Acute Renal Allograft Rejection Research Articles

Noninvasive detection of acute renal allograft rejection by measurement of soluble Tim-3 in urine.

The purpose of the present study was to assess whether urinary soluble T-cell immunoglobulin and mucin domain-containing protein 3 (sTim-3) could be adopted as a novel non‑invasive biomarker for acute rejection (AR) following renal transplantation. A total of 156patients were enrolled between January 2006 and December2009, comprising 49patients with biopsy‑proven AR, 58patients with stable grafts and no abnormal histological findings (NO‑AR), 10patients with subclinical rejection (SCR) in protocol biopsies, 10patients with acute tubular necrosis (ATN) and 29patients with chronic allograft nephropathy (CAN). Additionally, urine samples from 40 healthy individuals were also collected as controls. The urinary concentration of sTim‑3 was determined by ELISA in the 156 renal allograft recipients and 40 healthy controls. Compared with NO‑AR and healthy controls, patients with AR excreted urinary sTim‑3 at a significantly higher level (4,356±440.4, 95% CI: 3,473‑5,242ng/mmol creatinine). Likewise, patients with ATN exhibited a significantly lower level of urinary sTim‑3 (2,060±217, 95% CI: 1,679‑2,680ng/mmol creatinine) than patients with AR. The discriminatory value was measured by the area under the receiver operating characteristic curve (ROC), which had a value of 0.88 (95% CI: 0.809‑0.951), demonstrating that sTim‑3 was a suitable marker for the diagnosis of AR. At a cut-off point of 1,836ng/mmol creatinine, the sensitivity was 89.8% and the specificity was 82.8% (P<0.001). Amongst the patients with AR, patients with steroid‑resistant acute rejection (n=31) had significantly higher urinary sTim‑3 concentrations than patients with steroid‑sensitive acute rejection (n=18; 5,548±613.5, 95%CI: 4,287‑6,809ng/mmol creatinine vs. 2,653±391.7, 95% CI: 1,830‑3,476ng/mmol creatinine; P=0.0002). No significant difference in urinary sTim‑3 was found between patients with AR and CAN (3,920±543.5, 95% CI: 3,473‑5,242ng/mmol creatinine), and a significantly higher level of Tim‑3 was excreted by patients with CAN compared with patients with NO‑AR and healthy controls (P<0.001). The present study, therefore, suggests that urinary sTim‑3 may be used as a valuable non‑invasive biomarker for the detection of AR. In addition, urinary sTim‑3 levels were demonstrated to be associated with the response to anti‑rejection therapy. The results of the present study may provide support future research into the screening of novel immune suppressants.

COMPARISON OF DIFFERENT METHODS OF ANTI-HLA ANTIBODIES DETECTION IN DIAGNOSIS OF ANTIBODY-MEDIATED RENAL ALLOGRAFT REJECTION

Aim: to analyze the relationship between circulating anti-HLA antibodies (class-I and class-II), renal pathology and C4d deposition in cases of late acute and chronic antibody-mediated renal allograft rejection according to the method of antibodies detection (ELISA and LUMINEX). Materials and methods. Th e study included 192 patients with indicative graft biopsies (with C4d-staining) and screening detection of anti-HLA antibodies (109 patients by ELISA, 58 patients by LUMINEX, 25 patients – both methods). Patients were divided into 3 groups based on pathology fi ndings: 85 patients with chronic graft rejection, 39 patients with acute antibodymediated rejection (AMR), 68 patients of control group had no signs of AMR. Results. Anti-HLA antibodies (predominantly class-II anti-HLA) were identifi ed in 84.7% of patients with chronic graft rejection, in 84.6% of patients with acute AMR and 33.8% of control group (р &lt; 0.001). Close correlation between the levels of anti￾HLA antibodies detected by different methods was revealed for both classes of antibodies (r² class-I anti-HLA = 0.773, r² class-II anti-HLA = 0.379, р &lt; 0.01). LUMINEX proved to be more sensitive in anti-HLA antibodies detection in all groups. It was especially signifi cant for the diagnosis of C4d-negative acute AMR whose frequen￾cies were 22.2% and 4.8% in detection by LUMINEX and ELISA, respectively (р &lt; 0.01). On the other hand, anti-HLA antibodies being detected by LUMINEX in 55% of patients of the control group more often required determination of donor specifi city. Conclusion. Screening of anti-HLA antibodies (by ELISA and LUMINEX) along with specifi c renal pathology and C4d deposition is suffi cient for the diagnosis of acute and chronic AMR in most cases. Being more sensitive LUMINEX method is preferable for the revealing of C4d-negative AMR, but it requires specifi c DSA detection in many cases.

