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1.
Clin Transplant ; 25(4): 594-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21050272

RESUMO

BACKGROUND: Increasing numbers of patients undergo preemptive renal transplantation. Obtaining cardiac catheterizations prior to transplantation to screen for coronary artery disease is controversial because of the perceived risk of inducing contrast nephropathy and the need for dialysis in patients with marginal renal function. We sought to examine the true impact of cardiac catheterization on time to dialysis in a cohort of preemptive renal transplant candidates. METHODS: From a cohort of 376 transplant candidates evaluated preemptively at our program between 2/2001 and 4/2005, 34 patients had positive dobutamine stress echocardiograms. We reviewed the subsequent need for dialysis in these patients. RESULTS: Among candidates undergoing angiography, 8.7% required dialysis within 14 d of contrast administration and 26% eventually needed dialysis prior to transplantation at 5.3 ± 3.7 months after their pre-transplant evaluation. Among patients who did not undergo angiography, 27% needed dialysis prior to transplantation at 2.4 ± 1.8 months after pre-transplant evaluation. CONCLUSIONS: Our results demonstrate a low risk of hastening the need for dialysis after coronary angiography in preemptive renal transplant candidates. Undergoing angiography had no effect on the ultimate need for or timing of dialysis initiation. These findings support completion of full cardiac evaluation as indicated for high-risk preemptive renal transplant candidates.


Assuntos
Angiografia Coronária , Falência Renal Crônica/diagnóstico por imagem , Transplante de Rim/diagnóstico por imagem , Diálise Renal/estatística & dados numéricos , Adulto , Idoso , Estudos de Coortes , Ecocardiografia sob Estresse , Feminino , Humanos , Falência Renal Crônica/etiologia , Falência Renal Crônica/cirurgia , Masculino , Pessoa de Meia-Idade , Prognóstico
2.
Pediatr Transplant ; 15(6): 557-63, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21199216

RESUMO

Advances in anti-HLA antibody characterization have had a major impact on kidney transplantation. Comprehensive characterization of DSA has improved protocols for allosensitized transplant candidates, increasing access to acceptable donors. Sensitive and specific solid phase antibody detection assays have given important insight into the clinical characteristics of antibody-mediated allograft injury, resulting in the development of a classification system for acute AMR. In addition, important insights into the nature of chronic antibody-mediated allograft rejection have been achieved as a result of improvements in DSA characterization. Finally, assays initially developed as tools to detect DSA in the clinical setting have been employed in innovative research protocols, allowing the investigation of new therapeutic approaches.


Assuntos
Anticorpos/imunologia , Antígenos HLA/imunologia , Transplante de Rim/métodos , Insuficiência Renal/terapia , Anticorpos/química , Criança , Rejeição de Enxerto/imunologia , Antígenos HLA/química , Humanos , Rim/imunologia , Transplante de Rim/efeitos adversos , Pediatria/métodos , Insuficiência Renal/imunologia , Reprodutibilidade dos Testes , Risco , Fatores de Tempo , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/métodos , Transplante Homólogo/métodos , Resultado do Tratamento
3.
Nephrol Dial Transplant ; 25(1): 307-10, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19846396

RESUMO

Putative antibody-mediated rejection (AMR) in HLA-identical sibling transplantation has rarely been reported and occurred before routine calcineurin inhibitor use. A 29-year-old male developed allograft dysfunction following an HLA-identical renal transplant from his sibling. A pretransplant panel-reactive antibody (PRA) was elevated, pre-transplant crossmatch was negative and no donor-specific antibody (DSA) was identified. Induction with alemtuzumab was followed by maintenance immunosuppression with corticosteroids, tacrolimus and mycophenolate. A biopsy for allograft dysfunction suggested AMR, but DSA could not be detected. Treatment for rejection was transiently successful. Undetectable minor histocompatibility antibodies may have contributed.


