RESUMO
Despite the introduction of novel and more targeted immunosuppressive drugs, the long-term survival of kidney transplants has not improved satisfactorily. Early antigen-independent intragraft inflammation plays a critical role in the initiation of the alloimmune response and impacts long-term graft function. Complement activation is a key player both in ischemia/reperfusion injury (IRI) as well as in adaptive antigraft immune response after kidney transplantation. Since the alternative pathway (AP) amplifies complement activation regardless of the initiation pathways and renal IR injured cells undergo uncontrolled complement activation, we speculated whether selective blockade of AP could be a strategy for prolonging kidney graft survival. Here we showed that Balb/c kidneys transplanted in factor b deficient C57 mice underwent reduced IRI and diminished T cell-mediated rejection. In in vitro studies, we found that fb deficiency in T cells and dendritic cells conferred intrinsic impaired alloreactive/allostimulatory functions, respectively, both in direct and indirect pathways of alloantigen presentation. By administering anti-fB antibody to C57 wt recipients in the early post Balb/c kidney transplant phases, we documented that inhibition of AP during both ischemia/reperfusion and early adaptive immune response is necessary for prolonging graft survival. These findings may have implication for the use of AP inhibitors in clinical kidney transplantation.
Assuntos
Ativação do Complemento/imunologia , Fator B do Complemento/deficiência , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Transplante de Rim/efeitos adversos , Traumatismo por Reperfusão/prevenção & controle , Linfócitos T/imunologia , Aloenxertos , Animais , Fator B do Complemento/genética , Rejeição de Enxerto/etiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Traumatismo por Reperfusão/etiologiaRESUMO
Ex vivo gene transfer to the graft before transplantation is an attractive option for circumventing systemic side effects of chronic antirejection therapy. Gene delivery of the immunomodulatory protein cytotoxic T-lymphocyte-associated protein 4-immunoglobulin (CTLA4-Ig) prevented chronic kidney rejection in a rat model of allotransplantation without the need for systemic immunosuppression. Here we generated adeno-associated virus type 2 (AAV2) and AAV9 vectors encoding for LEA29Y, an optimized version of CTLA4-Ig. Both LEA29Y vectors were equally efficient for reducing T-cell proliferation in vitro. Serotype 9 was chosen for in vivo experiments owing to a lower frequency of preformed antibodies against the AAV9 capsid in 16 non-human primate tested sera. AAV9-LEA29Y was able to transduce the kidney of non-human primates in an autotransplantation model. Expression of LEA29Y mRNA by renal cells translated into the production of the corresponding protein, which was confined to the graft but not detected in serum. Results in non-human primates represent a step forward in maintaining the portability of this strategy into clinics.
Assuntos
Abatacepte/genética , Dependovirus/genética , Terapia Genética/métodos , Rejeição de Enxerto/terapia , Transplante de Rim/efeitos adversos , Abatacepte/metabolismo , Animais , Linhagem Celular Tumoral , Vetores Genéticos/genética , Rejeição de Enxerto/etiologia , Células HEK293 , Humanos , Macaca fascicularis , Masculino , Ratos , Ratos Endogâmicos Lew , Linfócitos T/imunologia , Transplante Autólogo/efeitos adversosRESUMO
AIMS: To develop and validate a model to simulate progression of diabetic kidney disease (DKD) from early onset until end-stage renal disease (ESRD), and to assess the effect of renin-angiotensin system (RAS) intervention in early, intermediate and advanced stages of DKD. METHODS: We used data from the BENEDICT, IRMA-2, RENAAL and IDNT trials that assessed effects of RAS intervention in patients with type 2 diabetes. We built a model with discrete disease stages based on albuminuria and estimated glomerular filtration rate (eGFR). Using survival analyses, we assessed the effect of RAS intervention on delaying ESRD in early [eGFR>60 ml/min/1.73 m(2) and albumin:creatinine ratio (ACR) <30 mg/g], intermediate (eGFR 30-60 ml/min/1.73 m(2) or ACR 30-300 mg/g) and advanced (eGFR <30 ml/min/1.73 m(2) or ACR >300 mg/g) stages of DKD for patients in different age groups. RESULTS: For patients at early, intermediate and advanced stage of disease, whose mean age was 60 years and who received placebo, the median time to ESRD was 21.4, 10.8 and 4.7 years, respectively. RAS intervention delayed the predicted time to ESRD by 4.2, 3.6 and 1.4 years, respectively. The benefit of early RAS intervention was more pronounced in younger patients; for example, for patients with a mean age of 45 years, RAS intervention at early, intermediate or advanced stage delayed ESRD by 5.9, 4.0 and 1.1 years versus placebo. CONCLUSIONS: RAS intervention early in the course of proteinuric DKD is more beneficial than late intervention in delaying ESRD.