Inhibition of histone methyltransferase EZH2 ameliorates early acute renal allograft rejection in rats.

BackgroundAlthough histone methyltransferases EZH2 has been proved to have significant regulatory effect on the immune rejection after hematopoietic stem cell transplantation, its role in solid-organ transplantation remains uncovered. In this study, we investigate whether histone methylation regulation can impact renal allograft rejection in rat models.ResultsAllogeneic rat renal transplantation model (Wistar to Lewis) was established, and the recipients were administrated with EZH2 inhibitor DZNep after transplantation. Renal allografts and peripheral blood were collected on day 5 after transplantation for histological examination and mechanism investigation. We found that inhibition of EZH2 by DZNep after transplantation significantly ameliorated acute rejection (AR), with decreased histological injury and reduced inflammatory infiltration in renal allografts. Attenuation of AR was due to the prohibited activation of alloreactive T cells, the subsequent impaired production of inflammatory cytokines, and also the elevated apoptosis of alloreactive T cells in both renal allografts and periphery. However, inhibition of EZH2 did not increase the regulatory T cells during the AR.ConclusionsDisruption of EZH2 by DZNep suppressed the immune responses of alloreactive T cells and ameliorated AR of renal allografts. This suggests a therapeutic potential of targeting histone methyltransferases EZH2 in treating allograft rejection after solid organ transplantation.

Antitumor activity of nivolumab on hemodialysis after renal allograft rejection

BackgroundNivolumab (Opdivo™) is a novel IgG4 subclass programmed death-1 (PD-1) inhibiting antibody that has demonstrated breakthrough-designation anti-tumor activity. To date, clinical trials of nivolumab and other checkpoint inhibitors have generally...

IFN-γ-producing Th1-like regulatory T cells may limit acute cellular renal allograft rejection: Paradoxical post-transplantation effects of IFN-γ

PurposeIFN-γ is a protypical proinflammatory cytokine that plays a central role in inflammation and acute graft rejection. Accumulating evidence indicates that IFN-γ can exert previously unexpected immunoregulatory activities. However, little is known about the role of IFN-γ secreted by Th1-like regulatory T cells in human kidney transplantation. MethodsTo determine the function of IFN-γ in acute T cell-mediated renal allograft rejection (ACR), we examined serum cytokine expression profiles in ACR patients by human cytokine multiplex immunoassay and analyzed the cellular origins of IFN-γ in peripheral blood and renal allograft biopsies from ACR cases and controls by flow cytometry and immunohistochemistry, respectively. ResultsThe results showed significant reduction in serum concentrations of Th1-inducing cytokines IL-12p70 and IFN-γ as well as Th2-related cytokine IL-4 in ACR patients compared with stable controls. However, levels of several Th1-, Th2- and Th17-related cytokines, such as IL-2, TNF-α, TNF-β, IL-12 (p40), IL-10, IL-15, IL-17, IL-21, and IL-23, as well as the frequencies of Th1 and Th17 cell, did not differ between ACR cases and stable controls. Moreover, we found the levels of IFN-γ were correlated with those of the anti-inflammatory factor, IL-1 receptor antagonist (IL-1Ra) in ACR. Notably, the Th1-like Treg cell-to-Foxp3− Th1 cell ratio was significantly lower in ACR patients compared with that in stable controls. In graft biopsies from ACR patients, Treg cells and Th1-like Treg cells were less abundant than those without ACR. ConclusionsOur study indicates that IFN-γ secreted from Th1-like Treg cells negatively modulates ACR.

The Uptake of 18F-FDG by Renal Allograft in Kidney Transplant Recipients Is Not Influenced by Renal Function.

