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Thongprayoon C, Vaitla P, Jadlowiec CC, Leeaphorn N, Mao SA, Mao MA, Pattharanitima P, Bruminhent J, Khoury NJ, Garovic VD, Cooper M, Cheungpasitporn W. Use of Machine Learning Consensus Clustering to Identify Distinct Subtypes of Black Kidney Transplant Recipients and Associated Outcomes. JAMA Surg 2022; 157:e221286. [PMID: 35507356 PMCID: PMC9069346 DOI: 10.1001/jamasurg.2022.1286] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Importance Among kidney transplant recipients, Black patients continue to have worse graft function and reduced patient and graft survival. Better understanding of different phenotypes and subgroups of Black kidney transplant recipients may help the transplant community to identify individualized strategies to improve outcomes among these vulnerable groups. Objective To cluster Black kidney transplant recipients in the US using an unsupervised machine learning approach. Design, Setting, and Participants This cohort study performed consensus cluster analysis based on recipient-, donor-, and transplant-related characteristics in Black kidney transplant recipients in the US from January 1, 2015, to December 31, 2019, in the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Each cluster's key characteristics were identified using the standardized mean difference, and subsequently the posttransplant outcomes were compared among the clusters. Data were analyzed from June 9 to July 17, 2021. Exposure Machine learning consensus clustering approach. Main Outcomes and Measures Death-censored graft failure, patient death within 3 years after kidney transplant, and allograft rejection within 1 year after kidney transplant. Results Consensus cluster analysis was performed for 22 687 Black kidney transplant recipients (mean [SD] age, 51.4 [12.6] years; 13 635 men [60%]), and 4 distinct clusters that best represented their clinical characteristics were identified. Cluster 1 was characterized by highly sensitized recipients of deceased donor kidney retransplants; cluster 2, by recipients of living donor kidney transplants with no or short prior dialysis; cluster 3, by young recipients with hypertension and without diabetes who received young deceased donor transplants with low kidney donor profile index scores; and cluster 4, by older recipients with diabetes who received kidneys from older donors with high kidney donor profile index scores and extended criteria donors. Cluster 2 had the most favorable outcomes in terms of death-censored graft failure, patient death, and allograft rejection. Compared with cluster 2, all other clusters had a higher risk of death-censored graft failure and death. Higher risk for rejection was found in clusters 1 and 3, but not cluster 4. Conclusions and Relevance In this cohort study using an unsupervised machine learning approach, the identification of clinically distinct clusters among Black kidney transplant recipients underscores the need for individualized care strategies to improve outcomes among vulnerable patient groups.
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Affiliation(s)
- Charat Thongprayoon
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | - Pradeep Vaitla
- Division of Nephrology, University of Mississippi Medical Center, Jackson
| | | | - Napat Leeaphorn
- Renal Transplant Program, University of Missouri-Kansas City School of Medicine, Saint Luke's Health System
| | - Shennen A Mao
- Division of Transplant Surgery, Mayo Clinic, Jacksonville, Florida
| | - Michael A Mao
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Jacksonville, Florida
| | | | - Jackrapong Bruminhent
- Ramathibodi Excellence Center for Organ Transplantation, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Division of Infectious Diseases, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Nadeen J Khoury
- Department of Nephrology, Department of Medicine, Henry Ford Hospital, Detroit, Michigan
| | - Vesna D Garovic
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, Minnesota
| | | | - Wisit Cheungpasitporn
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, Minnesota
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Marlais M, Martin K, Marks SD. Improved renal allograft survival for pre-emptive paediatric renal transplant recipients in the UK. Arch Dis Child 2021; 106:1191-1194. [PMID: 34016592 PMCID: PMC8666698 DOI: 10.1136/archdischild-2020-321277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/15/2021] [Accepted: 03/08/2021] [Indexed: 11/03/2022]
Abstract
BACKGROUND The aim of this study was to investigate whether being on dialysis at the time of renal transplantation affected renal allograft survival in paediatric renal transplant recipients (pRTRs). METHODS Retrospective study of UK Transplant Registry (National Health Service Blood and Transplant) data on all children (aged <18 years) receiving a kidney-only transplant from 1 January 2000 to 31 December 2015. Kaplan-Meier estimates of patient and renal allograft survival calculated and Cox regression modelling accounting for donor type. The relationship between time on dialysis and renal allograft survival was examined. RESULTS 2038 pRTRs were analysed: 607 (30%) were pre-emptively transplanted, 789 (39%) and 642 (32%) on peritoneal dialysis and haemodialysis, respectively, at the time of transplantation. Five-year renal allograft survival was significantly better in the pre-emptively transplanted group (90.6%) compared with those on peritoneal dialysis and haemodialysis (86.4% and 85.7%, respectively; p=0.02). After accounting for donor type, there was a significantly lower hazard of 5-year renal allograft failure in pre-emptively transplanted children (HR 0.742, p=0.05). Time spent on dialysis pre-transplant negatively correlated with renal allograft survival (p=0.002). There was no significant difference in 5-year renal allograft survival between children who were on dialysis for less than 6 months and children transplanted pre-emptively (87.5% vs 90.5%, p=0.25). CONCLUSIONS Pre-emptively transplanted children have improved 5-year renal allograft survival, compared with children on dialysis at the time of transplantation. Although increased time spent on dialysis correlated with poorer renal allograft survival, there was no evidence that short periods of dialysis pre-transplant affected renal allograft survival.
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Affiliation(s)
- Matko Marlais
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Kate Martin
- Statistics, NHS Blood and Transplant, Bristol, UK
| | - Stephen D Marks
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK .,NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, Great Ormond Street Institute of Child Health, London, UK
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3
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Koritzinsky EH, Tsuda H, Fairchild RL. Endogenous memory T cells with donor-reactivity: early post-transplant mediators of acute graft injury in unsensitized recipients. Transpl Int 2021; 34:1360-1373. [PMID: 33963616 PMCID: PMC8389524 DOI: 10.1111/tri.13900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/15/2021] [Accepted: 05/03/2021] [Indexed: 11/29/2022]
Abstract
The pretransplant presence of endogenous donor-reactive memory T cells is an established risk factor for acute rejection and poorer transplant outcomes. A major source of these memory T cells in unsensitized recipients is heterologously generated memory T cells expressing reactivity to donor allogeneic MHC molecules. Multiple clinical studies have shown that the pretransplant presence of high numbers of circulating endogenous donor-reactive memory T cells correlates with higher incidence of acute rejection and decreased graft function during the first-year post-transplant. These findings have spurred investigation in preclinical models to better understand mechanisms underlying endogenous donor-reactive memory T-cell-mediated allograft injury in unsensitized graft recipients. These studies have led to the identification of unique mechanisms underlying the activation of these memory T cells within allografts at early times after transplant. In particular, optimal activation to mediate acute allograft injury is dependent on the intensity of ischaemia-reperfusion injury. Therapeutic strategies directed at the recruitment and activation of endogenous donor-reactive memory T cells are effective in attenuating acute injury in allografts experiencing increased ischaemia-reperfusion injury in preclinical models and should be translatable to clinical transplantation.
