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1.
PLoS One ; 14(7): e0220052, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31365568

RESUMO

A Common Rejection Module (CRM) consisting of 11 genes expressed in allograft biopsies was previously reported to serve as a biomarker for acute rejection (AR), correlate with the extent of graft injury, and predict future allograft damage. We investigated the use of this gene panel on the urine cell pellet of kidney transplant patients. Urinary cell sediments collected from patients with biopsy-confirmed acute rejection, borderline AR (bAR), BK virus nephropathy (BKVN), and stable kidney grafts with normal protocol biopsies (STA) were analyzed for expression of these 11 genes using quantitative polymerase chain reaction (qPCR). We assessed these 11 CRM genes for their abundance, autocorrelation, and individual expression levels. Expression of 10/11 genes were elevated in AR when compared to STA. Psmb9 and Cxcl10could classify AR versus STA as accurately as the 11-gene model (sensitivity = 93.6%, specificity = 97.6%). A uCRM score, based on the geometric mean of the expression levels, could distinguish AR from STA with high accuracy (AUC = 0.9886) and correlated specifically with histologic measures of tubulitis and interstitial inflammation rather than tubular atrophy, glomerulosclerosis, intimal proliferation, tubular vacuolization or acute glomerulitis. This urine gene expression-based score may enable the non-invasive and quantitative monitoring of AR.


Assuntos
Biomarcadores/urina , Rejeição de Enxerto/genética , Transplante de Rim , Adolescente , Adulto , Idoso , Área Sob a Curva , Biomarcadores/metabolismo , Quimiocina CXCL10/genética , Criança , Pré-Escolar , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Expressão Gênica , Rejeição de Enxerto/diagnóstico , Humanos , Lactente , Rim/metabolismo , Rim/patologia , Pessoa de Meia-Idade , Curva ROC , Sensibilidade e Especificidade , Transplante Homólogo , Adulto Jovem
2.
Kidney Int Rep ; 3(3): 722-731, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29854981

RESUMO

INTRODUCTION: Studies are needed to assess the quality of transcriptome analysis in paired human tissue samples preserved by different methods and different gene amplification platforms to enable data comparisons across experimenters. METHODS: RNA was extracted from kidney biopsies, either submerged in RNA-stabilizing solution (RSS) or stored in formalin-fixed, paraffin-embedded (FFPE) blocks. RNA quality and integrity were compared. Gene expression of the common rejection module and other immune cell genes were quantified for both tissue preservation methods in the same sample using conventional quantitative polymerase chain reaction (QPCR) by 2 different commercial platforms, (fluidigm [FD]) or barcoded-oligos (nanostring [NS]). RESULTS: RNA quality was inferior in FFPE tissues. Despite this, gene expression for 19 measured genes on the same sample, stored in FFPE or RSS, were strongly correlated on the FD (r = 0.81) or NS platforms (r = 0.82). For the same samples, interplatform gene expression correlations were excellent (r = 0.80) for RSS and moderate (r = 0.66) for FFPE. Significant differences in gene expression were confirmed on both platforms (FD: P = 1.1E-03; NS: P = 2.5E-04) for biopsy-confirmed acute rejection. CONCLUSION: Our study provided supportive evidence that despite a low RNA quality of archival FFPE kidney transplantation tissue, small quantities of this tissue can be obtained from existing paraffin blocks to provide a viable and rich biospecimen source for focused gene expression assays. In addition, reliable and reproducible gene expression evaluation can be performed on these FFPE tissues using either a QPCR-based or a barcoded-oligo approach, which provides opportunities for collaborative analytics.

3.
Front Med (Lausanne) ; 4: 185, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29164120

RESUMO

Despite potent immunosuppression, clinical and biopsy confirmed acute renal allograft rejection (AR) still occurs in 10-15% of recipients, ~30% of patients demonstrate subclinical rejection on biopsy, and ~50% of them can show molecular inflammation, all which increase the risk of chronic dysfunction and worsened allograft outcomes. Mitochondria represent intracellular endogenous triggers of inflammation, which can regulate immune cell differentiation, and expansion and cause antigen-independent graft injury, potentially enhancing the development of acute rejection. In the present study, we investigated the role of mitochondrial DNA encoded gene expression in biopsy matched peripheral blood (PB) samples from kidney transplant recipients. Quantitative PCR was performed in 155 PB samples from 115 unique pediatric (<21 years) and adult (>21 years) renal allograft recipients at the point of AR (n = 61) and absence of rejection (n = 94) for the expression of 11 mitochondrial DNA encoded genes. We observed increased expression of all genes in adult recipients compared to pediatric recipients; separate analyses in both cohorts demonstrated increased expression during rejection, which also differentiated borderline rejection and showed an increasing pattern in serially collected samples (0-3 months prior to and post rejection). Our results provide new insights on the role of mitochondria during rejection and potentially indicate mitochondria as targets for novel immunosuppression.

