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1.
Am J Transplant ; 24(4): 619-630, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37940005

RESUMO

The recent shortage of the University of Wisconsin (UW) solution prompted increased utilization of histidine-tryptophan-ketoglutarate (HTK) solution for liver graft preservation. This contemporary study analyzed deceased donor liver transplant outcomes following preservation with HTK vs UW. Patients receiving deceased donor liver transplantations between January 1, 2019, and June 30, 2022, were retrospectively identified utilizing the Organ Procurement and Transplant Network database, stratified by preservation with HTK vs UW, and a propensity score matching analysis was performed. Outcomes assessed included rates of primary nonfunction, graft survival, and patient survival. There were 4447 patients in each cohort. Primary nonfunction occurred in 60 (1.35%) patients in the HTK group vs 25 (0.54%) in the UW group (P < .001). HTK was associated with lower 90-day graft survival (94.39% vs 96.09%; P < .001) and 90-day patient survival (95.97% vs 97.38%; P = .001). Unmatched donation after cardiac death-specific analysis of HTK vs UW demonstrated respective rates of primary nonfunction of 1.63% vs 0.82% (P = .20), 90-day graft survival of 92.50% vs 95.29% (P = .069), and 90-day patient survival of 93.90% vs 96.35% (P = .077). These results suggest that HTK may not be an equivalent preservation solution for deceased donor liver transplantation.


Assuntos
Transplante de Fígado , Soluções para Preservação de Órgãos , Humanos , Estudos Retrospectivos , Pontuação de Propensão , Doadores Vivos , Glucose , Manitol , Cloreto de Potássio , Procaína , Insulina , Glutationa , Alopurinol
2.
Curr Opin Organ Transplant ; 27(1): 70-74, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34939966

RESUMO

PURPOSE OF REVIEW: Kidney transplantation is a heavily regulated medical procedure with the Secretary of HHS ultimately responsible for oversight and authority derived from the NOTA and the Final Rule. Transplant Programs undergo publicly reported evaluations every 6 months based on outcomes from a 2-and-a-half-year period. The current Bayesian metrics for kidney transplant programs were created such that over ten percentage of programs are deemed underperformers, or 'flag', every 6 months. Newly suggested transplant metrics have been released for public comment in Summer 2021. In addition to graft outcomes, waiting list mortality and organ acceptance rate ratios are proposed. RECENT FINDINGS: Under the newly proposed kidney transplant metrics, over 10% of programs are expected to be deemed underperformers or 'flagged'. Transplant Center flagging is well correlated with decreased transplantation due to the transplant centres move to more conservative organ and patient acceptance. Death on the waiting list is a proposed metric over which transplant centres have little influence. SUMMARY: In the USA, the harsh regulation continued by Health Resources and Services Administration (HRSA) through the national organ procurement and transplant network (OPTN) and Scientific Registry for Transplant Recipients (SRTR) leads directly to high organ discard rates and limitations to transplanting patients with perceived unadjusted risks. Instead of loosening regulation in a highly functioning industry that achieves remarkable outcomes in end stage kidney patients, the OPTN with the SRTR persist in increasing potential penalties through more proposed metrics that continue to deem 10% of US kidney transplant programs as underperformers. HRSA must establish a reasonable regulatory environment that allows for innovation and increased transplant opportunities for US end-stage renal disease patients.


Assuntos
Transplante de Rim , Transplante de Órgãos , Obtenção de Tecidos e Órgãos , Teorema de Bayes , Benchmarking , Humanos , Transplante de Rim/efeitos adversos , Sistema de Registros , Transplantados , Listas de Espera
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(8): 2026-2029, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-31883214

RESUMO

With the Centers for Medicare and Medicaid Services proposing to remove outcome measures from the transplant centers' renewal for Conditions of Participation an exciting opportunity surfaces for the Organ Procurement and Transplantation Network to make an equally bold change and allow for increased transplantation options for patients in the United States.