F-FDG PET/CT has been recently proposed as a noninvasive tool for the diagnosis of renal allograft acute rejection (AR) in kidney transplant recipients (KTRs). Still, the influence of kidney function on F-FDG uptake by renal grafts remains unknown. We retrospectively identified all KTRs who underwent at least one F-FDG PET/CT. Kidney transplant recipients with documented pyelonephritis or AR were excluded. Estimated glomerular filtration rate (eGFR) was assessed using chronic kidney disease (CKD)-EPI equation. Mean standardized uptake values (SUVmean) of renal graft cortex and aorta were measured in 4 and 1 volumes of interest, respectively. Spearman rank correlation coefficient (ρ) and analysis of variance (ANOVA) were performed. Eighty-two KTRs underwent F-FDG PET/CT for tumor staging (n = 46), suspected infection (n = 11), or fever of unknown origin (n = 25). Mean eGFR was 50 ± 19 mL/min per 1.73 m, including CKD stage 1 (n = 3), stage 2 (n = 21), stage 3a (n = 20), stage 3b (n = 29), and stage 4 (n = 9). Mean kidney and aorta SUVmean were 1.8 ± 0.2 and 1.7 ± 0.3, respectively. No significant correlation was observed between eGFR and kidney SUVmean (ρ, 0.119; P, 0.28) or aorta SUVmean (ρ, -0.144; P, 0.20). ANOVA showed no difference of kidney (P, 0.62) and aorta (P, 0.85) SUVmean between CKD groups. Mean coefficient of variation (on the basis of kidney SUVmean of >3 consecutive F-FDG PET/CT in 15 patients with no significant change of eGFR) reached 13.1%. The uptake of F-FDG by renal allografts within an hour postinjection is not significantly impacted by CKD.

Plasma proteomics for the assessment of acute renal transplant rejection

Renal transplant is the best treatment for patients with chronical kidney disease however acute graft rejection is the major impediment to success in renal transplantation leading to loss of the organ the first year after transplantation. The aim of this study was to identify plasma proteins that may be early biomarkers of acute rejection of renal allograft, developing a diagnostic model that avoids the loss of the transplanted organ. Shotgun proteomics (LC-MS/MS) method was used to analyze a set of thirty-one plasma samples, including 06 from patients with acute graft rejection after transplantation (rejection group/Rej-group) and twenty-five from renal transplant patients with stable renal graft function (control group/Ct-group). As results nineteen proteins were upregulated in the rejection group compared to the control group, and two proteins were downregulated; and three were present exclusively in the rejection group. After analysis, we selected four proteins that were related to the acute phase response and that were strongly associated with each other: they are alpha-1 antitrypsin (A1AT), alpha-2 antiplasmin (A2AP), serum amyloid A (SAA) and apolipoprotein CIII (APOC3). We think that simultaneous monitoring of SAA and APOC3 can provide insights into a broad profile of signaling proteins and is highly valuable for the early detection of a possible acute renal graft rejection. Statement of significance of the studyIn this study we did plasma shotgun patients with and without acute rejection of renal allograft. In a clinical setting an acute rejection is typically suspected upon an increase in plasma creatinine and renal biopsy. But these methods are late and unspecific; sometimes the rejection process is already advanced when there is an increase in serum creatinine.Therefore, it is necessary to find proteins that can predict the allograft rejection process. In our study were able to identify changes in the concentration of plasma protein belonging to a network of protein interaction processes the acute phase response.We believe, therefore, that development of a routine diagnosis of these proteins can detect early acute rejection of renal allograft process, thus preventing its loss.

Prediction of Renal Allograft Acute Rejection Using a Novel Non-Invasive Model Based on Acoustic Radiation Force Impulse

Point shear wave elastography based on acoustic radiation force impulse is a novel technology used to quantify tissue stiffness by measuring shear wave speed. A total of 115 kidney transplantation recipients were consecutively enrolled in this prospective study. The patients were subdivided into two groups using 1 mo post-transplantation as the cutoff time for determining the development of acute rejection (AR). Shear wave speed was significantly higher in the AR group than in the non-AR group. We created a model called SEV, comprising shear wave speed, estimated glomerular filtration rate and kidney volume change, that could successfully discriminate patients with or without AR. The area under the receiver operating characteristic curve of SEV was 0.89, which was higher than values for other variables; it was even better in patients within 1 mo post-transplantation (0.954), but was lower than the estimated glomerular filtration rate in patients after 1 mo post-transplantation. Therefore, the SEV model may predict AR after renal transplantation with a high degree of accuracy, and it may be more useful in the early post-operative stage after renal transplantation.

