INTRODUÇÃO: O objetivo do estudo foi avaliar o perfil de marcadores imuno-histoquímicos relacionados às células NK em biópsias de aloenxertos renais com diagnóstico anatomopatológico de rejeição aguda (mediadas por células T ou anticorpos) e estabelecer relações desses marcadores com parâmetros morfológicos de lesão à microcirculação e sobrevida do enxerto. MÉTODOS: Estudo retrospectivo histórico que revisou 74 biópsias realizadas entre janeiro de 2009 e dezembro de 2012, de pacientes com rejeição aguda mediada por células T (n=36), rejeição aguda mediada por anticorpos com expressão positiva (n=19) ou negativa (n=19) para o marcador C4d, juntamente com levantamento de dados clínicos e laboratoriais pertinentes ao estudo. Foram realizadas reações imuno-histoquímicas, para os marcadores CD56, CD57, CD16, CD68, CD3, CD8 e CD4 com ênfase para os marcadores CD56 e CD16. Foi feita análise das células positivas em toda a cortical da biópsia nos compartimento intersticial, glomerular e vascular. Testes estatísticos foram aplicados conforme os pressupostos definidos no objetivo da pesquisa. RESULTADOS: No compartimento intersticial, células CD56+ (P = 0,004) e CD57+ (P < 0,001) foram expressas em maior quantidade em biópsias negativas para dosagem sérica de anticorpos específicos anti-doador (DSA) com diagnóstico de rejeição aguda mediada por células T. CD56 intersticial foi associado estatisticamente com presença de glomerulite (g >= 1) (P = 0,02) e ausência / leve capilarite peritubular (ptc <= 1) (P = 0,003). Células intersticiais positivas para o marcador CD56 com média superior a 0,56 céls/mm2 tiveram uma pior sobrevida do enxerto renal (P = 0,028). Biópsias com contagem inferior ou igual a 0,56 cél/mm2 tiveram associação estatisticamente significante para ausência ou leve capilarite peritubular (P = 0,012) e com contagem superior a 0,56 céls/mm2, foram associadas à presença de glomerulite (P = 0,002). Foi observado maior número de células positivas para o marcador CD16 no compartimento glomerular em biópsias positivas para dosagem sérica de DSA com diagnóstico de rejeição aguda mediada por anticorpos (P = 0,03) e em biópsias com presença de glomerulite (P = 0,009). Presença de maior número de células CD16+ no compartimento intersticial associou-se com capilarite peritubular (P = 0,0001). CONCLUSÕES: Maior expressão de células CD56 positivas no compartimento intersticial das biópsias foi significantemente associada com escores relacionados à lesão na microcirculação, especialmente glomerulite, com rejeição aguda mediada por células T e pior sobrevida do enxerto renal. Células CD16 positivas, no compartimento glomerular foram associadas com rejeição aguda mediada por anticorpos e glomerulite. As variações na expressão dos marcadores de células NK nos diferentes compartimentos da biópsia renal podem sugerir presença de envolvimento das células NK em diferentes vias do sistema imune nas rejeições agudas de aloenxertos renais / INTRODUCTION: The aim of this study was to investigate the immunohistochemical profile of markers related to NK cells from renal allograft biopsies with morphological diagnosis of acute rejection (T-cells or antibodies mediated rejection) and to study associations of those markers with types of rejection, microcirculation injury morphological parameters and graft survival. METHODOLOGY: Historical retrospective study that reviewed 74 biopsies performed between January 2009 and December 2012 in patients with acute T-cell-mediated rejection (n=36) and acute antibody-mediated rejection with (n=19) or without evident C4d deposition (n=19). The study was performed with relevant clinical and laboratory data. Immunohistochemical reactions were performed for CD56, CD57, CD16, CD68, CD3, CD8 and CD4 markers with highlights for CD56 and CD16. Counting of positive cells throughout cortical biopsy was performed in glomerular, interstitial and vascular compartments. Statistical tests were applied according to assumptions set out the goal of the study.RESULTS: DSA-negative biopsies-from patients with acute T-cell mediated rejection (aTCMR) had an increased expression of CD56+ and CD57+ cells (P = 0.004 and P < 0.001) in the interstitial compartment in comparison with donor-specific antibodies ( DSA)-positive biopsies from patients acute antibody-mediated rejection with and without C4d deposition. Interstitial CD56+ cells had an increased expression for presence of glomerulitis (g >= 1) (P = 0.02) and peritubular capillaritis (ptc >= 2) (P = 0.003). Interstitial CD56 + cells with mean superior to 0.56cells/mm2 had worse allograft survival (P = 0.028). CD56+ cells in the interstitial compartment with mean inferior or equal to 0.56cells/mm2 associated