Assuntos
Obtenção de Tecidos e Órgãos , Transplantes , Idoso , Centers for Medicare and Medicaid Services, U.S. , Humanos , Medicare , Políticas , Estados Unidos
5.
Am J Transplant ; 19(7): 1888-1895, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31012525

RESUMO

In accordance with the National Organ Transplant Act and Department of Health and Human Services' Final Rule, the Scientific Registry of Transplant Recipients (SRTR) publicly releases biannual program-specific reports that include analyses of transplant centers' risk-adjusted waitlist mortality, organ acceptance ratios, transplant rates, and graft and patient survival. Since the inception of these center metrics, 1-year posttransplant graft and patient survival have improved, and center variation has decreased, casting uncertainty on their clinical relevance. The SRTR has recently modified center evaluations by ranking centers into 5 tiers rather than 3 tiers in an attempt to discriminate between programs performing within a tight range, further exacerbating this uncertainty. The American Society of Transplantation/American Society of Transplant Surgeons convened an expert taskforce to examine both the utility and unintended consequences of transplant center metrics. Estimates of center variation in outcomes in adjacent tiers are imprecise and fleeting, but can result in consequential changes in clinician and center behavior. The taskforce has concerns that current metrics, based principally on 1-year graft and patient survival, provide minimal if any benefit in informing patient choice and access to transplantation, with the untoward effect of decreased utilization of organs and restriction of research and innovation.


Assuntos
Transplante , Humanos , Garantia da Qualidade dos Cuidados de Saúde , Sistema de Registros , Obtenção de Tecidos e Órgãos , Listas de Espera
6.
Am J Transplant ; 18(6): 1494-1501, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29316241

RESUMO

Outcomes of patients receiving solid organ transplants in the United States are systematically aggregated into bi-annual Program-Specific Reports (PSRs) detailing risk-adjusted survival by transplant center. Recently, the Scientific Registry of Transplant Recipients (SRTR) issued 5-tier ratings evaluating centers based on risk-adjusted 1-year graft survival. Our primary aim was to examine the reliability of 5-tier ratings over time. Using 10 consecutive PSRs for adult kidney transplant centers from June 2012 to December 2016 (n = 208), we applied 5-tier ratings to center outcomes and evaluated ratings over time. From the baseline period (June 2012), 47% of centers had at least a 1-unit tier change within 6 months, 66% by 1 year, and 94% by 3 years. Similarly, 46% of centers had at least a 2-unit tier change by 3 years. In comparison, 15% of centers had a change in the traditional 3-tier rating at 3 years. The 5-tier ratings at 4 years had minimal association with baseline rating (Kappa 0.07, 95% confidence interval [CI] -0.002 to 0.158). Centers had a median of 3 different 5-tier ratings over the period (q1 = 2, q3 = 4). Findings were consistent for center volume, transplant rate, and baseline 5-tier rating. Cumulatively, results suggest that 5-tier ratings are highly volatile, limiting their utility for informing potential stakeholders, particularly transplant candidates given expected waiting times between wait listing and transplantation.


Assuntos
Instalações de Saúde/normas , Transplante de Órgãos/normas , Adulto , Humanos , Estados Unidos
7.
J Hepatol ; 67(3): 517-525, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28483678

RESUMO

BACKGROUND & AIM: The goal of organ allocation is to distribute a scarce resource equitably to the sickest patients. In the United States, the Model for End-stage Liver Disease (MELD) is used to allocate livers for transplantation. Patients with greater MELD scores are at greater risk of death on the waitlist and are prioritized for liver transplant (LT). The MELD is capped at 40 however, and patients with calculated MELD scores >40 are not prioritized despite increased mortality. We aimed to evaluate waitlist and post-transplant survival stratified by MELD to determine outcomes in patients with MELD >40. METHODS: Using United Network for Organ Sharing data, we identified patients listed for LT from February 2002 through to December 2012. Waitlist candidates with MELD ⩾40 were followed for 30days or until the earliest occurrence of death or transplant. RESULTS: Of 65,776 waitlisted patients, 3.3% had MELD ⩾40 at registration, and an additional 7.3% had MELD scores increase to ⩾40 after waitlist registration. A total of 30,369 (46.2%) underwent LT, of which 2,615 (8.6%) had MELD ⩾40 at transplant. Compared to MELD 40, the hazard ratio of death within 30days of registration was 1.4 (95% CI 1.2-1.6) for patients with MELD 41-44, 2.6 (95% CI 2.1-3.1) for MELD 45-49, and 5.0 (95% CI 4.1-6.1) for MELD ⩾50. There was no difference in 1- and 3-year survival for patients transplanted with MELD >40 compared to MELD=40. A survival benefit associated with LT was seen as MELD increased above 40. CONCLUSIONS: Patients with MELD >40 have significantly greater waitlist mortality but comparable post-transplant outcomes to patients with MELD=40 and, therefore, should be given priority for LT. Uncapping the MELD will allow more equitable organ distribution aligned with the principle of prioritizing patients most in need. Lay summary: In the United States (US), organs for liver transplantation are allocated by an objective scoring system called the Model for End-stage Liver Disease (MELD), which aims to prioritize the sickest patients for transplant. The greater the MELD score, the greater the mortality without liver transplant. The MELD score, however, is artificially capped at 40 and thus actually disadvantages the sickest patients with end-stage liver disease. Analysis of the data advocates uncapping the MELD score to appropriately prioritize the patients most in need of a liver transplant.


