RESUMO
BENEFIT and BENEFIT-EXT were phase III studies of cytotoxic T-cell crossmatch-negative kidney transplant recipients randomized to belatacept more intense (MI)-based, belatacept less intense (LI)-based, or cyclosporine-based immunosuppression. Following study completion, presence/absence of HLA-specific antibodies was determined centrally via solid-phase flow cytometry screening. Stored sera from anti-HLA-positive patients were further tested with a single-antigen bead assay to determine antibody specificities, presence/absence of donor-specific antibodies (DSAs), and mean fluorescent intensity (MFI) of any DSAs present. The effect of belatacept-based and cyclosporine-based immunosuppression on MFI was explored post hoc in patients with preexisting DSAs enrolled to BENEFIT and BENEFIT-EXT. In BENEFIT, preexisting DSAs were detected in 4.6%, 4.9%, and 6.3% of belatacept MI-treated, belatacept LI-treated, and cyclosporine-treated patients, respectively. The corresponding values in BENEFIT-EXT were 6.0%, 5.7%, and 9.2%. In both studies, most preexisting DSAs were of class I specificity. Over the first 24 months posttransplant, a greater proportion of preexisting DSAs in belatacept-treated versus cyclosporine-treated patients exhibited decreases or no change in MFI. MFI decline was more apparent with belatacept MI-based versus belatacept LI-based immunosuppression in both studies and more pronounced in BENEFIT-EXT versus BENEFIT. Although derived post hoc, these data suggest that belatacept-based immunosuppression decreases preexisting DSAs more effectively than cyclosporine-based immunosuppression.
Assuntos
Abatacepte/uso terapêutico , Ciclosporina/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Isoanticorpos/sangue , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Feminino , Seguimentos , Rejeição de Enxerto/sangue , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Humanos , Tolerância Imunológica/imunologia , Imunossupressores/uso terapêutico , Agências Internacionais , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Fatores de Risco , TransplantadosRESUMO
Donor-specific antibodies (DSAs) are associated with an increased risk of antibody-mediated rejection and graft failure. In BENEFIT and BENEFIT-EXT, kidney-transplant recipients were randomized to receive belatacept more intense (MI)-based, belatacept less intense (LI)-based, or cyclosporine-based immunosuppression for up to 7 years (84 months). The presence/absence of HLA-specific antibodies was determined at baseline, at months 6, 12, 24, 36, 48, 60, and 84, and at the time of clinically suspected episodes of acute rejection, using solid-phase flow-cytometry screening. Samples from anti-HLA-positive patients were further tested with a single-antigen bead assay to determine antibody specificities, presence/absence of DSAs, and mean fluorescence intensity (MFI) of any DSAs present. In BENEFIT, de novo DSAs developed in 1.4%, 3.5%, and 12.1% of belatacept MI-treated, belatacept LI-treated, and cyclosporine-treated patients, respectively. The corresponding values in BENEFIT-EXT were 3.8%, 1.1%, and 11.2%. Per Kaplan-Meier analysis, de novo DSA incidence was significantly lower in belatacept-treated vs cyclosporine-treated patients over 7 years in both studies (P < .01). In patients who developed de novo DSAs, belatacept-based immunosuppression was associated with numerically lower MFI vs cyclosporine-based immunosuppression. Although derived post hoc, these data suggest that belatacept-based immunosuppression suppresses de novo DSA development more effectively than cyclosporine-based immunosuppression.