with absence or mild peritubular capillaritis (P = 0.012) and mean superior to 0.56cells/mm2 was associated with presence of glomerulitis (P = 0.002). CD16+ cells was increased in the glomerular compartment in DSA-positive biopsies (P = 0.03) and in the presence of glomerulitis (P = 0.009). Interstitial CD16+ cells associated with peritubular capillaritis (P = 0.0001).CONCLUSION: CD56+ cell infiltrates in the interstitial compartment were significantly associated with microcirculation injury scores, especially glomerulitis, acute T-cell mediated rejection and clinical outcomes. CD16+ cell infiltrates in glomerular compartment was associated with acute antibody-mediated rejection and glomerulitis. Our findings showed variations in expression of NK cells markers in renal biopsy different compartments which might suggest the involvement of NK cells in different immune system pathways in acute renal allograft rejection

L'objectif de notre projet de recherche est l'exploration de la faisabilité de l'allogreffe des tissus composites (ATC) chez les nouveau-nés ayant des anomalies congénitales sévères de la main ou du visage. Dans la partie bibliographique, nous avons étudié les mécanismes de tolérance néonatale chez la souris, ainsi que la transplantation in utero des cellules souches hématopoïétiques avec des modèles animaux et humains. Ensuite, les propriétés du système immunitaire du nouveau-né humain ont été décrites avec étude des différents protocoles de conditionnement non-myéloablatifs utilisés pour induire une tolérance aux greffes d'organes solides, afin de trouver le type de conditionnement utilisable chez les nouveaux nés pour l'induction de tolérance. La greffe du thymus et de la moelle osseuse vascularisée avec l'ATC ont été également étudiés. Enfin, une revue exhaustive des différentes études d'ATC concernant l'induction de tolérance chez les humains et les larges animaux a été faite. Un premier modèle préclinique expérimental d'ATC a été élaboré chez le porcelet nouveau-né. Des études ultérieures ont par suite étudié les agents immunosuppresseurs ainsi que le régime de conditionnement avec l'administration de cyclosporine A., des thymo-globulines de lapin anti-porc et du mycophénolate mofétil. Un protocole d'induction de tolérance pour l'ATC chez les porcelets nouveau-nés a été rédigé et l'expérimentation sera réalisée courant 2014-2015. Si la tolérance d'ATC spécifique du donneur pourra être induite avec notre protocole, nous allons par la suite élaborer un protocole d'induction de tolérance et un programme d'allogreffe de main applicable chez les nouveau-nés humains / This present research is devoted to the exploration of performing vascularized composite allografts as a treatment for severe congenital hand or face anomalies in neonates or very young infants. The bibliographic studies at first revised the discovery and mechanisms of neonatal tolerance in mice, as well as in utero hematopoietic stem cells transplantation in large-animal models and human fetuses. Then the properties of human neonatal immune system were described; and the non-myeloablative or non-toxic conditioning regimens for solid organ transplant tolerance induction were also studied, in order to give the clue to a applicable conditioning regimen for tolerance induction in neonates. The potent thymus and vascularized bone marrow transplantation in neonatal VCA were considered as advantages. Finally, the researches concerning tolerance induction for VCA in large animal models and in human patients were reviewed. ln experimental studies, the preclinical VCA was firstly established in neonatal swines. Subsequent experiments thus studied the immunosuppressive agents, as well as conditioning regimen, including the administration of cyclosporine A, rabbit anti-pig thymocyte globulin and mycophenolate mofetil for VCA in pig neonates. The findings in these experiments were then concluded. Based on these finding, a general tolerance induction protocol for VCA in neonatal swines was designed and experiment will be performed in year 2014-2015. lf donor-specific tolerance for VCA could be induced with present protocol, we will subsequently elaborate an applicable tolerance induction protocol and hand allotransplantation program in human newborn infants

Background: Arterial allografts are used as vascular conduits in the treatment of prosthetic graft infection. Immunosuppression decreases their rupture risk rate. However, immunosuppression can be unprofitable in florid infection. Previously, we confirmed inhibition of cell-mediated destruction of rat aortic grafts by delayed use of tacrolimus. In this work, we studied the influence of this protocol on the antibody-mediated rejection.