4.
Transplantation ; 101(6): 1400-1409, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27362314

RESUMO

BACKGROUND: Subclinical acute rejection (sc-AR) is a main cause for functional decline and kidney graft loss and may only be assessed through surveillance biopsies. METHODS: The predictive capacity of 2 novel noninvasive blood biomarkers, the transcriptional kidney Solid Organ Response Test (kSORT), and the IFN-γ enzyme-linked immunosorbent spot assay (ELISPOT) assay were assessed in the Evaluation of Sub-Clinical Acute rejection PrEdiction (ESCAPE) Study in 75 consecutive kidney transplants who received 6-month protocol biopsies. Both assays were run individually and in combination to optimize the use of these techniques to predict sc-AR risk. RESULTS: Subclinical acute rejection was observed in 22 (29.3%) patients (17 T cell-mediated subclinical rejection [sc-TCMR], 5 antibody-mediated subclinical rejection [sc-ABMR]), whereas 53 (70.7%) showed a noninjured, preserved (stable [STA]) parenchyma. High-risk (HR), low-risk, and indeterminate-risk kSORT scores were observed in 15 (20%), 50 (66.7%), and 10 (13.3%) patients, respectively. The ELISPOT assay was positive in 31 (41%) and negative in 44 (58.7%) patients. The kSORT assay showed high accuracy predicting sc-AR (specificity, 98%; positive predictive value 93%) (all sc-ABMR and 58% sc-TCMR showed HR-kSORT), whereas the ELISPOT showed high precision ruling out sc-TCMR (specificity = 70%, negative predictive value = 92.5%), but could not predict sc-ABMR, unlike kSORT. The predictive probabilities for sc-AR, sc-TCMR, and sc-ABMR were significantly higher when combining both biomarkers (area under the curve > 0.85, P < 0.001) and independently predicted the risk of 6-month sc-AR in a multivariate regression analysis. CONCLUSIONS: Combining a molecular and immune cell functional assay may help to identify HR patients for sc-AR, distinguishing between different driving alloimmune effector mechanisms.


Assuntos
ELISPOT , Rejeição de Enxerto/diagnóstico , Interferon gama/sangue , Transplante de Rim/efeitos adversos , Reação em Cadeia da Polimerase , Transcrição Gênica , Adulto , Idoso , Aloenxertos , Área Sob a Curva , Doenças Assintomáticas , Biomarcadores/sangue , Biópsia , Feminino , Marcadores Genéticos , Rejeição de Enxerto/sangue , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento
5.
Transplantation ; 100(10): 2062-70, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27140517

RESUMO

BACKGROUND: Polyomavirus nephropathy (PVAN) is a common cause of kidney allograft dysfunction and loss. To identify PVAN-specific gene expression and underlying molecular mechanisms, we analyzed kidney biopsies with and without PVAN. METHODS: The study included 168 posttransplant renal allograft biopsies (T cell-mediated rejection [TCMR] = 26, PVAN = 10, normal functioning graft = 73, and interstitial fibrosis/tubular atrophy = 59) from 168 unique kidney allograft recipients. We performed gene expression assays and bioinformatics analysis to identify a set of PVAN-specific genes. Validity and relevance of a subset of these genes are validated by quantitative polymerase chain reaction and immunohistochemistry. RESULTS: Unsupervised hierarchical clustering analysis of all the biopsies revealed high similarity between PVAN and TCMR gene expression. Increased statistical stringency identified 158 and 252 unique PVAN and TCMR injury-specific gene transcripts respectively. Although TCMR-specific genes were overwhelmingly involved in immune response costimulation and TCR signaling, PVAN-specific genes were mainly related to DNA replication process, RNA polymerase assembly, and pathogen recognition receptors. A principal component analysis (PCA) using these genes further confirmed the most optimal separation between the 3 different clinical phenotypes. Validation of 4 PVAN-specific genes (RPS15, complement factor D, lactotransferrin, and nitric oxide synthase interacting protein) by quantitative polymerase chain reaction and confirmation by immunohistochemistry of 2 PVAN-specific proteins with antiviral function (lactotransferrin and IFN-inducible transmembrane 1) was done. CONCLUSIONS: In conclusion, even though PVAN and TCMR kidney allografts share great similarities on gene perturbation, PVAN-specific genes were identified with well-known antiviral properties that provide tools for discerning PVAN and AR as well as attractive targets for rational drug design.


Assuntos
Antígenos de Diferenciação/genética , Nefropatias/metabolismo , Transplante de Rim/efeitos adversos , Lactoferrina/genética , Infecções por Polyomavirus/metabolismo , Adolescente , Adulto , Biópsia , Criança , Pré-Escolar , Rejeição de Enxerto , Humanos , Lactente , Rim/patologia , Linfócitos T/imunologia , Transplante Homólogo
6.
PLoS One ; 10(9): e0138133, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26367000