Assuntos
Abatacepte/uso terapêutico , Ciclosporina/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Isoanticorpos/sangue , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Adulto , Feminino , Seguimentos , Rejeição de Enxerto/sangue , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Humanos , Tolerância Imunológica/imunologia , Imunossupressores/uso terapêutico , Agências Internacionais , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Fatores de Risco , TransplantadosRESUMO
In the phase II IM103-100 study, kidney transplant recipients were first randomized to belatacept more-intensive-based (n = 74), belatacept less-intensive-based (n = 71), or cyclosporine-based (n = 73) immunosuppression. At 3-6 months posttransplant, belatacept-treated patients were re-randomized to receive belatacept every 4 weeks (4-weekly, n = 62) or every 8 weeks (8-weekly, n = 60). Patients initially randomized to cyclosporine continued to receive cyclosporine-based immunosuppression. Cumulative rates of biopsy-proven acute rejection (BPAR) from first randomization to year 10 were 22.8%, 37.0%, and 25.8% for belatacept more-intensive, belatacept less-intensive, and cyclosporine, respectively (belatacept more-intensive vs cyclosporine: hazard ratio [HR] = 0.95; 95% confidence interval [CI] 0.47-1.92; P = .89; belatacept less-intensive vs cyclosporine: HR = 1.61; 95% CI 0.85-3.05; P = .15). Cumulative BPAR rates from second randomization to year 10 for belatacept 4-weekly, belatacept 8-weekly, and cyclosporine were 11.1%, 21.9%, and 13.9%, respectively (belatacept 4-weekly vs cyclosporine: HR = 1.06, 95% CI 0.35-3.17, P = .92; belatacept 8-weekly vs cyclosporine: HR = 2.00, 95% CI 0.75-5.35, P = .17). Renal function trends were estimated using a repeated-measures model. Estimated mean GFR values at year 10 for belatacept 4-weekly, belatacept 8-weekly, and cyclosporine were 67.0, 68.7, and 42.7 mL/min per 1.73 m2 , respectively (P<.001 for overall treatment effect). Although not statistically significant, rates of BPAR were 2-fold higher in patients administered belatacept every 8 weeks vs every 4 weeks.
Assuntos
Abatacepte/uso terapêutico , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/efeitos dos fármacos , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Complicações Pós-Operatórias/mortalidade , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Humanos , Imunossupressores/uso terapêutico , Testes de Função Renal , Prognóstico , Fatores de Risco , Taxa de SobrevidaRESUMO
While most human T cells express the CD28 costimulatory molecule constitutively, it is well known that age, inflammation, and viral infection can drive the generation of CD28null T cells. In vitro studies have demonstrated that CD28null cell effector function is not impacted by the presence of the CD28 costimulation blocker belatacept. As such, a prevailing hypothesis suggests that CD28null cells may precipitate costimulation blockade-resistant rejection. However, CD28+ cells possess more proliferative and multifunctional capacity, factors that may increase their ability to successfully mediate rejection. Here, we performed a retrospective immunophenotypic analysis of adult renal transplant recipients who experienced acute rejection on belatacept treatment as compared to those who did not. Intriguingly, our findings suggest that patients possessing higher frequency of CD28+ CD4+ TEM prior to transplant were more likely to experience acute rejection following treatment with a belatacept-based immunosuppressive regimen. Mechanistically, CD28+ CD4+ TEM contained significantly more IL-2 producers. In contrast, CD28null CD4+ TEM isolated from stable belatacept-treated patients exhibited higher expression of the 2B4 coinhibitory molecule as compared to those isolated from patients who rejected. These data raise the possibility that pretransplant frequencies of CD28+ CD4+ TEM could be used as a biomarker to predict risk of rejection following treatment with belatacept.
Assuntos
Abatacepte/farmacologia , Antígenos CD28/imunologia , Linfócitos T CD8-Positivos/imunologia , Resistência a Medicamentos/imunologia , Rejeição de Enxerto/imunologia , Memória Imunológica/imunologia , Transplante de Rim/efeitos adversos , Adulto , Idoso , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Estudos de Casos e Controles , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Humanos , Imunossupressores/farmacologia , Falência Renal Crônica/cirurgia , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Estudos RetrospectivosRESUMO
Recently, newer therapies have been designed to more specifically target rejection in an effort to improve efficacy and limit unwanted toxicity. Belatacept, a CD28-CD80/86 specific reagent, is associated with superior patient survival and graft function compared with traditional therapy, but its adoption as a mainstay immunosuppressive therapy has been tempered by increased rejection rates. It is essential that the underlying mechanisms associated with this rejection be elucidated before belatacept is more widely used. To that end, we designed a study in a nonhuman primate kidney transplant model where animals were treated with either a belatacept- or a tacrolimus-based immunosuppressive regimen. Interestingly, we found that elevated pretransplant frequencies of CD28+ CD8+ TEMRA cells are associated with rejection on belatacept but not tacrolimus treatment. Further analysis showed that the CD28+ CD8+ TEMRA cells rapidly lose CD28 expression after transplant in those animals that go on to reject with the allograft infiltrate being predominantly CD28- . These data suggest that CD28+ memory T cells may be resistant to belatacept, capable of further differentiation including loss of CD28 expression while maintaining effector function. The unique signaling requirements of CD28+ memory T cells provide opportunities for the development of targeted therapies, which may synergize with belatacept to prevent costimulation-independent rejection.
