Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
2.
J Clin Med ; 10(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209541

RESUMO

The Food and Drug Administration (FDA) has been regulating human islets for allotransplantation as a biologic drug in the US. Consequently, the requirement of a biological license application (BLA) approval before clinical use of islet transplantation as a standard of care procedure has stalled the development of the field for the last 20 years. Herein, we provide our commentary to the multiple FDA's position papers and guidance for industry arguing that BLA requirement has been inappropriately applied to allogeneic islets, which was delivered to the FDA Cellular, Tissue and Gene Therapies Advisory Committee on 15 April 2021. We provided evidence that BLA requirement and drug related regulations are inadequate in reassuring islet product quality and potency as well as patient safety and clinical outcomes. As leaders in the field of transplantation and endocrinology under the "Islets for US Collaborative" designation, we examined the current regulatory status of islet transplantation in the US and identified several anticipated negative consequences of the BLA approval. In our commentary we also offer an alternative pathway for islet transplantation under the regulatory framework for organ transplantation, which would address deficiencies of in current system.

3.
Am J Transplant ; 21(4): 1365-1375, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33251712

RESUMO

Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and "more than minimally manipulated" human cell and tissue products (HCT/Ps). In contrast, across the world, human islets are appropriately defined as "minimally manipulated tissue" and not regulated as a drug, which has led to islet allotransplantation (allo-ITx) becoming a standard-of-care procedure for selected patients with type 1 diabetes mellitus. This regulatory distinction impedes patient access to islets for transplantation in the US. As a result only 11 patients underwent allo-ITx in the US between 2016 and 2019, and all as investigational procedures in the settings of a clinical trials. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States.


Assuntos
Produtos Biológicos , Diabetes Mellitus Tipo 1 , Transplante das Ilhotas Pancreáticas , Custos e Análise de Custo , Diabetes Mellitus Tipo 1/cirurgia , Humanos , Transplante Heterólogo , Estados Unidos
4.
Am J Transplant ; 20(1): 159-171, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31509331

RESUMO

This study assessed the efficacy and safety of the anti-CD40 monoclonal antibody bleselumab (ASKP1240) in de novo kidney transplant recipients over 36 months posttransplant. Transplant recipients were randomized (1:1:1) to standard of care (SoC: 0.1 mg/kg per day immediate-release tacrolimus [IR-TAC]; target minimum blood concentration [Ctrough ] 4-11 ng/mL plus 1 g mycophenolate mofetil [MMF] twice daily) or bleselumab (200 mg on days 0/7/14/28/42/56/70/90, and monthly thereafter) plus either MMF or IR-TAC (0.1 mg/kg per day; target Ctrough 4-11 ng/mL days 0-30, then 2-5 ng/mL). All received basiliximab induction (20 mg pretransplant and on days 3-5 posttransplant) and corticosteroids. One hundred thirty-eight transplant recipients received ≥1 dose of study drug (SoC [n = 48]; bleselumab + MMF [n = 46]; bleselumab + IR-TAC [n = 44]). For the primary endpoint (incidence of biopsy-proven acute rejection [BPAR] at 6 months), bleselumab + IR-TAC was noninferior to SoC (difference 2.8%; 95% confidence interval [CI] -8.1% to 13.8%), and bleselumab + MMF did not demonstrate noninferiority to SoC (difference 30.7%; 95% CI 15.2%-46.2%). BPAR incidence slightly increased through month 36 in all groups, with bleselumab + IR-TAC continuing to demonstrate noninferiority to SoC. Bleselumab had a favorable benefit-risk ratio. Most treatment-emergent adverse events were as expected for kidney transplant recipients (ClinicalTrials.gov NCT01780844).


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/uso terapêutico , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Complicações Pós-Operatórias/tratamento farmacológico , Estudos de Equivalência como Asunto , Feminino , Seguimentos , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/uso terapêutico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/patologia , Prognóstico , Fatores de Risco , Tacrolimo/uso terapêutico , Transplantados
5.
Transplantation ; 103(1): 160-167, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30095738