RESUMO

BACKGROUND: Whole genome microarray meta-analyses of 1030 kidney, heart, lung and liver allograft biopsies identified a common immune response module (CRM) of 11 genes that define acute rejection (AR) across different engrafted tissues. We evaluated if the CRM genes can provide a molecular microscope to quantify graft injury in acute rejection (AR) and predict risk of progressive interstitial fibrosis and tubular atrophy (IFTA) in histologically normal kidney biopsies. METHODS: Computational modeling was done on tissue qPCR based gene expression measurements for the 11 CRM genes in 146 independent renal allografts from 122 unique patients with AR (n = 54) and no-AR (n = 92). 24 demographically matched patients with no-AR had 6 and 24 month paired protocol biopsies; all had histologically normal 6 month biopsies, and 12 had evidence of progressive IFTA (pIFTA) on their 24 month biopsies. Results were correlated with demographic, clinical and pathology variables. RESULTS: The 11 gene qPCR based tissue CRM score (tCRM) was significantly increased in AR (5.68 ± 0.91) when compared to STA (1.29 ± 0.28; p < 0.001) and pIFTA (7.94 ± 2.278 versus 2.28 ± 0.66; p = 0.04), with greatest significance for CXCL9 and CXCL10 in AR (p <0.001) and CD6 (p<0.01), CXCL9 (p<0.05), and LCK (p<0.01) in pIFTA. tCRM was a significant independent correlate of biopsy confirmed AR (p < 0.001; AUC of 0.900; 95% CI = 0.705-903). Gene expression modeling of 6 month biopsies across 7/11 genes (CD6, INPP5D, ISG20, NKG7, PSMB9, RUNX3, and TAP1) significantly (p = 0.037) predicted the development of pIFTA at 24 months. CONCLUSIONS: Genome-wide tissue gene expression data mining has supported the development of a tCRM-qPCR based assay for evaluating graft immune inflammation. The tCRM score quantifies injury in AR and stratifies patients at increased risk of future pIFTA prior to any perturbation of graft function or histology.


Assuntos
Injúria Renal Aguda/imunologia , Simulação por Computador , Regulação da Expressão Gênica , Rejeição de Enxerto/imunologia , Transplante de Rim , Modelos Imunológicos , Adolescente , Adulto , Aloenxertos , Criança , Feminino , Humanos , Masculino
7.
Transplantation ; 99(9): 1882-93, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26154388

RESUMO

BACKGROUND: Understanding the regulatory interplay of relevant microRNAs (miRNAs) and messenger RNAs (mRNAs) in the rejecting allograft will result in a better understanding of the molecular pathophysiology of alloimmune injury. METHODS: One hundred sixty-seven allograft biopsies, with (n = 47) and without (n = 120) central histology for Banff scored acute rejection (AR), were transcriptionally profiled for mRNA and miRNA by whole genome microarrays and multiplexed microfluidic quantitative polymerase chain reaction, respectively. A customized database was curated (GO-Elite) and used to identify AR-specific dysregulated mRNAs and the role of perturbations of their relevant miRNAs targets during AR. RESULTS: The AR-specific changes in 1035 specific mRNAs were mirrored by AR-specific perturbations in 9 relevant miRNAs as predicted by Go-Elite and were regulated specifically by p53 and forkhead box P3. Infiltrating lymphocytes and the renal tubules drove the miRNA tissue pertubations in rejection, involving message degradation and transcriptional/translational activation. The expression of many of these miRNAs significantly associated with the intensity of the Banff-scored interstitial inflammation and tubulitis. CONCLUSIONS: There is a highly regulated interplay between specific mRNA/miRNAs in allograft rejection that drive both immune-mediated injury and tissue repair during AR.


Assuntos
Rejeição de Enxerto/genética , Transplante de Rim/efeitos adversos , Túbulos Renais/química , Linfócitos/química , MicroRNAs/genética , RNA Mensageiro/genética , Transcrição Gênica , Doença Aguda , Adolescente , Adulto , Biópsia , Estudos de Casos e Controles , Bases de Dados Genéticas , Feminino , Fatores de Transcrição Forkhead/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Humanos , Túbulos Renais/imunologia , Túbulos Renais/patologia , Linfócitos/imunologia , Masculino , Reação em Cadeia da Polimerase Multiplex , Análise de Sequência com Séries de Oligonucleotídeos , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Adulto Jovem
8.
J Am Soc Nephrol ; 26(8): 2042-53, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25429124

RESUMO

Organ transplant recipients face life-long immunosuppression and consequently are at high risk of comorbidities. Occasionally, kidney transplant recipients develop a state of targeted immune quiescence (operational tolerance) against an HLA-mismatched graft, allowing them to withdraw all immunosuppression and retain stable graft function while resuming immune responses to third-party antigens. Methods to better understand and monitor this state of alloimmune quiescence by transcriptional profiling may reveal a gene signature that identifies patients for whom immunosuppression could be titrated to reduce patient and graft morbidities. Therefore, we investigated 571 unique peripheral blood samples from 348 HLA-mismatched renal transplant recipients and 101 nontransplant controls in a four-stage study including microarray, quantitative PCR, and flow cytometry analyses. We report a refined and highly validated (area under the curve, 0.95; 95% confidence interval, 0.92 to 0.97) peripheral blood three-gene assay (KLF6, BNC2, CYP1B1) to detect the state of operational tolerance by quantitative PCR. The frequency of predicted alloimmune quiescence in stable renal transplant patients receiving long-term immunosuppression (n=150) was 7.3% by the three-gene assay. Targeted cell sorting of peripheral blood from operationally tolerant patients showed a significant shift in the ratio of circulating monocyte-derived dendritic cells with significantly different expression of the genes constituting the three-gene assay. Our results suggest that incorporation of patient screening by specific cellular and gene expression assays may support the safety of drug minimization trials and protocols.