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Affiliation(s)
- Erik H. Koritzinsky
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Hidetoshi Tsuda
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Robert L. Fairchild
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
- Transplant Center, Cleveland Clinic, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
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4
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Donor-specific ELISPOT assay for predicting acute rejection and allograft function after kidney transplantation: A systematic review and meta-analysis. Clin Biochem 2021; 94:1-11. [PMID: 33882287 DOI: 10.1016/j.clinbiochem.2021.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 12/29/2022]
Abstract
Acute rejection remains an important problem after kidney transplantation. Enzyme-linked immunosorbent spot (ELISPOT) assay has been investigated extensively and has shown promising results as a predictor of allograft rejection. The objective of this study was to systematically review and analyze the predictive value of the donor-specific ELISPOT assay to identify recipients at risk for acute rejection. Electronic databases were searched for studies reporting donor-specific ELISPOT and kidney transplantation outcomes. Odds ratio (OR) for acute rejection was calculated, along with standardized mean difference (SMD) of cytokine producing-cells between recipients with and without acute rejection. Pooled estimates were calculated using random-effect models. The positive ELISPOT cutoff frequencies were extracted from each study. From 665 articles found, 32 studies were included in the meta-analysis. IFN-γ was the most investigated cytokine (30 out of 32 studies). Patients with positive pre-transplantation donor-reactive IFN-γ ELISPOT had an OR of 3.3 for acute rejection (95%-CI 2.1 to 5.1), and OR of 6.8 (95%-CI 2.5 to 18.9) for post-transplantation ELISPOT. Recipients with rejection had significantly higher frequencies of pre- and post-transplantation cytokine producing-cells (SMD 0.47, 95%-CI 0.07 to 0.87 and SMD 3.68, 95%-CI 1.04 to 6.32, respectively). Pre-transplantation ELISPOT had a positive predictive value of 43% and a negative predictive value of 81% for acute rejection. A positive ELISPOT result was associated with a lower estimated glomerular filtration rate (SMD -0.59, 95%-CI -0.83 to -0.34). In conclusion, patients with a high frequency of donor-reactive IFN-γ ELISPOT are at higher risk for acute rejection. The donor-specific IFN-γ ELISPOT assay can serve as an immune-monitoring tool in kidney transplantation.
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Artemov DV, Zulkarnaev AB, Vatazin AV. Age-related features of the pattern of lymphocyte subpopulations and functional activity of peripheral blood mononuclear cells in patients with chronic kidney disease before and after transplantation. RUSSIAN JOURNAL OF TRANSPLANTOLOGY AND ARTIFICIAL ORGANS 2020. [DOI: 10.15825/1995-1191-2020-1-40-49] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- D. V. Artemov
- M.F. Vladimirsky Moscow Regional Clinical and Research Institute
| | - A. B. Zulkarnaev
- M.F. Vladimirsky Moscow Regional Clinical and Research Institute
| | - A. V. Vatazin
- M.F. Vladimirsky Moscow Regional Clinical and Research Institute
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6
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Pretransplant Donor-specific IFNγ ELISPOT as a Predictor of Graft Rejection: A Diagnostic Test Accuracy Meta-analysis. Transplant Direct 2019; 5:e451. [PMID: 31165086 PMCID: PMC6511445 DOI: 10.1097/txd.0000000000000886] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 02/18/2019] [Indexed: 12/15/2022] Open
Abstract
Supplemental Digital Content is available in the text. Background. Pretransplant interferon-γ enzyme-linked immunospot (IFN-γ ELISPOT) has been proposed as a tool to quantify alloreactive memory T cells and estimate the risk of acute rejection (AR) after kidney transplantation, but studies have been inconclusive so far. We performed a meta-analysis to evaluate the association between pretransplant IFN-γ ELISPOT and AR and assess its predictive accuracy at the individual level. Methods. We estimated the pooled summary of odds ratio for AR and the joined sensitivity and specificity for predicting AR using random-effects and hierarchical summary receiver-operating characteristic models. We used meta-regression models with the Monte Carlo permutation method to adjust for multiple tests to explain sensitivity and specificity heterogeneity across studies. The meta-analytic estimates of sensitivity and specificity were used to calculate positive and negative predictive values across studies. Results. The analysis included 12 studies and 1181 patients. IFN-γ ELISPOT was significantly associated with increased AR risk (odds ratio: 3.29; 95% confidence interval (CI), 2.34-4.60); hierarchical summary receiver operating characteristic jointly estimated sensitivity and specificity values were 64.9% (95% CI, 53.7%-74.6%) and 65.8% (95% CI, 57.4%-73.5%), respectively, with moderate heterogeneity across studies. After adjusting for multiple testing, meta-regression models showed that thymoglobulin induction, recipient black ethnicity, living versus deceased donors, and geographical location did not affect sensitivity or specificity. Because of the varying AR incidence of the studies, positive and negative predictive values ranged between 16%–60% and 70%–95%, respectively. Conclusions. Pretransplant IFN-γ ELISPOT is significantly associated with increased risk of AR but provides suboptimal predictive ability at an individual level. Prospective randomized clinical trials are warranted.
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7
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Lin HT, Liu FC, Lin JR, Pang ST, Yu HP. Impact of the pretransplant dialysis modality on kidney transplantation outcomes: a nationwide cohort study. BMJ Open 2018; 8:e020558. [PMID: 29866727 PMCID: PMC5988177 DOI: 10.1136/bmjopen-2017-020558] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Most patients with uraemia must undergo chronic dialysis while awaiting kidney transplantation; however, the role of the pretransplant dialysis modality on the outcomes of kidney transplantation remains obscure. The objective of this study was to clarify the associations between the pretransplant dialysis modality, namely haemodialysis (HD) or peritoneal dialysis (PD), and the development of post-transplant de novo diseases, allograft failure and all-cause mortality for kidney-transplant recipients. DESIGN Retrospective nationwide cohort study. SETTING Data retrieved from the Taiwan National Health Insurance Research Database. PARTICIPANTS The National Health Insurance database was explored for patients who received kidney transplantation in Taiwan during 1998-2011 and underwent dialysis >90 days before transplantation. OUTCOME MEASURES The pretransplant characteristics, complications during kidney transplantation and post-transplant outcomes were statistically analysed and compared between the HD and PD groups. Cox regression analysis was used to evaluate the HR of the dialysis modality on graft failure and all-cause mortality. The primary outcomes were long-term post-transplant death-censored allograft failure and all-cause mortality started after 90 days of kidney transplantation until the end of follow-up. The secondary outcomes were events during kidney transplantation and post-transplant de novo diseases adjusted by propensity score in log-binomial model. RESULTS There were 1812 patients included in our cohort, among which 1209 (66.7%) and 603 (33.3%) recipients received pretransplant HD and PD, respectively. Recipients with chronic HD were generally older and male, had higher risks of developing post-transplant de novo ischaemic heart disease, tuberculosis and hepatitis C after adjustment. Pretransplant HD contributed to higher graft failure in the multivariate analysis (HR 1.38, p<0.05) after adjustment for the recipient age, sex, duration of dialysis and pretransplant diseases. There was no significant between-group difference in overall survival. CONCLUSIONS Pretransplant HD contributed to higher risks of death-censored allograft failure after kidney transplantation when compared with PD.
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Affiliation(s)
- Huan-Tang Lin
- Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Fu-Chao Liu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Jr-Rung Lin
- Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Clinical Informatics and Medical Statistics Research Center, Graduate Institute of Clinical Medicine, Chang Gung University, Taoyuan, Taiwan
| | - See-Tong Pang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Urology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Huang-Ping Yu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Anesthesiology, Xiamen Changgung Hospital, Taoyuan, Taiwan
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8
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Nutritional treatment of advanced CKD: twenty consensus statements. J Nephrol 2018; 31:457-473. [PMID: 29797247 PMCID: PMC6061255 DOI: 10.1007/s40620-018-0497-z] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/04/2018] [Indexed: 12/12/2022]
Abstract
The Italian nephrology has a long tradition and experience in the field of dietetic-nutritional therapy (DNT), which is an important component in the conservative management of the patient suffering from a chronic kidney disease, which precedes and integrates the pharmacological therapies. The objectives of DNT include the maintenance of an optimal nutritional status, the prevention and/or correction of signs, symptoms and complications of chronic renal failure and, possibly, the delay in starting of dialysis. The DNT includes modulation of protein intake, adequacy of caloric intake, control of sodium and potassium intake, and reduction of phosphorus intake. For all dietary-nutritional therapies, and in particular those aimed at the patient with chronic renal failure, the problem of patient adherence to the dietetic-nutritional scheme is a key element for the success and safety of the DNT and it can be favored by an interdisciplinary and multi-professional approach of information, education, dietary prescription and follow-up. This consensus document, which defines twenty essential points of the nutritional approach to patients with advanced chronic renal failure, has been written, discussed and shared by the Italian nephrologists together with representatives of dietitians (ANDID) and patients (ANED).