RESUMO

BACKGROUND: All human islets used in research and for the clinical treatment of diabetes are subject to ischemic damage during pancreas procurement, preservation, and islet isolation. A major factor influencing islet function is exposure of pancreata to cold ischemia during unavoidable windows of preservation by static cold storage (SCS). Improved preservation methods may prevent this functional deterioration. In the present study, we investigated whether pancreas preservation by gaseous oxygen perfusion (persufflation) better preserved islet function versus SCS. METHODS: Human pancreata were preserved by SCS or by persufflation in combination with SCS. Islets were subsequently isolated, and preparations in each group matched for SCS or total preservation time were compared using dynamic glucose-stimulated insulin secretion as a measure of ß-cell function and RNA sequencing to elucidate transcriptomic changes. RESULTS: Persufflated pancreata had reduced SCS time, which resulted in islets with higher glucose-stimulated insulin secretion compared to islets from SCS only pancreata. RNA sequencing of islets from persufflated pancreata identified reduced inflammatory and greater metabolic gene expression, consistent with expectations of reducing cold ischemic exposure. Portions of these transcriptional responses were not associated with time spent in SCS and were attributable to pancreatic reoxygenation. Furthermore, persufflation extended the total preservation time by 50% without any detectable decline in islet function or viability. CONCLUSIONS: These data demonstrate that pancreas preservation by persufflation rather than SCS before islet isolation reduces inflammatory responses and promotes metabolic pathways in human islets, which results in improved ß cell function.


Assuntos
Temperatura Baixa , Mediadores da Inflamação/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Preservação de Órgãos/métodos , Oxigênio/farmacologia , Perfusão/métodos , Adolescente , Adulto , Sobrevivência Celular/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Masculino , Pessoa de Meia-Idade , Preservação de Órgãos/efeitos adversos , Via Secretória/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Coleta de Tecidos e Órgãos , Adulto Jovem
6.
Transpl Int ; 30(7): 670-678, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28295760

RESUMO

Polyomavirus nephropathy (PVN) is a major complication of kidney transplantation. Most reports describe polyomavirus viremia either precedes or is detectable at the time of diagnosis of PVN. This association is the basis of current screening recommendations. We retrospectively reviewed the PCR results of blood and urine samples from 29 kidney transplant recipients with biopsy-proven PVN. Biopsies were performed for a rise in serum creatinine or persistent high-level BK viruria. All biopsies showed polyoma virus large T-antigen expression in tubular epithelium using immunohistochemistry. All had viruria preceding or at the time of biopsy (range, 5.2 × 104 to >25 × 106 BKV DNA copies/ml). Twenty (69%) had viremia ranging from 2.5 × 103 to 4.3 × 106 copies/ml at the time of the biopsy. Via blood BK PCR assay, nine (31%) had no BK viremia detected either preceding or at the time of the biopsy. In five recipients where sufficient specimen permitted, additional plasma BK assessment revealed positive detection of viremia. A comparative analysis of assays from two centres was performed with spiked samples. BK DNA may not be detected in the blood of some kidney transplant recipients with histologically confirmed PVN. This may reflect limitation of whole blood as opposed to plasma-based BK DNA assessment.


Assuntos
Vírus BK , DNA Viral/sangue , Nefropatias/diagnóstico , Transplante de Rim/efeitos adversos , Infecções por Polyomavirus/diagnóstico , Infecções Tumorais por Vírus/diagnóstico , Viremia/diagnóstico , Antígenos Transformantes de Poliomavirus/metabolismo , DNA Viral/genética , Feminino , Humanos , Imuno-Histoquímica , Rim/virologia , Nefropatias/etiologia , Nefropatias/virologia , Masculino , Pessoa de Meia-Idade , Plasma/virologia , Reação em Cadeia da Polimerase , Infecções por Polyomavirus/etiologia , Infecções por Polyomavirus/virologia , Estudos Retrospectivos , Infecções Tumorais por Vírus/etiologia , Infecções Tumorais por Vírus/virologia , Viremia/etiologia , Viremia/virologia
7.
Surgery ; 160(6): 1533-1543, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27554622