Assuntos
Biomarcadores/sangue , Terapia de Imunossupressão , Transplante de Rim , Imunologia de Transplantes/genética , Adolescente , Adulto , Contagem de Células Sanguíneas , Antígeno CD11c/metabolismo , Estudos de Casos e Controles , Criança , Citocromo P-450 CYP1B1/genética , Citocromo P-450 CYP1B1/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Células Dendríticas/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Fator 6 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Adulto Jovem
9.
J Am Soc Nephrol ; 26(5): 1161-71, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25381426

RESUMO

The initial contact point between a recipient's immune system and a transplanted graft is the vascular endothelium. Clinical studies suggest a pathogenic role for non-HLA antiendothelial cell antibodies (AECAs) in allograft rejection; however, evidence linking AECAs of known specificity to in vivo vascular injury is lacking. Here, we used high-density protein arrays to identify target antigens for AECAs isolated from the sera of recipients of kidney transplants experiencing antibody-mediated rejection in the absence of donor-specific HLA antibodies. Four antigenic targets expressed on endothelial cells were identified: endoglin, Fms-like tyrosine kinase-3 ligand, EGF-like repeats and discoidin I-like domains 3, and intercellular adhesion molecule 4; the first three have been implicated in endothelial cell activation and leukocyte extravasation. To validate these findings, ELISAs were constructed, and sera from an additional 150 renal recipients were tested. All four AECAs were detected in 24% of pretransplant sera, and they were associated with post-transplant donor-specific HLA antibodies, antibody-mediated rejection, and early transplant glomerulopathy. AECA stimulation of endothelial cell cultures increased adhesion molecule expression and production of inflammatory cytokines: regulated on activation, normal T cell expressed and secreted PDGF and RESISTIN. These correlations between in vitro experiments and in vivo histopathology suggest that AECAs activate the vascular endothelium, amplifying the alloimmune response and increasing microvascular damage. Given the growing number of transplant candidates, a better understanding of the antigenic targets, beyond HLA, and mechanisms of immune injury will be essential for improving long-term allograft survival.


Assuntos
Células Endoteliais/imunologia , Endotélio Vascular/imunologia , Rejeição de Enxerto/imunologia , Transplante de Rim , Adulto , Idoso , Anticorpos/sangue , Antígenos/metabolismo , Células Cultivadas , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Rejeição de Enxerto/sangue , Antígenos HLA/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise Serial de Proteínas , Proteômica/métodos , Estudos Retrospectivos
10.
Sci Transl Med ; 6(256): 256ra136, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25273097

RESUMO

Recurrence of focal segmental glomerulosclerosis (rFSGS) after kidney transplantation is a cause of accelerated graft loss. To evaluate pathogenic antibodies (Abs) in rFSGS, we processed 141 serum samples from 64 patients with and without primary rFSGS and 34 non-FSGS control patients transplanted at four hospitals. We screened about 9000 antigens in pretransplant sera and selected 10 Abs targeting glomerular antigens for enzyme-linked immunosorbent assay (ELISA) validation. A panel of seven Abs (CD40, PTPRO, CGB5, FAS, P2RY11, SNRPB2, and APOL2) could predict posttransplant FSGS recurrence with 92% accuracy. Pretransplant elevation of anti-CD40 Ab alone had the best correlation (78% accuracy) with rFSGS risk after transplantation. Epitope mapping of CD40 with customized peptide arrays and rFSGS sera demonstrated altered immunogenicity of the extracellular CD40 domain in rFSGS. Immunohistochemistry of CD40 demonstrated a differential expression in FSGS compared to non-FSGS controls. Anti-CD40 Abs purified from rFSGS patients were particularly pathogenic in human podocyte cultures. Injection of anti-CD40/rFSGS Ab enhanced suPAR (soluble urokinase receptor)-mediated proteinuria in wild-type mice, yet no sensitizing effect was noted in mice deficient in CD40 or in wild-type mice that received blocking Ab to CD40. In conclusion, a panel of seven Abs can help identify primary FSGS patients at high risk of recurrence before transplantation. Intrarenal CD40 (and possibly other specific glomerular antigens) is an important contributor to FSGS disease pathogenesis. Human trials of anti-CD40 therapies are warranted to evaluate their efficacy for preventing rFSGS and improving graft survival.


Assuntos
Anticorpos/sangue , Glomerulosclerose Segmentar e Focal/fisiopatologia , Transplante de Rim , Adulto , Antígenos CD40/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Glomerulosclerose Segmentar e Focal/cirurgia , Humanos , Masculino , Recidiva
11.
Clin Proteomics ; 11(1): 7, 2014 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-24568099

