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Spivey TL, Uccellini L, Ascierto ML, Zoppoli G, De Giorgi V, Delogu LG, Engle AM, Thomas JM, Wang E, Marincola FM, Bedognetti D. Gene expression profiling in acute allograft rejection: challenging the immunologic constant of rejection hypothesis. J Transl Med 2011; 9:174. [PMID: 21992116 PMCID: PMC3213224 DOI: 10.1186/1479-5876-9-174] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 10/12/2011] [Indexed: 02/06/2023] Open
Abstract
In humans, the role and relationship between molecular pathways that lead to tissue destruction during acute allograft rejection are not fully understood. Based on studies conducted in humans, we recently hypothesized that different immune-mediated tissue destruction processes (i.e. cancer, infection, autoimmunity) share common convergent final mechanisms. We called this phenomenon the "Immunologic Constant of Rejection (ICR)." The elements of the ICR include molecular pathways that are consistently described through different immune-mediated tissue destruction processes and demonstrate the activation of interferon-stimulated genes (ISGs), the recruitment of cytotoxic immune cells (primarily through CXCR3/CCR5 ligand pathways), and the activation of immune effector function genes (IEF genes; granzymes A/B, perforin, etc.). Here, we challenge the ICR hypothesis by using a meta-analytical approach and systematically reviewing microarray studies evaluating gene expression on tissue biopsies during acute allograft rejection. We found the pillars of the ICR consistently present among the studies reviewed, despite implicit heterogeneity. Additionally, we provide a descriptive mechanistic overview of acute allograft rejection by describing those molecular pathways most frequently encountered and thereby thought to be most significant. The biological role of the following molecular pathways is described: IFN-γ, CXCR3/CCR5 ligand, IEF genes, TNF-α, IL-10, IRF-1/STAT-1, and complement pathways. The role of NK cell, B cell and T-regulatory cell signatures are also addressed.
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Affiliation(s)
- Tara L Spivey
- Infectious Disease and Immunogenetics Section (IDIS), Department of Transfusion Medicine, Clinical Center and trans-NIH Center for Human Immunology (CHI), National Institutes of Health, Bethesda, Maryland 20892, USA
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Gheith OAA. Gene expression profiling in organ transplantation. Int J Nephrol 2011; 2011:180201. [PMID: 21845224 PMCID: PMC3154482 DOI: 10.4061/2011/180201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 06/22/2011] [Indexed: 11/20/2022] Open
Abstract
Aim of Review.
Huge effort is being made among the transplant community investigating novel
biomarkers that enable transplant clinicians to identify patients at risk for allograft
rejection or those who will develop tolerance so that immunosuppression could be
safely minimized or even ideally withdrawn.
Despite the important advances achieved in the identification of several potential
biomarkers of tolerance, rejection, or both, validation and demonstration of their clinical
utility still needs to be tested, which will need international cooperative networks.
It is important to note that the reproducibility of differently expressed genes might be
affected by many factors such as gene ranking and selection methods, inherent
differences between types, and the choice of thresholds. However, because microarray
analyses are expensive and time consuming and their statistical evaluation is often very
difficult, gene expression analysis using the RTPCR method is nowadays
recommended.
Conclusions.
In the field of organ transplantation, gene-expression-based decision might help in
improving patient and graft outcome and there are a multitude of studies showing that
gene-expression profiling is feasible.
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Effects of Sample Timing and Treatment on Gene Expression in Early Acute Renal Allograft Rejection. Transplantation 2011; 91:323-9. [DOI: 10.1097/tp.0b013e3182029b16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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ISN Forefronts Symposium 2010 in Sylt, Germany: 'Induction and Resolution of Renal Inflammation'. Kidney Int 2011; 79:807-13. [PMID: 21289596 DOI: 10.1038/ki.2010.560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The International Society of Nephrology (ISN) Forefronts Symposium 'Induction and Resolution of Renal Inflammation' took place in May 2010 on the Island of Sylt, Germany. The program included basic and clinical aspects of inflammation with a special focus on human and experimental glomerulonephritis. Distinguished scientists from different fields of inflammation research reported their recent discoveries and discussed emerging topics including the role of resolution for inflammatory processes; the 'new and old' cellular players of innate immunity and their mediators; the fundamental role of T-cell subtypes and chemokines; new aspects of B cell-mediated immune responses; and finally the potential implication of results from basic science for human inflammatory renal disease.