RESUMO

BACKGROUND: Nonalcoholic steatohepatitis is expected to become the leading indication for liver transplantation. Use of extended criteria donors (ECD) may help with donor allocation in these patients. The objective of this study was to determine the use of ECDs in patients with nonalcoholic steatohepatitis undergoing liver transplantation to stimulate a liver-specific predictive model for ECD use. METHODS: The United Network for Organ Sharing database was used to identify patients undergoing liver transplantation for nonalcoholic steatohepatitis (2002-2014). Cox hazards models were created using (1) United Network for Organ Sharing ECD criteria (based on kidney allocation), (2) individual donor characteristics (age, sex, race, cause of death, body mass index, cold ischemic time), and (3) the Kidney Donor Profile Index (KDPI) to examine the effect of ECDs on mortality and graft failure. RESULTS: A total of 4,387 patients underwent liver transplantation for nonalcoholic steatohepatitis; 1,359 (30.9%) patients received an ECD. Transplantation with ECD livers had comparable patient survival (hazard ratio [HR] 1.06, 95% confidence interval [CI] 0.91-1.23) between donor types but an increased risk of graft failure (HR 1.18, 95% CI 1.03-1.36) compared to standard donors. Individual characteristics did not affect patient survival or graft failure. A 10% increase in KDPI was associated with a 28% increase in patient mortality (HR 1.28, 95% CI 1.02-1.60) and 45% increase in graft failure (HR 1.45, 95% CI 1.18-1.80). CONCLUSION: Based on the current United Network for Organ Sharing definition, ECDs in nonalcoholic steatohepatitis were associated with similar overall survival but increased risk of graft failure. Given the shortage of organs, creation of an easily calculated, liver-specific model similar to the KDPI may help risk stratify patients and improve organ allocation.


Assuntos
Seleção do Doador , Transplante de Fígado , Hepatopatia Gordurosa não Alcoólica/cirurgia , Adulto , Idoso , Índice de Massa Corporal , Estudos de Coortes , Sobrevivência de Enxerto , Humanos , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/mortalidade , Modelos de Riscos Proporcionais , Taxa de Sobrevida , Resultado do Tratamento , Estados Unidos
8.
J Surg Res ; 192(1): 1-5, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25151468

RESUMO

BACKGROUND: The Hemodialysis Reliable Outflow (HeRO) vascular access device is a hybrid polytetrafluoroethylene graft-stent construct designed to address central venous occlusive disease. Although initial experience has demonstrated excellent mid-term patency rates, subsequent studies have led to external validity questions. The purpose of this study was to examine a single center experience with this vascular access device in challenging access cases with associated costs. METHODS: A retrospective study representing the authors' cumulative HeRO vascular access device experience was undertaken. The primary endpoint was graft failure or death, with secondary endpoints including secondary intervention rates and cost. RESULTS: Forty-one patients with 15,579 HeRO days and a mean of 12.7 ± 1.5 mo with the vascular access device were available for analysis. Secondary patency was 81.6% at 6 mo and 53.7% at 12 mo. The reintervention rate was 2.84 procedures per HeRO vascular access device year. Associated HeRO costs related to subsequent procedures were estimated at $34,713.63 per patient/y. CONCLUSIONS: These data on the patency and primary outcome data diverge significantly from initial multicenter studies and represent a real-world application of this technology. It is costly to maintain patency. Use of HeRO vascular access devices should be judicious with outcome expectations reduced.


Assuntos
Derivação Arteriovenosa Cirúrgica/normas , Oclusão de Enxerto Vascular/prevenção & controle , Falência Renal Crônica/terapia , Diálise Renal/instrumentação , Dispositivos de Acesso Vascular/normas , Derivação Arteriovenosa Cirúrgica/economia , Feminino , Oclusão de Enxerto Vascular/economia , Oclusão de Enxerto Vascular/mortalidade , Gastos em Saúde/estatística & dados numéricos , Humanos , Estimativa de Kaplan-Meier , Falência Renal Crônica/economia , Falência Renal Crônica/mortalidade , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde/economia , Diálise Renal/economia , Diálise Renal/mortalidade , Estudos Retrospectivos , Dispositivos de Acesso Vascular/economia
9.
Transplantation ; 98(10): 1097-104, 2014 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-24911039

RESUMO

BACKGROUND: Many patients develop de novo donor-specific anti-human leukocyte antigen antibodies (dnDSA) after transplantation. Despite development of dnDSA, not all patients will immediately fail. This study analyzes dnDSA intensity and longitudinal trends as prospective clinical parameters to assess subsequent allograft function. METHODS: Twenty-four patients with dnDSA onset in the first 2 years after transplantation received antibody monitoring by LABScreen single antigen beads. Estimated glomerular filtration rate (eGFR) was recorded at time of dnDSA onset and up to 24 months thereafter. The dnDSA mean fluorescence intensity (MFI) of the stable function patient group (n=8; eGFR decline ≤ 25%) was compared with the impaired function patient group (n=16; eGFR decline>25%) using first year peak MFI (pMFI), eight month MFI change (ΔMFI), and eighteen month MFI trend (MFI slope). RESULTS: Both groups showed similar dnDSA characteristics (time to onset after transplantation, class I/II distribution, and initial MFI). Between groups, MFI trends were analyzed. Impaired patients showed a higher pMFI during the first year (median pMFI, 13,055 vs. 2,397; P=0.007). Longitudinal analysis revealed that ΔMFI was strongly associated with dysfunction. Both a ΔMFI increase greater than 20% as well as a stronger increase (ΔMFI>50%) were followed by graft dysfunction in almost all patients and could significantly differentiate between stable and impaired function patients (P=0.001 and P=0.04, respectively). CONCLUSION: Our study suggests that tracking dnDSA intensity, particularly in the early period after onset, is important to estimate the impact of dnDSA on the allograft and could, therefore, determine help on how best to monitor patients with dnDSA.