RESUMO

Analysis of native or endogenous peptides in biofluids can provide valuable insights into disease mechanisms. Furthermore, the detected peptides may also have utility as potential biomarkers for non-invasive monitoring of human diseases. The non-invasive nature of urine collection and the abundance of peptides in the urine makes analysis by high-throughput 'peptidomics' methods , an attractive approach for investigating the pathogenesis of renal disease. However, urine peptidomics methodologies can be problematic with regards to difficulties associated with sample preparation. The urine matrix can provide significant background interference in making the analytical measurements that it hampers both the identification of peptides and the depth of the peptidomics read when utilizing LC-MS based peptidome analysis. We report on a novel adaptation of the standard solid phase extraction (SPE) method to a modified SPE (mSPE) approach for improved peptide yield and analysis sensitivity with LC-MS based peptidomics in terms of time, cost, clogging of the LC-MS column, peptide yield, peptide quality, and number of peptides identified by each method. Expense and time requirements were comparable for both SPE and mSPE, but more interfering contaminants from the urine matrix were evident in the SPE preparations (e.g., clogging of the LC-MS columns, yellowish background coloration of prepared samples due to retained urobilin, lower peptide yields) when compared to the mSPE method. When we compared data from technical replicates of 4 runs, the mSPE method provided significantly improved efficiencies for the preparation of samples from urine (e.g., mSPE peptide identification 82% versus 18% with SPE; p = 8.92E-05). Additionally, peptide identifications, when applying the mSPE method, highlighted the biology of differential activation of urine peptidases during acute renal transplant rejection with distinct laddering of specific peptides, which was obscured for most proteins when utilizing the conventional SPE method. In conclusion, the mSPE method was found to be superior to the conventional, standard SPE method for urine peptide sample preparation when applying LC-MS peptidomics analysis due to the optimized sample clean up that provided improved experimental inference from the confidently identified peptides.

12.
Mol Cell Proteomics ; 13(2): 621-31, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24335474

RESUMO

Early transplant dysfunction and failure because of immunological and nonimmunological factors still presents a significant clinical problem for transplant recipients. A critical unmet need is the noninvasive detection and prediction of immune injury such that acute injury can be reversed by proactive immunosuppression titration. In this study, we used iTRAQ -based proteomic discovery and targeted ELISA validation to discover and validate candidate urine protein biomarkers from 262 renal allograft recipients with biopsy-confirmed allograft injury. Urine samples were randomly split into a training set of 108 patients and an independent validation set of 154 patients, which comprised the clinical biopsy-confirmed phenotypes of acute rejection (AR) (n = 74), stable graft (STA) (n = 74), chronic allograft injury (CAI) (n = 58), BK virus nephritis (BKVN) (n = 38), nephrotic syndrome (NS) (n = 8), and healthy, normal control (HC) (n = 10). A total of 389 proteins were measured that displayed differential abundances across urine specimens of the injury types (p < 0.05) with a significant finding that SUMO2 (small ubiquitin-related modifier 2) was identified as a "hub" protein for graft injury irrespective of causation. Sixty-nine urine proteins had differences in abundance (p < 0.01) in AR compared with stable graft, of which 12 proteins were up-regulated in AR with a mean fold increase of 2.8. Nine urine proteins were highly specific for AR because of their significant differences (p < 0.01; fold increase >1.5) from all other transplant categories (HLA class II protein HLA-DRB1, KRT14, HIST1H4B, FGG, ACTB, FGB, FGA, KRT7, DPP4). Increased levels of three of these proteins, fibrinogen beta (FGB; p = 0.04), fibrinogen gamma (FGG; p = 0.03), and HLA DRB1 (p = 0.003) were validated by ELISA in AR using an independent sample set. The fibrinogen proteins further segregated AR from BK virus nephritis (FGB p = 0.03, FGG p = 0.02), a finding that supports the utility of monitoring these urinary proteins for the specific and sensitive noninvasive diagnosis of acute renal allograft rejection.


Assuntos
Injúria Renal Aguda/urina , Biomarcadores/urina , Rejeição de Enxerto/urina , Reação Enxerto-Hospedeiro , Transplante de Rim/efeitos adversos , Proteômica/métodos , Injúria Renal Aguda/metabolismo , Adolescente , Adulto , Biomarcadores/metabolismo , Criança , Feminino , Rejeição de Enxerto/metabolismo , Humanos , Masculino , Mapas de Interação de Proteínas , Transdução de Sinais , Transplante Homólogo , Urinálise/métodos , Estudos de Validação como Assunto , Adulto Jovem
13.
PLoS One ; 8(12): e82153, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24358149

RESUMO

To test, whether 10 genes, diagnostic of renal allograft rejection in blood, are able to diagnose and predict cardiac allograft rejection, we analyzed 250 blood samples from heart transplant recipients with and without acute rejection (AR) and with cytomegalovirus (CMV) infection by QPCR. A QPCR-based logistic regression model was built on 5 of these 10 genes (AR threshold composite score >37%  = AR) and tested for AR prediction in an independent set of 109 samples, where it correctly diagnosed AR with 89% accuracy, with no misclassifications for AR ISHLT grade 1b. CMV infection did not confound the AR score. The genes correctly diagnosed AR in a blood sample within 6 months prior to biopsy diagnosis with 80% sensitivity and untreated grade 1b AR episodes had persistently elevated scores until 6 months after biopsy diagnosis. The gene score was also correlated with presence or absence of cardiac allograft vasculopathy (CAV) irrespective of rejection grade. In conclusion, there is a common transcriptional axis of immunological trafficking in peripheral blood in both renal and cardiac organ transplant rejection, across a diverse recipient age range. A common gene signature, initially identified in the setting of renal transplant rejection, can be utilized serially after cardiac transplantation, to diagnose and predict biopsy confirmed acute heart transplant rejection.