Assuntos
Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Rim/imunologia , Irmãos , Adulto , Biópsia , Humanos , Rim/patologia , Masculino , Transplante Homólogo
4.
Curr Opin Organ Transplant ; 15(4): 451-5, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20613525

RESUMO

PURPOSE OF REVIEW: To outline recent advances in our understanding of the role of B cells in transplantation. RECENT FINDINGS: While T-cell-mediated alloimmunity has been largely controlled using immunosuppression, the role of B cells in transplantation is just beginning to be understood. Recent studies have outlined some of the important clinical issues involving antibody including early acute humoral rejection and late transplant glomerulopathy. In addition, recent studies have identified bone-marrow-derived long-lived plasma cells that appear to be a major source of donor-specific alloantibody in sensitized renal transplant recipients. New agents are being tested that deplete these cells in vitro and in vivo. Memory B cells appear to be important in early acute humoral rejection, but few basic studies have been performed. Finally, recent studies involving patients undergoing tolerogenic regimens suggest that T-cell tolerance does not always convey tolerance in naive B cells. SUMMARY: Several B cell types have clear and specific roles in transplant recipients. Although our understanding of B cells in transplantation has improved, important gaps remain.


Assuntos
Linfócitos B/imunologia , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto , Transplante de Rim/imunologia , Animais , Rejeição de Enxerto/prevenção & controle , Humanos , Imunidade Humoral , Memória Imunológica , Isoanticorpos/imunologia , Resultado do Tratamento
5.
Curr Opin Organ Transplant ; 15(1): 8-10, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19890210

RESUMO

PURPOSE OF REVIEW: To outline recent studies describing the mechanisms of antibody-mediated rejection (AMR) and new clinical protocols aimed at prevention and/or treatment of this difficult clinical entity. RECENT FINDINGS: The natural history of acute AMR after positive cross-match kidney transplantation involves an acute rise in donor-specific alloantibody (DSA) in the first few weeks after transplantation. Whereas the exact cellular mechanisms responsible for AMR are not known, it seems likely that both pre-existing plasma cells and the conversion of memory B cells to new plasma cells play a role in the increased DSA production. One recent study suggested that combination therapy with plasmapheresis, high-dose IVIG and rituximab was more effective treatment for AMR than high-dose intravenous immunoglobulin (IVIG) alone, but the role of anti-CD20 antibody is still unclear. Two new promising approaches to AMR focus on depletion of plasma cells with the proteasome inhibitor, bortezomib, and the inhibition of terminal complement activation with a humanized, anti-C5 antibody, eculizumab. SUMMARY: The pathogenesis of AMR in several different clinical settings is becoming clearer and more effective treatments are being developed. Whether the prevention or successful treatment of AMR will decrease the prevalence of chronic injury and improved long-term graft survival will require longer-term studies.


Assuntos
Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto , Isoanticorpos/sangue , Transplante de Rim/efeitos adversos , Tolerância ao Transplante , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Anticorpos Monoclonais Murinos , Rejeição de Enxerto/terapia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Fatores Imunológicos/uso terapêutico , Plasmaferese , Rituximab , Transplante Homólogo , Resultado do Tratamento
6.
Pediatr Blood Cancer ; 52(4): 536-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19061212

RESUMO

Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening condition characterized by small-vessel thrombi and a rapid onset of multiorgan system failure associated with systemic inflammatory response syndrome. Current treatment options include anticoagulants, corticosteroids, plasma exchange, and intravenous immunoglobulin, but these are not always effective. Rituximab, a chimeric anti-CD20 monoclonal antibody, may help eliminate autoreactive B cells and thus limit the rapid inflammatory process involved in CAPS. We describe the use of rituximab in the successful initial management of a probable case of pediatric CAPS.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Síndrome Antifosfolipídica/tratamento farmacológico , Síndrome Antifosfolipídica/fisiopatologia , Adolescente , Anticorpos Monoclonais Murinos , Doença Catastrófica , Feminino , Humanos , Rituximab , Tomografia Computadorizada por Raios X
7.
Transplantation ; 84(2): 258-64, 2007 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-17667819