Assuntos
Doença Hepática Terminal/cirurgia , Transplante de Fígado , Obtenção de Tecidos e Órgãos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Listas de Espera , Adulto Jovem
9.
Transpl Int ; 28(4): 401-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25440520

RESUMO

The OPTN/UNOS Kidney Paired Donation (KPD) Pilot Program allocates priority to zero-HLA mismatches. However, in unrelated living donor kidney transplants (LDKT)-the same donor source in KPD-no study has shown whether zero-HLA mismatches provide any advantage over >0 HLA mismatches. We hypothesize that zero-HLA mismatches among unrelated LDKT do not benefit graft survival. This retrospective SRTR database study analyzed LDKT recipients from 1987 to 2012. Among unrelated LDKT, subjects with zero-HLA mismatches were compared to a 1:1-5 matched (by donor age ±1 year and year of transplantation) control cohort with >0 HLA mismatches. The primary endpoint was death-censored graft survival. Among 32,654 unrelated LDKT recipients, 83 had zero-HLA mismatches and were matched to 407 controls with >0 HLA mismatches. Kaplan-Meier analyses for death-censored graft and patient survival showed no difference between study and control cohorts. In multivariate marginal Cox models, zero-HLA mismatches saw no benefit with death-censored graft survival (HR = 1.46, 95% CI 0.78-2.73) or patient survival (HR = 1.43, 95% CI 0.68-3.01). Our data suggest that in unrelated LDKT, zero-HLA mismatches may not offer any survival advantage. Therefore, particular study of zero-HLA mismatching is needed to validate its place in the OPTN/UNOS KPD Pilot Program allocation algorithm.


Assuntos
Antígenos HLA-DR , Antígenos de Histocompatibilidade Classe I , Transplante de Rim , Imunologia de Transplantes , Adulto , Estudos de Coortes , Feminino , Sobrevivência de Enxerto , Humanos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
Front Transplant ; 3: 1449407, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39176402

RESUMO

Since the first liver transplant was performed over six decades ago, the landscape of liver transplantation in the US has seen dramatic evolution. Numerous advancements in perioperative and operative techniques have resulted in major improvements in graft and patient survival rates. Despite the increase in transplants performed over the years, the waitlist mortality rate continues to remain high. The obesity epidemic and the resultant metabolic sequelae continue to result in more marginal donors and challenging recipients. In this review, we aim to highlight the changing characteristics of liver transplant recipients and liver allograft donors. We focus on issues relevant in successfully transplanting a high model for end stage liver disease recipient. We provide insights into the current use of terms and definitions utilized to discuss marginal allografts, discuss the need to look into more consistent ways to describe these organs and propose two new concepts we coin as "Liver Allograft Variables" (LAV) and "Liver Allograft Composite Score" (LACS) for this. We discuss the development of spectrum of risk indexes as a dynamic tool to characterize an allograft in real time. We believe that this concept has the potential to optimize the way we allocate, utilize and transplant livers across the US.

