Human Renal Transplantation Research Articles

An intracellular matrix metalloproteinase-2 isoform induces tubular regulated necrosis: implications for acute kidney injury.

Acute kidney injury (AKI) causes severe morbidity, mortality, and chronic kidney disease (CKD). Mortality is particularly marked in the elderly and with preexisting CKD. Oxidative stress is a common theme in models of AKI induced by ischemia-reperfusion (I-R) injury. We recently characterized an intracellular isoform of matrix metalloproteinase-2 (MMP-2) induced by oxidative stress-mediated activation of an alternate promoter in the first intron of the MMP-2 gene. This generates an NH2-terminal truncated MMP-2 (NTT-MMP-2) isoform that is intracellular and associated with mitochondria. The NTT-MMP-2 isoform is expressed in kidneys of 14-mo-old mice and in a mouse model of coronary atherosclerosis and heart failure with CKD. We recently determined that NTT-MMP-2 is induced in human renal transplants with delayed graft function and correlated with tubular cell necrosis. To determine mechanism(s) of action, we generated proximal tubule cell-specific NTT-MMP-2 transgenic mice. Although morphologically normal at the light microscopic level at 4 mo, ultrastructural studies revealed foci of tubular epithelial cell necrosis, the mitochondrial permeability transition, and mitophagy. To determine whether NTT-MMP-2 expression enhances sensitivity to I-R injury, we performed unilateral I-R to induce mild tubular injury in wild-type mice. In contrast, expression of the NTT-MMP-2 isoform resulted in a dramatic increase in tubular cell necrosis, inflammation, and fibrosis. NTT-MMP-2 mice had enhanced expression of innate immunity genes and release of danger-associated molecular pattern molecules. We conclude that NTT-MMP-2 "primes" the kidney to enhanced susceptibility to I-R injury via induction of mitochondrial dysfunction. NTT-MMP-2 may be a novel AKI treatment target.

Enhanced expression of two discrete isoforms of matrix metalloproteinase-2 in experimental and human diabetic nephropathy.

BackgroundWe recently reported on the enhanced expression of two isoforms of matrix metalloproteinase-2 (MMP-2) in human renal transplantation delayed graft function. These consist of the conventional secreted, full length MMP-2 isoform (FL-MMP-2) and a novel intracellular N-Terminal Truncated isoform (NTT-MMP-2) generated by oxidative stress-mediated activation of an alternate promoter in the MMP-2 first intron. Here we evaluated the effect of hyperglycemia and diabetes mellitus on the in vitro and in vivo expression of the two MMP-2 isoforms.MethodsWe quantified the abundance of the FL-MMP-2 and NTT-MMP-2 transcripts by qPCR in HK2 cells cultured in high glucose or 4-hydroxy-2-hexenal (HHE) and tested the effects of the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC). The streptozotocin (STZ) murine model of Type I diabetes mellitus and renal biopsies of human diabetic nephropathy were used in this study.ResultsBoth isoforms of MMP-2 in HK2 cells were upregulated by culture in high glucose or with HHE. PDTC treatment did not suppress high glucose-mediated FL-MMP-2 expression but potently inhibited NTT-MMP-2 expression. With STZ-treated mice, renal cortical expression of both isoforms was increased (FL-MMP-2, 1.8-fold; NTT-MMP-2, greater than 7-fold). Isoform-specific immunohistochemical staining revealed low, but detectable levels of the FL-MMP-2 isoform in controls, while NTT-MMP-2 was not detected. While there was a modest increase in tubular epithelial cell staining for FL-MMP-2 in STZ-treated mice, NTT-MMP-2 was intensely expressed in a basolateral pattern. FL-MMP-2 and NTT-MMP-2 isoform expression as quantified by qPCR were both significantly elevated in renal biopsies of human diabetic nephropathy (12-fold and 3-fold, respectively).ConclusionsThe expression of both isoforms of MMP-2 was enhanced in an experimental model of diabetic nephropathy and in human diabetic nephropathy. Selective MMP-2 isoform inhibition could offer a novel approach for the treatment of diabetic renal disease.

Effect of TREM-1 blockade and single nucleotide variants in experimental renal injury and kidney transplantation.