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/tratamento farmacológico , Falência Renal Crônica/prevenção & controle , Tempo para o Tratamento , Fatores Etários , Idoso , Albuminas/análise , Albuminúria/complicações , Creatinina/análise , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/patologia , Progressão da Doença , Feminino , Taxa de Filtração Glomerular , Humanos , Falência Renal Crônica/etiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sistema Renina-Angiotensina/efeitos dos fármacos , Fatores de Risco , Análise de Sobrevida , Fatores de TempoRESUMO
Ischemia/reperfusion (I/R) injury is a major determinant of graft survival in kidney transplantation. Survivin, an inhibitor of apoptosis that participates in the control of mitosis and cell cycle progression, has been implicated in renal protection and repair after I/R injury; however, no study has been performed in the transplant setting. We investigated the role of survivin in modulating posttransplant I/R injury in syngeneic and allogeneic kidney grafts, and studied whether protection from I/R injury impacted on the recipient immune system, on chronic allograft nephropathy and rejection. We used genetically engineered mice with survivin haploinsufficiency and WT mice in which survivin over-expression was induced by gene-delivery. Survivin haploinsufficiency in syngeneic grafts was associated with exuberant I/R tissue injury, which triggered inflammation eventually resulting in graft loss. Conversely, survivin over-expression in the grafts minimized I/R injury and dysfunction in syngeneic grafts and in a clinically relevant fully MHC-mismatched allogeneic combination. In the latter, survivin over-expression translated into limited anti-donor adaptive immune response and less long-term allograft injury with protection from renal parenchymal damage. Our data support survivin over-expression in the graft as a novel target for protocols aimed at limiting tissue damage at the time of transplant ultimately modulating the recipient immune system.
Assuntos
Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/fisiologia , Inflamação/prevenção & controle , Proteínas Inibidoras de Apoptose/fisiologia , Transplante de Rim/efeitos adversos , Traumatismo por Reperfusão/prevenção & controle , Proteínas Repressoras/fisiologia , Animais , Apoptose , Proliferação de Células , Feminino , Técnicas de Transferência de Genes , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Inflamação/etiologia , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Survivina , Doadores de Tecidos , Transplante HomólogoRESUMO
Hemolytic uremic syndrome (HUS) is a disease of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. About 90% of cases are secondary to infections by Escherichia coli strains producing Shiga-like toxins (STEC-HUS), while 10% are associated with mutations in genes encoding proteins of complement system (aHUS). We describe two patients with a clinical history of STEC-HUS, who developed end-stage renal disease (ESRD) soon after disease onset. They received a kidney transplant but lost the graft for HUS recurrence, a complication more commonly observed in aHUS. Before planning a second renal transplantation, the two patients underwent genetic screening for aHUS-associated mutations that revealed the presence of a heterozygous CFI mutation in patient #1 and a heterozygous MCP mutation in patient #2, and also in her mother who donated the kidney. This finding argues that the two cases originally diagnosed as STEC-HUS had indeed aHUS triggered by STEC infection on a genetic background of impaired complement regulation. Complement gene sequencing should be performed before kidney transplantation in patients who developed ESRD following STEC-HUS since they may be undiagnosed cases of aHUS, at risk of posttransplant recurrence. Furthermore, genetic analysis of donors is mandatory before living-related transplantation to exclude carriers of HUS-predisposing mutations.