Assuntos
Antígenos HLA , Isoanticorpos/sangue , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Adulto , Idoso , Especificidade de Anticorpos , Feminino , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/fisiopatologia , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco
10.
Transplantation ; 97(5): 494-501, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24487396

RESUMO

BACKGROUND: With standard IgG donor-specific anti-HLA antibody (DSA) testing, it is unclear which immunoglobulin-G (IgG) DSA positive patients will fail. We looked further into the immune response by studying immunoglobulin-M (IgM) and IgG subclass 3 (IgG3) DSA to determine if these identify the IgG DSA patients at highest risk for allograft loss. METHODS: In 189 consecutively transplanted primary renal allograft recipients, sera were collected sequentially pre- and posttransplant. Of the 189, 179 patients had sera available to retrospectively test for anti-HLA IgG, IgM, and IgG3 antibodies via LABScreen single-antigen bead assay and were included in the study. All patients had a negative crossmatch. Per patient, all DSA (IgM, IgG3, and IgG) refers to the same serologic specificity. RESULTS: Overall, 100 (56%) patients developed an alloimmune response (IgM or IgG DSA positive, or both). Ninety-five patients developed IgM DSA and 47 patients developed IgG DSA. IgM DSA was detected in 42 of 47 patients with IgG DSA. IgM DSA alone did not increase the allograft loss risk, whereas IgG DSA did (P=0.002). Once IgG DSA appeared, IgM DSA persisted in 33 patients and an isotype switch to IgG3 positive DSA occurred in 25 patients. Patients with IgM persistent IgG3 positive DSA (n=19) were more likely to have allograft failure than those without (P=0.02). CONCLUSION: This study shows the evolution of the humoral immune response from IgM to IgG DSA posttransplant. We found that development of IgM persistent IgG3 positive DSA identifies the most dangerous IgG DSA subpopulation.


Assuntos
Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/imunologia , Imunoglobulina G/fisiologia , Imunoglobulina M/fisiologia , Isoanticorpos/fisiologia , Transplante de Rim , Transplante , Aloenxertos , Especificidade de Anticorpos/imunologia , Feminino , Humanos , Imunidade Humoral/fisiologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Isoanticorpos/sangue , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
11.
Transplantation ; 96(10): 919-25, 2013 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-23912173

RESUMO

BACKGROUND: Approximately 7% to 9% of patients with donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) fail within 1 year post-DSA onset. However, little is known as to how this DSA-associated failure temporally progresses. This longitudinal study investigates DSA's temporal relationship to allograft dysfunction and identifies predictors of allograft function's progressive deterioration post-DSA. METHODS: A cohort of 175 non-HLA identical patients receiving their first transplant between March 1999 and March 2006 were analyzed. Protocol testing for DSA via single antigen beads was done before transplantation and at 1, 3, 6, 9, and 12 months after transplantation then annually. Estimated glomerular filtration rate (eGFR) was analyzed before and after DSA onset. RESULTS: Forty-two patients developed DSA and had adequate eGFR information for analysis. Before DSA onset, the 42 patients had stable eGFR. By 1 year post-DSA, the cohort's eGFR was significantly lower (P<0.001); however, 30 of 42 had stable function. Twelve patients had failure or early allograft dysfunction (eGFR decline >25% from DSA onset). Those who failed early (by 1 year post-DSA) had more antibody-mediated rejection than stable patients (P=0.03). Late failures (after 1 year post-DSA) were predictable with evidence of early allograft dysfunction (eGFR decline >25% by 1 year post-DSA; P<0.001). Early allograft dysfunction preceded late failure by nearly 1 year. CONCLUSIONS: DSA is temporally related to allograft function deterioration. However, in many cases, late allograft failures are preceded by early allograft dysfunction. Therefore, monitoring for early allograft dysfunction provides treating physicians with a window of opportunity for treatment or continued monitoring.