Acute renal allograft rejection after immune checkpoint inhibitor therapy for metastatic melanoma

Immune checkpoint inhibitors such as ipilimumab and nivolumab improve survival in patients with advanced melanoma and are increasingly available to clinicians for use in the clinic. Their safety in organ transplant recipients is not well defined but published case reports describing treatment with ipilimumab have not been complicated by graft rejection. No cases of anti-programmed cell death protein 1 administration are reported in this group. We describe a case of acute graft rejection in a kidney transplant recipient after treatment with nivolumab, after progression on ipilimumab. Potential factors increasing the risk of graft rejection in this case are discussed, in particular the contribution of nivolumab.

A Promoter Polymorphism in the CD46 Complement Regulatory Protein Gene Is Associated With Acute Renal Allograft Rejection

ObjectivesCD46 molecule (complement regulatory protein [CD46]), known as a human cell surface receptor, plays an important role in complement and T-cell regulation for organ transplantation. This study was performed to evaluate the association of promoter polymorphism (rs2796267, -496 A/G) of the CD46 gene with acute renal allograft rejection (AR), late acute rejection (LAR), and graft loss (GL) in Korean patients. MethodsA total of 334 patients with kidney transplants were recruited. Transplantation outcomes were determined in terms of AR, LAR, and GL criteria. The promoter single nucleotide polymorphism (SNP) of CD46 was genotyped by direct sequencing. ResultsThe rs2796267 SNP exhibited significant differences between the AR group and non-AR group (codominant1 model, P = .012; odds ratio [OR], 0.47 [95% confidence interval, 0.26–0.84]; dominant model, P = .012; OR, 0.50 [95% CI, 0.29–0.86]; and allele distribution, P = .034; OR, 0.64 [95% CI, 0.43–0.94]). In addition, the SNP also exhibited significant associations with LAR (codominant2 model, P = .041; OR, 0.12 [95% CI, 0.02–0.92]; recessive model, P = .005; OR, 0.13 [95% CI, 0.02–0.94]; and allele distribution, P = .038; OR, 0.58 [95% CI, 0.35–0.97]). ConclusionsThis study suggests that the promoter polymorphism (rs2796267, -496 A/G) CD46 gene may be related to susceptibility of AR in Korean kidney transplantation recipients.

Editorial: Memory T Cells: Effectors, Regulators, and Implications for Transplant Tolerance.

Editorial: Memory T Cells: Effectors, Regulators, and Implications for Transplant Tolerance.

Validation of Urinary PD-1 and FOXP3 mRNA in a Cohort of Egyptian Renal Allograft Recipients.

We investigated the diagnostic and prognostic value of urinary programmed death 1 (PD-1) and FOXP3 (Forkhead transcription factors) mRNA in acute renal allograft rejection. Urine samples from 31 acute renal allograft rejection subjects and 23 stable recipients were collected. Messenger RNA of PD-1 and FOXP3 were analyzed with real-time RT-PCR. The associations with acute rejection, disease severity, and outcome were investigated. Both PD-1 and FOXP3 mRNA were higher in acute rejection than subjects with stable grafts. In acute rejection, PD-1 and FOXP3 mRNA were significantly correlated with serum creatinine and Banff histological grade. Both PD-1 and FOXP3 mRNA performed well in diagnosing acute rejection (AUC 0.81 and 0.91, respectively). However, a combination of both FOXP3 mRNA at cutoff level 1.5 and PD-1 mRNA at cutoff level 2.6 had 94% sensitivity, 97% specificity, and AUC 0.98 in diagnosing acute rejection. Only FOXP3 mRNA was correlated with rejection reversibility and predicted graft salvage (98% sensitivity, 87% specificity, and AUC 0.93) at cutoff level 1.7. PD-1 and FOXP3 mRNA were high in acute rejection, and performed well in diagnosing rejection episodes, and were correlated with rejection severity. The combination of FOXP3 and PD-1 mRNA had better sensitivity and specificity in diagnosing acute rejection than each separately. Only FOXP3 anticipated rejection outcome.