RESUMO

BACKGROUND: We evaluated the effect of antithymocyte globulin (ATG) on anti-human leukocyte antigen (HLA) antibody assays. METHODS: We tested sera from six in vivo ATG-treated kidney transplant patients after measuring serum concentrations, as well as six nonsensitized sera with ATG added in vitro. T- and B-cell complement-dependent cytotoxicity (CDC), flow cytometric (FXM), and solid-phase HLA class I and II assays based on antigen-coated microspheres and enzyme-linked immunosorbent assay (ELISA) were studied. Sera were then retested after treatment to remove ATG. RESULTS: We found that ATG affects test results differently depending on whether sera is obtained from in vivo treated patients or added in vitro. In vitro treated sera produced ATG concentration-dependent positive results for T/B CDC, FXM, and flow bead testing for HLA I/II, while the ELISA-based assay was unaffected. In vivo treated sera from ATG-treated patients produced positive test results for T CDC and T/B FXM, while the B-cell CDC crossmatch remained negative. Solid phase assays were minimally affected using in vivo treated sera. After ATG extraction, all tests became negative. CONCLUSION: We conclude that ATG produces positive results in anti-HLA antibody testing, and treatment to remove ATG abolishes this effect. This treatment allows ATG-treated patients to be monitored for anti-HLA antibodies.


Assuntos
Soro Antilinfocitário/farmacologia , Antígenos HLA/imunologia , Imunossupressores/farmacologia , Isoanticorpos , Transplante de Rim/imunologia , Linfócitos B/imunologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/patologia , Rejeição de Enxerto/prevenção & controle , Antígenos HLA/efeitos dos fármacos , Teste de Histocompatibilidade/métodos , Humanos , Isoanticorpos/análise , Isoanticorpos/efeitos dos fármacos , Isoanticorpos/imunologia , Prognóstico , Linfócitos T/imunologia
8.
Transplantation ; 80(11): 1572-7, 2005 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-16371928

RESUMO

BACKGROUND: Although most protocols for ABO-incompatible kidney transplantation have employed splenectomy, its utility is unproven. The aim of the current study was to compare the outcomes of ABO-incompatible living donor kidney transplantation with splenectomy versus a protocol involving intensive posttransplant antibody monitoring to maintain low levels of antiblood group antibody. METHODS: We retrospectively studied all ABO-incompatible living donor kidney transplants at our institution between September 1999 and November 2004 (n=34). Prior to May 2003, all patients were included in a protocol involving pretransplant plasmapheresis and splenectomy at the time of transplant (n=23). After May 2003, splenectomy was not performed and a protocol that involved pretransplant anti-CD20 antibody and a more intensive posttransplant plasmapheresis regiment aimed at maintaining low levels of antiblood group antibody during the first 2 weeks following transplantation was utilized (n=11). RESULTS: Patient and graft survival was similar in the two groups. Humoral rejection occurred in 18% nonsplenectomized and 30% of splenectomized patients (P=0.68). Humoral rejection correlated with the baseline antibody titer in both groups. Individuals with elevated baseline antibody titer (> or =1:256) appear to be at high risk for humoral rejection regardless of protocol used. Antiblood group antibody levels 3 and 12 months after transplantation were similar in both groups. CONCLUSIONS: Splenectomy is not essential for successful ABO-incompatible kidney transplantation, although individuals with high baseline antidonor blood group antibody titers are at high risk for humoral rejection. The use of intensive posttransplant monitoring may help prevent antibody-mediated graft damage.


Assuntos
Sistema ABO de Grupos Sanguíneos , Incompatibilidade de Grupos Sanguíneos/cirurgia , Rejeição de Enxerto/imunologia , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Esplenectomia , Quimioterapia Combinada , Feminino , Rejeição de Enxerto/epidemiologia , Humanos , Masculino , Complicações Pós-Operatórias/imunologia , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Análise de Sobrevida , Doadores de Tecidos , Condicionamento Pré-Transplante/métodos , Resultado do Tratamento
9.
Transplantation ; 78(5): 635-40, 2004 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-15371661

RESUMO

When a renal transplant candidate's only medically-acceptable living kidney donor is ABO incompatible, the most common practice is to place them on the deceased donor list. Over the past few years, the implementation of paired kidney donor exchange programs and the development of protocols to overcome the ABO blood group barrier have become much more successful and widespread. Here we review the therapeutic options for patients whose only living kidney donor is ABO incompatible, with a specific emphasis on the rationale for and the current outcomes of ABO incompatible living donor kidney transplantation.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Incompatibilidade de Grupos Sanguíneos , Transplante de Rim/imunologia , Cadáver , Sobrevivência de Enxerto/imunologia , Humanos , Doadores Vivos , Doadores de Tecidos , Listas de Espera
10.
Transplantation ; 78(2): 221-7, 2004 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-15280682