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Fischer M, Leyking S, Schäfer M, Elsäßer J, Janssen M, Mihm J, van Bentum K, Fliser D, Sester M, Sester U. Donor-specific alloreactive T cells can be quantified from whole blood, and may predict cellular rejection after renal transplantation. Eur J Immunol 2017; 47:1220-1231. [PMID: 28426152 DOI: 10.1002/eji.201646826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/06/2017] [Accepted: 04/18/2017] [Indexed: 11/07/2022]
Abstract
Preformed cellular alloreactivity can exist prior to transplantation and may contribute to rejection. Here, we used a rapid flow-cytometric whole-blood assay to characterize the extent of alloreactive T cells among 1491 stimulatory reactions from 61 renal transplant candidates and 75 controls. The role of preformed donor-specific alloreactive T cells in cellular rejection was prospectively analyzed in 21 renal transplant recipients. Alloreactive CD8+ T cells were more frequent than respective CD4+ T cells, and these levels were stable over time. CD8+ T cells were effector-memory T cells largely negative for expression of CD27, CD62L, and CCR7, and were susceptible to steroid and calcineurin inhibitor inhibition. Alloreactivity was more frequent in samples with higher number of HLA mismatches. Moreover, the percentage of individuals with alloreactive T cells was higher in transplant candidates than in controls. Among transplant candidates, 5/61 exhibited alloreactive CD8+ T cells against most stimulators, 23/61 toward a limited number of stimulators, and 33/61 did not show any alloreactivity. Among 21 renal transplant recipients followed prospectively, one had donor-specific preformed T-cell alloreactivity. She was the only patient who developed cellular rejection posttransplantation. In conclusion, donor-specific alloreactive T cells may be rapidly quantified from whole blood, and may predict cellular rejection after transplantation.
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Affiliation(s)
- Michaela Fischer
- Department of Transplant and Infection Immunology, Saarland University, Homburg, Germany
| | - Sarah Leyking
- Department of Internal Medicine IV, Saarland University, Homburg, Germany
| | - Marco Schäfer
- HLA-Laboratory, Stefan-Morsch-Stiftung, Birkenfeld, Germany
| | - Julia Elsäßer
- Department of Transplant and Infection Immunology, Saarland University, Homburg, Germany
| | - Martin Janssen
- Department of Urology and Paediatric Urology, Saarland University, Homburg, Germany
| | - Janine Mihm
- Department of Internal Medicine IV, Saarland University, Homburg, Germany
| | - Kai van Bentum
- Department of Transplant and Infection Immunology, Saarland University, Homburg, Germany.,Department of Internal Medicine IV, Saarland University, Homburg, Germany
| | - Danilo Fliser
- Department of Internal Medicine IV, Saarland University, Homburg, Germany
| | - Martina Sester
- Department of Transplant and Infection Immunology, Saarland University, Homburg, Germany
| | - Urban Sester
- Department of Internal Medicine IV, Saarland University, Homburg, Germany
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Benichou G, Gonzalez B, Marino J, Ayasoufi K, Valujskikh A. Role of Memory T Cells in Allograft Rejection and Tolerance. Front Immunol 2017; 8:170. [PMID: 28293238 PMCID: PMC5328996 DOI: 10.3389/fimmu.2017.00170] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/02/2017] [Indexed: 12/30/2022] Open
Abstract
Memory T cells are characterized by their low activation threshold, robust effector functions, and resistance to conventional immunosuppression and costimulation blockade. Unlike their naïve counterparts, memory T cells reside in and recirculate through peripheral non-lymphoid tissues. Alloreactive memory T cells are subdivided into different categories based on their origins, phenotypes, and functions. Recipients whose immune systems have been directly exposed to allogeneic major histocompatibility complex (MHC) molecules display high affinity alloreactive memory T cells. In the absence of any prior exposure to allogeneic MHC molecules, endogenous alloreactive memory T cells are regularly generated through microbial infections (heterologous immunity). Regardless of their origin, alloreactive memory T cells represent an essential element of the allograft rejection process and a major barrier to tolerance induction in clinical transplantation. This article describes the different subsets of alloreactive memory T cells involved in transplant rejection and examine their generation, functional properties, and mechanisms of action. In addition, we discuss strategies developed to target deleterious allospecific memory T cells in experimental animal models and clinical settings.
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Affiliation(s)
- Gilles Benichou
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Bruno Gonzalez
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Jose Marino
- Center for Transplantation Sciences, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Katayoun Ayasoufi
- Department of Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Anna Valujskikh
- Department of Immunology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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Abstract
PURPOSE OF REVIEW Altered differentiation and activation of T-cell subsets occur in patients with chronic kidney disease (CKD), but the impact on graft rejection and protective immunity during transplantation are not fully understood. RECENT FINDINGS Patients with CKD have decreased frequency of naïve T cells, accumulation of activated, terminally differentiated memory cells, and skewed regulatory versus T helper 17 ratio. Naïve and memory T-cell subsets do not appear to improve following kidney transplantation. Retained thymic output is associated with acute rejection, whereas naïve lymphopenia and accumulation of CD8 TEMRA cells correlate with long-term graft dysfunction. CD28 memory cells accumulate during CKD and appear to confer protection against acute rejection under standard immunosuppression and possibly costimulation blockade. T cells bearing CD57 are also increased in patients with CKD and may underlie rejection during costimulation blockade. SUMMARY The mechanisms by which CKD alters the differentiation and activation status of T-cell subsets is poorly understood. Further research is also needed to understand which cell populations mediate rejection under various immunosuppressive regimens. To date, there is little use of animal models of organ failure in transplant immunology research. CKD mouse models may help identify novel pathways and targets to better control alloimmunity in posttransplant.
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Affiliation(s)
- Pamela D Winterberg
- aPediatric Nephrology, Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta bEmory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, Georgia, USA
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Menon MC, Murphy B, Heeger PS. Moving Biomarkers toward Clinical Implementation in Kidney Transplantation. J Am Soc Nephrol 2017; 28:735-747. [PMID: 28062570 DOI: 10.1681/asn.2016080858] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Long-term kidney transplant outcomes remain suboptimal, delineating an unmet medical need. Although current immunosuppressive therapy in kidney transplant recipients is effective, dosing is conventionally adjusted empirically on the basis of time after transplant or altered in response to detection of kidney dysfunction, histologic evidence of allograft damage, or infection. Such strategies tend to detect allograft rejection after significant injury has already occurred, fail to detect chronic subclinical inflammation that can negatively affect graft survival, and ignore specific risks and immune mechanisms that differentially contribute to allograft damage among transplant recipients. Assays and biomarkers that reliably quantify and/or predict the risk of allograft injury have the potential to overcome these deficits and thereby, aid clinicians in optimizing immunosuppressive regimens. Herein, we review the data on candidate biomarkers that we contend have the highest potential to become clinically useful surrogates in kidney transplant recipients, including functional T cell assays, urinary gene and protein assays, peripheral blood cell gene expression profiles, and allograft gene expression profiles. We identify barriers to clinical biomarker adoption in the transplant field and suggest strategies for moving biomarker-based individualization of transplant care from a research hypothesis to clinical implementation.
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Affiliation(s)
- Madhav C Menon
- Renal Division, Department of Medicine, Translational Transplant Research Center, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Barbara Murphy
- Renal Division, Department of Medicine, Translational Transplant Research Center, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Peter S Heeger
- Renal Division, Department of Medicine, Translational Transplant Research Center, Icahn School of Medicine at Mount Sinai, New York, New York
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13
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Bestard O, Cravedi P. Monitoring alloimmune response in kidney transplantation. J Nephrol 2016; 30:187-200. [PMID: 27245689 DOI: 10.1007/s40620-016-0320-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 05/15/2016] [Indexed: 01/22/2023]
Abstract
Currently, immunosuppressive therapy in kidney transplant recipients is generally performed by protocols and adjusted according to functional or histological evaluation of the allograft and/or signs of drug toxicity or infection. As a result, a large fraction of patients are likely to receive too much or too little immunosuppression, exposing them to higher rates of infection, malignancy and drug toxicity, or increased risk of acute and chronic graft injury from rejection, respectively. Developing reliable biomarkers is crucial for individualizing therapy aimed at extending allograft survival. Emerging data indicate that many assays, likely used in panels rather than single assays, have potential to be diagnostic and predictive of short and also long-term outcome. While numerous cross-sectional studies have found associations between the results of these assays and the presence of clinically relevant post-transplantation outcomes, data from prospective studies are still scanty, thereby preventing widespread implementation in the clinic. Of note, some prospective, randomized, multicenter biomarker-driven studies are currently on-going aiming at confirming such preliminary data. These works as well as other future studies are highly warranted to test the hypothesis that tailoring immunosuppression on the basis of results offered by these biomarkers leads to better outcomes than current standard clinical practice.