Assuntos
Fator I do Complemento/genética , Infecções por Escherichia coli/complicações , Síndrome Hemolítico-Urêmica/complicações , Falência Renal Crônica/etiologia , Proteína Cofatora de Membrana/genética , Mutação/genética , Adulto , Estudos de Casos e Controles , Primers do DNA/química , Primers do DNA/genética , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Feminino , Testes Genéticos , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/etiologia , Síndrome Hemolítico-Urêmica/genética , Síndrome Hemolítico-Urêmica/microbiologia , Heterozigoto , Humanos , Falência Renal Crônica/patologia , Falência Renal Crônica/terapia , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Linhagem , Prognóstico , Recidiva , Fatores de Risco , Escherichia coli Shiga Toxigênica , Trombocitopenia/complicações , Trombocitopenia/genética , Trombocitopenia/microbiologia , Adulto JovemRESUMO
BACKGROUND: Atypical hemolytic-uremic syndrome is a genetic, life-threatening, chronic disease of complement-mediated thrombotic microangiopathy. Plasma exchange or infusion may transiently maintain normal levels of hematologic measures but does not treat the underlying systemic disease. METHODS: We conducted two prospective phase 2 trials in which patients with atypical hemolytic-uremic syndrome who were 12 years of age or older received eculizumab for 26 weeks and during long-term extension phases. Patients with low platelet counts and renal damage (in trial 1) and those with renal damage but no decrease in the platelet count of more than 25% for at least 8 weeks during plasma exchange or infusion (in trial 2) were recruited. The primary end points included a change in the platelet count (in trial 1) and thrombotic microangiopathy event-free status (no decrease in the platelet count of >25%, no plasma exchange or infusion, and no initiation of dialysis) (in trial 2). RESULTS: A total of 37 patients (17 in trial 1 and 20 in trial 2) received eculizumab for a median of 64 and 62 weeks, respectively. Eculizumab resulted in increases in the platelet count; in trial 1, the mean increase in the count from baseline to week 26 was 73×10(9) per liter (P<0.001). In trial 2, 80% of the patients had thrombotic microangiopathy event-free status. Eculizumab was associated with significant improvement in all secondary end points, with continuous, time-dependent increases in the estimated glomerular filtration rate (GFR). In trial 1, dialysis was discontinued in 4 of 5 patients. Earlier intervention with eculizumab was associated with significantly greater improvement in the estimated GFR. Eculizumab was also associated with improvement in health-related quality of life. No cumulative toxicity of therapy or serious infection-related adverse events, including meningococcal infections, were observed through the extension period. CONCLUSIONS: Eculizumab inhibited complement-mediated thrombotic microangiopathy and was associated with significant time-dependent improvement in renal function in patients with atypical hemolytic-uremic syndrome. (Funded by Alexion Pharmaceuticals; C08-002 ClinicalTrials.gov numbers, NCT00844545 [adults] and NCT00844844 [adolescents]; C08-003 ClinicalTrials.gov numbers, NCT00838513 [adults] and NCT00844428 [adolescents]).
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Complemento C5/antagonistas & inibidores , Síndrome Hemolítico-Urêmica/tratamento farmacológico , Microangiopatias Trombóticas/prevenção & controle , Adolescente , Adulto , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/sangue , Anticorpos Monoclonais Humanizados/farmacocinética , Terapia Combinada , Feminino , Síndrome Hemolítico-Urêmica/sangue , Síndrome Hemolítico-Urêmica/genética , Síndrome Hemolítico-Urêmica/terapia , Humanos , Nefropatias/tratamento farmacológico , Nefropatias/etiologia , Masculino , Pessoa de Meia-Idade , Mutação , Troca Plasmática , Contagem de Plaquetas , Qualidade de Vida , Adulto JovemRESUMO
Focal segmental glomerulosclerosis (FSGS) is a glomerular disease characterized by proteinuria, frequent progression to end-stage renal disease, and recurrence after kidney transplantation in â¼25% of patients, which negatively impacts long-term allograft survival. Experimental studies suggest that abnormalities in T and, possibly, B cells may represent one initial pathogenic trigger, leading to podocyte injury and progressive loss. New data also support the existence of circulating permeability factors able to damage the podocytes, but no single molecule has been consistently identified as the causal pathogenic element in FSGS recurrence. Unfortunately, major progress from mechanistic studies has not translated into substantial advancements in patient treatment, with plasmapheresis (PP) and high doses of cyclosporine (CsA) remaining the mainstays of therapy. Despite consistent experimental and clinical evidence that treatment of proteinuria slows renal function decline in proteinuric nephropathies, maximal use of antiproteinuric agents such as renin angiotensin system antagonists is not routine in the management of FSGS recurrence. More recently, encouraging results have been reported with anti-CD20 depleting antibody rituximab, but further studies are needed to establish its safety/efficacy profile.