Renal ischemia reperfusion (IR)-injury induces activation of innate immune response which sustains renal injury and contributes to the development of delayed graft function (DGF). Triggering receptor expressed on myeloid cells-1 (TREM-1) is a pro-inflammatory evolutionary conserved pattern recognition receptor expressed on a variety of innate immune cells. TREM-1 expression increases following acute and chronic renal injury. However, the function of TREM-1 in renal IR is still unclear. Here, we investigated expression and function of TREM-1 in a murine model of renal IR using different TREM-1 inhibitors: LP17, LR12 and TREM-1 fusion protein. In a human study, we analyzed the association of non-synonymous single nucleotide variants in the TREM1 gene in a cohort comprising 1263 matching donors and recipients with post-transplant outcomes, including DGF. Our findings demonstrated that, following murine IR, renal TREM-1 expression increased due to the influx of Trem1 mRNA expressing cells detected by in situ hybridization. However, TREM-1 interventions by means of LP17, LR12 and TREM-1 fusion protein did not ameliorate IR-induced injury. In the human renal transplant cohort, donor and recipient TREM1 gene variant p.Thr25Ser was not associated with DGF, nor with biopsy-proven rejection or death-censored graft failure. We conclude that TREM-1 does not play a major role during experimental renal IR and after kidney transplantation.

The characteristics of patients with mycobacterium tuberculosis blood stream infections in Beijing, China: a retrospective study.

BackgroundPublished information regarding the clinical characteristics, laboratory findings, and outcomes of patients with Mycobacterium tuberculosis (MTB) blood stream infection (BSI) is limited. We aimed in this study to evaluate the clinical characteristics, laboratory evaluation, and outcomes of patients with MTB BSI.MethodsAll patients diagnosed with MTB BSI at Peking Union Medical College Hospital between January 2008 and May 2014 were identified by examining the electronic database listing results of all blood cultures. Data on demographics, clinical characteristics, laboratory manifestations, management, and outcomes were abstracted from medical records.ResultsSix thousand nine hundred seventy-four patients had mycobacterial blood cultures during the study period. Of 48 patients (0.7%) with MTB BSI, 26 patients (54%) were considered to be immunocompromised (refers to a person who has a significantly impaired immune system). This was due to human immunodeficiency virus (HIV) infection (n = 2 of 48 tested), receiving steroids (n = 17, including 16 with rheumatic diseases and one with myasthenia gravis), malignancy (n = 3), diabetes mellitus (n = 3), and renal transplantation (n = 1). The main clinical manifestations were fever (100%, with a median of 40 °C), weight loss (48%) and cough with sputum production (46%). Most patients had one or more organs involved (81%). The median time from onset of fever to diagnosis was 8 weeks (IQR 5 ~ 14). Six patients died within 1 week after diagnosis. Of the 17 patients completing treatment, 14 patients (82%) recovered without major complications and they had a shorter time interval between onsets of symptoms to treatment compared to those died of TB.ConclusionsIn this group of patients with MTB BSI, fever and multiple organs involvement were common, the outcome was poor and timely diagnosis and treatment might favor outcome.

MiR-182-5p Inhibition Ameliorates Ischemic Acute Kidney Injury

Acute kidney injury (AKI) remains a major clinical event with high mortality rates. We previously identified renal miR-182 as the main driver of post-transplantation AKI. Therefore, we tested the causal inference of miR-182 by inhibiting its renal expression invivo. In 45 rats AKI was induced by right nephrectomy and contralateral clamping of the renal pedicle for 40 minutes. Systemically administered antisense oligonucleotide (ASO) inhibited miR-182 in the kidneys up to 96 hours. The maximum creatinine elevation was on day 2 after injury (mg/dL; median and interquartile range): ASO 2.5mg/kg: 1.9 (1.3; 3.2), ASO 25mg/kg: 2.8 (0.7; 5.0), mismatch oligonucleotide (MM) 25mg/kg: 5.7 (5,0; 5.8), saline: 4.4 (3.5; 5.8) (P = 0.016, analysis of variance). Blinded semiquantitative histologic evaluation of renal biopsies showed better preserved morphology in both ASO groups than saline- and MM-treated kidneys (median and interquartile range of overall injury scores): ASO both concentrations 1 (1, 1), saline 3 (3, 3) and MM 3 (3, 3) (P< 0.001, analysis of variance). ASO facilitated cell proliferation, metabolism, and angiogenesis on a genome-wide level. ASO when applied in normothermic kidney machine perfusion reduced renal miR-182 expression by more than two magnitudes. In summary, we showed that invivo inhibition of miR-182 by ASO improved kidney function and morphology after AKI. This technique may be applicable to reduce the high rate of AKI in the human renal transplantation setting.