Assuntos
Taxa de Filtração Glomerular/fisiologia , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/fisiologia , Antígenos HLA/imunologia , Isoanticorpos/imunologia , Transplante de Rim , Adulto , Feminino , Seguimentos , Rejeição de Enxerto/fisiopatologia , Teste de Histocompatibilidade , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doadores de Tecidos , Transplante Homólogo
12.
Transplantation ; 95(9): 1113-9, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23514959

RESUMO

BACKGROUND: Anti-HLA-DQ antibodies are the predominant HLA class II donor-specific antibodies (DSAs) after transplantation. Recently, de novo DQ DSA has been associated with worse allograft outcomes. The aim of this study was to determine the further complement-binding characteristics of the most harmful DQ DSA. METHODS: Single-antigen bead technology was used to screen 284 primary kidney transplant recipients for the presence of posttransplantation DQ DSA. Peak DSA sera of 34 recipients with only de novo DQ DSA and of 20 recipients with de novo DQ plus other DSAs were further analyzed by a modified single-antigen bead assay using immunoglobulin (Ig)-G subclass-specific reporter antibodies and a C1q-binding assay. RESULTS: Compared with recipients who did not have DSA, those with de novo persistent DQ-only DSA and with de novo DQ plus other DSAs had more acute rejection (AR) episodes (22%, P=0.005; and 36%, P=0.0009), increased risk of allograft loss (hazards ratio, 3.7, P=0.03; and hazards ratio, 11.4, P=0.001), and a lower 5-year allograft survival. De novo DQ-only recipients with AR had more IgG1/IgG3 combination and C1q-binding antibodies (51%, P=0.01; and 63%, P=0.001) than patients with no AR. Furthermore, the presence of C1q-binding de novo DQ DSA was associated with a 30% lower 5-year allograft survival (P=0.003). CONCLUSIONS: The presence of de novo persistent, complement-binding DQ DSA negatively impacts kidney allograft outcomes. Therefore, early posttransplantation detection, monitoring, and removal of complement-binding DQ might be crucial for improving long-term kidney transplantation outcomes.


Assuntos
Complemento C1q/imunologia , Antígenos HLA-DQ/imunologia , Imunoglobulina G/classificação , Isoanticorpos/imunologia , Transplante de Rim , Doadores de Tecidos , Adulto , Idoso , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Homólogo
13.
Transplantation ; 95(3): 410-7, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23380861

RESUMO

BACKGROUND: To date, limited information is available describing the incidence and impact of de novo donor-specific anti-human leukocyte antigen (HLA) antibodies (dnDSA) in the primary renal transplant patient. This report details the dnDSA incidence and actual 3-year post-dnDSA graft outcomes. METHODS: The study includes 189 consecutive nonsensitized, non-HLA-identical patients who received a primary kidney transplant between March 1999 and March 2006. Protocol testing for DSA via LABScreen single antigen beads (One Lambda) was done before transplantation and at 1, 3, 6, 9, and 12 months after transplantation then annually and when clinically indicated. RESULTS: Of 189 patients, 47 (25%) developed dnDSA within 10 years. The 5-year posttransplantation cumulative incidence was 20%, with the largest proportion of patients developing dnDSA in the first posttransplantation year (11%). Young patients (18-35 years old at transplantation), deceased-donor transplant recipients, pretransplantation HLA (non-DSA)-positive patients, and patients with a DQ mismatch were the most likely to develop dnDSA. From DSA appearance, 9% of patients lost their graft at 1 year. Actual 3-year death-censored post-dnDSA graft loss was 24%. CONCLUSION: We conclude that 11% of the patients without detectable DSA at transplantation will have detectable DSA at 1 year, and over the next 4 years, the incidence of dnDSA will increase to 20%. After dnDSA development, 24% of the patients will fail within 3 years. Given these findings, future trials are warranted to determine if treatment of dnDSA-positive patients can prevent allograft failure.


