Identification of Gene Transcripts Implicated in Peritoneal Membrane Alterations.

♦ BACKGROUND: Permanent stimulation of the peritoneum during peritoneal dialysis (PD) is likely to result in increased expression of genes encoding proteins involved in inflammation and tissue remodeling. Peritoneal fibrosis and neoangiogenesis may develop. ♦ OBJECTIVE: To assess highly expressed genes potentially in volved in peritoneal alterations during PD treatment using an animal model.

Molecular diagnostics identifies risks for graft dysfunction despite borderline histologic changes.

The significance of borderline changes in kidney allograft biopsies is widely debated. To help resolve this, we studied differences in intrarenal gene expression patterns between early clinical and 3-month protocol biopsies, all of which had borderline histologic changes. The gene expression profiles in training set of patients by microarray analysis and data were validated in a larger cohort using RT-qPCR.

Molecular profiling of acute and chronic rejections of renal allografts.

Both antibody mediated (AMR) and T-cell mediated (TCMR) rejections either acute or chronic represent the main reason for late graft dysfunction. In this study we aimed to evaluate differences in the intrarenal expression patterns of immune system related genes in acute and chronic rejections. Graft biopsies were performed and evaluated according to Banff classification.

Tubular atrophy and low netrin-1 gene expression are associated with delayed kidney allograft function.

Background: Delayed graft function (DGF) caused by ischemia/reperfusion injury (I/RI) negatively influences the outcome of kidney transplantation. This prospective single-center study characterized the intrarenal transcriptome during I/RI as a means of identifying genes associated with DGF development.

Methods: Characterization of the intrarenal transcription profile associated with I/RI was carried out on three sequential graft biopsies from respective allografts before and during transplantation.

Molecular markers of rejection and tolerance: lessons from clinical research.

In terms of finding specific molecular markers associated with graft outcome, attempts have been made to study whole genome transcripts using microarray assays or to study the effect of number of genes of interest using quantitative real-time polymerase chain reaction. Using these techniques, molecular phenotypes of rejection have been characterized, and the variability of the clinical outcome besides similar morphology explained in part. Recently, several specific transcripts including naïve B cell regulation have been identified in the peripheral blood of operationally tolerant kidney transplant recipients.

Molecular networks involved in the immune control of BK polyomavirus.

BK polyomavirus infection is the important cause of virus-related nephropathy following kidney transplantation. BK virus reactivates in 30%-80% of kidney transplant recipients resulting in BK virus-related nephropathy in 1%-10% of cases. Currently, the molecular processes associated with asymptomatic infections in transplant patients infected with BK virus remain unclear.

B-cell-related biomarkers of tolerance are up-regulated in rejection-free kidney transplant recipients.

Background: Molecular signatures have recently been identified in operationally tolerant long-term kidney transplant patients; however, their expression in patients on immunosuppression remains unclear.

Methods: In this prospective study, the gene expression profiles of eight selected tolerance-associated genes (MS4A1, CD79B, TCL1A, TMEM176B, FOXP3, TOAG-1, MAN1A1, and TLR5) in the peripheral blood of 67 kidney transplant recipients at days 0, 7, 14, 21, 28, 60, 90, and at 6 and 12 months, and in graft biopsies were measured. Similarly, using flow cytometry, CD45CD19CD3 B-cell counts were evaluated in the follow-up.

Cytokine gene expression profile in monocytic cells after a co-culture with epithelial cells.

Epithelial cells represent an important source of cytokines that may modulate the influx and functions of mononuclear phagocytes. The aim of our study was to characterize changes in the gene expression of selected cytokines in human macrophages co-cultured with respiratory epithelial cells. The A549 alveolar type II-like cell line was co-cultured with THP-1 cells (monocyte/macrophage cell line) in filter-separated mode to avoid their cell-cell contact.

Differential regulation of the nuclear factor-κB pathway by rabbit antithymocyte globulins in kidney transplantation.

Background: Induction therapy is associated with excellent short-term kidney graft outcome. The aim of this study was to evaluate differences in the intragraft transcriptome after successful induction therapy using two rabbit antithymocyte globulins.

Methods: The expression of 376 target genes involved in tolerance, inflammation, T- and B-cell immune response, and apoptosis was evaluated using the quantitative real-time reverse-transcriptase polymerase chain reaction (2(-ΔΔCt)) method in kidney graft biopsies with normal histological findings and stable renal function, 3 months posttransplantation after induction therapy with Thymoglobulin, ATG-Fresenius S (ATG-F), and a control group without induction therapy.

Regulatory T cells in kidney transplant recipients: the effect of induction immunosuppression therapy.