Clinical Course, Radiological Manifestations, and Outcome of Pneumocystis jirovecii Pneumonia in HIV Patients and Renal Transplant Recipients.

BackgroundPneumocystis jirovecii pneumonia (PCP) is a frequent opportunistic infection in immunocompromised patients. In literature, presentation and outcome of PCP differs between patients with human immunodeficiency virus (HIV) infection and renal transplant recipients (RTRs).MethodsWe conducted a cross-sectional study of patients with PCP based on the HIV and renal transplant registries at our institution. Radiological and clinical data from all confirmed PCP cases between 2005 and 2012 were compared.ResultsForty patients were included: 16 with HIV and 24 RTRs. Radiologically, HIV patients had significantly more areas of diffuse lung affection (81% HIV vs. 25% RTR; p = 0.02), more ground glass nodules 5–10 mm (69% vs. 4%; p = <0.001) and enlarged hilar lymph nodes were found only in HIV patients (44%). Cough and dyspnea were the most common clinical signs (>80%) in both groups. Duration from illness onset to hospital presentation was longer in the HIV patients (median of 18 vs. 10 days (p = 0.02)), implying a less fulminant clinical course. Sixty percent of PCP cases in RTRs occurred >12 months after transplantation. Lengths of hospitalization, admission rates to the intensive care unit, and requirements for mechanical ventilation were similar. Outcome in both groups was favourable.ConclusionsWhile important differences in radiological presentation of PCP between HIV patients and RTRs were found, clinical presentation was similar. PCP only rarely presented with fulminant respiratory symptoms requiring ICU admission, with similar results and outcomes for HIV patients and RTRs. Early diagnosis and treatment is mandatory for clinical success.

Celiac Disease Secondary to Tacrolimus after Human Renal Transplantation: A Case Report

Celiac disease is an autoimmune disorder affecting primarily the small intestine. Although rare celiac disease is a possible cause of diarrhea after renal transplantation. Our case is the first to report that tacrolimus could be cause of celiac disease after renal transplantation. A woman aged 34 years old, with a renal transplantation from a cadaveric donor. For maintenance therapy, she underwent tri-therapy with Tacrolimus. She was complaining from chronic diarrhea with weight loss unimproved at 16 months after the TR and despite the switch from Mycophenolate mofetil to Azathioprine. She had an anemia and signs of malabsorption with a congestive duodenitis in the gastroscopy and villous atrophy in moderate area in the biopsy. Celiac serology was positive. The patient underwent gluten-free diet during 6 months without improvement. Tacrolimus was stopped and switched to Cyclosporine A. After this attitude the diarrhea disappeared and we note a weight gain and improvement of biological parameters. Control of antibodies after conversion to cyclosporine A was negative. Celiac disease is rare in the transplant recipient and never confirmed with immunogical test. There was no case in the literature that reported tacrolimus as cause of celiac disease. Our case is the first witch reported celiac disease after transplantation and confirmed with an immunological test and it was caused by tacrolimus.

Toll-Like Receptor Family Polymorphisms Are Associated with Primary Renal Diseases but Not with Renal Outcomes Following Kidney Transplantation

Toll-like receptors (TLRs) play a crucial role in innate- and adaptive immunity. The TLR pathways were shown to play key functional roles in experimental acute and chronic kidney injury, including the allo-immune response after experimental renal transplantation. Data about the precise impact of TLRs and their negative regulators on human renal transplant outcomes however are limited and contradictory. We studied twelve non-synonymous single nucleotide polymorphisms (SNPs) of which eleven in TLR1-8 and one in SIGIRR in a final cohort comprising 1116 matching donors and recipients. TLR3 p.Leu412Phe and SIGIRR p.Gln312Arg significantly deviated from Hardy-Weinberg equilibrium and were excluded. The frequency distribution of the minor alleles of the remaining 10 TLR variants were compared between patients with end-stage renal disease (recipients) and controls (kidney donors) in a case-control study. Secondly, the associations between the minor allele frequency of the TLR variants and delayed graft function, biopsy-proven acute rejection and death-censored graft failure after transplantation were investigated with Cox regression. Carrier frequencies of the minor alleles of TLR1 p.His305Leu (OR = 4.79, 95% CI = 2.35–9.75, P = 0.0002), TLR1 p.Asn248Ser (OR = 1.26, 95% CI = 1.07–1.47, P = 0.04) and TLR8 p.Met1Val (OR = 1.37, 95% CI = 1.14–1.64, P = 0.008) were significantly higher in patients with ESRD, with little specificity for the underlying renal disease entity (adjusted for age, gender and donor-recipient relatedness). The minor allele frequency of none of the TLR variants significantly associated with the surrogate and definite outcomes, even when multivariable models were created that could account for TLR gene redundancy. In conclusion, genetic variants in TLR genes were associated with the prevalence of ESRD but not renal transplant outcomes. Therefore, our data suggests that specific TLR signaling routes might play a role in the final common pathway of primary renal injury. A role for TLR signaling in the context of renal transplantation is probably limited.