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Affiliation(s)
- Oriol Bestard
- Kidney Transplant Unit, Nephrology Department, Bellvitge University Hospital, Barcelona University, IDIBELL, Barcelona, Spain
| | - Paolo Cravedi
- Renal Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, Annenberg Building, New York, NY, 10029, USA.
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14
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Starling RC, Stehlik J, Baran DA, Armstrong B, Stone JR, Ikle D, Morrison Y, Bridges ND, Putheti P, Strom TB, Bhasin M, Guleria I, Chandraker A, Sayegh M, Daly KP, Briscoe DM, Heeger PS. Multicenter Analysis of Immune Biomarkers and Heart Transplant Outcomes: Results of the Clinical Trials in Organ Transplantation-05 Study. Am J Transplant 2016; 16:121-36. [PMID: 26260101 PMCID: PMC4948061 DOI: 10.1111/ajt.13422] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 05/20/2015] [Accepted: 06/14/2015] [Indexed: 01/25/2023]
Abstract
Identification of biomarkers that assess posttransplant risk is needed to improve long-term outcomes following heart transplantation. The Clinical Trials in Organ Transplantation (CTOT)-05 protocol was an observational, multicenter, cohort study of 200 heart transplant recipients followed for the first posttransplant year. The primary endpoint was a composite of death, graft loss/retransplantation, biopsy-proven acute rejection (BPAR), and cardiac allograft vasculopathy (CAV) as defined by intravascular ultrasound (IVUS). We serially measured anti-HLA- and auto-antibodies, angiogenic proteins, peripheral blood allo-reactivity, and peripheral blood gene expression patterns. We correlated assay results and clinical characteristics with the composite endpoint and its components. The composite endpoint was associated with older donor allografts (p < 0.03) and with recipient anti-HLA antibody (p < 0.04). Recipient CMV-negativity (regardless of donor status) was associated with BPAR (p < 0.001), and increases in plasma vascular endothelial growth factor-C (OR 20; 95%CI:1.9-218) combined with decreases in endothelin-1 (OR 0.14; 95%CI:0.02-0.97) associated with CAV. The remaining biomarkers showed no relationships with the study endpoints. While suboptimal endpoint definitions and lower than anticipated event rates were identified as potential study limitations, the results of this multicenter study do not yet support routine use of the selected assays as noninvasive approaches to detect BPAR and/or CAV following heart transplantation.
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Affiliation(s)
| | - Josef Stehlik
- University of Utah Health Sciences Center, Salt Lake City UT
| | | | | | | | | | - Yvonne Morrison
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville MD
| | - Nancy D. Bridges
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville MD
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15
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Crespo E, Bestard O. Biomarkers to assess donor-reactive T-cell responses in kidney transplant patients. Clin Biochem 2015; 49:329-37. [PMID: 26279496 DOI: 10.1016/j.clinbiochem.2015.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 07/23/2015] [Accepted: 08/09/2015] [Indexed: 02/07/2023]
Abstract
Different to antibody-mediated rejection (ABMR), T-cell mediated rejection (TCMR) still unpredictably occurs after kidney transplantation in a great part because of a poor immunologic evaluation of the cellular allogeneic immune response. However, in the last years, important efforts have focused on the development of novel and more sensitive assays to monitor T-cell alloimmune responses at different biological levels that may improve the understanding of the functional status of the cellular immune compartment in patients undergoing organ transplantation. In this direction, immune assays evaluating T-cell proliferation, intracellular ATP release, multiparameter flow cytometry, profiling T-cell receptor repertoires and measurements of frequencies of cytokine-producing T-cells using an IFN-γ enzyme-linked immunospot assay (IFN-γ ELISPOT) have been reported showing interesting associations between the cellular alloimmune response and kidney transplant outcomes. In summary, an important progress has been made in the assessment of alloreactive T-cell responses in the context of organ transplantation using novel immune assays at different biological levels. However, there is an urgent need for prospective, randomized clinical studies to validate these encouraging preliminary data to ultimately introduce them in current clinical practice for refining current immune-risk stratification in kidney transplantation.
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Affiliation(s)
- Elena Crespo
- Laboratory of Experimental Nephrology, IDIBELL, Barcelona, Spain
| | - Oriol Bestard
- Laboratory of Experimental Nephrology, IDIBELL, Barcelona, Spain; Kidney Transplant Unit, Nephrology Department, Bellvitge University Hospital, Barcelona University, Barcelona, Spain.
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16
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Pre-transplant donor-specific Interferon-gamma-producing cells and acute rejection of the kidney allograft. Transpl Immunol 2015; 33:63-8. [PMID: 26254561 DOI: 10.1016/j.trim.2015.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/31/2015] [Accepted: 07/31/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Our retrospective study included a cohort of 47 patients who underwent living donor kidney transplantation.The pre-transplant frequencies of donor-specific Interferon-gamma (IFN-γ) producing cells were define dusing enzyme-linked immunosorbent spot (ELISpot) assay and correlated with incidence of acute cellular(ACR), antibody-mediated rejection (AMR) and kidney graft survival up to one year after transplantation. RESULTS We found a statistically significant correlation between the frequencies of IFN-γ-producing cells and the number of mismatches in HLA antigens between patients and their respective donors – for Class I – A and B (r = 0.399, p b 0.01) and for Class I and Class II antigens – A, B and DR (r = 0.409, p b 0.01). No significant relationship was observed between the numbers of IFN-γ-secreting cells and incidence of acute rejection (neither ACR, nor AMR). However, there was a trend of elevated frequencies of IFN-γ-producing cells in patients who developed ACR or AMR in comparison with kidney recipients free of rejection (91 ± 82 and 114 ± 75 vs. 72 ± 70/5 × 10(4) peripheral blood mononuclear cells respectively). Patients with concurrent acute cellular and antibody-mediated rejection had also higher numbers of IFN-γ-producing memory/effector cells compared to patients with cellular rejection only. CONCLUSION Pre-transplant determination of the numbers of IFN-γ-producing donor-specific memory cells using the ELISpot technique may provide clinically relevant results when evaluating the risk of development of acute cellular and antibody-mediated rejection. These frequencies are influenced by the degree of HLA mismatching between patients and their respective kidney donors.
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Crespo E, Lucia M, Cruzado JM, Luque S, Melilli E, Manonelles A, Lloberas N, Torras J, Grinyó JM, Bestard O. Pre-transplant donor-specific T-cell alloreactivity is strongly associated with early acute cellular rejection in kidney transplant recipients not receiving T-cell depleting induction therapy. PLoS One 2015; 10:e0117618. [PMID: 25689405 PMCID: PMC4331510 DOI: 10.1371/journal.pone.0117618] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 12/29/2014] [Indexed: 01/08/2023] Open
Abstract
Preformed T-cell immune-sensitization should most likely impact allograft outcome during the initial period after kidney transplantation, since donor-specific memory T-cells may rapidly recognize alloantigens and activate the effector immune response, which leads to allograft rejection. However, the precise time-frame in which acute rejection is fundamentally triggered by preformed donor-specific memory T cells rather than by de novo activated naïve T cells is still to be established. Here, preformed donor-specific alloreactive T-cell responses were evaluated using the IFN-γ ELISPOT assay in a large consecutive cohort of kidney transplant patients (n = 90), to assess the main clinical variables associated with cellular sensitization and its predominant time-frame impact on allograft outcome, and was further validated in an independent new set of kidney transplant recipients (n = 67). We found that most highly T-cell sensitized patients were elderly patients with particularly poor HLA class-I matching, without any clinically recognizable sensitizing events. While one-year incidence of all types of biopsy-proven acute rejection did not differ between T-cell alloreactive and non-alloreactive patients, Receiver Operating Characteristic curve analysis indicated the first two months after transplantation as the highest risk time period for acute cellular rejection associated with baseline T-cell sensitization. This effect was particularly evident in young and highly alloreactive individuals that did not receive T-cell depletion immunosuppression. Multivariate analysis confirmed preformed T-cell sensitization as an independent predictor of early acute cellular rejection. In summary, monitoring anti-donor T-cell sensitization before transplantation may help to identify patients at increased risk of acute cellular rejection, particularly in the early phases after kidney transplantation, and thus guide decision-making regarding the use of induction therapy.
