMC on day +10, Rapa at 0.3 mg/kg on day +8 plus alternate days +15 to +39 significantly increased overall survival and was compatible with long-term survival after immunosuppression (6 grafts, 1 graft > 212 days, 1 graft > 470 days). Rapa appeared to prevent early rejections that can occur during treatment with these ALS/BMC/CsA protocols. Little toxicity of Rapa was observed with any treatment.
Assuntos
Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/administração & dosagem , Transplante de Rim/imunologia , Polienos/administração & dosagem , Animais , Soro Antilinfocitário/administração & dosagem , Medula Óssea/imunologia , Ciclosporina/administração & dosagem , Cães , Imunização , Polienos/efeitos adversos , Sirolimo , Doadores de TecidosRESUMO
BACKGROUND: Advances in perioperative care and immunosuppression have enabled clinicians to broaden the indications for organ transplantation. Advanced age is no longer considered a contraindication to transplantation at most centers. Although short-term studies of elderly liver transplant recipients have demonstrated that the incidence of complications and overall patient survival are similar to those of younger adults, transplant center-specific, long-term data are not available. METHODS: From August of 1984 to September of 1997, 91 patients 60 years of age or older received primary liver transplants at the University of Wisconsin, Madison. This group of patients was compared with a group of younger adults (n=387) ranging in age from 18 to 59 years who received primary liver transplants during the same period. The most common indications for transplantation in both groups were Laennec's cirrhosis, hepatitis C, primary biliary cirrhosis, primary sclerosing cholangitis, and cryptogenic cirrhosis. There was no difference in the preoperative severity of illness between the groups. Results. The length of hospitalization was the same for both groups, and there were no significant differences in the incidence of rejection, infection (surgical or opportunistic), repeat operation, readmission, or repeat transplantation between the groups. The only significant difference identified between the groups was long-term survival. Five-year patient survival was 52% in the older group and 75% in the younger group (P<0.05). Ten-year patient survival was 35% in the older group and 60% in the younger group (P<0.05). The most common cause of late mortality in elderly liver recipients was malignancy (35.0%), whereas most of the young adult deaths were the result of infectious complications (24.2%). CONCLUSION: Although older recipients at this center did as well as younger recipients in the early years after liver transplantation, long-term survival results were not as encouraging.
Assuntos
Transplante de Fígado/mortalidade , Idoso , Envelhecimento/fisiologia , Causas de Morte , Feminino , Rejeição de Enxerto/epidemiologia , Humanos , Transplante de Fígado/imunologia , Masculino , Taxa de Sobrevida/tendências , SobreviventesRESUMO
Little attention has been given to the fate of patients who lose their grafts. We reviewed outcomes of 438 recipients of first renal allografts who underwent transplantation at our institution between January 1, 1988, and December 31, 1997, and lost their grafts or died with a functioning transplant. Of the 438 patients, 168 patients died with a functioning transplant. The most common causes of death were cardiac disease, infection, and cancer. Patients who died with a functioning graft were older (>49 years, 64.3%) than patients who died after returning to dialysis therapy or who are still alive (>49 years, 25.9%). Eighty-six patients (39%) who returned to dialysis therapy were again placed on a cadaveric waiting list. Only 44 patients received a second transplant, of which 30 transplants (68.2%) are still functioning. Our study shows that relatively few patients who lose kidney transplants are returned to the cadaveric waiting list and even fewer undergo retransplantation.
Assuntos
Rejeição de Enxerto/mortalidade , Transplante de Rim/mortalidade , Adolescente , Adulto , Idoso , Cadáver , Causas de Morte , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Taxa de Sobrevida , Fatores de TempoRESUMO
BACKGROUND: Living unrelated renal donation (LURD) has the potential to reduce the current waiting list significantly for kidney transplantation. The purpose of this study was to examine the long-term results of 150 LURDs performed at our center during a 16-year period. METHODS: From Dec 23, 1981, to Feb 13, 1998, 150 LURDs, 219 human leukocyte antigen (HLA)-identical, 577 haploidentical, and 1789 cadaveric kidney transplant procedures were performed. Surgical complications, rejection episodes, infectious complications, and the cause of graft loss and death were examined. Ten-year patient and graft survival rates between groups were compared. RESULTS: Fourteen surgical complications including lymphocele (n = 7), ureteral stricture (n = 4), and ureteral leak (n = 3) were seen. Seventy-eight patients (52%) had 123 rejection episodes and 66 patients (44%) had 1 or more infections. Thirty-six allografts were lost and 25 deaths occurred. Patient survival rates at 10 years for HLA-identical, haploidentical, LURD, and cadaveric transplant procedures were 86%, 82%, 63%, and 64%, respectively. Allograft survival rates at 10 years for HLA-identical, haploidentical, LURD, and cadaver transplant procedures were 75%, 59%, 56%, and 44%, respectively. CONCLUSIONS: Long-term LURD allograft survival rates are lower than those for HLA-identical but equivalent to those of haploidentical and better than those of cadaveric kidney transplantations. Spousal and nonspousal LURDs should be actively encouraged to help alleviate the current donor kidney shortage.