RNA Profiling in Human and Murine Transplanted Hearts: Identification and Validation of Therapeutic Targets for Acute Cardiac and Renal Allograft Rejection

Acute cellular rejection (ACR) is the adverse response of the recipient's immune system against the allogeneic graft. Using human surveillance endomyocardial biopsies (EMBs) manifesting ACR and murine allogeneic grafts, we profiled implicated microRNAs (miRs) and mRNAs. MiR profiling showed that miR‐21, ‐142‐3p, ‐142‐5p, ‐146a, ‐146b, ‐155, ‐222, ‐223, and ‐494 increased during ACR in humans and mice, whereas miR‐149‐5p decreased. mRNA profiling revealed 70 common differentially regulated transcripts, all involved in immune signaling and immune‐related diseases. Interestingly, 33 of 70 transcripts function downstream of IL‐6 and its transcription factor spleen focus forming virus proviral integration oncogene (SPI1), an established target of miR‐155, the most upregulated miR in human EMBs manifesting rejection. In a mouse model of cardiac transplantation, miR‐155 absence and pharmacological inhibition attenuated ACR, demonstrating the causal involvement and therapeutic potential of miRs. Finally, we corroborated our miR signature in acute cellular renal allograft rejection, suggesting a nonorgan specific signature of acute rejection. We concluded that miR and mRNA profiling in human and murine ACR revealed the shared significant dysregulation of immune genes. Inflammatory miRs, for example miR‐155, and transcripts, in particular those related to the IL‐6 pathway, are promising therapeutic targets to prevent acute allograft rejection.

Kidney Transplantation: Multiparametric Functional Magnetic Resonance Imaging for Assessment of Renal Allograft Pathophysiology in Mice.

The aims of this experimental study were to investigate renal allograft pathophysiology by multiparametric functional magnetic resonance imaging (MRI) and to directly correlate MRI parameters with renal histopathology in mouse models of allogenic and isogenic kidney transplantation (ktx). Allograft rejection was induced by transplantation of C57BL/6 (B6) donor kidneys into BALB/c recipients (allogenic ktx). B6 mice that received B6 kidneys served as controls (isogenic ktx). Three weeks after ktx, MRI was performed using a 7-T small-animal scanner. Flow sensitive alternating inversion recovery echoplanar imaging arterial spin labeling, multiecho turbo spin echo, and diffusion-weighted imaging sequences were acquired. Maps of renal perfusion, T2 and T1 relaxation times, and apparent diffusion coefficients were calculated. Histological changes in the kidney were evaluated according to Banff criteria. Renal cell infiltrates and fibrosis were quantified by immunohistochemistry. Differences between groups were assessed using the Mann-Whitney U test, and the correlation of MRI parameters with renal histopathology was determined by Spearman correlation analysis. After allogenic, but not isogenic, ktx, animals developed acute allograft rejection. Allogenic grafts were infiltrated by macrophages and T-lymphocytes and exhibited marked renal fibrosis. Magnetic resonance imaging revealed stronger impairment of renal perfusion (56 ± 7 vs 293 ± 44 mL/[min × 100 g]; P < 0.01) and more pronounced increases in T2 (60.1 ± 2.0 vs 45.7 ± 1.2 milliseconds, P < 0.01) and T1 relaxation times (1938 ± 53 vs 1350 ± 27 milliseconds, P < 0.01) in allogenic than in isogenic kidneys. Apparent diffusion coefficient was reduced to 1.39 ± 0.14 × 10(-3) mm2/s in kidneys with an acute rejection and was 1.83 ± 0.05 × 10(-3) mm2/s in isogenic kidneys without rejection (P < 0.05). Magnetic resonance imaging parameters significantly correlated with the amount of cellular infiltration and renal fibrosis observed histologically. Functional MRI allows detection of acute renal allograft rejection after allogenic ktx in mice. Functional MRI parameters correlate with cell infiltrates and fibrosis. Thus, MRI may be used noninvasively and longitudinally to investigate mechanisms of renal allograft rejection and evaluate novel therapeutic strategies in experimental studies.

Imaging-based diagnosis of acute renal allograft rejection.