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Affiliation(s)
- Elena Crespo
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Marc Lucia
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Josep M. Cruzado
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
- Renal Transplant Unit, Nephrology department, Bellvitge University Hospital, Barcelona, Spain
| | - Sergio Luque
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Edoardo Melilli
- Renal Transplant Unit, Nephrology department, Bellvitge University Hospital, Barcelona, Spain
| | - Anna Manonelles
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
- Renal Transplant Unit, Nephrology department, Bellvitge University Hospital, Barcelona, Spain
| | - Nuria Lloberas
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Joan Torras
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
- Renal Transplant Unit, Nephrology department, Bellvitge University Hospital, Barcelona, Spain
| | - Josep M. Grinyó
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
- Renal Transplant Unit, Nephrology department, Bellvitge University Hospital, Barcelona, Spain
| | - Oriol Bestard
- Experimental Nephrology Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
- Renal Transplant Unit, Nephrology department, Bellvitge University Hospital, Barcelona, Spain
- * E-mail:
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Mehrotra A, Leventhal J, Purroy C, Cravedi P. Monitoring T cell alloreactivity. Transplant Rev (Orlando) 2014; 29:53-9. [PMID: 25475045 DOI: 10.1016/j.trre.2014.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 10/03/2014] [Accepted: 11/09/2014] [Indexed: 01/06/2023]
Abstract
Currently, immunosuppressive therapy in kidney transplant recipients is center-specific, protocol-driven, and adjusted according to functional or histological evaluation of the allograft and/or signs of drug toxicity or infection. As a result, a large fraction of patients receive too much or too little immunosuppression, exposing them to higher rates of infection, malignancy and drug toxicity, or increased risk of acute and chronic graft injury from rejection, respectively. The individualization of immunosuppression requires the development of assays able to reliably quantify and/or predict the magnitude of the recipient's immune response toward the allograft. As alloreactive T cells are central mediators of allograft rejection, monitoring T cell alloreactivity has become a priority for the transplant community. Among available assays, flow cytometry based phenotyping, T cell proliferation, T cell cytokine secretion, and ATP release (ImmuKnow), have been the most thoroughly tested. While numerous cross-sectional studies have found associations between the results of these assays and the presence of clinically relevant post-transplantation outcomes, data from prospective studies are still scanty, thereby preventing widespread implementation in the clinic. Future studies are required to test the hypothesis that tailoring immunosuppression on the basis of results offered by these biomarkers leads to better outcomes than current standard clinical practice.
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Affiliation(s)
- Anita Mehrotra
- Renal Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Jeremy Leventhal
- Renal Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Carolina Purroy
- Renal Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Paolo Cravedi
- Renal Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA.
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Effect of cholecalciferol supplementation on inflammation and cellular alloimmunity in hemodialysis patients: data from a randomized controlled pilot trial. PLoS One 2014; 9:e109998. [PMID: 25296334 PMCID: PMC4190314 DOI: 10.1371/journal.pone.0109998] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 09/02/2014] [Indexed: 12/15/2022] Open
Abstract
Background Memory T-cells are mediators of transplant injury, and no therapy is known to prevent the development of cross-reactive memory alloimmunity. Activated vitamin D is immunomodulatory, and vitamin D deficiency, common in hemodialysis patients awaiting transplantation, is associated with a heightened alloimmune response. Thus, we tested the hypothesis that vitamin D3 supplementation would prevent alloreactive T-cell memory formation in vitamin D-deficient hemodialysis patients. Methods and Findings We performed a 12-month single-center pilot randomized, controlled trial of 50,000 IU/week of cholecalciferol (D3) versus no supplementation in 96 hemodialysis patients with serum 25(OH)D<25 ng/mL, measuring effects on serum 25(OH)D and phenotypic and functional properties of T-cells. Participants were randomized 2∶1 to active treatment versus control. D3 supplementation increased serum 25(OH)D at 6 weeks (13.5 [11.2] ng/mL to 42.5 [18.5] ng/mL, p<0.001) and for the duration of the study. No episodes of sustained hypercalcemia occurred in either group. Results of IFNγ ELISPOT-based panel of reactive T-cell assays (PRT), quantifying alloreactive memory, demonstrated greater increases in the controls over 1 year compared to the treatment group (delta PRT in treatment 104.8+/−330.8 vs 252.9+/−431.3 in control), but these changes in PRT between groups did not reach statistical significance (p = 0.25). Conclusions D3 supplements are safe, effective at treating vitamin D deficiency, and may prevent time-dependent increases in T-cell alloimmunity in hemodialysis patients, but their effects on alloimmunity need to be confirmed in larger studies. These findings support the routine supplementation of vitamin D-deficient transplant candidates on hemodialysis and highlight the need for large-scale prospective studies of vitamin D supplementation in transplant candidates and recipients. Trial Registration Clinicaltrials.gov NCT01175798
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20
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Whitehouse G, Sanchez-Fueyo A. Postoperative Monitoring: Biomarkers and Alloimmune Responses and Their Relevance to Vascularized Composite Allotransplantation. CURRENT TRANSPLANTATION REPORTS 2014. [DOI: 10.1007/s40472-014-0022-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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21
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Bestard O, Crespo E, Stein M, Lúcia M, Roelen DL, de Vaal YJ, Hernandez-Fuentes MP, Chatenoud L, Wood KJ, Claas FH, Cruzado JM, Grinyó JM, Volk HD, Reinke P. Cross-validation of IFN-γ Elispot assay for measuring alloreactive memory/effector T cell responses in renal transplant recipients. Am J Transplant 2013; 13:1880-90. [PMID: 23763435 DOI: 10.1111/ajt.12285] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 02/12/2013] [Accepted: 03/25/2013] [Indexed: 01/25/2023]
Abstract
Assessment of donor-specific alloreactive memory/effector T cell responses using an IFN-γ Elispot assay has been suggested to be a novel immune-monitoring tool for evaluating the cellular immune risk in renal transplantation. Here, we report the cross-validation data of the IFN-γ Elispot assay performed within different European laboratories taking part of the EU RISET consortium. For this purpose, development of a standard operating procedure (SOP), comparisons of lectures of IFN-γ plates assessing intra- and interlaboratory assay variability of allogeneic or peptide stimuli in both healthy and kidney transplant individuals have been the main objectives. We show that the use of a same SOP and count-settings of the Elispot bioreader allow low coefficient variation between laboratories. Frozen and shipped samples display slightly lower detectable IFN-γ frequencies than fresh samples. Importantly, a close correlation between different laboratories is obtained when measuring high frequencies of antigen-specific primed/memory T cell alloresponses. Interestingly, significant high donor-specific alloreactive T cell responses can be similarly detected among different laboratories in kidney transplant patients displaying histological patterns of acute T cell mediated rejection. In conclusion, assessment of circulating alloreactive memory/effector T cells using an INF-γ Elispot assay can be accurately achieved using the same SOP, Elispot bioreader and experienced technicians in kidney transplantation.
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Affiliation(s)
- O Bestard
- Nephrology Department, Renal Transplant Unit, Bellvitge University Hospital, Barcelona University, Barcelona, Spain.