Assuntos
Infecções por Citomegalovirus/complicações , Expressão Gênica , Rejeição de Enxerto/diagnóstico , Transplante de Coração , Transplante de Rim , Adulto , Idoso , Aloenxertos , Biomarcadores/sangue , Infecções por Citomegalovirus/sangue , Feminino , Rejeição de Enxerto/sangue , Rejeição de Enxerto/complicações , Humanos , Masculino , Pessoa de Meia-Idade
14.
Transplantation ; 96(1): 97-101, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23756769

RESUMO

BACKGROUND: The copy number of donor-derived cell-free DNA (dd-cfDNA) in blood correlates with acute rejection (AR) in heart transplantation. We analyzed urinary dd-cfDNA as a surrogate marker of kidney transplant injury. METHODS: Sixty-three biopsy-matched urine samples (41 stable and 22 allograft injury) were analyzed from female recipients of male donors for chromosome Y (donor)-specific dd-cfDNA. All biopsies were semiquantitatively scored by a single pathologist. Standard statistical measures of correlation and significance were used. RESULTS: There was baseline scatter for urinary dd-cfDNA/µg urine creatinine across different patients, even at the time of stable graft (STA) function (undetected to 12.26 copies). The mean urinary dd-cfDNA in AR (20.5 ± 13.9) was significantly greater compared with STA (2.4 ± 3.3; P<0.0001) or those with chronic allograft injury (CAI; 2.4 ± 2.4; P=0.001) but no different from BK virus nephropathy (BKVN; 20.3±15.7; P=0.98). In AR and BKVN, the intrapatient drift was highly significant versus STA or CAI patients (10.3 ± 7.4 in AR; 12.3 ± 8.4 in BKVN vs. -0.5 ± 3.5 in STA and 2.3 ± 2.6 in CAI; P<0.05). Urinary dd-cfDNA correlated with protein/creatinine ratio (r=0.48; P<0.014) and calculated glomerular filtration rate (r=-0.52; P<0.007) but was most sensitive for acute allograft injury (area under the curve=0.80; P<0.0006; 95% confidence interval, 0.67-0.93). CONCLUSION: Urinary dd-cfDNA after renal transplantation has patient specific thresholds, reflecting the apoptotic injury load of the donor organ. Serial monitoring of urinary dd-cfDNA can be a surrogate sensitive biomarker of acute injury in the donor organ but lacks the specificity to distinguish between AR and BKVN injury.


Assuntos
Cromossomos Humanos Y , Rejeição de Enxerto/diagnóstico , Transplante de Rim/efeitos adversos , Traumatismo por Reperfusão/diagnóstico , Doença Aguda , Adolescente , Adulto , Apoptose , Vírus BK/genética , Biomarcadores/sangue , Biomarcadores/urina , Criança , DNA/sangue , Variações do Número de Cópias de DNA , Feminino , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/metabolismo , Humanos , Imunossupressores/uso terapêutico , Masculino , Infecções por Polyomavirus/diagnóstico , Traumatismo por Reperfusão/metabolismo , Sensibilidade e Especificidade , Fatores Sexuais , Transplante Homólogo , Infecções Tumorais por Vírus/diagnóstico , Adulto Jovem
15.
J Am Soc Nephrol ; 24(4): 655-64, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23449533

RESUMO

The development of anti-donor humoral responses after transplantation associates with higher risks for acute rejection and 1-year graft survival in adults, but the influence of humoral immunity on transplant outcomes in children is not well understood. Here, we studied the evolution of humoral immunity in low-risk pediatric patients during the first 2 years after renal transplantation. Using data from 130 pediatric renal transplant patients randomized to steroid-free (SF) or steroid-based (SB) immunosuppression in the NIH-SNSO1 trial, we correlated the presence of serum anti-HLA antibodies to donor HLA antigens (donor-specific antibodies) and serum MHC class 1-related chain A (MICA) antibody with both clinical outcomes and histology identified on protocol biopsies at 0, 6, 12, and 24 months. We detected de novo antibodies after transplant in 24% (23% of SF group and 25% of SB group), most often after the first year. Overall, 22% developed anti-HLA antibodies, of which 6% were donor-specific antibodies, and 6% developed anti-MICA antibody. Presence of these antibodies de novo associated with significantly higher risks for acute rejection (P=0.02), chronic graft injury (P=0.02), and decline in graft function (P=0.02). In summary, antibodies to HLA and MICA antigens appear in approximately 25% of unsensitized pediatric patients, placing them at greater risk for acute and chronic rejection with accelerated loss of graft function. Avoiding steroids does not seem to modify this incidence. Whether serial assessments of these antibodies after transplant could guide individual tailoring of immunosuppression requires additional study.


Assuntos
Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Imunidade Humoral , Transplante de Rim/imunologia , Criança , Humanos , Transplante de Rim/efeitos adversos
16.
PLoS One ; 8(2): e56657, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23437201