Kidney transplantation is the best available treatment for patients with end stage renal disease. Despite the introduction of effective immunosuppressant drugs, episodes of acute allograft rejection still endanger graft survival. Since efficient treatment of acute rejection is available, rapid diagnosis of this reversible graft injury is essential. For diagnosis of rejection, invasive core needle biopsy of the graft is the "gold-standard". However, biopsy carries the risk of significant graft injury and is not immediately feasible in patients taking anticoagulants. Therefore, a non-invasive tool assessing the whole organ for specific and fast detection of acute allograft rejection is desirable. We herein review current imaging-based state of the art approaches for non-invasive diagnostics of acute renal transplant rejection. We especially focus on new positron emission tomography-based as well as targeted ultrasound-based methods.

Fluorodeoxyglucose F18 Positron Emission Tomography Coupled With Computed Tomography in Suspected Acute Renal Allograft Rejection

Management of kidney transplant recipients (KTRs) with suspected acute rejection (AR) ultimately relies on kidney biopsy; however, noninvasive tests predicting nonrejection would help avoid unnecessary biopsy. AR involves recruitment of leukocytes avid for fluorodeoxyglucose F(18) ((18) F-FDG), thus (18) F-FDG positron emission tomography (PET) coupled with computed tomography (CT) may noninvasively distinguish nonrejection from AR. From January 2013 to February 2015, we prospectively performed 32 (18) F-FDG PET/CT scans in 31 adult KTRs with suspected AR who underwent transplant biopsy. Biopsies were categorized into four groups: normal (n = 8), borderline (n = 10), AR (n = 8), or other (n = 6, including 3 with polyoma BK nephropathy). Estimated GFR was comparable in all groups. PET/CT was performed 201 ± 18 minutes after administration of 3.2 ± 0.2 MBq/kg of (18) F-FDG, before any immunosuppression change. Mean standard uptake values (SUVs) of both upper and lower renal poles were measured. Mean SUVs reached 1.5 ± 0.2, 1.6 ± 0.3, 2.9 ± 0.8, and 2.2 ± 1.2 for the normal, borderline, AR, and other groups, respectively. One-way analysis of variance demonstrated a significant difference of mean SUVs among groups. A positive correlation between mean SUV and acute composite Banff score was found, with r(2) = 0.49. The area under the receiver operating characteristic curve was 0.93, with 100% sensitivity and 50% specificity using a mean SUV threshold of 1.6. In conclusion, (18) F-FDG PET/CT may help noninvasively prevent avoidable transplant biopsies in KTRs with suspected AR.

Exogenous Lipocalin 2 Ameliorates Acute Rejection in a Mouse Model of Renal Transplantation.

Lipocalin 2 (Lcn2) is rapidly produced by damaged nephron epithelia and is one of the most promising new markers of renal injury, delayed graft function and acute allograft rejection (AR); however, the functional importance of Lcn2 in renal transplantation is largely unknown. To understand the role of Lcn2 in renal AR, kidneys from Balb/c mice were transplanted into C57Bl/6 mice and vice versa and analyzed for morphological and physiological outcomes of AR at posttransplantation days 3, 5, and 7. The allografts showed a steady increase in intensity of interstitial infiltration, tubulitis and periarterial aggregation of lymphocytes associated with a substantial elevation in serum levels of creatinine, urea and Lcn2. Perioperative administration of recombinant Lcn2:siderophore:Fe complex (rLcn2) to recipients resulted in functional and morphological amelioration of the allograft at day 7 almost as efficiently as daily immunosuppression with cyclosporine A (CsA). No significant differences were observed in various donor–recipient combinations (C57Bl/6 wild‐type and Lcn2−/−, Balb/c donors and recipients). Histochemical analyses of the allografts showed reduced cell death in recipients treated with rLcn2 or CsA. These results demonstrate that Lcn2 plays an important role in reducing the extent of kidney AR and indicate the therapeutic potential of Lcn2 in transplantation.