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Tsai EW, Wallace WD, Gjertson DW, Reed EF, Ettenger RB. Significance of intragraft CD138+ lymphocytes and p-S6RP in pediatric kidney transplant biopsies. Transplantation 2010; 90:875-81. [PMID: 20736897 DOI: 10.1097/tp.0b013e3181f24e3c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND We have previously shown that intragraft CD20+ B cells are associated with acute cellular rejection (ACR) and allograft loss. Phosphorylation of S6 ribosomal protein, a downstream target of the PI3K/Akt/mTOR pathway, promotes growth and proliferation of cells and could identify metabolically active cells such as alloantibody secreting plasma cells. Because CD20+ lymphocytes can differentiate into CD138+ plasma cells, we aimed to identify functionally active plasma cells by using intragraft CD138 quantification and p-S6RP staining and correlate these results with allograft rejection, function, and survival. METHODS We examined 46 renal transplant biopsies from 32 pediatric patients who were biopsied for clinical suspicion of rejection. Immunohistochemical staining for C4d, CD20, CD138, and p-S6RP was performed. Patient creatinine clearance and graft status was followed up postbiopsy. RESULTS Patients with greater than or equal to six CD138+ cells/high power field (hpf) had worse graft survival with a hazard ratio of 3.4 (95% CI 1.3-9.2) 2 years postbiopsy compared with those with 0 to 5 cells/hpf (P=0.016). CD138+ cells were stained for p-S6RP, indicating functionally active plasma cells. They were associated with ACR (P=0.004) and deteriorating graft function (R=0.22, P=0.001). Intragraft CD20+ and CD138+ cells found together in ACR were associated with poorer graft survival than either marker alone, hazard ratio 1.5 (95% CI 1.1-2.2, P=0.01). CONCLUSIONS A threshold of greater than or equal to six CD138+ metabolically active plasma cells per hpf, coexisting with CD20+ B cells, was associated with poor allograft function and survival. This may represent an additional antibody-mediated process present in the setting of ACR and could play an important role in characterization and treatment of transplant rejection.
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Affiliation(s)
- Eileen W Tsai
- Mattel Children's Hospital UCLA, Division of Pediatric Nephrology, Los Angeles, CA, USA.
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58
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Halloran PF, de Freitas DG, Einecke G, Famulski KS, Hidalgo LG, MengeL M, Reeve J, Sellares J, Sis B. An integrated view of molecular changes, histopathology and outcomes in kidney transplants. Am J Transplant 2010; 10:2223-30. [PMID: 20931696 DOI: 10.1111/j.1600-6143.2010.03268.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Data-driven approaches to deteriorating kidney transplants, incorporating histologic, molecular and HLA antibody findings, have created a new understanding of transplant pathology and why transplants fail. Transplant dysfunction is best understood in terms of three elements: diseases, the active injury-repair response and the cumulative burden of injury. Progression to failure is mainly attributable to antibody-mediated rejection, nonadherence and glomerular disease. Antibody-mediated rejection usually develops late due to de novo HLA antibodies, particularly anti-class II, and is often C4d negative. Pure treated T cell-mediated rejection does not predispose to graft loss because it responds well, even with endothelialitis, but it may indicate nonadherence. The cumulative burden of injury results in atrophy-fibrosis (nephron loss), arterial fibrous intimal thickening and arteriolar hyalinosis, but these are not progressive without ongoing disease/injury, and do not explain progression. Calcineurin inhibitor toxicity has been overestimated because burden-of-injury lesions invite this default diagnosis when diseases such as antibody-mediated rejection are missed. Disease/injury triggers a stereotyped active injury-repair response, including de-differentiation, cell cycling and apoptosis. The active injury-repair response is the strongest correlate of organ function and future progression to failure, but should always prompt a search for the initiating injury or disease.
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Affiliation(s)
- P F Halloran
- Department of Medicine, Division of Nephrology & Immunology, University of Alberta, Edmonton, Canada.