Assuntos
Transplante de Rim , Doadores Vivos , Adolescente , Adulto , Idoso , Cadáver , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Antígenos HLA/análise , Humanos , Transplante de Rim/efeitos adversos , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Taxa de SobrevidaRESUMO
This article discusses the guidelines for brain death determination, the criteria for donor selection, the management of the cadaveric donor, the surgical techniques of isolated renal and multiorgan retrieval, methods of organ preservation, and proper transport of organs to the recipient.
Assuntos
Transplante de Rim , Preservação de Órgãos , Obtenção de Tecidos e Órgãos , Adenosina/uso terapêutico , Alopurinol/uso terapêutico , Morte Encefálica/classificação , Morte Encefálica/diagnóstico , Cadáver , Criopreservação , Glutationa/uso terapêutico , Humanos , Insulina/uso terapêutico , Nefrectomia , Preservação de Órgãos/métodos , Soluções para Preservação de Órgãos/uso terapêutico , Transplante de Órgãos , Seleção de Pacientes , Perfusão , Rafinose/uso terapêutico , Doadores de Tecidos/classificação , Obtenção de Tecidos e Órgãos/métodosRESUMO
Involvement of the inferior vena cava (IVC) by hepatic tumors, although uncommon, is considered to be unresectable by standard surgical techniques. Recent advances in hepatic surgery have made combined hepatic and vena caval resection possible. The purpose of this study is to describe the surgical techniques and early results of combined resection of the liver and IVC. From 1997 to 2000, 11 patients underwent resection of the IVC along with four to seven liver segments. Resections were carried out for hepatocellular carcinoma (four); colorectal metastases (four); and hepatoblastoma, gastrointestinal stromal tumor metastases, and squamous cell carcinoma in one patient each. Ex vivo procedures were performed twice, and total vascular isolation was used in the nine other cases. The IVC was reconstructed with ringed Gore-Tex tube graft (five), primarily (five), or with Gore-Tex patches (one). There were two early deaths: one from liver failure at 3 weeks and one from sepsis secondary to a perforated segment of small bowel 4 months postresection. One patient with a gastrointestinal stromal tumor died at 32 months of recurrent tumor and one patient with hepatocellular carcinoma is alive with recurrent tumor at 16 months. The remaining patients are alive and disease free with follow-up ranging from 3 to 40 months without evidence of IVC occlusion. Combined resection of the liver and IVC is a formidable undertaking with substantial surgical risk. However, this aggressive surgical approach offers a chance for cure in patients with tumors involving the IVC that would otherwise have a dismal prognosis.
Assuntos
Implante de Prótese Vascular , Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Veia Cava Inferior/cirurgia , Adolescente , Adulto , Carcinoma Hepatocelular/patologia , Criança , Pré-Escolar , Neoplasias Colorretais/patologia , Feminino , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Veia Cava Inferior/patologiaRESUMO
METHODS: From July 1984 to July 1995, 99 pediatric patients underwent 127 orthotopic liver transplants (OLT) at the University of Wisconsin Children's Hospital. The patients were divided into four groups according to age at time of transplant: group I, 0 to 6 months (n = 20); group II, 6 to 12 months (n = 18); group III, 1 to 2 years (n = 10); and group IV, 2 to 18 years (n = 51). A retrospective analysis was performed to compare these four groups with regard to preoperative indications and demographics, intraoperative technique, complications, and survival. All patients were followed up for 2 to 13 years. RESULTS: Biliary atresia was the most common indication for OLT in all four groups. The average waiting period varied from 19+/-18 days for group I to 44+/-64 days for group IV. Reduced-size liver transplant (I, 41%; II, 52%; III, 28%; IV, 21%), split-liver transplant (I, 0%; II, 7.4%; III, 17%; IV, 2.9%), or whole-liver transplant techniques were used. Although postoperative Intensive Care Unit stay was longer for the 0- to 6-month-old patients (I, 20+/-64; II, 7.6+/-9; III, 13+/-17; IV, 6.8+/-14 days), the total hospital stay (I, 43+/-63; II, 33+/-34; III, 32+/-20; IV, 29+/-31 days) was similar for all patients. The incidence of hepatic artery thrombosis (I, 19%; II, 19%; III, 27%; IV, 16%), biliary tract complications (I, 4.8%; II, 15%; III, 20%; IV, 14%), and retransplantation (I, 9.5%; II, 41%; III, 33%; IV, 14%) were not significantly different between the four groups. Portal vein thrombosis (I, 9.5%; II, 11%; III, 6.6; IV, 0%) and primary nonfunction (I, 9.5%; II, 7.4%; III, 0%; IV, 3.1%) occurred more frequently in the 0- to 6-month and 6- to 12-month groups, however, the 1-, 5-, and 10-year survival rate for patients (I, 85%, 79%, 79%; II, 89%, 74%, 74%; III, 80%, 80%, 80%; IV, 84%, 75%, 75%, respectively) and primary liver allografts (I, 69%, 69%, 69%; II, 72%, 72%, 63%; III, 70%, 70%, 70%; IV, 71%, 57%, 57%, respectively) were not significantly different (P = .98 and P = .83). CONCLUSION: These results demonstrate that OLT can be effectively performed on infants of all ages and that OLT should not be delayed because of age.