RESUMO
The first vascularized composite allograft (VCA) transplant in the United States was performed in 1998 in a 40-year-old man who received a laryn-geal transplant after experiencing severe trauma to the throat 20 years before. The following VCA was a hand transplant in 1999 in a 37-year-old man who lost his left hand 13 years before. Since then, the field of VCA transplantation has made significant strides. On July 3, 2014, the Or gan Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) oversight of VCA procurement and transplant in the United States went into effect. In the last decade, the number of candidates listed for and transplanted with VCA has increased. While patient demographic data, whether listed candidates or patients undergoing VCA transplant, is limited by sample size, the trend is a predominance toward a young/middle-aged, White population. Overall outcomes data have been promising, with the vast majority of VCA transplants resulting in functioning grafts.
Assuntos
Aloenxertos Compostos , Obtenção de Tecidos e Órgãos , Transplantes , Alotransplante de Tecidos Compostos Vascularizados , Adulto , Aloenxertos Compostos/transplante , Humanos , Masculino , Pessoa de Meia-Idade , Doadores de Tecidos , Estados UnidosRESUMO
Vascularized composite allografts (VCAs) are technically feasible. Similar to other organ transplants, VCAs are hampered by the toxicity and incomplete efficacy associated with conventional immunosuppression. Complications attributable to calcineurin inhibitors remain prevalent in the clinical cases reported to date, and these loom particularly large given the nonlifesaving nature of VCAs. Additionally, acute rejection remains almost ubiquitous, albeit controllable with current agents. Costimulation blockade offers the potential to provide prophylaxis from rejection without the adverse consequences of calcineurin-based regimens. In this study, we used a nonhuman-primate model of VCA in conjunction with immunosuppressive regimens containing combinations of B7-specific costimulation blockade with and without adhesion blockade with LFA3-Ig to determine what adjunctive role these agents could play in VCA transplantation when combined with more conventional agents. Compared to tacrolimus, the addition of belatacept improved rejection free allograft survival. The combination with LFA3-Ig reduced CD2(hi) memory T cells, however did not provide additional protection against allograft rejection and hindered protective immunity. Histology paralleled clinical histopathology and Banff grading. These data provide the basis for the study of costimulation blockade in VCA in a relevant preclinical model.
Assuntos
Aloenxertos , Neovascularização Patológica , Animais , PrimatasRESUMO
The 12th Banff Conference on Allograft Pathology was held in Comandatuba, Brazil, from August 19-23, 2013, and was preceded by a 2-day Latin American Symposium on Transplant Immunobiology and Immunopathology. The meeting was highlighted by the presentation of the findings of several working groups formed at the 2009 and 2011 Banff meetings to: (1) establish consensus criteria for diagnosing antibody-mediated rejection (ABMR) in the presence and absence of detectable C4d deposition; (2) develop consensus definitions and thresholds for glomerulitis (g score) and chronic glomerulopathy (cg score), associated with improved inter-observer agreement and correlation with clinical, molecular and serological data; (3) determine whether isolated lesions of intimal arteritis ("isolated v") represent acute rejection similar to intimal arteritis in the presence of tubulointerstitial inflammation; (4) compare different methodologies for evaluating interstitial fibrosis and for performing/evaluating implantation biopsies of renal allografts with regard to reproducibility and prediction of subsequent graft function; and (5) define clinically and prognostically significant morphologic criteria for subclassifying polyoma virus nephropathy. The key outcome of the 2013 conference is defining criteria for diagnosis of C4d-negative ABMR and respective modification of the Banff classification. In addition, three new Banff Working Groups were initiated.
Assuntos
Arterite/etiologia , Complemento C4b/metabolismo , Rejeição de Enxerto/etiologia , Isoanticorpos/imunologia , Transplante de Órgãos/efeitos adversos , Fragmentos de Peptídeos/metabolismo , Arterite/metabolismo , Rejeição de Enxerto/metabolismo , Humanos , Relatório de PesquisaRESUMO
Composite tissue allotransplantation (CTA) is a recently introduced option for limb replacement and reconstruction of tissue defects. As with other allografts, CTA can undergo immune-mediated rejection; therefore standardized criteria are required for characterizing and reporting severity and types of rejection. This article documents the conclusions of a symposium on CTA rejection held at the Ninth Banff Conference on Allograft Pathology in La-Coruna, Spain, on 26 June 2007, and proposes a working classification, the Banff CTA-07, for the categorization of CTA rejection. This classification was derived from a consensus discussion session attended by the first authors of three published classification systems, pathologists and researchers from international centers where clinical CTA has been performed. It was open to all attendees to the Banff conference. To the extent possible, the format followed the established National Institutes of Health (NIH) guidelines on Consensus Development Programs. By consensus, the defining features to diagnose acute skin rejection include inflammatory cell infiltration with involvement of epidermis and/or adnexal structures, epithelial apoptosis, dyskeratosis and necrosis. Five grades of severity of rejection are defined. This classification refines proposed schemas, represents international consensus on this topic, and establishes a working collective classification system for CTA reporting of rejection in skin-containing CTAs.
Assuntos
Extremidades/patologia , Extremidades/transplante , Rejeição de Enxerto/classificação , Transplante de Pele/patologia , Pele/patologia , Humanos , Pele/imunologia , Transplante de Pele/imunologia , Transplante HomólogoRESUMO
The surgical techniques necessary to perform hand transplantation have been available for at least 25 years. In this article, the authors provide a review of hand transplantation, including its history, preoperative evaluation, and case reports. Data on transplant preparation, operation data, immunosuppression, rejection, immunologic assessment, and functional assessment are presented in easy-to-use table format.