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Halloran PF, de Freitas DG, Einecke G, Famulski KS, Hidalgo LG, Mengel M, Reeve J, Sellares J, Sis B. The molecular phenotype of kidney transplants. Am J Transplant 2010; 10:2215-22. [PMID: 20931695 DOI: 10.1111/j.1600-6143.2010.03267.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Microarray studies of kidney transplant biopsies provide an opportunity to define the molecular phenotype. To facilitate this process, we used experimental systems to annotate transcripts as members of pathogenesis-based transcript sets (PBTs) representing biological processes in injured or diseased tissue. Applying this annotation to microarray results revealed that changes in single molecules and PBTs reflected a large-scale coordinate disturbance, stereotyped across various diseases and injuries, without absolute specificity of individual molecules or PBTs for rejection. Nevertheless, expression of molecules and PBTs was quantitatively specific: IFNG effects for rejection; T cell and macrophage transcripts for T cell-mediated rejection; endothelial and NK transcripts for antibody-mediated rejection. Various diseases and injuries induced the same injury-repair response, undetectable by histopathology, involving epithelium, stroma and endothelium, with increased expression of developmental, cell cycle and apoptosis genes and decreased expression of differentiated epithelial features. Transcripts reflecting this injury-repair response were the best correlates of functional disturbance and risk of future graft loss. Late biopsies with atrophy-fibrosis, reflecting their cumulative burden of injury, displayed more transcripts for B cells, plasma cells and mast cells. Thus the molecular phenotype is best described in terms of three elements: specific diseases, including rejection; the injury-repair response and the cumulative burden of injury.
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Affiliation(s)
- P F Halloran
- Department of Medicine, Division of Nephrology & Immunology, University of Alberta, Edmonton, Canada.
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60
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Mengel M, Sis B, Kim D, Chang J, Famulski KS, Hidalgo LG, Einecke G, de Freitas DG, Tymchak W, Burton J, Halloran PF. The molecular phenotype of heart transplant biopsies: relationship to histopathological and clinical variables. Am J Transplant 2010; 10:2105-15. [PMID: 20883545 DOI: 10.1111/j.1600-6143.2010.03182.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Histopathology of endomyocardial biopsies (EMB) is the standard rejection surveillance for heart transplants. However, ISHLT consensus criteria for interpreting biopsies are arbitrarily defined. Gene expression offers an independent re-evaluation of existing diagnostic systems. We performed histologic and microarray analysis on 105 EMB from 45 heart allograft recipients. Histologic lesions, diagnosis and transcripts were compared to one another, time posttransplantation, indication for biopsy and left ventricular ejection fraction (LVEF). Histologic lesions presented in two groups: myocyte-interstitial and microcirculation lesions. Expression of transcript sets reflecting T cell and macrophage infiltration, and γ-interferon effects correlated strongly with each other and with transcripts indicating tissue/myocardium injury. This molecular phenotype correlated with Quilty (p < 0.005), microcirculation lesions (p < 0.05) and decreased LVEF (p < 0.007), but not with the histologic diagnosis of rejection. In multivariate analysis, LVEF was associated (p < 0.03) with γ-interferon inducible transcripts, time posttransplantation, ischemic injury and clinically indicated biopsies, but not the diagnosis of rejection. The results indicate that (a) the current ISHLT system for diagnosing rejection does not reflect the molecular phenotype in EMB and lacks clinical relevance; (b) the interpretation of Quilty lesions has to be revisited; (c) the assessment of molecules in heart biopsy can guide improvements of current diagnostics.
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Affiliation(s)
- M Mengel
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
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61
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Hidalgo LG, Sis B, Sellares J, Campbell PM, Mengel M, Einecke G, Chang J, Halloran PF. NK cell transcripts and NK cells in kidney biopsies from patients with donor-specific antibodies: evidence for NK cell involvement in antibody-mediated rejection. Am J Transplant 2010; 10:1812-22. [PMID: 20659089 DOI: 10.1111/j.1600-6143.2010.03201.x] [Citation(s) in RCA: 300] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To explore the mechanisms of antibody-mediated rejection (ABMR) in kidney transplants, we studied the transcripts expressed in clinically indicated biopsies from patients with donor-specific antibody (DSA). Comparison of biopsies from DSA-positive versus DSA-negative patients revealed 132 differentially expressed transcripts: all were associated with class II DSA but none with class I DSA. Many transcripts were expressed in DSA-positive ABMR but were also expressed in T-cell-mediated rejection (TCMR), reflecting shared molecular features. Removal of shared transcripts created 23 DSA selective transcripts (DSASTs). Some DSASTs (6/23) showed selective high expression in NK cells, whereas others (8/23) were expressed in endothelium or in endothelium plus other cell types (7/23). Of 145 biopsies ranked by DSAST expression, the 25 with highest DSAST expression primarily consisted of ABMR (22/25, 88%), either C4d-positive or C4d-negative. By immunostaining, CD56+ and CD68+ cells in peritubular capillaries, but not CD3+ cells, were increased in ABMR compared to TCMR, compatible with a role for NK cells, as well as macrophages, as effectors in endothelial injury during ABMR. Thus, the strategy of using DSASTs in the biopsy to identify mechanism-related transcripts in biopsies from patients with clinical phenotypes indicates the selective involvement of NK cells in ABMR.