11.
Clin Transplant ; 27(3): 397-402, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23448282

RESUMO

BACKGROUND: The impact of parathyroidectomy on allograft function in kidney transplant patients is unclear. METHODS: We conducted a retrospective, observational study of all kidney transplant recipients from 1988 to 2008 who underwent parathyroidectomy for uncontrolled hyperparathyroidism (n = 32). Post-parathyroidectomy, changes in estimated glomerular filtration rate (eGFR) and graft loss were recorded. Cross-sectional associations at baseline between eGFR and serum calcium, phosphate, and parathyroid hormone (PTH), and associations between their changes within subjects during the first two months post-parathyroidectomy were assessed. RESULTS: Post-parathyroidectomy, the mean eGFR declined from 51.19 mL/min/1.73 m(2) at parathyroidectomy to 44.78 mL/min/1.73 m(2) at two months (p < 0.0001). Subsequently, graft function improved, and by 12 months, mean eGFR recovered to 49.76 mL/min/1.73 m(2) (p = 0.035). Decrease in serum PTH was accompanied by a decrease in eGFR (p = 0.0127) in the first two months post-parathyroidectomy. Patients whose eGFR declined by ≥20% (group 1) in the first two months post-parathyroidectomy were distinguished from the patients whose eGFR declined by <20% (group 2). The two groups were similar except that group 1 had a higher baseline mean serum PTH compared with group 2, although not significant (1046.7 ± 1034.2 vs. 476.6 ± 444.9, p = 0.14). In group 1, eGFR declined at an average rate of 32% (p < 0.0001) during the first month post-parathyroidectomy compared with 7% (p = 0.1399) in group 2, and the difference between these two groups was significant (p = 0.0003). The graft function recovered in both groups by one yr. During median follow-up of 66.00 ± 49.45 months, 6 (18%) patients lost their graft with a mean time to graft loss from parathyroidectomy of 37.2 ± 21.6 months. The causes of graft loss were rejection (n = 2), pyelonephritis (n = 1) and chronic allograft nephropathy (n = 3). No graft loss occurred during the first-year post-surgery. CONCLUSION: Parathyroidectomy may lead to transient kidney allograft dysfunction with eventual recovery of graft function by 12 months post-parathyroidectomy. Higher level of serum PTH pre-parathyoidectomy is associated with a more profound decrease in eGFR post-parathyroidectomy.


Assuntos
Rejeição de Enxerto/prevenção & controle , Hiperparatireoidismo/cirurgia , Nefropatias/complicações , Transplante de Rim/efeitos adversos , Paratireoidectomia , Aloenxertos , Estudos Transversais , Feminino , Seguimentos , Taxa de Filtração Glomerular , Humanos , Hiperparatireoidismo/etiologia , Nefropatias/mortalidade , Nefropatias/cirurgia , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Prognóstico , Estudos Retrospectivos , Fatores de Risco
12.
medRxiv ; 2023 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-37397983

RESUMO

Background: Inter- and intra-individual variability in tacrolimus dose requirements mandates empirical clinician-titrated dosing that frequently results in deviation from a narrow target range. Improved methods to individually dose tacrolimus are needed. Our objective was to determine whether a quantitative, dynamically-customized, phenotypic-outcome-guided dosing method termed Phenotypic Personalized Medicine (PPM) would improve target drug trough maintenance. Methods: In a single-center, randomized, pragmatic clinical trial ( NCT03527238 ), 62 adults were screened, enrolled, and randomized prior to liver transplantation 1:1 to standard-of-care (SOC) clinician-determined or PPM-guided dosing of tacrolimus. The primary outcome measure was percent days with large (>2 ng/mL) deviation from target range from transplant to discharge. Secondary outcomes included percent days outside-of-target-range and mean area-under-the-curve (AUC) outside-of-target-range per day. Safety measures included rejection, graft failure, death, infection, nephrotoxicity, or neurotoxicity. Results: 56 (29 SOC, 27 PPM) patients completed the study. The primary outcome measure was found to be significantly different between the two groups. Patients in the SOC group had a mean of 38.4% of post-transplant days with large deviations from target range; the PPM group had 24.3% of post-transplant days with large deviations; (difference -14.1%, 95% CI: -26.7 to -1.5 %, P=0.029). No significant differences were found in the secondary outcomes. In post-hoc analysis, the SOC group had a 50% longer median length-of-stay than the PPM group [15 days (Q1-Q3: 11-20) versus 10 days (Q1-Q3: 8.5-12); difference 5 days, 95% CI: 2-8 days, P=0.0026]. Conclusions: PPM guided tacrolimus dosing leads to better drug level maintenance than SOC. The PPM approach leads to actionable dosing recommendations on a day-to-day basis. Lay Summary: In a study on 62 adults who underwent liver transplantation, researchers investigated whether a new dosing method called Phenotypic Personalized Medicine (PPM) would improve daily dosing of the immunosuppression drug tacrolimus. They found that PPM guided tacrolimus dosing leads to better drug level maintenance than the standard-of-care clinician-determined dosing. This means that the PPM approach leads to actionable dosing recommendations on a day-to-day basis and can help improve patient outcomes.