Assuntos
Abatacepte/farmacologia , Antígenos CD28/imunologia , Linfócitos T CD8-Positivos/imunologia , Resistência a Medicamentos/imunologia , Rejeição de Enxerto/imunologia , Memória Imunológica/imunologia , Transplante de Rim/efeitos adversos , Animais , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Imunossupressores/farmacologia , Falência Renal Crônica/cirurgia , Testes de Função Renal , Macaca mulatta , Complicações Pós-OperatóriasRESUMO
The intent of this National Institutes of Health-sponsored study was to compare a belatacept-based immunosuppressive regimen with a maintenance regimen of tacrolimus and mycophenolate. Nineteen primary, Epstein-Barr virus-immune renal transplant recipients with a negative cross-match were randomized to one of three groups. All patient groups received perioperative steroids and maintenance mycophenolate mofetil. Patients in groups 1 and 2 were induced with alemtuzumab and maintained on tacrolimus or belatacept, respectively. Patients in group 3 were induced with basiliximab, received 3 mo of tacrolimus, and maintained on belatacept. There was one death with a functioning allograft due to endocarditis (group 1). There were three graft losses due to vascular thrombosis (all group 2) and one graft loss due to glomerular disease (group 1). Biopsy-proven acute cellular rejection was more frequent in the belatacept-treated groups, with 10 treated episodes in seven participants compared with one episode in group 1; however, estimated GFR was similar between groups at week 52. There were no episodes of posttransplant lymphoproliferative disorder or opportunistic infections in any group. Protocol enrollment was halted prematurely because of a high rate of serious adverse events. Such negative outcomes pose challenges to clinical investigators, who ultimately must weigh the risks and benefits in randomized trials.
Assuntos
Abatacepte/uso terapêutico , Corticosteroides/uso terapêutico , Inibidores de Calcineurina/uso terapêutico , Imunossupressores/uso terapêutico , Transplante de Rim , Adolescente , Adulto , Idoso , Feminino , Taxa de Filtração Glomerular , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
Belatacept, a T cell costimulation blocker, demonstrated superior renal function, lower cardiovascular risk, and improved graft and patient survival in renal transplant recipients. Despite the potential benefits, adoption of belatacept has been limited in part due to concerns regarding higher rates and grades of acute rejection in clinical trials. Since July 2011, we have utilized belatacept-based immunosuppression regimens in clinical practice. In this retrospective analysis of 745 patients undergoing renal transplantation at our center, we compared patients treated with belatacept (n = 535) with a historical cohort receiving a tacrolimus-based protocol (n = 205). Patient and graft survival were equivalent for all groups. An increased rate of acute rejection was observed in an initial cohort treated with a protocol similar to the low-intensity regimen from the BENEFIT trial versus the historical tacrolimus group (50.5% vs. 20.5%). The addition of a transient course of tacrolimus reduced rejection rates to acceptable levels (16%). Treatment with belatacept was associated with superior estimated GFR (belatacept 63.8 mL/min vs. tacrolimus 46.2 mL/min at 4 years, p < 0.0001). There were no differences in serious infections including rates of cytomegalovirus or BK viremia. We describe the development of a costimulatory blockade-based strategy that ultimately allows renal transplant recipients to achieve calcineurin inhibitor-free immunosuppression.