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22
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Bestard O, Cruzado JM, Lucia M, Crespo E, Casis L, Sawitzki B, Vogt K, Cantarell C, Torras J, Melilli E, Mast R, Martinez-Castelao A, Gomà M, Reinke P, Volk HD, Grinyó JM. Prospective assessment of antidonor cellular alloreactivity is a tool for guidance of immunosuppression in kidney transplantation. Kidney Int 2013; 84:1226-36. [PMID: 23783240 DOI: 10.1038/ki.2013.236] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 04/21/2013] [Accepted: 04/25/2013] [Indexed: 01/08/2023]
Abstract
Current characterization of the immune risk in renal transplant patients is only focused on the assessment of preformed circulating alloantibodies; however, alloreactive memory T cells are key players in mediating allograft rejection. Immune monitoring of antidonor alloreactive memory/effector T cells using an IFN-γ Elispot has been shown to distinguish patients at risk for immune-mediated graft dysfunction, suggesting a potential tool for immunosuppression individualization. In this nonrandomized study, we prospectively assessed donor and nondonor T-cell alloreactivity in 60 highly alloreactive patients receiving calcineurin inhibitor-based immunosuppression and in non-T-cell alloreactive transplant recipients treated with a calcineurin inhibitor-free regimen. The impact was evaluated using 1-year allograft outcome. We found a strong association between ongoing antidonor T-cell alloreactivity and histological lesions of acute T cell-mediated rejection in 6-month protocol biopsies, distinguishing those patients with better 1-year graft function, regardless of immunosuppression regimen. Interestingly, evidence for enhanced immune regulation, driven by circulating Foxp3-demethylated regulatory T cells, was only observed among patients achieving antidonor T-cell hyporesponsiveness. Thus, prospective evaluation of donor-specific T-cell sensitization may add crucial information on the alloimmune state of transplanted patients to be used in daily clinical practice.
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Affiliation(s)
- Oriol Bestard
- 1] Renal Transplant Unit, Nephrology Department, Bellvitge University Hospital, Barcelona, Spain [2] Experimental Nephrology Department, IDIBELL, Barcelona University, Barcelona, Spain
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Health-related quality of life and long-term survival and graft failure in kidney transplantation: a 12-year follow-up study. Transplantation 2013; 95:740-9. [PMID: 23354297 DOI: 10.1097/tp.0b013e31827d9772] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Although the prognosis of kidney transplantation is generally good, long-term survival varies substantially between patients. This study examined whether health-related quality of life (HRQOL) predicts long-term mortality in kidney transplantation after adjustment for known risk factors. METHODS A cohort of 347 (46.77 ± 13.96 years) kidney transplant recipients was followed up for 12 years after enrolment (1999-2001). Patients completed measures of HRQOL and medical records were reviewed to document clinical and cardiovascular risk factors and comorbidities at study entry (mean [SD], 8.57 [6.55] years after transplantation). The primary outcomes were ensuing all-cause mortality and all-cause graft failure (a composite endpoint consisting of return to dialysis therapy, preemptive retransplantation, or death with function). Cox proportional hazards multivariate models were developed to identify predictors of long-term patient and graft survival. RESULTS During the 12-year follow-up, 86 (24.8%) patients died, 64 (18.3%) died with a functioning graft, and 35 (11.1%) were placed back to dialysis. Physical QOL impairment increased the risk of mortality and graft failure during the follow-up period. The risk remained significant after adjusting for sociodemographic and clinical risk factors (adjusted hazard ratio, 1.89; 95% confidence interval, 1.09-2.95; P=0.022 and adjusted hazard ratio, 1.68; 95% confidence interval, 1.12-2.52; P=0.012 for patient and graft survival, respectively). Other significant risk factors were older age, time elapsed since transplantation, and Charlson comorbidity index. Risk of graft failure was also associated with glomerular filtration rate. CONCLUSIONS Physical HRQOL predicts long-term mortality and graft failure independently of sociodemographic and clinical risk factors in renal transplant patients. Future research should identify the determinants of HRQOL and refine interventions to improve it.
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Influence of maintenance steroids on the outcomes in deceased-donor kidney transplant recipients exposed to prolonged pretransplantation dialysis. Transplant Proc 2013; 45:99-101. [PMID: 23375281 DOI: 10.1016/j.transproceed.2012.07.148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 07/27/2012] [Indexed: 11/23/2022]
Abstract
BACKGROUND Pre-transplant dialysis duration exerts a graded negative influence on outcomes after kidney transplantation. Higher immune reactivity associated with prolonged dialysis with consequent increased acute rejection could be contributory. METHODS Using the Organ Procurement and Transplant Network/United Network of Organ Sharing database, we identified patients ≥ 18 years of age who received deceased-donor kidney (DDK) transplants from 2000 to 2008 after being on maintenance dialysis for ≥ 4 years. Patients received induction therapy with rabbit antithymocyte globulin (r-ATG), alemtuzumab, or an interleukin-2 receptor blocker (IL-2B) and were discharged on calcineurin inhibitor (CNI)/mycophenolate mofetil (MMF)-based immunosuppression with or without steroid. Unadjusted and adjusted graft/patient survivals were compared in steroid versus no-steroid groups by induction type. RESULTS A total of 14,459 patients were identified, of which 7,684 received r-ATG (steroid, 6,098; no-steroid, 1,586), 1,292 alemtuzumab (steroid, 362; no-steroid, 930), and 5,483 an IL-2B agent (steroid, 5,107; no-steroid, 376). Adjusted graft survivals were similar for steroid versus no-steroid groups in r-ATG (hazard ratio [HR] 1.10, 95% confidence interval (CI) 0.96-1.26, P = .16), alemtuzumab (HR 0.88, 95% CI 0.65-1.19; P = .40), and IL-2B (HR 0.91, 95% CI 0.73-1.13; P = .38) groups. Adjusted patient survival for steroid versus no-steroid groups was inferior in r-ATG (HR 1.41, 95% CI 1.17-1.71; P < .001) but similar in alemtuzumab (HR 1.05, 95% CI 0.70-1.59; P = .80) and IL-2B (HR 1.17, 95% CI 0.86-1.58; P = .32) groups. CONCLUSIONS Our analysis failed to show a graft survival benefit for the addition of steroid to a CNI/MMF-based immunosuppression after induction with r-ATG, alemtuzumab, or an IL-2B agent in DDK recipients exposed to prolonged pretransplantation dialysis.
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Abstract
PURPOSE OF REVIEW Chronic injury and late allograft loss remain major causes of morbidity in clinical transplantation. Biomarkers that can reliably assess the risk of posttransplant complications are required to direct and individualize therapy aimed at prolonging graft survival and improving patient health. The purpose of this review is to provide a framework for understanding how to use biomarkers in the context of clinical transplantation and to summarize current data on available noninvasive cellular-based immune monitoring methods to predict transplant outcome. RECENT FINDINGS New microarray and gene profiling data reveal peripheral blood cell gene expression patterns that identify operational tolerance, raising the possibility that the measurements can be used to direct immunosuppression withdrawal. Additional data support the use of selective urine gene products and soluble CD30 measurements in serum as reliable biomarkers of acute graft injury. Finally, recent studies demonstrate that measurement of T-cell alloimmunity by cytokine enzyme-linked immunospot is a promising, supplementary pretransplant risk assessment tool. SUMMARY Recently published studies in organ transplantation suggest that results derived from assays focused on markers of T-cell immunity can segregate transplant candidates or recipients into high and low-risk subgroups for posttransplant graft injury. Larger prospective studies are needed, however, before any proposed biomarker can be incorporated into the transplant physicians' armamentarium to guide individualized therapeutic decision-making.
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Augustine JJ, Hricik DE. T-cell immune monitoring by the ELISPOT assay for interferon gamma. Clin Chim Acta 2012; 413:1359-63. [PMID: 22732764 DOI: 10.1016/j.cca.2012.03.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 03/08/2012] [Accepted: 03/08/2012] [Indexed: 12/13/2022]
Abstract
The enzyme-linked immunosorbent spot (ELISPOT) assay for interferon gamma has been available for more than twenty years and has been used for a number of applications, including the monitoring of T cell immunity in solid organ transplant recipients. Studies from single centers indicate that heightened T cell alloreactivity measured with this assay correlates with acute and chronic rejection and with poor long-term allograft function. The assay has been used not only to assess T cell reactivity after transplantation, but also as a tool for assessing immune risk prior to transplantation. Additional work is needed to validate the assay in larger multicenter clinical trials.