Incipient renal transplant dysfunction associates with tubular syndecan-1 expression and shedding.

Syndecan-1 is a transmembrane heparan sulfate proteoglycan involved in regenerative growth and cellular adhesion. We hypothesized that the induction of tubular syndecan-1 is a repair response to incipient renal damage in apparently stable, uncomplicated renal transplant recipients. We quantified tubular syndecan-1 in unselected renal protocol biopsies taken 1 yr after transplantation. Spearman rank correlation analysis revealed an inverse correlation between tubular syndecan-1 expression and creatinine clearance at the time of biopsy (r = -0.483, P < 0.03). In a larger panel of protocol and indication biopsies from renal transplant recipients, tubular syndecan-1 correlated with tubular proliferation marker Ki67 (r = 0.518, P < 0.0001). In a rat renal transplantation model, 2 mo after transplantation, mRNA expression of syndecan-1 and its major sheddase, A disintegrin and metalloproteinase-17, were upregulated (both P < 0.03). Since shed syndecan-1 might end up in the circulation, in a stable cross-sectional human renal transplant population (n = 510), we measured plasma syndecan-1. By multivariate regression analysis, we showed robust independent associations of plasma syndecan-1 with renal (plasma creatinine and plasma urea) and endothelial function parameters (plasma VEGF-A, all P < 0.01). By various approaches, we were not able to localize syndecan-1 in vessel wall or endothelial cells, which makes shedding of syndecan-1 from the endothelial glycocalyx unlikely. Our data suggest that early damage in transplanted kidneys induces repair mechanisms within the graft, namely, tubular syndecan-1 expression for tubular regeneration and VEGF production for endothelial repair. Elevated plasma syndecan-1 levels in renal transplantation patients might be interpreted as repair/survival factor related to loss of tubular and endothelial function in transplanted kidneys.

Renal expression of Toll-like receptor 2 and 4: Dynamics in human allograft injury and comparison to rodents

Activation of the innate immunity through Toll-like receptors (TLRs) has been postulated to play an important role in the pathophysiology of renal allograft dysfunction. TLR2 and TLR4 dynamics in different human post-transplant pathological entities has never been studied. Therefore, we evaluated pre- and post-transplantation protein expression of TLR2 and TLR4 in human kidney biopsies.Human kidney biopsies obtained from living kidney donors and patients with acute tubular necrosis, acute cellular and vascular rejection and interstitial fibrosis/tubular atrophy (IF/TA) were used. Translating results from animal studies to the clinical situation is highly important considering the upcoming clinical studies with TLR inhibitors in human renal transplantation. Hence, the TLR2 and TLR4 expression in healthy mouse and rat kidneys was analyzed and compared with human kidneys. In healthy human kidneys, TLR2 is expressed on the endothelium and Bowman's capsule, while TLR4 is expressed on the endothelium only. No tubular staining was found for both receptors in human kidneys. In contrast to human biopsies, TLR2 and TLR4 expression in rodents was observed on tubular epithelial cells. In all acute rejection human biopsies, increased infiltration of TLR4+ leukocytes was observed. In conclusion, a discrepancy exists between human and rodent renal TLR expression, which suggests careful attention when translating results from rodent studies to the human situation. Additionally, this study revealed human TLR2 and TLR4 expression dynamics in human biopsies pre- and post-transplantation.