RESUMO

Despite advanced immunosuppression, redundancy in the molecular diversity of acute rejection (AR) often results in incomplete resolution of the injury response. We present a bioinformatics based approach for identification of these redundant molecular pathways in AR and a drug repositioning approach to suppress these using FDA approved drugs currently available for non-transplant indications. Two independent microarray data-sets from human renal allograft biopsies (n = 101) from patients on majorly Th1/IFN-y immune response targeted immunosuppression, with and without AR, were profiled. Using gene-set analysis across 3305 biological pathways, significant enrichment was found for the IL17 pathway in AR in both data-sets. Recent evidence suggests IL17 pathway as an important escape mechanism when Th1/IFN-y mediated responses are suppressed. As current immunosuppressions do not specifically target the IL17 axis, 7200 molecular compounds were interrogated for FDA approved drugs with specific inhibition of this axis. A combined IL17/IFN-y suppressive role was predicted for the antilipidemic drug Fenofibrate. To assess the immunregulatory action of Fenofibrate, we conducted in-vitro treatment of anti-CD3/CD28 stimulated human peripheral blood cells (PBMC), and, as predicted, Fenofibrate reduced IL17 and IFN-γ gene expression in stimulated PMBC. In-vivo Fenofibrate treatment of an experimental rodent model of cardiac AR reduced infiltration of total leukocytes, reduced expression of IL17/IFN-y and their pathway related genes in allografts and recipients' spleens, and extended graft survival by 21 days (p<0.007). In conclusion, this study provides important proof of concept that meta-analyses of genomic data and drug databases can provide new insights into the redundancy of the rejection response and presents an economic methodology to reposition FDA approved drugs in organ transplantation.


Assuntos
Rejeição de Enxerto , Interleucina-17/metabolismo , Transplante de Rim/imunologia , Leucócitos Mononucleares/efeitos dos fármacos , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Biologia Computacional , Feminino , Fenofibrato/administração & dosagem , Expressão Gênica/efeitos dos fármacos , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/metabolismo , Transplante de Coração/métodos , Humanos , Terapia de Imunossupressão , Interferon gama/metabolismo , Interleucina-17/imunologia , Transplante de Rim/métodos , Leucócitos Mononucleares/imunologia , Masculino , Camundongos , Análise Serial de Tecidos , Transplante Homólogo , Adulto Jovem
17.
J Am Soc Nephrol ; 23(4): 750-63, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22302197

RESUMO

Chronic allograft injury (CAI) results from a humoral response to mismatches in immunogenic epitopes between the donor and recipient. Although alloantibodies against HLA antigens contribute to the pathogenesis of CAI, alloantibodies against non-HLA antigens likely contribute as well. Here, we used high-density protein arrays to identify non-HLA antibodies in CAI and subsequently validated a subset in a cohort of 172 serum samples collected serially post-transplantation. There were 38 de novo non-HLA antibodies that significantly associated with the development of CAI (P<0.01) on protocol post-transplant biopsies, with enrichment of their corresponding antigens in the renal cortex. Baseline levels of preformed antibodies to MIG (also called CXCL9), ITAC (also called CXCL11), IFN-γ, and glial-derived neurotrophic factor positively correlated with histologic injury at 24 months. Measuring levels of these four antibodies could help clinicians predict the development of CAI with >80% sensitivity and 100% specificity. In conclusion, pretransplant serum levels of a defined panel of alloantibodies targeting non-HLA immunogenic antigens associate with histologic CAI in the post-transplant period. Validation in a larger, prospective transplant cohort may lead to a noninvasive method to predict and monitor for CAI.


Assuntos
Epitopos/imunologia , Rejeição de Enxerto/imunologia , Isoanticorpos/sangue , Transplante de Rim/efeitos adversos , Adolescente , Adulto , Análise de Variância , Formação de Anticorpos/imunologia , Biomarcadores/sangue , Biópsia por Agulha , Doença Crônica , Estudos de Coortes , Feminino , Seguimentos , Antígenos HLA/imunologia , Humanos , Imuno-Histoquímica , Rim/imunologia , Rim/patologia , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/cirurgia , Transplante de Rim/imunologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Transplante Homólogo/efeitos adversos , Transplante Homólogo/imunologia , Adulto Jovem
18.
Transplantation ; 91(9): 1010-8, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-21403590

RESUMO

BACKGROUND: Recently published pediatric trial of Rituximab for the treatment of CD20+ acute renal allograft rejection (AR) demonstrated transient depletion of circulating/intragraft B cells (Zarkhin et al., Am J Transplant 2008; 8: 2607). In this study, we have evaluated phenotypic definition of circulating B-cell subsets before and after standard of care and B-cell depletional AR therapies. METHODS: We assessed peripheral B cells by flow cytometry at the time of AR and after AR treatment in 35 pediatric renal transplant recipients: 17 patients with AR who received Rituximab (R-AR; n=11) or steroid pulsing (S-AR; n=6), 18 stable patients with stable graft function with (iSTA; n=10) or without interval infection (hSTA; n=8), and 3 healthy volunteers. RESULTS: Infections increased memory (P=0.02) and CD19+/CD27⁻/IgD⁻ double negative (DN) B cells (P=0.02) and decreased naive B cells (P=0.01) in iSTA group compared to hSTA patients. Decrease in naive/memory B cells ratio at AR was observed compared with hSTA patients (P=0.01). One year after AR treatment, S-AR patients had persistently lower naive/memory B-cell ratio (P=0.01) and higher DN B cells (P=0.0001) than hSTA patients, whereas after R-AR treatment naive/memory B-cell ratio (P=0.6) and DN B cells (P=0.13) recovered to levels of hSTA patients. R-AR patients with sustained AR resolution (n=8) had trend toward better graft survival (P=0.06) and higher naive B cells (P=0.004) than R-AR relapsers (n=3). CONCLUSIONS: Increase in circulating memory B cells was seen in pediatric patients at AR. B cells persist as memory after S-AR treatment, whereas Rituximab resulted in repopulation of mostly naive B cells. The heterogeneity in B-cells reconstitution after rejection therapies deserves further investigation as a possible means to follow the clinical and immunologic outcomes of graft rejection.