RESUMO

BACKGROUND: : Desensitization protocols have been developed to allow successful kidney transplantation in sensitized recipients. However, a detailed analysis of the impact of these protocols on alloantibody has not been performed. METHODS: : We studied 12 living-donor kidney-transplant recipients with positive antihuman globulin-enhanced complement dependent cytotoxicity (AHG-CDC) crossmatches against their donors. Using a variety of crossmatch techniques and single-antigen flowbeads (SAFBs), we characterized the specificity and amount of alloantibody at baseline before desensitization, after desensitization (using plasmapheresis followed by 100 mg/kg intravenous immunoglobulin, and anti-CD20 antibody), and 4 months after transplantation (after splenectomy and on maintenance immunosuppression). RESULTS: : All 12 patients with a positive baseline AHG-CDC crossmatch were AHG-CDC crossmatch negative at the time of transplant (after desensitization). However, despite desensitization, the majority of patients had low-level donor-specific alloantibodies demonstrable on the day of transplantation by both flow crossmatch (FXM 8/12) and SAFBs (10/11). Four months after transplantation, no patient had a positive AHG-CDC crossmatch, but again the majority had persistent low levels of donor-specific alloantibodies by FXM (6/12) and SAFBs (9/11). No patient experienced hyperacute rejection, and the persistence of low levels of donor-specific alloantibodies did not correlate with the development of humoral rejection in the early posttransplant period. CONCLUSIONS: : Despite desensitization, a majority of positive crossmatch transplant recipients demonstrate low levels of donor-specific alloantibodies both on the day of transplant and 4 months after transplantation. The impact of these antibodies appears to be minimal early after transplant, but their long-term significance bears further study.


Assuntos
Antígenos HLA/imunologia , Teste de Histocompatibilidade/métodos , Isoanticorpos/sangue , Transplante de Rim/imunologia , Doadores Vivos , Linfócitos B/imunologia , Creatinina/sangue , Citometria de Fluxo/métodos , Seguimentos , Humanos , Imunização , Terapia de Imunossupressão/métodos , Isoantígenos/imunologia , Reoperação , Linfócitos T/imunologia , Fatores de Tempo
11.
Transplantation ; 77(6): 844-9, 2004 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-15077024

RESUMO

BACKGROUND: Pancreas transplant alone (PTA) has become accepted therapy for select nonuremic patients with type 1 diabetes mellitus. However, PTA may lead to significant complications including a decline in native renal function. This study examines trends in native renal function during the first posttransplant year in PTA recipients with a spectrum of pretransplant glomerular filtration rates (GFR). METHODS: Renal function was studied in 23 recipients of bladder-drained PTA who underwent transplantation from April 1998 through September 2001. GFR was measured by corrected iothalamate clearance at the time of transplant evaluation and 1 year posttransplant and also calculated using the Cockcroft-Gault method at the transplant evaluation; at the day of transplantation; and at 1, 6, and 12 months posttransplant. RESULTS: Iothalamate clearance decreased in the first year in 96% of patients (22 of 23). The mean measured GFR decreased from 84 +/- 33 mL/min/1.73 m2 pretransplant to 52 +/- 26 mL/min/1.73 m2 at 1 year (P <0.001). Calculated creatinine clearance declined in the majority of patients at both 1 and 12 months after PTA, but some patients, including a few with low GFR, maintained stable renal function. Calculated GFR generally correlated well with measured GFR in most patients, with a few notable exceptions. One patient (baseline GFR, 42 mL/min/1.73 m2) developed renal failure in the first year after transplant and required kidney transplantation. CONCLUSIONS: Bladder-drained PTA results in a decline in native renal function in the majority of patients regardless of the pretransplant GFR. These data suggest the need for strategies to prevent or minimize the decline in renal function after PTA.