Assuntos
Glomerulosclerose Segmentar e Focal/fisiopatologia , Glomerulosclerose Segmentar e Focal/terapia , Transplante de Rim/métodos , Nefrologia/tendências , Animais , Anticorpos Monoclonais Murinos/farmacologia , Biópsia , Ciclosporina/farmacologia , Sobrevivência de Enxerto , Humanos , Nefrologia/métodos , Podócitos/citologia , Proteinúria/diagnóstico , Ratos , Recidiva , Sistema Renina-Angiotensina , RituximabRESUMO
Mesenchymal stem cells (MSCs) of bone marrow origin appear to be an attractive candidate for cell-based therapies. However, the major barrier to the effective implementation of MSC-based therapies is the lack of specific homing of exogenously infused cells and overall the inability to drive them to the diseased or damaged tissue. In order to circumvent these limitations, we developed a preconditioning strategy to optimize MSC migration efficiency and potentiate their beneficial effect at the site of injury. Initially, we screened different molecules by using an in vitro injury-migration setting, and subsequently, we evaluated the effectiveness of the different strategies in mice with acute kidney injury (AKI). Our results showed that preconditioning of MSCs with IGF-1 before infusion improved cell migration capacity and restored normal renal function after AKI. The present study demonstrates that promoting migration of MSCs could increase their therapeutic potential and indicates a new therapeutic paradigm for organ repair.
Assuntos
Injúria Renal Aguda/terapia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Injúria Renal Aguda/patologia , Animais , Células da Medula Óssea/citologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Fator Neurotrófico Derivado de Linhagem de Célula Glial/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores CXCR4/metabolismo , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Multipotent mesenchymal stromal cells (MSC) have recently emerged as promising candidates for cell-based immunotherapy in solid-organ transplantation. However, optimal conditions and settings for fully harnessing MSC tolerogenic properties need to be defined. We recently reported that autologous MSC given posttransplant in kidney transplant patients was associated with transient renal insufficiency associated with intragraft recruitment of neutrophils and complement C3 deposition. Here, we moved back to a murine kidney transplant model with the aim to define the best timing of MSC infusion capable of promoting immune tolerance without negative effects on early graft function. We also investigated the mechanisms of the immunomodulatory and/or proinflammatory activities of MSC according to whether cells were given before or after transplant. Posttransplant MSC infusion in mice caused premature graft dysfunction and failed to prolong graft survival. In this setting, infused MSC localized mainly into the graft and associated with neutrophils and complement C3 deposition. By contrast, pretransplant MSC infusion induced a significant prolongation of kidney graft survival by a Treg-dependent mechanism. MSC-infused pretransplant localized into lymphoid organs where they promoted early expansion of Tregs. Thus, pretransplant MSC infusion may be a useful approach to fully exploit their immunomodulatory properties in kidney transplantation.