CD16+ monocytes with smooth muscle cell characteristics are reduced in human renal chronic transplant dysfunction

In chronic transplant dysfunction (CTD), persistent (allo)immune-mediated inflammation eventually leads to tissue remodeling including neointima formation in intragraft arteries. We previously showed that recipient-derived neointimal α-SMA+ smooth muscle-like cells are present in human renal allografts with CTD. Human PBMC contain myeloid cells capable of differentiating into α-SMA+ cells in vitro; the phenotype of the ancestral subset is as yet unknown. This study aimed to investigate whether monocyte subsets contain cells with smooth muscle-like cell differentiation capacity and whether CTD in renal transplant recipients is associated with a shift in these monocyte subsets. To accomplish this goal, monocyte subsets from healthy controls were sorted based on CD14 and CD16 expression to investigate gene expression levels of mesenchymal markers α-SMA and SM22α. CD14+/CD16++ monocytes displayed increased α-SMA and SM22α mRNA expression compared with CD14++/CD16− monocytes, suggesting increased differentiation potential toward smooth muscle-like cells. Flow cytometry revealed that in non-CTD transplant recipients the percentage of CD14+/CD16++ monocytes was reduced, with an even further reduction in patients with CTD. To determine a potential correlation between CD14+/CD16++ monocytes and α-SMA+ cell outgrowth potential in vitro, PBMC of healthy controls and transplant recipients with and without CTD were cultured under fibrotic culture conditions, and indeed a significant correlation (p=0.0002, r=0.62) was observed. Finally, double staining for α-SMA and CD16 revealed presence of α-SMA+CD16+ cells in kidney explants from CTD patients, albeit at very low numbers.Our data represent evidence that, compared to CD14++CD16− monocytes, CD14+CD16++ monocytes have an increased expression of smooth muscle cell-associated genes. This monocyte subpopulation is reduced in renal transplant patients with CTD, possibly due to selective migration into the allograft.

Expression of hypoxia-inducible factor-1α and hepatocyte growth factor in development of fibrosis in the transplanted kidney.

Late renal graft loss is associated with interstitial fibrosis. Hypoxia-inducible factor-1α (HIF-1α) is thought to facilitate fibrosis through interaction with TGF-β1, while hepatocyte growth factor (HGF) may act antifibrotic in the kidney allograft. The aim of this study was to investigate the expression of HIF-1α and HGF in protocol biopsies as possible prognostic biomarkers for renal fibrosis. Thirty-nine renal transplant recipients were included in the study. Protocol biopsies performed 1 and 2years after transplantation were used for immunohistochemistry analysis. The correlation between HIF-1α/HGF and the Banff score was analysed. In addition, progression in renal fibrosis and graft survival among recipients with high or low expression of HIF-1α/HGF after transplantation was compared. There was no significant correlation between fibrosis and the HIF-1α expression 1 and 2years after transplantation, but an inverse significant correlation between the HGF expression and the fibrosis score 1year after transplantation was shown. Even when adjusting for human leucocyte antigen mismatches, there was a significant relationship between fibrosis and HGF expression. Graft survival was not significantly correlated to HIF-1α or HGF at 1year, although the trend was towards better graft survival with high HGF. HGF may have antifibrotic effects in human renal transplants. (Central.Denmark.Region.Committee number: 1-10-72-318-13).

Mouse kidney transplantation: models of allograft rejection.

Rejection of the transplanted kidney in humans is still a major cause of morbidity and mortality. The mouse model of renal transplantation closely replicates both the technical and pathological processes that occur in human renal transplantation. Although mouse models of allogeneic rejection in organs other than the kidney exist, and are more technically feasible, there is evidence that different organs elicit disparate rejection modes and dynamics, for instance the time course of rejection in cardiac and renal allograft differs significantly in certain strain combinations. This model is an attractive tool for many reasons despite its technical challenges. As inbred mouse strain haplotypes are well characterized it is possible to choose donor and recipient combinations to model acute allograft rejection by transplanting across MHC class I and II loci. Conversely by transplanting between strains with similar haplotypes a chronic process can be elicited were the allograft kidney develops interstitial fibrosis and tubular atrophy. We have modified the surgical technique to reduce operating time and improve ease of surgery, however a learning curve still needs to be overcome in order to faithfully replicate the model. This study will provide key points in the surgical procedure and aid the process of establishing this technique.