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Affiliation(s)
- L G Hidalgo
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
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62
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Einecke G, Reeve J, Sis B, Mengel M, Hidalgo L, Famulski KS, Matas A, Kasiske B, Kaplan B, Halloran PF. A molecular classifier for predicting future graft loss in late kidney transplant biopsies. J Clin Invest 2010; 120:1862-72. [PMID: 20501945 DOI: 10.1172/jci41789] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 04/26/2010] [Indexed: 01/05/2023] Open
Abstract
Kidney transplant recipients that develop signs of renal dysfunction or proteinuria one or more years after transplantation are at considerable risk for progression to renal failure. To assess the kidney at this time, a "for-cause" biopsy is performed, but this provides little indication as to which recipients will go on to organ failure. In an attempt to identify molecules that could provide this information, we used microarrays to analyze gene expression in 105 for-cause biopsies taken between 1 and 31 years after transplantation. Using supervised principal components analysis, we derived a molecular classifier to predict graft loss. The genes associated with graft failure were related to tissue injury, epithelial dedifferentiation, matrix remodeling, and TGF-beta effects and showed little overlap with rejection-associated genes. We assigned a prognostic molecular risk score to each patient, identifying those at high or low risk for graft loss. The molecular risk score was correlated with interstitial fibrosis, tubular atrophy, tubulitis, interstitial inflammation, proteinuria, and glomerular filtration rate. In multivariate analysis, molecular risk score, peritubular capillary basement membrane multilayering, arteriolar hyalinosis, and proteinuria were independent predictors of graft loss. In an independent validation set, the molecular risk score was the only predictor of graft loss. Thus, the molecular risk score reflects active injury and is superior to either scarring or function in predicting graft failure.
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Affiliation(s)
- Gunilla Einecke
- Alberta Transplant Applied Genomics Centre, University of Alberta, Edmonton, Alberta, Canada
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63
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Keown PA, McMaster WR, McManus BM. Tools to identify organ rejection and immune quiescence for biological understanding and personalized medical care. Biomark Med 2010; 4:115-21. [PMID: 20387307 DOI: 10.2217/bmm.09.73] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Juan Alberto Fierro C. Monitoreo inmunológico: el comienzo de una nueva era en trasplantes. REVISTA MÉDICA CLÍNICA LAS CONDES 2010. [DOI: 10.1016/s0716-8640(10)70529-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Hueso M, Navarro E, Moreso F, O'Valle F, Pérez-Riba M, Del Moral RG, Grinyó JM, Serón D. Intragraft expression of the IL-10 gene is up-regulated in renal protocol biopsies with early interstitial fibrosis, tubular atrophy, and subclinical rejection. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:1696-704. [PMID: 20150436 DOI: 10.2353/ajpath.2010.090411] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Grafts with subclinical rejection associated with interstitial fibrosis and tubular atrophy (SCR+IF/TA) show poorer survival than grafts with subclinical rejection without IF/TA (SCR). Aiming to detect differences among SCR+IF/TA and SCR, we immunophenotyped the inflammatory infiltrate (CD45, CD3, CD20, CD68) and used a low-density array to determine levels of T(H)1 (interleukin IL-2, IL-3, gamma-interferon, tumor necrosis factor-alpha, lymphotoxin-alpha, lymphotoxin-beta, granulocyte-macrophage colony-stimulating factor) and T(H)2 (IL-4, IL-5, IL-6, IL-10, and IL-13) transcripts as well as of IL-2R (as marker for T-cell activation) in 31 protocol biopsies of renal allografts. Here we show that grafts with early IF/TA and SCR can be distinguished from grafts with SCR on the basis of the activation of IL-10 gene expression and of an increased infiltration by B-lymphocytes in a cellular context in which the degree of T-cell activation is similar in both groups of biopsies, as demonstrated by equivalent levels of IL-2R mRNA. These results suggest that the up-regulation of the IL-10 gene expression, as well as an increased proportion of B-lymphocytes in the inflammatory infiltrates, might be useful as markers of early chronic lesions in grafts with SCR.