Assuntos
Diabetes Mellitus Tipo 1/cirurgia , Rim/fisiopatologia , Transplante de Pâncreas/efeitos adversos , Bexiga Urinária/cirurgia , Adulto , Meios de Contraste , Creatinina/metabolismo , Drenagem , Feminino , Taxa de Filtração Glomerular , Humanos , Ácido Iotalâmico/farmacocinética , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Transplante de Pâncreas/métodos
12.
Transplantation ; 77(6): 838-43, 2004 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-15077023

RESUMO

BACKGROUND: Historically, the clinical acceptability of pancreas-after-kidney (PAK) transplantation has been hampered by relatively high acute rejection rates and lower pancreas graft survival rates when compared with the more commonly performed simultaneous pancreas-kidney (SPK) transplantation. The purpose of this study was to compare PAK transplantation to SPK transplantation in the Thymoglobulin induction era. METHODS: The authors reviewed all bladder-drained PAK (n=47) transplants receiving rabbit antithymocyte globulin induction from June 1998 to June 2002 and compared them with SPK (n=25) transplants during the same time period at their institution. The authors retrospectively studied data on demographics, patient survival, graft (pancreas and kidney) survival, complications, and biopsy-proven rejection episodes. RESULTS: The actuarial 1-year patient survival was 93% for the PAK group versus 100% for the SPK group (P =not significant [NS]). The actuarial 1-year pancreas graft survival was 87% for the PAK group versus 92% for the SPK group (P =NS). Waiting time for PAK was significantly shorter than for SPK (6.3 +/- 5.2 vs. 16.2 + -13.7 months, P <0.05). Clinical acute rejection rates were similar in the two groups (4.3% for PAK vs. 4.0% for SPK). PAK recipients demonstrated a greater decline in renal function after transplantation compared with SPK. A multivariate analysis failed to elucidate the cause. CONCLUSIONS: Newer immunosuppressive regimens allow PAK transplant patients to achieve immunologic outcomes similar to SPK transplant patients. Although the shorter waiting time and the ability to use living-donor kidneys make PAK an increasingly attractive alternative to SPK transplantation, its effect on renal allograft function deserves further attention.


Assuntos
Transplante de Rim/métodos , Transplante de Pâncreas/métodos , Soro Antilinfocitário/uso terapêutico , Creatinina/sangue , Esquema de Medicação , Feminino , Rejeição de Enxerto/epidemiologia , Humanos , Imunossupressores/uso terapêutico , Transplante de Rim/mortalidade , Transplante de Rim/fisiologia , Masculino , Pessoa de Meia-Idade , Transplante de Pâncreas/mortalidade , Transplante de Pâncreas/fisiologia , Infecções por Pneumocystis/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Análise de Sobrevida , Fatores de Tempo
13.
Transplantation ; 75(7): 971-7, 2003 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-12698082

RESUMO

BACKGROUND: Given the scarcity of cadaveric organs, efforts are intensifying to increase the availability of living donors. The current study assessed the feasibility of using ABO-incompatible living-donor kidneys to expand the donor pool. METHODS: The authors performed 18 ABO-incompatible living-donor kidney transplants between May 1999 and April 2001. Ten patients received living-donor kidneys from A2 and eight patients received kidneys from non-A2 blood group donors. Immunosuppression consisted of Thymoglobulin antibody induction, tacrolimus, mycophenolate mofetil, and prednisone. Eight non-A2 and two A2 kidney recipients also received a pretransplant conditioning regimen of four plasmapheresis treatments followed by intravenous immunoglobulin and splenectomy at the time of transplantation. Antidonor blood group antibody titer was measured at baseline, pretransplant, at 1- to 3-month and 1-year follow-up, and at the time of diagnosis of antibody-mediated rejection. RESULTS: No hyperacute rejection episodes occurred. One-year graft and patient survival rates in the 18 ABO-incompatible recipients were only slightly lower than those of 81 patients who received ABO-compatible kidney transplants during the same period (89% vs. 96% and 94% vs. 99%, respectively). Glomerular filtration rate and serum creatinine levels did not differ between the groups. Antibody-mediated rejection occurred in 28% of ABO-incompatible recipients, and was reversible with plasmapheresis, intravenous immunoglobulin, and increasing immunosuppression in all patients except one. CONCLUSIONS: ABO-incompatible living donor kidney transplants can achieve an acceptable 1-year graft survival rate using an immunosuppressive regimen consisting of Thymoglobulin induction, tacrolimus, mycophenolate mofetil, and prednisone combined with pretransplant plasmapheresis, intravenous immunoglobulin, and splenectomy.