Assuntos
Rejeição de Enxerto/epidemiologia , Antígenos HLA/imunologia , Isoanticorpos/sangue , Transplante de Rim/imunologia , Doadores de Tecidos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Rejeição de Enxerto/imunologia , Teste de Histocompatibilidade , Humanos , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Transplante Homólogo , Adulto Jovem
14.
Clin Transpl ; : 319-24, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-25095524

RESUMO

Donor specific human leukocyte antigen (HLA) antibodies (DSA) are a significant cause of allograft failure. However, it has been reported that some DSA negative patients still experience allograft failure. In addition, some DSA positive patients maintain good graft function for >20 years. These findings suggest that while DSA is a cause of failure, it is not the sole risk factor for graft dysfunction and that the presence of DSA alone may not predict the time course of graft failure. Here, we report the predictive value of a proprietary panel of four biomarkers in long-term renal allograft outcome. A total of 310 consecutive patients, who received kidney transplants between 1999 and 2012, were included in this study. Recipient sera was tested for HLA antibodies and biomarkers at 3, 6, 12, 24, and 36 months post-transplant. HLA antibodies were identified using Labscreen single antigen beads. The biomarker combination (BMC) test consisted of a proprietary panel of 4 biomarkers and was performed using Luminex. Sera were defined as positive when any one of the 4 biomarkers became detectable. Sera of normal healthy people were used as negative controls. Graft survival analyses were performed and compared between different patient groups based on the positivity of DSA and BMC. Our results indicate that 57% of DSA negative patients and 54% of DSA positive patients had detectable biomarkers. There was no significant difference in BMC positive patients between the DSA positive and negative groups, which suggests that presence of BMC is not associated with HLA DSA. DSA positive patients had a 10% lower 10-year graft survival rate than patients without DSA, while BMC positive patients had a 25% lower 10-year graft survival rate than patients without detectable BMC. When DSA negative patients were divided into two groups based on the positivity of BMC, BMC positive patients had a 20% lower 10-year graft survival rate compared to BMC negative patients (p<0.05). Similarly, when DSA positive patients were divided into two groups based on the positivity of BMC, BMC positive patients had a 30% lower 10-year graft survival rate compared to BMC negative patients (p<0.01). When both DSA and BMC testing results were considered, DSA and BMC double positive patients had the lowest and double negative patients had the highest graft survival rates. The survival rates for the BMC alone and DSA alone positive groups were in between (p<0.001). Multivariate Cox models confirmed that BMC was an independent risk factor for graft failure, with a higher hazard ratio than DSA (BMC=2.60 versus DSA=1.64). In conclusion, serum BMC is an independent predictor of graft failure. BMC was more significantly associated with graft failure than DSA. In combination with DSA, BMC better predicted graft outcome than DSA or BMC alone.


Assuntos
Rejeição de Enxerto , Antígenos HLA/imunologia , Transplante de Rim/mortalidade , Biomarcadores , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/mortalidade , Sobrevivência de Enxerto/imunologia , Humanos , Isoanticorpos/imunologia , Análise Multivariada , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Fatores de Risco , Transplante Homólogo
15.
Clin Kidney J ; 5(5): 434-437, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23986860

RESUMO

Longer wait times for deceased donor kidney transplant have prompted newer initiatives to expedite the process. Reuse of a previously transplanted kidney might be appropriate in certain circumstances. However, one must also consider the unique issues that may arise after such transplants. We describe our experience in one such case where the donor kidney had lesions of focal and segmental glomerulosclerosis and signs of alloreactivity (positive C4d staining) prior to transplantation and the recipient developed ganciclovir-resistant cytomegalovirus (CMV) infection, which was perhaps transmitted from the donor. Despite the challenges, the allograft function remained stable 5 years after reuse.

16.
Clin Transpl ; : 337-40, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22755428

RESUMO

The donor specific anti-HLA antibody (DSA) has been increasingly recognized as the major cause of allograft loss. Despite this, no published reports exist describing the true epidemiology of de novo DSA.Here we describe the epidemiology of DSA based on the results of one of the longest running antibody study in consecutive renal transplant recipients. The study includes 224 non-sensitized, non-HLA-identical patients who received a primary kidney transplant between 3/1999-3/2006. Protocol testing for DSA was done pre-transplant, at 1, 3, 6, 9, and 12 months, and then annually. DSA was tested using single antigen beads. Data from the East Carolina University transplant cohort indicate that the prevalence of DSA in the first year post-transplant is 12.1 cases per 100. The average annual incidence of DSA is 4.7 per 100 cases, per year. The highest incidence of DSA was in the first year post transplant. Although deceased donors and African-Americans have a higher incidence rate of DSA than the comparator living donors and non-African American groups, respectively, these factors were not associated with DSA onset. The one factor found to be predictive of DSA was DQ mismatch (p = 0.036). Based on these epidemiologic findings in combination with previous reports showing DSA is a cause of allograft failure, it seems reasonable that at least annual testing should be done even in "low-risk" transplant patients, because every year a new 5% of patients will develop DSA.