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Affiliation(s)
- Miguel Hueso
- Departament de Nefrologia, Hospital Universitari de Bellvitge. IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
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Zarkhin V, Chalasani G, Sarwal MM. The yin and yang of B cells in graft rejection and tolerance. Transplant Rev (Orlando) 2010; 24:67-78. [PMID: 20149626 DOI: 10.1016/j.trre.2010.01.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Various lineages of B cells are being increasingly recognized as important players in the etiology and prognosis of both acute and chronic graft rejection. The role of immature, chronically activated B cells, as efficient antigen-presenting cells, supporting recalcitrant cell-mediated graft rejection and late lineage B cells driving humoral rejections, is being increasingly recognized. This review captures the recent literature on this subject and discusses the various roles of the B cell in renal graft rejection and conversely, also in graft tolerance, both in animal and human studies. In addition, novel therapies targeting specific B-cell lineages in graft rejection are also discussed, with a view to developing more targeted therapies for graft rejection.
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Affiliation(s)
- Valeriya Zarkhin
- Department of Pediatrics, Stanford University, Stanford, CA, USA.
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67
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Detection of plasma cells, C4d deposits and donor-specific antibodies on sequential graft biopsies of renal transplant recipients with chronic dysfunction. Transpl Immunol 2010; 22:110-4. [DOI: 10.1016/j.trim.2009.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/29/2009] [Accepted: 11/02/2009] [Indexed: 11/20/2022]
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68
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Endothelial transcripts uncover a previously unknown phenotype: C4d-negative antibody-mediated rejection. Curr Opin Organ Transplant 2010; 15:42-8. [DOI: 10.1097/mot.0b013e3283352a50] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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69
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Functional genomic analysis of peripheral blood during early acute renal allograft rejection. Transplantation 2010; 88:942-51. [PMID: 19935467 DOI: 10.1097/tp.0b013e3181b7ccc6] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Acute graft rejection is an important clinical problem in renal transplantation and an adverse predictor for long-term graft survival. Peripheral blood biomarkers that provide evidence of early graft rejection may offer an important option for posttransplant monitoring, optimize the utility of graft biopsy, and permit timely and effective therapeutic intervention to minimize the graft damage. METHODS In this feasibility study (n=58), we have used gene expression profiling in a case-control design to compare whole blood samples between normal subjects (n=20) and patients with (n=11) or without (n=22) biopsy-confirmed acute rejection (BCAR) or borderline changes (n=5). RESULTS A total of 183 probe sets representing 160 genes were differentially expressed (false discovery rate [FDR] <0.01) between subjects with or without BCAR, from which linear discriminant analysis and cross-validation identified an initial gene signature of 24 probe sets, and a more refined set of 11 probe sets found to classify subject samples correctly. Cross-validation suggested an out-of-sample sensitivity of 73% and specificity of 91% for identification of samples with or without BCAR. An increase in classifier gene expression correlated closely with acute rejection during the first 3 months posttransplant. Biological evaluation indicated that the differentially expressed genes encompassed processes related to immune response, signal transduction, and cytoskeletal reorganization. CONCLUSION Preliminary evidence indicates that gene expression in the peripheral blood may yield a relevant measure for the occurrence of BCAR and offer a potential tool for immunologic monitoring. These results now require confirmation in a larger cohort.