Assuntos
Abatacepte/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Sobrevivência de Enxerto/efeitos dos fármacos , Isoanticorpos/imunologia , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Adulto , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Humanos , Imunossupressores/uso terapêutico , Isoanticorpos/efeitos dos fármacos , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Estudos Retrospectivos , Fatores de Risco , TransplantadosRESUMO
The advent of costimulation blockade provides the prospect for targeted therapy with improved graft survival in transplant patients. Perhaps the most effective costimulation blockade in experimental models is the use of reagents to block the CD40/CD154 pathway. Unfortunately, successful clinical translation of anti-CD154 therapy has not been achieved. In an attempt to develop an agent that is as effective as previous CD154 blocking antibodies but lacks the risk of thromboembolism, we evaluated the efficacy and safety of a novel anti-human CD154 domain antibody (dAb, BMS-986004). The anti-CD154 dAb effectively blocked CD40-CD154 interactions but lacked crystallizable fragment (Fc) binding activity and resultant platelet activation. In a nonhuman primate kidney transplant model, anti-CD154 dAb was safe and efficacious, significantly prolonging allograft survival without evidence of thromboembolism (Median survival time 103 days). The combination of anti-CD154 dAb and conventional immunosuppression synergized to effectively control allograft rejection (Median survival time 397 days). Furthermore, anti-CD154 dAb treatment increased the frequency of CD4+ CD25+ Foxp3+ regulatory T cells. This study demonstrates that the use of a novel anti-CD154 dAb that lacks Fc binding activity is safe without evidence of thromboembolism and is equally as potent as previous anti-CD154 agents at prolonging renal allograft survival in a nonhuman primate preclinical model.
Assuntos
Anticorpos Monoclonais/farmacologia , Ligante de CD40/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Imunoglobulina G/imunologia , Transplante de Rim/efeitos adversos , Animais , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/efeitos dos fármacos , Testes de Função Renal , Primatas , Fatores de Risco , Linfócitos T Reguladores/imunologia , Imunologia de TransplantesRESUMO
Although stable mixed-hematopoietic chimerism induces robust immune tolerance to solid organ allografts in mice, the translation of this strategy to large animal models and to patients has been challenging. We have previously shown that in MHC-matched nonhuman primates (NHPs), a busulfan plus combined belatacept and anti-CD154-based regimen could induce long-lived myeloid chimerism, but without T cell chimerism. In that setting, donor chimerism was eventually rejected, and tolerance to skin allografts was not achieved. Here, we describe an adaptation of this strategy, with the addition of low-dose total body irradiation to our conditioning regimen. This strategy has successfully induced multilineage hematopoietic chimerism in MHC-matched transplants that was stable for as long as 24 months posttransplant, the entire length of analysis. High-level T cell chimerism was achieved and associated with significant donor-specific prolongation of skin graft acceptance. However, we also observed significant infectious toxicities, prominently including cytomegalovirus (CMV) reactivation and end-organ disease in the setting of functional defects in anti-CMV T cell immunity. These results underscore the significant benefits that multilineage chimerism-induction approaches may represent to transplant patients as well as the inherent risks, and they emphasize the precision with which a clinically successful regimen will need to be formulated and then validated in NHP models.
Assuntos
Infecções por Citomegalovirus/complicações , Citomegalovirus/imunologia , Transplante de Pele , Linfócitos T/imunologia , Quimeras de Transplante/imunologia , Tolerância ao Transplante/imunologia , Ativação Viral/imunologia , Animais , Doenças Transmissíveis/etiologia , Doenças Transmissíveis/patologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas , Macaca mulatta , Condicionamento Pré-Transplante , Transplante HomólogoRESUMO
The phase III Belatacept Evaluation of Nephroprotection and Efficacy as First-Line Immunosuppression Trial-Extended Criteria Donors Trial (BENEFIT-EXT) study compared more or less intensive belatacept-based immunosuppression with cyclosporine (CsA)-based immunosuppression in recipients of extended criteria donor kidneys. In this post hoc analysis, patient outcomes were assessed according to donor kidney subtype. In total, 68.9% of patients received an expanded criteria donor kidney (United Network for Organ Sharing definition), 10.1% received a donation after cardiac death kidney, and 21.0% received a kidney with an anticipated cold ischemic time ≥24 h. Over 7 years, time to death or graft loss was similar between belatacept- and CsA-based immunosuppression, regardless of donor kidney subtype. In all three donor kidney cohorts, estimated mean GFR increased over months 1-84 for belatacept-based treatment but declined for CsA-based treatment. The estimated differences in GFR significantly favored each belatacept-based regimen versus the CsA-based regimen in the three subgroups (p < 0.0001 for overall treatment effect). No differences in the safety profile of belatacept were observed by donor kidney subtype.