Assuntos
Sistema ABO de Grupos Sanguíneos , Incompatibilidade de Grupos Sanguíneos/fisiopatologia , Transplante de Rim , Doadores Vivos , Adulto , Idoso , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/patologia , Rejeição de Enxerto/terapia , Sobrevivência de Enxerto , Humanos , Incidência , Isoanticorpos/análise , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Condicionamento Pré-Transplante
14.
Transplantation ; 73(12): 1965-8, 2002 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-12131699

RESUMO

BACKGROUND: Subclinical rejection, defined as histologic acute rejection in the absence of graft dysfunction, has been suggested as a cause of chronic allograft rejection. In cyclosporine-treated patients, the incidence of subclinical rejection 3 months after transplant is reported to be approximately 30%. The intent of our study was to determine the incidence of subclinical rejection in tacrolimus-treated renal allograft recipients. METHODS: We prospectively studied the incidence of subclinical rejection on surveillance biopsies performed 3 months after transplantation in 114 patients transplanted between September 1, 1998 and November 30, 2000. All patients received tacrolimus, mycophenolate mofetil, and prednisone, and 56% received antibody induction. RESULTS: Subclinical rejection was detected in 2.6% of patients (3/114, 95% confidence interval 0.5-7.5%). Borderline changes were detected in 11% (12/114). Subclinical rejections were treated with bolus methylprednisolone. CONCLUSIONS: The incidence of subclinical rejection early after kidney transplantation is extremely low in tacrolimus-treated patients in whom early rejections are aggressively treated, suggesting that surveillance biopsies may not be necessary with this regimen.


Assuntos
Rejeição de Enxerto/epidemiologia , Imunossupressores/uso terapêutico , Transplante de Rim/efeitos adversos , Tacrolimo/uso terapêutico , Adulto , Idoso , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
15.
Transpl Immunol ; 27(2-3): 95-100, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22813834

RESUMO

BACKGROUND: Eculizumab, a potent inhibitor of terminal complement activation, appears promising in reducing early antibody-mediated rejection in positive crossmatch kidney transplantation. However, its concomitant use with polyclonal rabbit antithymocyte globulin (rATG) might reduce the efficacy of rATG. This study aimed to evaluate the effect of eculizumab on the efficacy of rATG in vivo and determine the role of complement in rATG-induced lymphocyte cell depletion. PATIENTS AND METHODS: Thirty-six kidney transplant recipients were classified into 3 groups according to induction regime: anti-IL-2 receptor antibody alone induction group (basiliximab, n=8); rATG induction (n=20), and rATG+eculizumab induction group (n=8). Peripheral blood T-cell subsets and NK cells were measured 3-4 days after transplant (after 3 doses of rATG). RESULTS: Compared to anti-IL-2 receptor antibody induction group, both groups treated with rATG demonstrated significant depletion of all T-cell subsets (CD3-positive cells) (P<0.0001 for rATG vs. anti-IL-2 receptor antibody induction group; P<0.001 for rATG+eculizumab vs. anti-IL-2 receptor antibody group). However, while T-cell counts were low in all rATG-treated patients, eculizumab treatment resulted in higher peripheral blood T-cell counts in rATG treated patients (P=0.005). Before induction, median total lymphocyte counts were normal for the three study groups. By 1, 4 months and 1 year, median the total lymphocyte count was normal for the anti-IL-2 receptor antibody group but was below normal range or at the lower edge of normality for rATG and rATG+eculizumab groups. CONCLUSIONS: This small-sample size study suggests that peripheral T cells are depleted by rATG in the presence of terminal complement inhibition. However, eculizumab appears to have a mild inhibitory effect on peripheral blood T-cell depletion by rATG in kidney transplant recipients.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Inativadores do Complemento/administração & dosagem , Rejeição de Enxerto/tratamento farmacológico , Transplante de Rim , Células Matadoras Naturais/efeitos dos fármacos , Complicações Pós-Operatórias/tratamento farmacológico , Linfócitos T/efeitos dos fármacos , Adulto , Idoso , Animais , Anticorpos Monoclonais/administração & dosagem , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Soro Antilinfocitário/administração & dosagem , Basiliximab , Ativação do Complemento/efeitos dos fármacos , Interações Medicamentosas/imunologia , Feminino , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/imunologia , Humanos , Imunossupressores/administração & dosagem , Células Matadoras Naturais/imunologia , Depleção Linfocítica , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/imunologia , Coelhos , Proteínas Recombinantes de Fusão/administração & dosagem , Linfócitos T/imunologia , Transplante Homólogo/imunologia
16.
Acad Radiol ; 19(7): 834-41, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22503893