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71
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Zuber J, Brodin-Sartorius A, Lapidus N, Patey N, Tosolini M, Candon S, Rabant M, Snanoudj R, Panterne C, Thervet E, Legendre C, Chatenoud L. FOXP3-enriched infiltrates associated with better outcome in renal allografts with inflamed fibrosis. Nephrol Dial Transplant 2009; 24:3847-54. [PMID: 19729462 DOI: 10.1093/ndt/gfp435] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND FOXP3-expressing regulatory T cells (Tregs) play a crucial role in maintaining allogeneic transplant tolerance in experimental models. In clinical transplantation, there are few data about their role in chronic inflammation. We hypothesized that Tregs might accumulate within the graft since enrichment of Tregs has been frequently described in chronically inflamed tissues. METHODS Sixty-seven biopsies, indicated by a rise in creatinine level, were studied. Thirty-four biopsies showing acute T-cell-mediated rejection and 33 displaying inflamed fibrosis were selected. Tregs frequency was calculated for each infiltrate by counting FOXP3+ and CD3+ cells on two contiguous serial sections. RESULTS A total of 121 infiltrates were scored with a mean of 309 CD3+ cells per infiltrate (range: 50-700). Tregs were enriched within allografts exhibiting inflamed fibrosis versus acute cellular rejection (10.6 +/- 6.8% versus 5.5 +/- 2.6%, respectively, P = 0.005). In those with inflammation within scarred areas, the subset of patients with a low FOXP3/CD3 ratio (below the median value) displayed a lower frequency of B-cell-enriched nodular cell clusters (20% versus 86%, P = 0.001) and had a significantly lower graft survival (log-rank, P = 0.02). In multivariate analysis, the low FOXP3/CD3 ratio remained an independent indicator of outcome (P = 0.03). Consistently, the FOXP3+/IL-17+ cell ratio was higher in nodular than in diffuse infiltrates. CONCLUSIONS Our results suggest that Tregs may dampen the graft injury in chronic (versus acute) inflammation and stress the importance of devising strategies to enhance Tregs efficiency.
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Mengel M, Reeve J, Bunnag S, Einecke G, Jhangri GS, Sis B, Famulski K, Guembes-Hidalgo L, Halloran PF. Scoring total inflammation is superior to the current Banff inflammation score in predicting outcome and the degree of molecular disturbance in renal allografts. Am J Transplant 2009; 9:1859-67. [PMID: 19563338 DOI: 10.1111/j.1600-6143.2009.02727.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Emerging molecular analysis can be used as an objective and independent assessment of histopathological scoring systems. We compared the existing Banff i-score to the total inflammation (total i-) score for assessing the molecular phenotype in 129 renal allograft biopsies for cause. The total i-score showed stronger correlations with microarray-based gene sets representing major biological processes during allograft rejection. Receiver operating characteristic curves showed that total-i was superior (areas under the curves 0.85 vs. 0.73 for Banff i-score, p = 0.012) at assessing an abnormal cytotoxic T-cell burden, because it identified molecular disturbances in biopsies with advanced scarring. The total-i score was also a better predictor of graft survival than the Banff i-score and essentially all current diagnostic Banff categories. The exception was antibody-mediated rejection which is able to predict graft loss with greater specificity (96%) but at low sensitivity (38%) due to the fact that it only applies to cases with this diagnosis. The total i-score is able to achieve moderate sensitivities (60-80%) with losses in specificity (60-80%) across the whole population. Thus, the total i-score is superior to the current Banff i-score and most diagnostic Banff categories in predicting outcome and assessing the molecular phenotype of renal allografts.
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Affiliation(s)
- M Mengel
- Department of Laboratory Medicine and Pathology, Alberta Transplant Applied Genomics Centre, Canada.
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73
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Reeve J, Einecke G, Mengel M, Sis B, Kayser N, Kaplan B, Halloran PF. Diagnosing rejection in renal transplants: a comparison of molecular- and histopathology-based approaches. Am J Transplant 2009; 9:1802-10. [PMID: 19519809 DOI: 10.1111/j.1600-6143.2009.02694.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The transcriptome has considerable potential for improving biopsy diagnoses. However, to realize this potential the relationship between the molecular phenotype of disease and histopathology must be established. We assessed 186 consecutive clinically indicated kidney transplant biopsies using microarrays, and built a classifier to distinguish rejection from nonrejection using predictive analysis of microarrays (PAM). Most genes selected by PAM were interferon-gamma-inducible or cytotoxic T-cell associated, for example, CXCL9, CXCL11, GBP1 and INDO. We then compared the PAM diagnoses to those from histopathology, which are based on the Banff diagnostic criteria. Disagreement occurred in approximately 20% of diagnoses, principally because of idiosyncratic limitations in the histopathology scoring system. The problematic diagnosis of 'borderline rejection' was resolved by PAM into two distinct classes, rejection and nonrejection. The diagnostic discrepancies between Banff and PAM in these cases were largely due to the Banff system's requirement for a tubulitis threshold in defining rejection. By examining the discrepancies between gene expression and histopathology, we provide external validation of the main features of the histopathology diagnostic criteria (the Banff consensus system), recommend improvements and outline a pathway for introducing molecular measurements.