Assuntos
Abatacepte/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Falência Renal Crônica/cirurgia , Transplante de Rim/métodos , Doadores de Tecidos , Feminino , Seguimentos , Taxa de Filtração Glomerular , Sobrevivência de Enxerto , Humanos , Imunossupressores/uso terapêutico , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , SegurançaRESUMO
Frailty is associated with inferior survival and increased resource requirements among kidney transplant candidates, but assessments are time-intensive and costly and require direct patient interaction. Waitlist hospitalization may be a proxy for patient fitness and could help those at risk of poor outcomes. We examined United States Renal Data System data from 51 111 adult end-stage renal disease patients with continuous Medicare coverage who were waitlisted for transplant from January 2000 to December 2011. Heavily admitted patients had higher subsequent resource requirements, increased waitlist mortality and decreased likelihood of transplant (death after listing: 1-7 days: hazard ratio [HR] 1.24, 95% confidence interval [CI] 1.20-1.28; 8-14 days: HR 1.49, 95% CI 1.42-1.56; ≥15 days: HR 2.07, 95% CI 1.99-2.15; vs. 0 days). Graft and recipient survival was inferior, with higher admissions, although survival benefit was preserved. A model including waitlist admissions alone performed better (C statistic 0.76, 95% CI 0.74-0.80) in predicting postlisting mortality than estimated posttransplant survival (C statistic 0.69, 95% CI 0.67-0.73). Although those with a heavy burden of admissions may still benefit from kidney transplant, less utility is derived from allografts placed in this population. Current kidney allocation policy, which is based in part on longevity matching, could be significantly improved by consideration of hospitalization records of transplant candidates.
Assuntos
Rejeição de Enxerto/mortalidade , Hospitalização/estatística & dados numéricos , Falência Renal Crônica/mortalidade , Transplante de Rim/mortalidade , Listas de Espera , Feminino , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Humanos , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
Two common polymorphisms in APOL1 (G1 and G2) are conserved in persons of African ancestry, and the presence of two polymorphisms (commonly referred to as risk variants) has been identified as a risk factor for chronic kidney disease and focal seg-mental glomerulosclerosis. In kidney transplantation, deceased donors with two APOL1 risk variants carry an increased risk of renal allograft failure in the recipient. An emerging question is whether these data should influence deceased donor assessment or be used to refine prediction of allograft survival. We present the first detailed report of two cases of recipient glomerular disease in the first year following transplant from a deceased donor later defined as carrying two APOL1 risk variants. A possible "second hit" predisposing to renal disease in these recipients is discussed, one with active cytomegalovirus infection concurrent with collapsing glomerulopathy and renal failure and the other with chronic, slowly healing wound infection and focal segmental glomeru-losclerosis but stable renal function. In retrospect, awareness of the donor APOL1 risk alleles would not have influenced donor selection and ultimately did not influence posttransplant management. These case reports inform further discussion of the value of APOL1 testing for deceased donors.
RESUMO
Costimulation blockade with the fusion protein belatacept provides a desirable side effect profile and improvement in renal function compared with calcineurin inhibition in renal transplantation. This comes at the cost of increased rates of early acute rejection. Blockade of the integrin molecule leukocyte function-associated antigen 1 (LFA-1) has been shown to be an effective adjuvant to costimulation blockade in a rigorous nonhuman primate (NHP) model of islet transplantation; therefore, we sought to test this combination in an NHP renal transplant model. Rhesus macaques received belatacept maintenance therapy with or without the addition of LFA-1 blockade, which was achieved using a murine-derived LFA-1-specific antibody TS1/22. Additional experiments were performed using chimeric rhesus IgG1 (TS1/22R1) or IgG4 (TS1/22R4) variants, each engineered to limit antibody clearance. Despite evidence of proper binding to the target molecule and impaired cellular egress from the intravascular space indicative of a therapeutic effect similar to prior islet studies, LFA-1 blockade failed to significantly prolong graft survival. Furthermore, evidence of impaired protective immunity against cytomegalovirus was observed. These data highlight the difficulties in translating treatment regimens between organ models and suggest that the primarily vascularized renal model is more robust with regard to belatacept-resistant rejection than the islet model.