RESUMO

RATIONALE AND OBJECTIVES: Magnetic resonance elastography (MRE) images the propagation of mechanical shear waves in tissue and uses that information to generate quantitative measures of tissue stiffness. Hepatic MRE has been successfully performed in thousands of patients, with good correlation between histologic grade of fibrosis and tissue stiffness. There has been no prior investigation of the utility of MRE for the assessment of kidney transplants. The aims of this study were to prospectively evaluate the feasibility of MRE in a small group of kidney transplant recipients and to correlate the measured magnetic resonance elastographic stiffness values with biopsy-proven histopathologic fibrosis. MATERIALS AND METHODS: MRE of renal transplants was performed in 11 patients returning for protocol allograft biopsies. Calculated tissue stiffness values were compared to histologic degree of fibrosis in nine of the 11 patients. RESULTS: The mean stiffness of two patients with moderate interstitial fibrosis was higher than the mean of six patients with mild interstitial fibrosis, but not significantly so (90 Hz, P = .12; 120 Hz, P = .17; 150 Hz, P = .26). The mean stiffness of the two patients with moderate interstitial fibrosis was slightly greater than the mean of one patient with no significant interstitial fibrosis at 90 Hz (P = .78) and slightly less at 120 and 150 Hz (P = .88 and P = .76). The mean stiffness of the six patients with mild interstitial fibrosis did not differ significantly from that of the one patient with no interstitial fibrosis (90 Hz, P = .35; 120 Hz, P = .22; 150 Hz, P = .16). CONCLUSIONS: Preliminary results demonstrate feasibility and support known multifactorial influences on renal stiffness.


Assuntos
Biópsia por Agulha , Técnicas de Imagem por Elasticidade , Transplante de Rim , Rim/patologia , Imageamento por Ressonância Magnética , Adulto , Idoso , Estudos de Viabilidade , Feminino , Fibrose/patologia , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Transplante Homólogo
17.
Transplantation ; 91(5): 536-41, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21283064

RESUMO

BACKGROUND: Donor specific alloantibody producing plasma cells (DSA-PCs) appear resistant to conventional immunosuppressive agents. This study aimed to determine the impact of pretransplant monotherapy with the proteasome inhibitor bortezomib on DSA-PCs in sensitized renal allograft candidates and to assess if DSA-PC depletion would enhance the efficacy of DSA removal using plasma exchange (PE). METHODS: Only patients with DSA levels considered too high to successfully undergo transplantation with PE alone were included in this study: i.e. those with a baseline B flow cytometric crossmatch (BFXM) >450 against a potential living donor.Four sensitized patients received 4 doses (1.3 mg/m/dose) of bortezomib and 4 received 16 doses. The number of DSA-PCs was determined pre and post-treatment using an ELISPOT assay. Five of these patients underwent post-treatment PE and their response was compared to 8 highly-sensitized patients (BFXM >450) who underwent PE alone. RESULTS: When considering all 8 patients as one group, bortezomib treatment decreased DSA-PCs in the marrow (mean±SD=16.7±14.5 DSA-PCs/ml pre-treatment vs. 6.2±3.6 DSA-PCs/ml after treatment, P=0.048). In the time frame of the study, bortezomib alone did not decrease serum DSA levels. However, five bortezomib treated patients underwent PE and showed a greater decease in DSA compared to the historical control group of 8 sensitized patients who underwent PE alone (mean decrease in BFXM channel shift=272.6±92.1 with bortezomib vs 95.4±72.2 in PE alone P=0.008). CONCLUSIONS: Bortezomib depletes DSA-PCs and appears to potentiate DSA removal by PE in sensitized renal transplant recipients.