Hepatic Syndecan-1 Changes Associate With Dyslipidemia After Renal Transplantation

Syndecan-1 is a transmembrane heparan sulfate (HS) proteoglycan present on hepatocytes and involved in uptake of triglyceride-rich lipoproteins via its HS polysaccharide side chains. We hypothesized that altered hepatic syndecan-1 metabolism could be involved in dyslipidemia related to renal transplantation. In a rat renal transplantation model elevated plasma triglycerides were associated with fivefold increased expression of hepatic syndecan-1 mRNA (p < 0.01), but not protein. Expression of syndecan-1 sheddases (ADAM17, MMP9) and heparanase was significantly up-regulated after renal transplantation (all p < 0.05). Profiling of HS side chains revealed loss of hepatic HS upon renal transplantation accompanied by significant decreased functional capacity for VLDL binding (p = 0.02). In a human renal transplantation cohort (n = 510), plasma levels of shed syndecan-1 were measured. Multivariate analysis showed plasma syndecan-1 to be independently associated with triglycerides (p < 0.0001) and inversely with HDL cholesterol (p < 0.0001). Last, we show a physical association of syndecan-1 to HDL from renal transplant recipients (RTRs), but not to HDL from healthy controls. Our data suggest that after renal transplantation loss of hepatic HS together with increased syndecan-1 shedding hampers lipoprotein binding and uptake by the liver contributing to dyslipidemia. Our data open perspectives toward improvement of lipid profiles by targeted inhibition of syndecan-1 catabolism in renal transplantation.

Changes in Non-Donor-Specific Antibodies After Human Leukocyte Antigen-Incompatible Renal Transplantation Would Also Be Worthy of Attention.

Changes in Non-Donor-Specific Antibodies After Human Leukocyte Antigen-Incompatible Renal Transplantation Would Also Be Worthy of Attention.

Clinical significance of myeloid-derived suppressor cells in human renal transplantation with acute T cell-mediated rejection.

Myeloid-derived suppressor cells (MDSCs) are negative regulators of the immune response and are in part responsible for the inhibition of the T cell-mediated immune response. A recent paper indicated that MDSCs were involved in prolonged allograft survival in animal models of transplantation, but the significance of MDSCs in human renal transplantation is still unknown. In our study, 50 patients with biopsy-proven acute T cell-mediated rejection (ATCMR) were included. The ratio of MDSCs in peripheral blood mononuclear cell (PBMC) was evaluated with FACS, and the patients were divided into the MDSCs high group (MDSCs, >10 %) or the MDSCs low group (MDSCs, <10 %). We compared the allograft function, severity of tissue injury, and long-time survival between the two groups. In the MDSCs high group, allograft function was significantly increased compared with the MDSCs low group. Furthermore, we found that isolated MDSCs from transplant recipients are capable of expanding regulatory T cell (Treg), meanwhile, inhibiting production of IL-17 in vitro. We also found that the ratio between Foxp3(+) and IL-17-producing CD4(+) T cells positively correlated with MDSCs frequency in PBMC. In conclusion, we demonstrated a potential role for MDSCs in prolonging allograft survival after ATCMR, and this was associated with higher CD4(+)Foxp3(+)/CD4(+)IL-17(+) ratio in PBMC.

Serum Metabolomics Study of the Acute Graft Rejection in Human Renal Transplantation Based on Liquid Chromatography–Mass Spectrometry

Acute graft rejection is one of the most common and serious postcomplications in renal transplantation. A noninvasive method is needed to specifically monitor acute graft rejection. We investigated metabolic alterations of acute graft rejection in human renal transplantation by applying a metabolomics approach. Sera from 11 acute graft rejection subjects and 16 nonacute graft rejection subjects were analyzed by a nontargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics approach including both hydrophilic interaction chromatography and reversed-phase liquid chromatography separations. Discriminative metabolites of acute graft rejection after transplantation were detected, including creatinine, kynurenine, uric acid, polyunsaturated fatty acid, phosphatidylcholines, sphingomyelins, lysophosphatidylcholines, etc. The lower level of serum dehydroepiandrosterone sulfate was found in the acute graft rejection group before transplantation. The results revealed comprehensive metabolic abnormalities in acute graft rejection. The findings are valuable for the clinic noninvasive diagnosis or therapy of acute graft rejection.