Assuntos
Abatacepte/uso terapêutico , Modelos Animais de Doenças , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Falência Renal Crônica/imunologia , Transplante de Rim/efeitos adversos , Antígeno-1 Associado à Função Linfocitária/imunologia , Animais , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Memória Imunológica , Falência Renal Crônica/cirurgia , Testes de Função Renal , Antígeno-1 Associado à Função Linfocitária/administração & dosagem , Macaca mulatta , Transplante HomólogoRESUMO
INTRODUCTION: Ig deposits identified on renal biopsy samples by paraffin immunofluorescence that show negative staining by routine immunofluorescence on frozen tissue have become known as "masked" deposits. Membranous-like glomerulopathy with masked IgG kappa (κ) deposits is a recently recognized pattern of immune complex deposition characterized by masked deposits that show IgG κ restriction and are subepithelial and mesangial by electron microscopy. Based on the frequent presence of C3-only staining by routine immunofluorescence microscopy (IF), these cases could be misdiagnosed as C3 glomerulonephritis in the absence of paraffin immunofluorescence evaluation. METHODS: The clinicopathologic details of all cases of membranous-like glomerulopathy with masked IgG κ deposits diagnosed in our laboratory were included, beginning with the initial recognition of this entity in 2011 through the end of 2015. Inclusion was based on renal biopsy sample morphologic features including glomerular deposits that stain for IgG κ and have a staining intensity that is significantly brighter by paraffin IF than by routine IF on frozen tissue. RESULTS: This pattern of immune complex deposition has been seen in 41 patients in our laboratory over a 5-year period. The patients with these biopsy findings are most commonly young female individuals with a mean age of 27.5 years, with 88% being less than 40 years. All patients had proteinuria with a mean 24-hour urine protein of 3.5 g (range 0.5-12.8 years) and 35% with nephrotic-range proteinuria. Hematuria was present in 88% of patients, and 29% had elevated serum creatinine at presentation. Autoimmune serologic tests were positive in 55% of patients, with a weakly positive antinuclear antibody being most common. Despite this, only 1 patient (2%) fulfilled the diagnostic criteria for systemic lupus erythematosus. The outcome data were mixed, as some patients showed spontaneous remission and mild disease whereas others progressed to end-stage renal disease. There was no apparent correlation between the treatment used and outcome in this retrospective analysis. One patient underwent transplantation and developed biopsy-proven recurrence of disease in the graft 42 months posttransplantation. The etiology of this entity remains unknown. DISCUSSION: We provide an expanded case series detailing the clinicopathologic findings of patients with membranous-like glomerulopathy with masked IgG κ deposits. Patients are most commonly young female individuals <40 years of age and commonly have positive autoimmune serologic studies such as antinuclear antibody, although few carry a diagnosis of any well-defined autoimmune disease such as lupus. The outcome data were mixed, as some patients showed spontaneous remission and mild disease whereas others progressed to ESRD. There was no apparent correlation between the treatment used and outcome in this retrospective analysis.
RESUMO
Recent studies have shown that the quantity of donor-reactive memory T cells is an important factor in determining the relative heterologous immunity barrier posed during transplantation. Here, we hypothesized that the quality of T cell memory also potently influences the response to costimulation blockade-based immunosuppression. Using a murine skin graft model of CD8(+) memory T cell-mediated costimulation blockade resistance, we elicited donor-reactive memory T cells using three distinct types of pathogen infections. Strikingly, we observed differential efficacy of a costimulation and integrin blockade regimen based on the type of pathogen used to elicit the donor-reactive memory T cell response. Intriguingly, the most immunosuppression-sensitive memory T cell populations were composed primarily of central memory cells that possessed greater recall potential, exhibited a less differentiated phenotype, and contained more multi-cytokine producers. These data, therefore, demonstrate that the memory T cell barrier is dependent on the specific type of pathogen infection via which the donor-reactive memory T cells are elicited, and suggest that the immune stimulation history of a given transplant patient may profoundly influence the relative barrier posed by heterologous immunity during transplantation.