The prognostic significance of glomerular infiltrating leukocytes during acute renal allograft rejection

Transplant glomerulitis, observed in T cell-mediated and antibody-mediated rejection, is histologically characterized by intracapillary mononuclear cell infiltration. However, the prognostic value of counting various glomerular inflammatory cells during rejection has not been elucidated, which is a key step for the introduction of novel biomarkers in the clinics. We immunophenotyped glomerulitis during episodes of acute rejection in order to investigate their predictive value for transplant outcomes. To do so, we included 57 transplant biopsies of 57 renal transplant recipients with biopsy-proven acute rejection with a median follow-up of 4.2years. We determined average glomerular cell counts for T cells, B cells, Tregs, IL-17+ cells, neutrophils and macrophages. Logistic and Cox regression models were used to investigate the association of glomerular inflammatory cells with response to therapy and graft failure on a population level. We used novel time-dependent ROC curve analyses to investigate the value of glomerular inflammatory cell infiltrates for the prediction of transplant outcomes, applicable to the individual patient. We identified three cell types that were responsible for glomerulitis during rejection: macrophages, T cells and neutrophils. By quantification of glomerular macrophages, an emerging cell type associated with antibody-mediated rejection, we were able to predict the progression towards death-censored graft failure within the first 500days after the initial episode of rejection. With the use of novel time-dependent ROC analyses, we propose dynamic sensitivities, specificities, and positive and negative predictive values with their corresponding cut-off values for the average amount of glomerular macrophages, depending on what time after rejection death-censored graft failure needs prediction.

Immunosuppression and its use in kidney transplantation

Current immunosuppressive protocols effectively prevent acute rejection of renal allografts. Extensive drug toxicity and the deleterious effects of long-term immunosuppression are associated with significant morbidity and mortality. The purpose of this article is to provide an overview over modern immunosuppressants and their unwanted side effects and to discuss strategies for improved long-term transplant survival. Review of the current topic-related literature and discussion of our own experience. The use of antibody induction together with an initial combination therapy of calcineurin inhibitors, mycophenolate and steroids is recommended and results in excellent early outcomes. Detrimental effects include an increased incidence of infections, malignomas, and cardiovascular diseases. Long-term transplant survival is impaired by extensive drug toxicity and the frequent development of donor specific antibodies. Reduction of overall cumulative exposure to immunosuppressants or the reduction of specific toxic drugs such as calcineurin inhibitors and steroids may improve long-term results. Alternative immunosuppressants like mTOR inhibitors and belatacept appear to be effective and safe but their long-term effects on patient and allograft survival needs to be established in clinical trials. Current immunosuppressants provide effective protection from renal allograft rejection. However, their use is complicated by serious side effects. In the future, development of novel immunosuppressants and optimization of minimization strategies may help to improve long-term success after kidney transplantation.

Differential Expression of Specific Dermatan Sulfate Domains in Renal Pathology.

Dermatan sulfate (DS), also known as chondroitin sulfate (CS)-B, is a member of the linear polysaccharides called glycosaminoglycans (GAGs). The expression of CS/DS and DS proteoglycans is increased in several fibrotic renal diseases, including interstitial fibrosis, diabetic nephropathy, mesangial sclerosis and nephrosclerosis. Little, however, is known about structural alterations in DS in renal diseases. The aim of this study was to evaluate the renal expression of two different DS domains in renal transplant rejection and glomerular pathologies. DS expression was evaluated in normal renal tissue and in kidney biopsies obtained from patients with acute interstitial or vascular renal allograft rejection, patients with interstitial fibrosis and tubular atrophy (IF/TA), and from patients with focal segmental glomerulosclerosis (FSGS), membranous glomerulopathy (MGP) or systemic lupus erythematosus (SLE), using our unique specific anti-DS antibodies LKN1 and GD3A12. Expression of the 4/2,4-di-O-sulfated DS domain recognized by antibody LKN1 was decreased in the interstitium of transplant kidneys with IF/TA, which was accompanied by an increased expression of type I collagen, decorin and transforming growth factor beta (TGF-β), while its expression was increased in the interstitium in FSGS, MGP and SLE. Importantly, all patients showed glomerular LKN1 staining in contrast to the controls. Expression of the IdoA-Gal-NAc4SDS domain recognized by GD3A12 was similar in controls and patients. Our data suggest a role for the DS domain recognized by antibody LKN1 in renal diseases with early fibrosis. Further research is required to delineate the exact role of different DS domains in renal fibrosis.