13.
Liver Transpl ; 18(6): 641-58, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22298469

RESUMO

There is a paucity of data concerning the correlation of complement component 4d (C4d) staining in liver allografts and antibody-mediated rejection. Data about the location and character of C4d deposits in native and allograft liver tissues are inconsistent. We performed C4d immunofluorescence (IF) on 141 fresh-frozen liver allograft biopsy samples and native livers, documented the pattern of C4d IF staining, and correlated the findings with the presence of donor-specific alloantibodies (DSAs). A linear/granular sinusoidal pattern of C4d IF was noted in 18 of 28 biopsy samples obtained after transplantation from patients with positive crossmatch and detectable donor-specific alloantibody (pos-XM/DSA) findings. None of the 59 tested biopsy samples from patients with negative crossmatch and detectable donor-specific alloantibody (neg-XM/DSA) findings were C4d-positive (P < 0.001). No significant association was found between pos-XM/DSA and C4d IF staining in other nonsinusoidal liver compartments. To compare the results of sinusoidal C4d staining with IF and 2 immunohistochemistry (IHC) techniques, C4d IHC was performed on 19 liver allograft biopsy samples in which a sinusoidal pattern of C4d IF had been noted. Sinusoidal C4d IHC findings were negative for 17 of the 19 biopsy samples; 2 showed weak and focal staining, and both patients had pos-XM/DSA findings. Portal vein endothelium staining was present in only 1 IF-stained biopsy sample (pos-XM/DSA) but in 11 IHC-stained biopsy samples (2 of the 11 samples had neg-XM/DSA findings). We conclude that sinusoidal C4d deposits detected by IF in frozen tissue samples from liver allograft recipients correlate with the presence of DSAs and an antibody-mediated alloresponse. These observations are similar to findings reported for other solid organ transplants and can provide relevant information for patient management. Further validation of IHC techniques for C4d detection in liver allograft tissue is required.


Assuntos
Complemento C4b/imunologia , Complemento C4b/metabolismo , Rejeição de Enxerto/diagnóstico , Transplante de Fígado , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Adolescente , Adulto , Idoso , Especificidade de Anticorpos , Ductos Biliares Intra-Hepáticos/imunologia , Ductos Biliares Intra-Hepáticos/metabolismo , Biomarcadores/metabolismo , Feminino , Imunofluorescência , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/metabolismo , Humanos , Fígado/imunologia , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Veia Porta/imunologia , Veia Porta/metabolismo , Valor Preditivo dos Testes , Transplante Homólogo , Adulto Jovem
14.
Int Urol Nephrol ; 54(3): 637-646, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34216339

RESUMO

PURPOSE: We conducted this observational study to examine the impact of antibody inductions administered at kidney transplant (KT) on outcomes of 5 year exposure to post-transplant diabetes (PTDM) in adult deceased-donor kidney transplant recipients (DDKTRs). We also studied the risk of PTDM associated with antibody inductions. METHODS: Using 2000-2016 Organ Procurement Transplantation Network data, we employed multivariable Cox models to determine the adjusted hazard ratios (HR) of death, and overall and death-censored graft loss (OAGL, DCGL; respectively) at the 5 year landmark period in antibody induction cohorts with and without PTDM at the 1 year post-transplant index time point. We used multivariable logistic regression in determining the risk factors for PTDM. All multivariable analyses were adjusted for the potential confounding effects of maintenance immunosuppression, steroid regimens, and other relevant covariates. RESULTS: 48,031 adult DDKTRs were classified into cohorts based on antibody induction at transplant: (anti-thymocyte globulin) ATG (n = 26, 788); (alemtuzumab) ALM (n = 5916); and interleukin-2 receptor antagonist (IL-2RA) (n = 15,327). PTDM was a risk factor for 5 year OAGL and death, not DCGL [(HR = 1.25, CI = 1.16-1.36), (HR = 1.13, CI = 1.06-1.21), and (HR = 1.05, CI = 0.96-1.16); respectively]. Induction regimens were not risk factors for 5 year outcomes in DDKTRs with and without PTDM. Risk factors for PTDM included DDKTR obesity, age > / = 50 years, acute rejection, and ATG induction, among others. CONCLUSIONS: In adult DDKTRs, after controlling the confounding effects of clinically relevant variables including maintenance and steroid regimens, PTDM at 1 year post-transplant is associated with death and OAGL, not DCGL in the following 5 years: induction received at KT did not modify these associations.