Assuntos
Bactérias/patogenicidade , Infecções Bacterianas/terapia , Linfócitos T CD8-Positivos/imunologia , Rejeição de Enxerto/terapia , Memória Imunológica/imunologia , Integrinas/antagonistas & inibidores , Transplante de Pele , Doadores de Tecidos , Animais , Infecções Bacterianas/etiologia , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Humanos , Terapia de Imunossupressão , Imunossupressores/uso terapêutico , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fatores de Risco , Transplante HomólogoRESUMO
Islet xenotransplantation is a potential treatment for diabetes without the limitations of tissue availability. Although successful experimentally, early islet loss remains substantial and attributed to an instant blood-mediated inflammatory reaction (IBMIR). This syndrome of islet destruction has been incompletely defined and characterization in pig-to-primate models has been hampered by logistical and statistical limitations of large animal studies. To further investigate IBMIR, we developed a novel in vivo dual islet transplant model to precisely characterize IBMIR as proof-of-concept that this model can serve to properly control experiments comparing modified xenoislet preparations. WT and α1,3-galactosyltransferase knockout (GTKO) neonatal porcine islets were studied in nonimmunosuppressed rhesus macaques. Inert polyethylene microspheres served as a control for the effects of portal embolization. Digital analysis of immunohistochemistry targeting IBMIR mediators was performed at 1 and 24 h after intraportal islet infusion. Early findings observed in transplanted islets include complement and antibody deposition, and infiltration by neutrophils, macrophages and platelets. Insulin, complement, antibody, neutrophils, macrophages and platelets were similar between GTKO and WT islets, with increasing macrophage infiltration at 24 h in both phenotypes. This model provides an objective and internally controlled study of distinct islet preparations and documents the temporal histology of IBMIR.
Assuntos
Inflamação/imunologia , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/citologia , Animais , Animais Geneticamente Modificados , Glicemia/química , Plaquetas/imunologia , Ativação do Complemento , Modelos Animais de Doenças , Galactosiltransferases/genética , Imuno-Histoquímica , Macaca mulatta , Macrófagos/imunologia , Neutrófilos/imunologia , Fenótipo , Suínos , Fatores de Tempo , Transplante HeterólogoRESUMO
Many critical issues remain concerning how best to deploy adoptive regulatory T cell (Treg) immunotherapy to the clinic. These include a determination of their pharmacokinetic characteristics, their optimal dose, their phenotypic stability and the best therapies with which to pair Tregs. By performing a CFSE-labeled autologous Treg pulse experiment, we determined that the accessible peripheral blood Treg pool in rhesus macaques is quite large (75 ± 11 × 10(6) Tregs/kg). Pharmacokinetic analysis revealed that Tregs have two phases of elimination: an α phase, with a T1/2 in the peripheral blood of 32.4 ± 11.3 h and a ß phase with a T1/2 of 120.4 ± 19.7 h. In addition to their short initial half-life, Tregs underwent rapid phenotypic shifts after infusion, with significant loss of both CD25 and FoxP3 by day +6. While tacrolimus stabilized CD25 expression, it did not improve T1/2 , nor mitigate the loss of FoxP3. In contrast, rapamycin significantly stabilized both CD25 and FoxP3, and supported an increased half-life, with an α phase of 67.7 ± 6.9 h and a ß phase of 252.1 ± 54.9 h. These results suggest that rapamycin may be a necessary addition to Treg immunotherapy, and that tacrolimus may be deleterious to Treg integrity posttransfer.