Assuntos
Antígenos HLA/imunologia , Histocompatibilidade , Isoanticorpos/sangue , Transplante de Rim/imunologia , Tolerância ao Transplante , Dessensibilização Imunológica , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto , Histocompatibilidade/efeitos dos fármacos , Teste de Histocompatibilidade , Humanos , Imunossupressores/uso terapêutico , Transplante de Rim/efeitos adversos , Masculino , Monitorização Imunológica , North Carolina/epidemiologia , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Tolerância ao Transplante/efeitos dos fármacos , Resultado do Tratamento
17.
Clin J Am Soc Nephrol ; 5(9): 1637-41, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20595695

RESUMO

BACKGROUND AND OBJECTIVES: Influenza infection in transplant recipients is often associated with significant morbidity. Surveys were conducted in 1999 and 2009 to find out if the influenza vaccination practices in the U.S. transplant programs had changed over the past 10 years. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In 1999, a survey of the 217 United Network for Organ Sharing-certified kidney and kidney-pancreas transplant centers in the U.S. was conducted regarding their influenza vaccination practice patterns. A decade later, a second similar survey of 239 transplant programs was carried out. RESULTS: The 2009 respondents, compared with 1999, were more likely to recommend vaccination for kidney (94.5% versus 84.4%, P = 0.02) and kidney-pancreas recipients (76.8% versus 48.5%, P < 0.001), family members of transplant recipients (52.5% versus 21.0%, P < 0.001), and medical staff caring for transplant patients (79.6% versus 40.7%, P < 0.001). Physicians and other members of the transplant team were more likely to have been vaccinated in 2009 compared with 1999 (84.2% versus 62.3% of physicians, P < 0.001 and 91.2% versus 50.3% of nonphysicians, P < 0.001). CONCLUSIONS: Our study suggests a greater adoption of the Centers for Disease Control and Prevention influenza vaccination guidelines by U.S. transplant programs in vaccinating solid-organ transplant recipients, close family contacts, and healthcare workers.


Assuntos
Atitude do Pessoal de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Transplante de Rim/efeitos adversos , Padrões de Prática Médica/estatística & dados numéricos , Fidelidade a Diretrizes/estatística & dados numéricos , Pesquisas sobre Atenção à Saúde , Humanos , Esquemas de Imunização , Vacinas contra Influenza/efeitos adversos , Influenza Humana/mortalidade , Influenza Humana/transmissão , Influenza Humana/virologia , Transplante de Rim/mortalidade , Guias de Prática Clínica como Assunto , Fatores de Tempo , Estados Unidos
19.
Transplantation ; 84(12): 1602-9, 2007 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-18165771

RESUMO

BACKGROUND: A widely reported ABO-mismatch accident in March of 2003 raised concerns about the reliability of the transplantation system. Because this type of failure is rare and significant, we performed a probabilistic risk assessment (PRA) of the donor-recipient matching processes for thoracic organ transplantation. METHODS: A probabilistic risk assessment was performed. RESULTS: The likelihood of accidental incompatible implantation was already low in 2003. The PRA model indicates that the likelihood of such an event was 1.38x10 per donated organ. This estimate correlates closely with the observed rate of these accidents. Based on this model, process changes put in place shortly after the accident reduced the probability to approximately 3.08x10 and changes put in place in October 2004 further reduced the probability to approximately 2.22x10 per organ donated. CONCLUSIONS: The observed and predicted likelihoods of accidental incompatible thoracic organ transplantation are comparable. These likelihoods are several orders of magnitude smaller than other hazards associated with solid organ transplantation. The PRA model indicates that changes that followed the March 2003 accident further reduced the likelihood of accidental incompatible implantation by roughly two orders of magnitude. Quantitative estimates from PRA can be used to assess risks in healthcare and to gauge the impact of system changes on these risks.


Assuntos
Sistema ABO de Grupos Sanguíneos , Incompatibilidade de Grupos Sanguíneos/epidemiologia , Imunologia de Transplantes , Humanos , Medição de Risco , Tórax , Falha de Tratamento , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...