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Affiliation(s)
- Joshua J Augustine
- Division of Nephrology and Hypertension, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio 44116, USA
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27
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Padiyar A, Hricik DE. Immune factors influencing ethnic disparities in kidney transplantation outcomes. Expert Rev Clin Immunol 2012; 7:769-78. [PMID: 22014018 DOI: 10.1586/eci.11.32] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An influence of ethnicity on the outcomes of kidney transplant recipients has been recognized for several decades. Both immune and nonimmune factors have been explored as potential explanations. Most studies have focused on the inferior outcomes of African-Americans. As a group, African-Americans differ from Caucasians with respect to a number of measurable components of the alloimmune response, including the T-cell repertoire and the expression and function of costimulatory molecules and various cytokines and chemokines. In general, these differences suggest that African-Americans may be high immune responders. However, no single difference in any of these components of alloimmunity satisfactorily explains the disparities in outcomes. It seems probable that some combination of immune factors interacts with nonimmune factors, such as socioeconomic resources, to influence transplant outcomes in a complex manner.
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Affiliation(s)
- Aparna Padiyar
- Division of Nephrology and Hypertension and Transplantation Service, Case Western Reserve University and University Hospitals University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, OH 44106, USA
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28
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Sawitzki B, Schlickeiser S, Reinke P, Volk HD. Monitoring tolerance and rejection in organ transplant recipients. Biomarkers 2011; 16 Suppl 1:S42-50. [PMID: 21707443 DOI: 10.3109/1354750x.2011.578754] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
To avoid toxic side effects caused by permanent immunosuppressive treatment, research in transplantation focuses on new treatment strategies inducing tolerance or allowing drug weaning. Implementing drug minimization into clinical routine can be only safely achieved when guided by biomarkers reflecting the individual immune reactivity. We review recently described biomarkers and assays allowing identification of patients suitable for drug weaning or at risk of rejection. However, the majority of described biomarkers and assays have not been validated in prospective clinical trials. Thus, collaborative efforts are needed to design and perform prospective multicenter trials to validate the identified biomarkers across different laboratories.
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Affiliation(s)
- Birgit Sawitzki
- Institute of Medical Immunology, Charite University Medicine, Berlin, Germany.
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Padiyar A, Augustine JJ, Bodziak KA, Aeder M, Schulak JA, Hricik DF. Influence of African-American ethnicity on acute rejection after early steroid withdrawal in primary kidney transplant recipients. Transplant Proc 2010; 42:1643-7. [PMID: 20620492 DOI: 10.1016/j.transproceed.2010.02.081] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 02/02/2010] [Indexed: 10/19/2022]
Abstract
BACKGROUND AND PURPOSE The influence of African-American ethnicity on outcomes of kidney transplant recipients subjected to early steroid withdrawal remains controversial. Recent studies that suggest no higher risk among African Americans may be biased by recruitment of relatively small number of African Americans or by patient selection. We compared outcomes of African Americans to non-African Americans in a center in which early steroid withdrawal has become the standard of practice. METHODS This was a single-center prospective study of 133 consecutive patients receiving primary kidney transplants between January 2006 and December 2008, followed for >or=3 months, and managed with a similar immunosuppression regimen that included induction antibody therapy, tacrolimus, mycophenolate mofetil, and withdrawal of steroids on postoperative day 5. Acute rejection and other outcomes were compared in African-American patients (n = 55) and compared with those of non-African-American patients (n = 78). RESULTS During the first 12 months after early steroid withdrawal, African-American patients experienced a significantly higher cumulative incidence of acute rejection than non-African Americans (23.6% vs 7.7%; P = .020). Using multivariate logistic regression, ethnicity (odds ratio 3.33; P = .047) and HLA mismatch (odds ratio 1.44; P = .041) were significantly correlated with acute rejection independent of recipient age, gender, historical peak panel reactive antibody level (PRA) or PRA at time of transplant, time on dialysis, or donor source. CONCLUSIONS African Americans are at increased risk of acute rejection after early steroid withdrawal, particularly when they receive kidneys from poorly matched donors.
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Affiliation(s)
- A Padiyar
- Department of Medicine, University Hospitals Case Medical Center, Cleveland, Ohio 44106, USA.
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Sawinski D, Uribarri J, Peace D, Yao T, Wauhop P, Trzcinka P, Ostrow K, Poggio ED, Heeger PS. 25-OH-vitamin D deficiency and cellular alloimmunity as measured by panel of reactive T cell testing in dialysis patients. Am J Transplant 2010; 10:2287-95. [PMID: 20840475 PMCID: PMC2948589 DOI: 10.1111/j.1600-6143.2010.03264.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Primed antidonor alloreactive T cells are detrimental to transplant outcome, but factors that impact the strength of this immune response prior to transplantation are unknown. We tested peripheral blood mononuclear cells from dialysis patients, against panels of allogeneic, primary B-cell lines in a newly standardized IFNγ ELISPOT panel of reactive T cell (PRT) assay. Results were correlated with known alloantibody-sensitizing events and other clinical parameters. As 25-OH-vitamin D deficiency is associated with enhanced cellular immunity, is common in dialysis patients and is correctable, we assessed the relationship between serum 25-OH-vitamin D and the PRT. Using independent test and validation cohorts we found that low serum levels of 25-OH-vitamin D (<26 ng/mL) correlated with high-PRT values (in the upper 50th percentile, OR 0.02, p = 0.01) independent of age, sex, race, previous transplant, transfusion, pregnancy, time on dialysis, panel of reactive antibody, iPTH, and treatment with 1,25-OH-vitamin D. The data provide a potential mechanism for the possible relationship between vitamin D deficiency and poor posttransplant outcome, and support studies to test the impact of 25-OH-vitamin D repletion on alloimmunity and allograft injury in kidney transplant candidates.
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Affiliation(s)
- Deirdre Sawinski
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY
| | - Jaime Uribarri
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY
| | - Denise Peace
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY
| | - Tina Yao
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY
| | - Praeophayom Wauhop
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY
| | - Paulina Trzcinka
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY
| | - Katya Ostrow
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY
| | - Emilio D. Poggio
- Department of Nephrology and Hypertension, Cleveland Clinic, Cleveland, OH
| | - Peter S. Heeger
- Department of Nephrology, Institute Mount Sinai School of Medicine, New York, NY,Recanati-Miller Transplant, Institute Mount Sinai School of Medicine, New York, NY
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Schold JD, Sehgal AR, Srinivas TR, Poggio ED, Navaneethan SD, Kaplan B. Marked variation of the association of ESRD duration before and after wait listing on kidney transplant outcomes. Am J Transplant 2010; 10:2008-16. [PMID: 20645941 PMCID: PMC3881969 DOI: 10.1111/j.1600-6143.2010.03213.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Numerous studies report a strong association between pretransplant end-stage renal disease (ESRD) duration and diminished transplant outcomes. However, cumulative waiting time may reflect distinct phases and processes related to patients' physiological condition as well as pre-existing morbidity and access to care. The relative impact of pre- and postlisting ESRD durations on transplant outcomes is unknown. We examined the impact of these intervals from a national cohort of kidney transplant recipients from 1999 to 2008 (n = 112,249). Primary factors explaining prelisting ESRD duration were insurance and race, while primary factors explaining postlisting ESRD duration were blood type, PRA% and variation between centers. Extended time from ESRD to waitlisting had significant dose-response association with overall graft loss (AHR = 1.26 for deceased donors [DD], AHR = 1.32 for living donors [LD], p values < 0.001). Contrarily, time from waitlisting (after ESRD) to transplantation had negligible effects (p = 0.10[DD], p = 0.57[LD]). There were significant associations between pre- and postlisting ESRD time with posttransplant patient survival, however prelisting time had over sixfold greater effect. Prelisting ESRD time predominately explains the association of waiting time with transplant outcomes suggesting that factors associated with this interval should be prioritized for interventions and allocation policy. The degree to which the effect of prelisting ESRD time is a proxy for comorbid conditions, socioeconomic status or access to care requires further study.