Assuntos
Transferência Adotiva , Linfócitos T CD4-Positivos/imunologia , Imunossupressores/farmacologia , Sirolimo/farmacologia , Linfócitos T Reguladores/imunologia , Tacrolimo/farmacologia , Animais , Proliferação de Células , Células Cultivadas , Citometria de Fluxo , Fluoresceínas , Corantes Fluorescentes , Fatores de Transcrição Forkhead/metabolismo , Meia-Vida , Imunossupressores/farmacocinética , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Macaca mulatta , Fenótipo , Sirolimo/farmacocinética , Succinimidas , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/transplante , Tacrolimo/farmacocinética , Distribuição Tecidual , Transplante AutólogoRESUMO
Membranous glomerulopathy (MG) is most commonly caused by autoantibodies directed against the podocyte phospholipase A2 receptor (PLA2R1) and common variants in this gene are associated with MG. Here for the first time, we carried out a large case-control association study (n=1512) of PLA2R-positive and -negative MG to determine the extent of association in these pathologic subtypes. We performed four separate sets of analyses to determine significance of the single-nucleotide polymorphisms (SNPs) and their haplotypes followed by joint analysis and trans-ethnic mapping to increase power. The PLA2R1 SNP rs35771982 was most strongly associated with PLA2R-positive MG (P=1.4 × 10(-14), odds ratio (ORGG)=1.98). The associations of other SNPs in PLA2R1 could be explained because of linkage disequilibrium with the G-allele. Haplotypes in PLA2R1 did not exceed the significance of rs35771982 even after 10 000 permutations. PLA2R1 variants were only associated with PLA2R-positive MG and predominantly in Caucasians. PLA2R1 variants did not associate with MG in African Americans (AA). There was strong epistasis between HLA-DQA1 SNP rs2187668 and the PLA2R1 variant rs35771982. Thus, common variants in the PLA2R1, particularly rs35771982, modulate PLA2R-positive MG with HLA-DQA1 in Caucasians. PLA2R-negative MG especially in AA, may provide a novel opportunity to discover new genes underlying MG.
Assuntos
Predisposição Genética para Doença/genética , Glomerulonefrite Membranosa/genética , Cadeias alfa de HLA-DQ/genética , Polimorfismo de Nucleotídeo Único , Receptores da Fosfolipase A2/genética , Adulto , Negro ou Afro-Americano/genética , Idoso , Alelos , Estudos de Casos e Controles , Epistasia Genética , Feminino , Frequência do Gene , Predisposição Genética para Doença/etnologia , Genótipo , Glomerulonefrite Membranosa/etnologia , Haplótipos , Humanos , Desequilíbrio de Ligação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , População Branca/genéticaRESUMO
Kidney transplantation remains limited by toxicities of calcineurin inhibitors (CNIs) and steroids. Belatacept is a less toxic CNI alternative, but existing regimens rely on steroids and have higher rejection rates. Experimentally, donor bone marrow and sirolimus promote belatacept's efficacy. To investigate a belatacept-based regimen without CNIs or steroids, we transplanted recipients of live donor kidneys using alemtuzumab induction, monthly belatacept and daily sirolimus. Patients were randomized 1:1 to receive unfractionated donor bone marrow. After 1 year, patients were allowed to wean from sirolimus. Patients were followed clinically and with surveillance biopsies. Twenty patients were transplanted, all successfully. Mean creatinine (estimated GFR) was 1.10 ± 0.07 mg/dL (89 ± 3.56 mL/min) and 1.13 ± 0.07 mg/dL (and 88 ± 3.48 mL/min) at 12 and 36 months, respectively. Excellent results were achieved irrespective of bone marrow infusion. Ten patients elected oral immunosuppressant weaning, seven of whom were maintained rejection-free on monotherapy belatacept. Those failing to wean were successfully maintained on belatacept-based regimens supplemented by oral immunosuppression. Seven patients declined immunosuppressant weaning and three patients were denied weaning for associated medical conditions; all remained rejection-free. Belatacept and sirolimus effectively prevent kidney allograft rejection without CNIs or steroids when used following alemtuzumab induction. Selected, immunologically low-risk patients can be maintained solely on once monthly intravenous belatacept.