Assuntos
Ácidos Borônicos/farmacologia , Isoanticorpos/sangue , Transplante de Rim/imunologia , Plasmócitos/efeitos dos fármacos , Plasmócitos/metabolismo , Inibidores de Proteases/farmacologia , Inibidores de Proteassoma , Pirazinas/farmacologia , Adulto , Bortezomib , Relação Dose-Resposta a Droga , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/imunologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Troca Plasmática , Estudos Prospectivos , Doadores de Tecidos , Resultado do Tratamento
19.
Transplantation ; 89(9): 1088-94, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20216485

RESUMO

BACKGROUND.: Anti-human leukocyte antigen antibodies (a-HLA) cause graft injury identified by C4d in peritubular capillaries. We investigated whether a-HLA relate to episodes of C4d negative acute rejection (AR). METHODS.: We analyzed 878 kidney recipients transplanted from January 2000 to December 2006. Pretransplant, 36% of these crossmatch negative recipients had a-HLA measured by solid phase assays. RESULTS.: AR occurred in 154 patients (18%) and 11 of them (9.4%) were C4d+. Forty-six percent of ARs were diagnosed by protocol biopsy. The risk of C4d-AR was increased in patients with a-HLA class I with donor specificity (DSA-I) (hazard ratio=1.519; confidence interval, 1.02-2.26; P=0.039). DSA-II were not associated with an increased risk of C4d-AR. The relationship between DSA-I and C4d-AR was independent of recipient age, BK nephropathy, and HLA mismatches. Compared with DSA-, in DSA+ recipients C4d-AR were most often histologically "borderline." DSA+ was associated with capillaritis in the biopsy (glomerulitis, 6.1% vs. 32%, P=0.003; peritubular capillaritis: 13% vs. 40%, P=0.0009). Compared with no AR, C4d-AR with capillaritis was associated with reduced graft survival (hazard ratio=4.164; confidence interval, 1.763-9.832; P=0.001), independent of other variables. This association was observed even in the cases of borderline AR. CONCLUSIONS.: DSA-I increases the risk of C4d-AR. The presence of DSA-I or II is associated with capillaritis during AR. Capillaritis is associated with reduced graft survival.


Assuntos
Capilares/patologia , Complemento C4b/análise , Rejeição de Enxerto/imunologia , Transplante de Rim/efeitos adversos , Fragmentos de Peptídeos/análise , Doença Aguda , Adulto , Idoso , Autoanticorpos/sangue , Cadáver , Capilares/imunologia , Feminino , Rejeição de Enxerto/patologia , Antígenos HLA/imunologia , Teste de Histocompatibilidade , Humanos , Transplante de Rim/imunologia , Transplante de Rim/mortalidade , Transplante de Rim/patologia , Doadores Vivos , Masculino , Sobreviventes , Doadores de Tecidos , Transplante Homólogo/imunologia , Transplante Homólogo/patologia
20.
Transplantation ; 87(8): 1232-9, 2009 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-19384172

RESUMO

BACKGROUND: For a subset of adults and children with primary focal segmental glomerulosclerosis (FSGS), proteinuria and renal dysfunction recur after kidney transplantation (KTx). Predicting recurrence and response to plasmapheresis (PP) or other interventions remains problematic. METHODS: The prevalence, recurrence rate, outcomes, and treatment responses of patients with FSGS were determined among 1573 KTx recipients. Although 5.0% carried some diagnosis of FSGS, only 1.9% (n=30) met strict diagnostic criteria for primary FSGS including biopsy-proven FSGS, lack of secondary factors, negative family history, and progression to end-stage renal disease within 10 years. RESULTS: Of these, 47% had recurrent FSGS compared with 8% of those not meeting strict criteria (P<0.001). Recurrence was more common in children compared with adults (86% vs. 35%, P=0.01). Graft survival was lower for recipients with primary FSGS compared with all others and inferior graft survival was attributable to recurrent FSGS. Fourteen patients received PP preemptively (pre-KTx) or therapeutically (post-KTx) for recurrent disease. Four pediatric patients additionally received anti-CD20 (rituximab) therapy. Of the different treatment approaches, only PP combined with rituximab was associated with prolonged remission of proteinuria. CONCLUSIONS: The results indicate that patients at high risk for FSGS recurrence can be identified and may benefit from carefully planned peritransplant interventions.


Assuntos
Glomerulosclerose Segmentar e Focal/cirurgia , Transplante de Rim/fisiologia , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Murinos , Criança , Feminino , Glomerulosclerose Segmentar e Focal/prevenção & controle , Sobrevivência de Enxerto , Humanos , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Rituximab , Análise de Sobrevida , Resultado do Tratamento
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