Background: Regulatory T cells have been suggested to down-regulate the alloimmune response. The aim of this prospective open study was to evaluate the effects of different inductive agents on peripheral blood regulatory T cells in kidney transplant patients and to analyse their association with short-term graft outcome.

Methods: Regulatory and effector T cell numbers in peripheral blood were determined by flow cytometry in 71 prospectively followed kidney transplant recipients at postoperative day 0, 7, 14, 21, 28, 60 and 90.

The FTO gene polymorphism is associated with end-stage renal disease: two large independent case-control studies in a general population.

Background: Genome-wide association studies identified the FTO (fat mass and obesity gene) gene as an important determinant of body weight. More recently, the FTO gene was reported to be associated with other outcomes, including major risk factors for chronic kidney disease (CKD). We investigated the role of this gene in the risk of end-stage renal disease (ESRD) caused by CKD.

A prospective longitudinal study of BK virus infection in 120 Czech renal transplant recipients.

Polyomavirus BK (BKV) is a common human polyomavirus that rarely causes clinical symptoms in immunocompetent individuals. However, BK virus reactivation occurs in 20-40% of kidney transplant patients and 1-10% of cases present with BK virus-associated nephropathy (BKVN) and reduced kidney allograft survival. In this study, 120 consecutive renal allograft recipients were monitored for BK virus replication by real-time PCR (qPCR) in the blood and urine during the first year post-transplantation and risk factors for BK viremia, viruria, and polyoma BKV-associated nephropathy were evaluated.

Association of advanced vasculopathy and transforming growth factor-beta1 gene expression with immunoglobulin A nephropathy progression.

Background: The mechanism of IgA nephropathy (IgAN) progression remains ill-defined. In this prospective study, the prognostic role of clinical, histological and molecular markers over a 2-year follow-up was evaluated.

Methods: Fifty-one patients with biopsy-proven IgAN were followed for 24 months.

Potential predictive markers in protocol biopsies for premature renal graft loss.

Background/aims: Protocol biopsies offer new possibilities to predict kidney allograft outcome. The aim of this study was to find clinical, laboratory, morphological and molecular predictors of short-term renal graft survival.

Methods: Three-month protocol kidney graft biopsy was carried out on 257 patients.

RAGE polymorphisms, renal function and histological finding at 12 months after renal transplantation.

Objectives: Rage (receptor for advanced glycation end products) is involved in pathogenesis of many diseases. The aim of the study was to test whether polymorphisms of RAGE gene are associated with the outcome of kidney transplantation.

Design And Methods: Four polymorphisms of the RAGE gene (-429T/C, -374T/A, Gly82Ser and 2184A/G) were assessed in 145 renal transplant recipients and their relationship to histological changes in 12 months protocol kidney graft biopsy and renal function was examined.

Haplotypic structure of ABCB1/MDR1 gene modifies the risk of the acute allograft rejection in renal transplant recipients.

Background: Bioavailability of tacrolimus (Tac) and cyclosporine is determined by cytochrome P450IIIA and by P-glycoprotein encoded by the CYP3A4/CYP3A5 and ABCB1 genes. Polymorphisms in these genes have been suggested to influence acute rejection and pharmacokinetics in renal transplantation. We aimed to validate these findings in a haplotype analysis.

Genetic variability of major inflammatory mediators has no impact on the outcome of kidney transplantation.

Background: Functionally relevant polymorphisms in genes of the Th1 and Th2-inflammatory pathway influence the susceptibility to acute rejection (AR), chronic allograft nephropathy (CAN), and subclinical rejection (SR) as well as graft survival after renal transplantation. Because these findings have not been validated, we sought confirmatory evidence of these associations in a larger group of renal transplant recipients.

Methods: A total of 436 kidney transplant recipients were genotyped for 9 single nucleotide polymorphisms (TNF-alpha-308G/A, MCP-1-2518A/G, RANTES-403G/A, -109T/C and -28C/G, CCR2+190G/A, IFN-gamma+874A/T, TGF-beta+869T/C and +915G/C) and for the 32-bp indel polymorphism in CCR5.

Intrarenal cytokine and chemokine gene expression and kidney graft outcome.

Aims: Proinflammatory cytokines are thought to play an important role in various kidney graft diseases resulting in interstitial fibrosis and tubular atrophy frequently found in case biopsies. To explore the role of various cytokines and chemokines in the long-term graft outcome, the transcription patterns of their genes in kidney allograft biopsies were evaluated.

Methods: The real-time RT-PCR was used to identify intragraft mRNA expression of cytokines and chemokines in 74 kidney graft recipients and the results were correlated with histological and clinical parameters and long-term graft outcome.