Assuntos
Transplante de Rim/imunologia , Células-Tronco Mesenquimais/imunologia , Animais , Sobrevivência de Enxerto , Imuno-Histoquímica , Imunoterapia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Dendritic cells (DCs) are the most potent antigen-presenting cells and play a crucial role by modulating the T cell immune response against infective agents, tumour antigens and alloantigens. The current study shows that differentiating bone marrow (BM)-derived DCs but not fully differentiated DCs are targets of erythropoietin (EPO). Indeed, DCs emerging from rat bone marrow, but not splenic DCs, express the EPO receptor (Epo-R) and respond to EPO stimulation displaying a more activated phenotype with increased CD86, CD40 and interleukin (IL)-12 expression levels and a higher allostimulatory capacity on T cells than untreated DCs. Moreover, results here presented show that EPO up-regulates Toll-like receptor (TLR)-4 in differentiating DCs rendering these cells more sensitive to stimulation by the TLR-4 ligand lipopolysaccharide (LPS). Indeed, DCs treated with EPO and then stimulated by LPS were strongly allostimulatory and expressed CCR7, CD86, CD40, IL-12 and IL-23 at higher levels than those observed in DCs stimulated with LPS alone. It is tempting to speculate that EPO could act as an additional danger signal in concert with TLR-4 engagement. Thus, EPO, beyond its erythropoietic and cytoprotective effects, turns out to be an immune modulator.
Assuntos
Células Dendríticas/imunologia , Eritropoetina/análogos & derivados , Fatores Imunológicos , Animais , Antígeno B7-2/biossíntese , Western Blotting , Células da Medula Óssea/metabolismo , Antígenos CD40/biossíntese , Diferenciação Celular , Darbepoetina alfa , Células Dendríticas/metabolismo , Eritropoetina/imunologia , Eritropoetina/metabolismo , Eritropoetina/farmacologia , Fatores Imunológicos/metabolismo , Fatores Imunológicos/farmacologia , Interleucina-12/biossíntese , Interleucina-23/biossíntese , Lipopolissacarídeos/imunologia , Reação em Cadeia da Polimerase , Ratos , Ratos Endogâmicos BN , Receptores CCR7/biossíntese , Receptores da Eritropoetina/genética , Receptores da Eritropoetina/metabolismo , Receptor 4 Toll-Like/biossíntese , Receptor 4 Toll-Like/genéticaRESUMO
Thrombotic microangiopathy (TMA) is a severe complication of kidney transplantation that often causes graft failure. TMA may occur de novo, often triggered by immunosuppressive drugs and acute antibody-mediated rejection, or recur in patients with previous history of hemolytic uremic syndrome (HUS). Recurrent TMA is very rare in patients who had developed end-stage renal failure following HUS caused by Shiga-toxin producing E. scherichia coli, whereas disease recurrence is common in patients with atypical HUS (aHUS). The underlying genetic defect greatly impacts the risk of posttransplant recurrence in aHUS. Indeed recurrence is almost the rule in patients with mutations in genes encoding factor H or factor I, whereas patients with a mutation in membrane-cofactor-protein gene have a good transplant outcome. Prophylactic and therapeutic options for posttransplant TMA, including plasma therapy, combined kidney and liver transplantation and targeted complement inhibitors are discussed in this review.
Assuntos
Transplante de Rim/efeitos adversos , Microangiopatias Trombóticas/epidemiologia , Autoanticorpos/genética , Transfusão de Componentes Sanguíneos , Criança , Fator H do Complemento/genética , Via Alternativa do Complemento/genética , Proteínas do Sistema Complemento/genética , Infecções por Escherichia coli/epidemiologia , Fibrinogênio/genética , Síndrome Hemolítico-Urêmica/epidemiologia , Síndrome Hemolítico-Urêmica/genética , Humanos , Transplante de Fígado/efeitos adversos , Mutação , Plasma , Complicações Pós-Operatórias/epidemiologia , Recidiva , Falha de Tratamento , Resultado do TratamentoAssuntos
Glomerulonefrite Membranosa , Adulto , Anticorpos Monoclonais , Anticorpos Monoclonais Murinos , Feminino , Glomerulonefrite Membranosa/diagnóstico , Glomerulonefrite Membranosa/tratamento farmacológico , Glomerulonefrite Membranosa/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , RituximabRESUMO
ADAMTS13 is a plasma metalloprotease that regulates the size of the von Willebrand factor (VWF) multimers. Genetic or acquired deficiency of ADAMTS13 causes thrombotic thrombocytopenic purpura (TTP) in humans. Plasma infusion is the treatment of choice for patients with congenital ADAMTS13 deficiency. However, this practice exposes patients to the risk of infections, allergies and fluid volume overload. The search for alternative treatments is required. Here, we tested the ability of systemically administered adenovirus encoding human ADAMTS13 to restore the deficient protein in the circulation of Adamts13(-/-) mice. Injection of the adenovirus efficiently transduced the liver, kidney, lung, heart and spleen, resulting in the secretion of ADAMTS13 into plasma. A reduced area of thrombi was observed when blood from Ad-ADAMTS13-treated mice was perfused over a collagen-coated surface in a parallel plate flow chamber compared with blood of Ad-betaGal-treated controls. The secreted ADAMTS13 protein was functionally active even after 2 months from injection. The data provide the proof of principle for developing a novel therapy for the correction of ADAMTS13 deficiency in patients with hereditary TTP.