Assuntos
Alemtuzumab/efeitos adversos , Soro Antilinfocitário/efeitos adversos , Diabetes Mellitus/induzido quimicamente , Diabetes Mellitus/imunologia , Fatores Imunológicos/efeitos adversos , Transplante de Rim , Complicações Pós-Operatórias/induzido quimicamente , Complicações Pós-Operatórias/imunologia , Receptores de Interleucina-2/antagonistas & inibidores , Adolescente , Adulto , Anticorpos , Diabetes Mellitus/epidemiologia , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Sistema de Registros , Medição de Risco , Adulto Jovem
15.
Liver Transpl ; 17(4): 357-68, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21445918

RESUMO

The importance of antibody-mediated rejection (AMR) in ABO-compatible liver transplantation is controversial. Here we report a prospective series of liver recipients with a preoperative positive crossmatch. To establish the diagnosis of AMR in liver recipients, the criteria described for kidney allografts were adopted. In approximately 10% of 197 liver transplants, we observed a positive T and B cell flow crossmatch before transplantation. Fifteen of 19 patients converted to negative crossmatches early after transplantation and displayed normal liver function while they were on routine immunosuppression. Four patients maintained positive crossmatches. Three of the 4 met the criteria for AMR and showed evidence of graft dysfunction, the presence of donor-specific antibodies (DSAs), morphological tissue destruction with positive C4d linear staining on the graft sinusoidal endothelium, and improved function with attempts to eliminate DSAs. A persistently positive crossmatch after liver transplantation may lead to early, severe AMR and liver failure. C4d staining in the liver sinusoidal endothelium should alert one to the possibility of AMR. In our experience, patients with a positive crossmatch should have it repeated at 2 weeks and, if it is positive, again at 3 to 5 weeks. Recipients with an unknown preoperative crossmatch who develop early cholestasis of unclear etiology should be crossmatched or tested for the presence of DSAs to evaluate for AMR.


Assuntos
Complemento C4b/análise , Rejeição de Enxerto/etiologia , Isoanticorpos/imunologia , Transplante de Fígado/efeitos adversos , Fragmentos de Peptídeos/análise , Doadores de Tecidos , Adulto , Teste de Histocompatibilidade , Humanos , Isoanticorpos/sangue , Pessoa de Meia-Idade , Transplante Homólogo
16.
CEN Case Rep ; 10(4): 483-489, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33728600

RESUMO

In recent times, increasing reports of exit site infections (ESI) in peritoneal dialysis (PD) patients related to environmentally acquired atypical organisms, such as nontuberculous mycobacterium (NTM), have been reported in the literature. Among these NTM, Mycobacterium abscessus (M. abscessus) is unique and is associated with high morbidity and treatment failure rates. The international society of PD guidelines suggests individualizing therapeutic options for NTM-related ESI. Moreover, the guidelines encourage simultaneous catheter removal and reinsertion (SCRR) in isolated ESI, not responding to antimicrobial therapy to avoid PD interruptions. Physicians should be aware of the limitations of such approaches as delay in appropriate PD catheter intervention can be fraught with complications in patients with M. abscessus ESI. We report an M. abscessus ESI in a PD patient who underwent SCRR in conjunction with targeted antimicrobial therapy, and developed M. abscessus peritonitis requiring PD catheter removal and conversion to hemodialysis. The patient also developed ESI at the new exit site long after the PD catheter was removed, requiring prolonged antimicrobial therapy. Our case, taken together with available published case reports, highlights the futility of the SCRR approach towards the M. abscessus ESI and makes the cases for early PD catheter removal in these patients.


Assuntos
Infecções Relacionadas a Cateter/terapia , Infecções por Mycobacterium não Tuberculosas/terapia , Mycobacterium abscessus/isolamento & purificação , Idoso , Infecções Relacionadas a Cateter/microbiologia , Humanos , Masculino , Infecções por Mycobacterium não Tuberculosas/microbiologia , Diálise Peritoneal/instrumentação , Falha de Tratamento
17.
J Am Coll Surg ; 232(4): 526-534, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33444709