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Affiliation(s)
- J Reeve
- Department of Laboratory Medicine and Pathology, Arizona Health Science Centre, University of Arizona, Tucson, AZ, USA
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Bunnag S, Einecke G, Reeve J, Jhangri GS, Mueller TF, Sis B, Hidalgo LG, Mengel M, Kayser D, Kaplan B, Halloran PF. Molecular correlates of renal function in kidney transplant biopsies. J Am Soc Nephrol 2009; 20:1149-60. [PMID: 19389845 DOI: 10.1681/asn.2008080863] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The molecular changes in the parenchyma that reflect disturbances in the function of kidney transplants are unknown. We studied the relationships among histopathology, gene expression, and renal function in 146 human kidney transplant biopsies performed for clinical indications. Impaired function (estimated GFR) correlated with tubular atrophy and fibrosis but not with inflammation or rejection. Functional deterioration before biopsy correlated with inflammation and tubulitis and was greater in cases of rejection. Microarray analysis revealed a correlation between impaired renal function and altered expression of sets of transcripts consistent with tissue injury but not with those consistent with cytotoxic T cell infiltration or IFN-gamma effects. Multivariate analysis of clinical variables, histologic lesions, and transcript sets confirmed that expression of injury-related transcript sets independently correlated with renal function. Analysis of individual genes confirmed that the transcripts with the greatest positive or negative correlations with renal function were those suggestive of response to injury and parenchymal dedifferentiation not inflammation. We defined new sets of genes based on individual transcripts that correlated with renal function, and these highly correlated with the previously developed injury sets and with atrophy and fibrosis. Thus, in biopsies performed for clinical reasons, functional disturbances are reflected in transcriptome changes representing tissue injury and dedifferentiation but not the inflammatory burden.
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Affiliation(s)
- Sakarn Bunnag
- Department of Medicine, Division of Nephrology & Immunology, University of Alberta, Edmonton, Alberta, Canada
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Mengel M, Reeve J, Bunnag S, Einecke G, Sis B, Mueller T, Kaplan B, Halloran PF. Molecular correlates of scarring in kidney transplants: the emergence of mast cell transcripts. Am J Transplant 2009; 9:169-78. [PMID: 18976290 DOI: 10.1111/j.1600-6143.2008.02462.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the Banff consensus, infiltrates in areas of scarring are ignored. This study aimed to characterize the molecular correlates and clinical significance of scarring and inflammation in scarred areas. We assessed the extent of interstitial infiltrates, tubulitis and scarring in 129 clinically indicated renal allograft biopsies, and correlated the results with microarray expression data and allograft survival. Findings were validated in 50 additional biopsies. Transplants with scarring had a worse prognosis if the scarred area showed infiltrates. Infiltration in unscarred and scarred areas was associated with reduced death censored graft survival. In microarray analysis, infiltration in unscarred areas strongly (>r +/- 0.4) correlated with 484 transcripts associated with cytotoxic T cells, interferon-gamma, macrophages and injury. Scarring correlated with a distinct set of 172 transcripts associated with B cells, plasma cells, and others of unknown significance. The strongest correlation was with four mast cell transcripts. In biopsies with scarring, high expression of mast cell transcripts was associated with reduced graft survival and poor functional recovery. In renal allograft biopsies, infiltrates in scarred areas have implications for poor outcomes. Scarring is associated with a distinct pattern of inflammatory molecules, including B cell/immunoglobulin but particularly mast cell-associated transcripts, which correlated with poor outcomes.
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Affiliation(s)
- M Mengel
- Department of Medicine, Division of Nephrology and Immunology, Alberta Transplant Applied Genomics Centre, Edmonton, Canada
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Zand MS. Rituximab in pediatric renal transplantation: a treatment for allograft rejection with B-cell infiltrates? Am J Transplant 2008; 8:2489-90. [PMID: 19032220 DOI: 10.1111/j.1600-6143.2008.02454.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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77
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Sensitivity, specificity and clinical relevance of different cross-matching assays in deceased-donor renal transplantation. Transpl Immunol 2008; 20:61-7. [DOI: 10.1016/j.trim.2008.09.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 09/12/2008] [Accepted: 09/12/2008] [Indexed: 01/03/2023]
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