Assuntos
Adenoviridae/genética , Terapia Genética/métodos , Vetores Genéticos , Metaloendopeptidases/genética , Púrpura Trombocitopênica Trombótica/terapia , Proteína ADAMTS13 , Animais , Metaloendopeptidases/sangue , Metaloendopeptidases/deficiência , Camundongos , Camundongos Knockout , Púrpura Trombocitopênica Trombótica/sangue , Transdução GenéticaRESUMO
BACKGROUND: Patients with diabetic nephropathy are at high risk for further progressive renal function loss. Treatments that decrease albuminuria have been linked with renal and cardiovascular protection. However, even when taking optimal treatment, residual renal and cardiovascular risk remains high which correlates with the magnitude of residual albuminuria. Use of vitamin D receptor activators, such as calcitriol and paricalcitol, is associated with improved sur- vival. A small study with paricalcitol showed reductions in albuminuria. The VITAL study tests the hypothesis whether paricalcitol persistently reduces albuminuria in diabetic subjects already receiving angiotensin-converting enzyme inhibitor (ACEI) and/or angiotensin receptor blocker (ARB) therapy. METHODS: Randomization in this double-blind trial is equal allocation to paricalcitol 1 micro/day, 2 microg/day, or placebo. Inclusion criteria include: a diagnosis of type 2 diabetes, urinary albumin/creatinine ratio (UACR) between 100-3,000 mg/g, estimated glomerular filtration rate (eGFR) between 15-90 ml/min/1.73 m(2), serum calcium <9.8 mg/dl, and parathyroid hormone (PTH) between 35-500 pg/ml. RESULTS: Baseline characteristics of the 281 subjects are: 69% men, mean age 64.9 +/- 10.4 years, eGFR 40.7 +/- 16.7 ml/min, median UACR (interquartile range) 612.3 mg/g (281-1,181 mg/g) and PTH 98.4 +/- 63.8 pg/ml. CONCLUSION: This trial will be the first clinical test of the hypothesis that paricalcitol possesses pleiotropic effects and can modulate albuminuria in the setting of ACEI and/or ARB therapy. Results will have important clinical implications and are expected in November 2009.
Assuntos
Albuminúria/tratamento farmacológico , Ergocalciferóis/uso terapêutico , Receptores de Calcitriol/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Type 1 diabetes is associated with a progressive loss of beta cells and pancreatic islet transplantation could represent a cure for this disease. Herein we explored whether transplantation of bone marrow-derived mesenchymal stem cells (MSCs) allowed a reduced number of pancreatic islets to improve glycemic control in diabetic rats, by promoting islet vascularization. We transplanted 2000 syngenic islets alone or in combination with MSCs (10(6) cells) under the kidney capsules of diabetic Lewis rats. Animals transplanted with 2000 islets never reached normoglycemia. In contrast, rats transplanted with 2000 islets plus MSCs, showed a gradual fall in glycemia after transplantation, with normoglycemia maintained until killing. Comparable glycemic control was obtained with transplantation of 3000 islets alone. The MSC preparation used for in vivo experiments expressed high levels of vascular endothelial growth factor (VEGF(165)) and, at less extent, VEGF(189), as evaluated by reverse transcriptase polymerase chain reaction (RT-PCR). In transplanted animals, vascularization was quantified by morphometric analysis of islet grafts with anti-RECA and anti-insulin antibodies. MSCs were stained with PKH-26. Mean capillary density was 1002 +/- 55 capillaries/mm(2) in islets transplanted alone. Co-infusion of MSCs with islets significantly increased the number of capillaries to 1459 +/- 66 capillaries/mm(2). In conclusion, our study indicated that co-transplantation of MSCs with pancreatic islets improved islet graft function by promoting graft vascularization.