RESUMO

BACKGROUND: Previous studies have demonstrated disparities in transplantation for women, non-Caucasians, the uninsured or publicly insured, and rural populations. We sought to correlate transplant center characteristics with patient access to the waiting list and liver transplantation. We hypothesized that liver transplant centers vary greatly in providing equitable access to the waiting list and liver transplantation. STUDY DESIGN: Center-specific, adult, deceased-donor liver transplant and waitlist data for the years 2013 to 2018 were obtained from the United Network for Organ Sharing. Waitlist race/ethnicity distributions from liver transplant centers performing ≥ 250 transplants over this period (n = 109) were compared with those of their donor service area, as calculated from 5-year US Census Bureau estimates of 2017. Center-specific characteristics correlating with disparities were analyzed using a linear regression model with a log transformed outcome. RESULTS: Non-Hispanic Blacks (NHBs) are under-represented in liver transplant listing compared with center donation service area (88/109, 81%), whereas, non-Hispanic Whites are over-represented (65/109, 58%) (p < 0.0001). Hispanics were also under-represented on the waitlist at the majority of transplant centers (68/109, 62%) (p = 0.02). Although the racial/ethnic distribution of transplantation is more reflective of the waitlist, there is a higher than expected rate of transplantation for NHBs compared to the waitlist. Predictors of disparity in listing include percentage of transplant recipients at the center who had private insurance, racial composition of the donation service area, and the distance recipients had to travel for transplant. CONCLUSIONS: Non-Hispanic Blacks are listed for liver transplantation less than would be expected. Once listed, however, racial disparities in transplantation are greatly diminished. Improvements in access to adequate health insurance appear to be essential to diminishing disparities in access to this life-saving care.


Assuntos
Doença Hepática Terminal/cirurgia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Disparidades em Assistência à Saúde/estatística & dados numéricos , Transplante de Fígado/estatística & dados numéricos , População Negra/estatística & dados numéricos , Escolaridade , Doença Hepática Terminal/diagnóstico , Feminino , Acessibilidade aos Serviços de Saúde/economia , Disparidades em Assistência à Saúde/economia , Hispânico ou Latino/estatística & dados numéricos , Humanos , Cobertura do Seguro/estatística & dados numéricos , Transplante de Fígado/economia , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Estados Unidos , Listas de Espera , População Branca/estatística & dados numéricos
18.
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.

19.
Liver Transpl ; 16(12): 1428-33, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21117253

RESUMO

Primary liver allograft nonfunction immediately after transplantation poses a life-threatening situation for the recipient. Emergency retransplantation may not be immediately possible due to organ unavailability. Total hepatectomy with temporary portacaval shunt has been described as a bridge to retransplantation when the presence of the graft appears to be harming the recipient. Case reports of retransplantation after total hepatectomy with anhepatic times greater than 48 hours routinely describe poor outcomes. We present a case with excellent patient outcome after 95 hours of clinical anhepatic state, including 67 hours of anatomical anhepatic time, because of primary liver allograft nonfunction. This case report documents the longest anhepatic time with subsequent successful transplant to date.


Assuntos
Hepatopatias/cirurgia , Transplante de Fígado/fisiologia , Fígado/fisiopatologia , Sobreviventes , Adulto , Feminino , Hepatectomia , Humanos , Fígado/cirurgia , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Transplante Homólogo , Resultado do Tratamento
20.
Clin Transplant ; 24(1): 23-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19919609

RESUMO

The evolution of organ transplantation has produced results so successful that many transplant programs commonly see recipients with medical risks, which in the past, would have prohibited transplantation. The Eighth Annual American Society of Transplant Surgeons State-of-the-Art Winter Symposium focused on the high-risk recipient. The assessment of risk has evolved over time, as transplantation has matured. The acceptance of risk associated with a given candidate today is often made in consideration of the relative value of the organ to other candidates, the regulatory environment, and philosophical notions of utility, equity, and fairness. In addition, transplant programs must balance outcomes, transplant volume, and the costs of organ transplantation, which are impacted by high-risk recipients. Discussion focused on various types of high-risk recipients, such as those with coronary artery disease, morbid obesity, and hepatitis C; strategies to reduce risk, such as down-staging of hepatocellular carcinoma and treatment of pulmonary hypertension; the development of alternatives to transplantation; and the degree to which risk can or should be used to define candidate selection. These approaches can modify the impact of recipient risk on transplant outcomes and permit transplantation to be applied successfully to a greater variety of patients.


Assuntos
Transplante de Órgãos , Seleção do Doador , Humanos , Doadores Vivos , Transplante de Órgãos/efeitos adversos , Transplante de Órgãos/economia , Transplante de Órgãos/métodos , Seleção de Pacientes , Medição de Risco , Fatores de Risco
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