The Alarmin Concept Applied to Human Renal Transplantation: Evidence for a Differential Implication of HMGB1 and IL-33

The endogenous molecules high mobility group box 1 (HMGB1) and interleukin-33 (IL-33) have been identified as alarmins, capable of mediating danger signals during tissue damage. Here, we address their possible role as innate-immune mediators in ischemia-reperfusion injury (IRI) following human kidney transplantation. We analysed serum and urinary HMGB1 and IL-33 levels, all determined by enzyme-linked immunosorbent assay, in a cohort of 26 deceased renal transplant recipients. Urinary HMGB1 and IL-33 levels were significantly increased as soon as 30 min after reperfusion, as compared to those before treatment. Moreover, both serum and urinary IL-33 (but not HMGB1) increase was positively correlated with cold ischemia time, from 30 min to 3 days post-transplantation. In vitro, human umbilical vein endothelial cells subjected to hypoxia conditions released both HMGB-1 and IL-33, while only the latter was further increased upon subsequent re-oxygenation. Finally, we postulate that leukocytes from renal recipient patients are targeted by both HMGB1 and IL-33, as suggested by increased transcription of their respective receptors (TLR2/4 and ST2L) shortly after transplantation. Consistent with this view, we found that iNKT cells, an innate-like T cell subset involved in IRI and targeted by IL-33 but not by HMGB1 was activated 1 hour post-transplantation. Altogether, these results are in keeping with a potential role of IL-33 as an innate-immune mediator during kidney IRI in humans.

Rabbit anti-thymocyte globulin induction in renal transplantation: review of the literature

Rabbit anti-thymocyte globulin induction in renal transplantation: review of the literature Leah Andress,1 Anjali Gupta,2 Nida Siddiqi,3 Kwaku Marfo2,3 1University at Buffalo School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacy Practice, Buffalo, 2Montefiore Medical Center, The University Hospital for Albert Einstein College of Medicine Department of Abdominal Organ Transplant Program, Bronx, 3Montefiore Medical Center, Department of Pharmacy, Bronx, NY, USA Abstract: Rabbit anti-thymocyte globulin (rATG) has proven benefit as induction therapy in renal transplant recipients, achieving reduced acute rejection rates and better short-term allograft function, with slightly higher rates of complications such as infections and malignancy. Compared with other agents, the most benefit from rATG induction has been observed in renal transplant recipients at high immunologic risk for rejection. However, in special populations, such as pediatrics, the elderly, and hepatitis C-positive and human immunodeficiency virus-positive renal transplant recipients, additional information is needed to delineate the absolute benefit of rATG induction compared with other induction agents. Selection of rATG as the choice of induction therapy in renal transplant recipients should be guided by a cost-effective approach in balancing efficacy, safety, and cost. This review summarizes the published literature on efficacy, safety, and cost of rATG induction in renal transplantation. Keywords: anti-thymocyte globulin, renal transplantation, induction therapy

Body mass index and body fat distribution as renal risk factors: a focus on the role of renal haemodynamics

Weight excess and/or central body fat distribution are associated with increased long-term renal risk, not only in subjects with renal disease or renal transplant recipients, but also in the general population. As the prevalence of weight excess is rising worldwide, this may become a main renal risk factor on a population basis, even more so because the risk extends to the overweight range. Understanding the mechanisms of this detrimental effect of weight excess on the kidneys is needed in order to design preventive treatment strategies. The increased risk associated with weight excess is partly attributed to associated comorbid conditions, such as hypertension, dyslipidaemia, insulin resistance and diabetes; however, current evidence supports a direct pathogenetic role for renal haemodynamics as well. Weight excess is associated with an altered renal haemodynamic profile, i.e. an increased glomerular filtration rate relative to effective renal plasma flow, resulting in an increased filtration fraction (FF). This renal haemodynamic profile is considered to reflect glomerular hyperfiltration and glomerular hypertension, resulting from a dysbalance between afferent and efferent arterial vasomotor balance. This unfavorable renal haemodynamic profile was found to be associated with renal outcome in experimental models and in human renal transplant recipients, and is associated with a blunted sodium excretion, and reversible by weight loss, renin-angiotensin-aldosterone system blockade or by dietary sodium restriction. More recent evidence showed that a central body fat distribution is also associated with an increased FF, even independent of overall weight excess. In this review, we provide an overview on current literature on the impact of weight excess and central body fat distribution on the renal haemodynamic profile in humans, and its possible role in progressive renal damage.