Assuntos
Glicemia/metabolismo , Diabetes Mellitus Experimental/cirurgia , Transplante das Ilhotas Pancreáticas/métodos , Transplante das Ilhotas Pancreáticas/fisiologia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Primers do DNA , Masculino , Neovascularização Fisiológica , Ratos , Ratos Endogâmicos Lew , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ensaio de Cápsula Sub-Renal , Transcrição GênicaRESUMO
OBJECTIVES: Daily nocturnal hemodialysis (NHD) has been proposed as a valuable strategy to improve outcomes for patients on conventional hemodialysis (CHD), but it is burdened by high costs and logistic issues. Thrice NHD might represent a more affordable approach to improve hemodialysis patient outcome. METHODS: Here we retrospectively analyzed the data on blood pressure, body weight, and hematochemical parameters in a cohort of 7 patients (mean age 50.4-/+11.0 years, duration of CHD 14.3-/+11.5 years) who registered in the NHD program at the dialysis unit of Ospedali Riuniti, Bergamo, Italy. Data for the 2 first years of NHD were compared with those of the last year on CHD. RESULTS: At 2 years after start of NHD, we found a significant decrease in systolic (149.4-/+16.6 vs. 128.4+/-26.0 mm Hg, p<0.001) and diastolic (87.7-/+11.1 vs. 79.6-/+16.7 mm Hg, p<0.05) blood pressure, along with a significant reduction in the use of per-patient antihypertensive agents (1.17-/+1.19 vs. 0.47-/+0.89, p<0.05 and an increase in dry body weight (61.4-/+21.8 vs. 67.1-/+16.4 kg, p<0.001). Moreover, patients had a significant reduction in phosphate levels (6.2-/+2.4 vs. 5.4-/+3.0 mg/dL, p<0.01). The procedure was safe and well tolerated and did not require extra cost for ad hoc facilities. CONCLUSION: NHD is an effective approach to optimize chronic dialysis therapy.
Assuntos
Falência Renal Crônica/terapia , Diálise Renal/métodos , Adulto , Anti-Hipertensivos/uso terapêutico , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal , Cálcio/sangue , Feminino , Unidades Hospitalares de Hemodiálise , Humanos , Itália , Falência Renal Crônica/sangue , Falência Renal Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fosfatos/sangue , Avaliação de Programas e Projetos de Saúde , Diálise Renal/efeitos adversos , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
A 12-month-old boy and his 16-year-old aunt became acutely ill 6 months apart and were diagnosed to have atypical hemolytic uremic syndrome (aHUS). Genetic analysis revealed heterozygous R1215Q mutation in complement factor H (CFH) in both patients. The same mutation was found in five healthy adult relatives indicating incomplete penetrance of the disease. The patients developed terminal renal failure and experienced reversible neurological symptoms in spite of plasma exchange (PE) therapy. In both cases, liver-kidney transplantation was successfully performed 6 months after the onset of the disease. To minimize complement activation and prevent thrombotic microangiopathy or overt thrombotic events due to the malfunctioning CFH, extensive PE with fresh frozen plasma was performed pre- and perioperatively and anticoagulation was started a few hours after the operation. No circulatory complications appeared and all four grafts started to function immediately. Also, no recurrence or other major clinical setbacks have appeared during the postoperative follow-up (15 and 9 months) and the grafts show excellent function. While more experience is needed, it seems that liver-kidney transplantation combined with pre- and perioperative PE is a rational option in the management of patients with aHUS caused by CFH mutation.