Assuntos
Anticorpos Monoclonais Murinos/uso terapêutico , Subpopulações de Linfócitos B/imunologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/terapia , Imunossupressores/uso terapêutico , Transplante de Rim/efeitos adversos , Doença Aguda , Adolescente , Fatores Etários , Fator Ativador de Células B/sangue , Receptor do Fator Ativador de Células B/sangue , Subpopulações de Linfócitos B/efeitos dos fármacos , Criança , Pré-Escolar , Feminino , Rejeição de Enxerto/etiologia , Humanos , Memória Imunológica , Lactente , Transplante de Rim/imunologia , Depleção Linfocítica , Masculino , Fenótipo , Rituximab , Esteroides/uso terapêutico , Viremia/etiologia , Viremia/imunologia , Viremia/terapia , Adulto Jovem
19.
PLoS Comput Biol ; 6(9)2010 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-20885780

RESUMO

Serum proteins are routinely used to diagnose diseases, but are hard to find due to low sensitivity in screening the serum proteome. Public repositories of microarray data, such as the Gene Expression Omnibus (GEO), contain RNA expression profiles for more than 16,000 biological conditions, covering more than 30% of United States mortality. We hypothesized that genes coding for serum- and urine-detectable proteins, and showing differential expression of RNA in disease-damaged tissues would make ideal diagnostic protein biomarkers for those diseases. We showed that predicted protein biomarkers are significantly enriched for known diagnostic protein biomarkers in 22 diseases, with enrichment significantly higher in diseases for which at least three datasets are available. We then used this strategy to search for new biomarkers indicating acute rejection (AR) across different types of transplanted solid organs. We integrated three biopsy-based microarray studies of AR from pediatric renal, adult renal and adult cardiac transplantation and identified 45 genes upregulated in all three. From this set, we chose 10 proteins for serum ELISA assays in 39 renal transplant patients, and discovered three that were significantly higher in AR. Interestingly, all three proteins were also significantly higher during AR in the 63 cardiac transplant recipients studied. Our best marker, serum PECAM1, identified renal AR with 89% sensitivity and 75% specificity, and also showed increased expression in AR by immunohistochemistry in renal, hepatic and cardiac transplant biopsies. Our results demonstrate that integrating gene expression microarray measurements from disease samples and even publicly-available data sets can be a powerful, fast, and cost-effective strategy for the discovery of new diagnostic serum protein biomarkers.


Assuntos
Proteínas Sanguíneas/genética , Biologia Computacional/métodos , Rejeição de Enxerto/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA/análise , Biomarcadores/sangue , Biomarcadores/metabolismo , Biomarcadores/urina , Proteínas Sanguíneas/análise , Mineração de Dados , Bases de Dados Genéticas , Ensaio de Imunoadsorção Enzimática , Perfilação da Expressão Gênica , Rejeição de Enxerto/sangue , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/urina , Transplante de Coração/efeitos adversos , Transplante de Coração/imunologia , Histocitoquímica , Humanos , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Transplante de Rim/efeitos adversos , Transplante de Rim/imunologia , Proteinúria/sangue , Proteinúria/urina , RNA/biossíntese , RNA/genética , Curva ROC , Reprodutibilidade dos Testes
20.
J Inherit Metab Dis ; 33(6): 775-86, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20865335

RESUMO

Nephropathic cystinosis is a rare, inherited metabolic disease caused by functional defects of cystinosin associated with mutations in the CTNS gene. The mechanisms underlying the phenotypic alterations associated with this disease are not well known. In this study, gene expression profiles in peripheral blood of nephropathic cystinosis patients (N = 7) were compared with controls (N = 7) using microarray technology. In unsupervised hierarchical clustering analysis, cystinosis samples co-clustered, and 1,604 genes were significantly differentially expressed between both groups. Gene ontology analysis revealed that differentially expressed genes in cystinosis were enriched in cell organelles such as mitochondria, lysosomes, and endoplasmic reticulum (p ≤ 0.030). The majority of the differentially regulated genes were involved in oxidative phosphorylation, apoptosis, mitochondrial dysfunction, endoplasmic reticulum stress, antigen processing and presentation, B-cell-receptor signaling, and oxidative stress (p ≤ 0.003). Validation of selected genes involved in apoptosis and oxidative phosphorylation was performed by quantitative real-time polymerase chain reaction (PCR). Electron microscopy and confocal imaging of cystinotic renal proximal tubular epithelial cells further confirmed anomalies in the cellular organelles and pathways identified by microarray analysis. Further analysis of these genes and pathways may offer critical insights into the clinical spectrum of cystinosis patients and ultimately lead to novel links for targeted therapy.


Assuntos
Cistinose/complicações , Cistinose/genética , Perfilação da Expressão Gênica , Nefropatias/complicações , Nefropatias/genética , Adolescente , Adulto , Sistemas de Transporte de Aminoácidos Neutros/genética , Técnicas de Cultura de Células , Células Cultivadas , Criança , Cistinose/patologia , Progressão da Doença , Feminino , Humanos , Nefropatias/patologia , Masculino , Análise em Microsséries , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Estudos de Validação como Assunto , Adulto Jovem
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