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Affiliation(s)
- J. D. Schold
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH,Corresponding author: Jesse D. Schold,
| | - A. R. Sehgal
- Division of Nephrology, MetroHealth Medical Center, Cleveland, OH,Center for Reducing Health Disparities, Case Western University, Cleveland, OH
| | - T. R. Srinivas
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH
| | - E. D. Poggio
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH
| | - S. D. Navaneethan
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH
| | - B. Kaplan
- Department of Medicine, University of Arizona, Tucson, AZ
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Abstract
BACKGROUND Alloreactive T cells and anti-human leukocyte antigen antibodies mediate transplant injury. Environmental exposures, including vaccinations, may activate the alloimmune repertoire leading to accelerated allograft injury. To test whether vaccination impacts human alloimmunity, we analyzed humoral and cellular immune reactivity in subjects undergoing influenza vaccination. METHODS We serially obtained blood samples from 30 healthy subjects and 8 kidney and 9 lung transplant recipients who received influenza vaccination, and from 20 healthy unvaccinated controls. We measured cellular and humoral anti-influenza responses, anti-human leukocyte antigen antibodies, and alloreactive T-cell immunity (interferon-gamma ELISPOT) at 0, 2, 4, and 12 weeks after vaccination. RESULTS Vaccination induced influenza-reactive humoral and cellular responses in control subjects and in transplant recipients. Only two of 30 vaccinated volunteers developed new alloantibodies, but none of the transplant patients. Vaccination also specifically and significantly augmented cellular alloimmunity based on reactivity to a panel of stimulators in both healthy subjects and in transplant recipients within 4 weeks of vaccination. The enhanced cellular alloresponse waned toward prevaccine levels by week 12. CONCLUSION Our findings newly demonstrate that influenza vaccination can have a significant impact on the potency of the alloimmune repertoire. Because the strength of the alloresponse influences long-term graft function, our results suggest that further investigation of alloimmune monitoring after vaccination is needed.
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Abstract
PURPOSE OF REVIEW Despite the introduction of advanced immunosuppressive drug therapies, clinical and subclinical rejections still occur in many graft recipients with a negative impact on the long-term transplant outcome. The immunological status of the patients awaiting the transplantation is a key factor for these processes. Here we summarize the recent efforts to identify and develop biomarkers and functional assays that allow an individual pretransplant risk assessment. RECENT FINDINGS New sensitive techniques assessing T-cell memory and B-cell activation have been developed. Furthermore, the expression level of soluble and molecular markers reflecting the activation state of the immune system and donor graft intrinsic factors have been shown to influence graft outcome. SUMMARY A variety of parameters and assays that determine the pretransplant immune activation status has been developed. Some of these assays have already been used prospectively to define high-risk patients receiving advanced immunosuppressive induction therapy.However, the conflicting results obtained in different studies show that biomarker analysis and functional assays performance need to be further standardized and validated in large prospective trials before they can be routinely implemented into a pretransplant risk assessment. Subsequently, a combined effort to design pretransplant risk stratification algorithms should lead to personalized immunosuppressive treatment regimes and improved graft survival and long-term graft function.
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Abstract
Chronic allograft injury remains the leading cause of graft loss despite improvements in immunosuppression, clinical risk stratification, and state-of-the-art antibody testing. Emerging results indicate that T-cell immune monitoring by cytokine enzyme-linked immunosorbent spot, as part of a comprehensive risk assessment platform, has the potential to guide decision making and improve outcomes after transplantation.
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Lymphocyte markers and prediction of long-term renal allograft acceptance. Curr Opin Nephrol Hypertens 2009; 18:489-94. [DOI: 10.1097/mnh.0b013e3283318f82] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Diagnostic value of T-cell monitoring assays in kidney transplantation. Curr Opin Organ Transplant 2009; 14:426-31. [DOI: 10.1097/mot.0b013e32832c5999] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gerrits JH, van de Wetering J, Drabbels JJ, IJzermans JNM, Claas FHJ, Weimar W, van Besouw NM. Non-HLA T-cell reactivity during the first year after HLA-identical living-related kidney transplantation. Clin Transplant 2009; 23:740-7. [PMID: 19563488 DOI: 10.1111/j.1399-0012.2009.01014.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND It has been reported that donor-reactive T-cell responses may decrease during the first year after HLA-mismatched organ transplantation. We wondered whether donor-reactive T-cell responses directed to minor histocompatibility antigens (mHAgs) or other non-HLA antigens also decrease after HLA-identical living-related (LR) kidney transplantation. METHODS We studied donor-reactive T-cell responses by IFN-gamma and granzyme B (GrB) Elispot assays in 15 HLA-identical LR kidney transplant recipients before, six months and one yr after transplantation. Third-party reactivity was used as control. Patient and donor peripheral blood mononuclear cells were typed for 11 known mHAgs. RESULTS During the study period, 60% and 36% of the patients demonstrated donor-reactive IFN-gamma and GrB producing cells (pc), respectively. The number of donor-reactive IFN-gamma and GrB pc was significantly lower than the number of third-party reactive IFN-gamma and GrB pc. After transplantation, donor-reactivity and third-party reactivity were comparable to pre-transplant values. No relation was found in mHAg mismatches between donor and recipient and donor-reactive T-cell response. CONCLUSIONS Donor-reactivity could be detected before and after HLA-identical LR kidney transplantation, but was not related with the number of mHAg mismatches, and did not decrease after transplantation.
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Affiliation(s)
- Jeroen H Gerrits
- Department of Internal Medicine-Transplantation, Erasmus Medical Center-University Medical Center Rotterdam, Rotterdam, The Netherlands
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Can We Use Biomarkers and Functional Assays to Implement Personalized Therapies in Transplantation? Transplantation 2009; 87:1595-601. [DOI: 10.1097/tp.0b013e3181a6b2cf] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bremer S, Mandla R, Vethe NT, Rasmussen I, Rootwelt H, Line PD, Midtvedt K, Bergan S. Expression of IMPDH1 and IMPDH2 after transplantation and initiation of immunosuppression. Transplantation 2008; 85:55-61. [PMID: 18192912 DOI: 10.1097/01.tp.0000296854.68123.03] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Mycophenolic acid (MPA) mediates immunosuppressive effects by inhibiting inosine monophosphate dehydrogenase (IMPDH). Induction of IMPDH activity has been observed in whole blood and erythrocyte samples during immunosuppressive therapy. Information concerning the mechanisms for increased IMPDH activity is limited and the potential implications of induction have been debated. METHODS Whole blood, CD4+ cell, and reticulocyte samples were collected from 30 renal transplant patients pre- and posttransplantation. The expressions of two IMPDH isoforms, type 1 and 2, were analyzed by real-time reverse-transcription polymerase chain reaction and quantified using a housekeeping gene index. The IMPDH activity was determined by ultraviolet high-performance liquid chromatography. RESULTS Transplantation and the initiation of immunosuppressive therapy was associated with increased IMPDH1 (50-88%, P<0.0005) and decreased IMPDH2 (42-56%, P<0.0005) expression. In CD4+ cells, however, IMPDH2 increased (15%, P=0.009). These changes are probably related to glucocorticoid effects. Two weeks posttransplant, MPA-treated patients displayed elevated IMPDH 1 and 2 in reticulocytes, suggesting enzyme induction in these cells during prolonged MPA therapy. Patients with acute rejection during follow-up demonstrated higher IMPDH2 expression in CD4+ cells pretransplant than nonrejecting patients (median expression 1.26 vs. 0.87 respectively, P=0.017). CONCLUSIONS Knowledge of changes in IMPDH 1 and 2 expression after transplantation and initiation of immunosuppression is important considering the action of MPA on IMPDH and the potential for pharmacodynamic monitoring of MPA by measuring IMPDH activity. The expression of IMPDH2 in CD4+ cells pretransplant may be an indicator of immune activation.
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Affiliation(s)
- Sara Bremer
- Department of Medical Biochemistry, Rikshospitalet Medical Centre, Institute of Clinical Biochemistry, University of Oslo, Norway
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