Urinary soluble PD-1 as a biomarker of checkpoint inhibitor-induced acute tubulointerstitial nephritis.

Background: Acute interstitial nephritis (AIN) related to immune checkpoint inhibitors (ICI-AIN) has a not completely understood pathophysiology. Our objectives were to analyze possible biomarkers for the differentiation between acute tubular necrosis (ATN) and AIN, especially in cancer patients, and to study the participation of the immune checkpoint pathway in ICI-AIN. Methods: We performed an observational study. We recruited patients with incident diagnosis of ICI-AIN (n = 19). We measured soluble PD-1 (sPD-1), sPD-L1, and sPD-L2 in serum and urine at diagnosis and compared to it patients with non-ICI-related AIN (non-ICI-AIN) (n = 18) and ATN (n = 21). The findings were validated in an independent cohort from another institution (n = 30). Also, we performed PD-L1 and PD-L2 immunostaining of kidney biopsies from patients with ICI-AIN and compared to patients with non-ICI-AIN. Results: Urinary sPD-1 (usPD-1) was higher in patients with AIN compared to ATN (P = .03). Patients with AIN also showed higher serum sPD-1 (ssPD-1) than patients with ATN (P = .021). In cancer patients, usPD-1 <129.3 pg/ml had a 71.43% sensitivity and 94.44% specificity to differentiate ATN from ICI-AIN, with a likelihood ratio of 12.86. In the external validation cohort, the same cutoff showed a sensitivity of 80%. In kidney biopsies, patients with ICI-AIN showed higher density of PD-L1 positive tubules than patients with non-ICI-AIN (P = .02). The proportion of patients having >2.64/mm2 PD-L2 positive tubules was higher among patients with ICI-AIN compared to non-ICI-AIN (P = .034). There was a positive correlation (P = .009, r = 0.72) between usPD-1 and the number of PD-L1 positive tubules. Conclusions: UsPD-1 and ssPD-1 are higher in AIN than ATN. Moreover, there was a strong correlation between usPD-1 and renal tubular PD-L1 expression. Our findings suggest a role of usPD-1 as non-invasive biomarker to differentiate ICI-AIN from ATN, especially in cancer patients, which has been confirmed in an external validation cohort.

Immune checkpoint inhibitors induce acute interstitial nephritis in mice with increased urinary MCP1 and PD-1 glomerular expression.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) induce acute interstitial nephritis (AIN) in 2-5% of patients, with a clearly higher incidence when they are combined with platinum derivatives. Unfortunately, suitable disease models and non-invasive biomarkers are lacking. To fill this gap in our understanding, we investigated the renal effects of cisplatin and anti-PD-L1 antibodies in mice, assessing PD-1 renal expression and cytokine levels in mice with AIN, and then we compared these findings with those in AIN-diagnosed cancer patients. METHODS: Twenty C57BL6J mice received 200 µg of anti-PD-L1 antibody and 5 mg/kg cisplatin intraperitoneally and were compared with those receiving cisplatin (n = 6), anti-PD-L1 (n = 7), or saline (n = 6). After 7 days, the mice were euthanized. Serum and urinary concentrations of TNFα, CXCL10, IL-6, and MCP-1 were measured by Luminex. The kidney sections were stained to determine PD-1 tissue expression. Thirty-nine cancer patients with AKI were enrolled (AIN n = 33, acute tubular necrosis (ATN) n = 6), urine MCP-1 (uMCP-1) was measured, and kidney sections were stained to assess PD-1 expression. RESULTS: Cisplatin and anti PD-L1 treatment led to 40% AIN development (p = 0.03) in mice, accompanied by elevated serum creatinine and uMCP1. AIN-diagnosed cancer patients also had higher uMCP1 levels than ATN-diagnosed patients, confirming our previous findings. Mice with AIN exhibited interstitial PD-1 staining and stronger glomerular PD-1 expression, especially with combination treatment. Conversely, human AIN patients only showed interstitial PD-1 positivity. CONCLUSIONS: Only mice receiving cisplatin and anti-PDL1 concomitantly developed AIN, accompanied with a more severe kidney injury. AIN induced by this drug combination was linked to elevated uMCP1, consistently with human AIN, suggesting that uMCP1 can be potentially used as an AIN biomarker.

Acute tubulointerstitial nephritis induced by checkpoint inhibitors versus classical acute tubulointerstitial nephritis: are they the same disease?

BACKGROUND: The incidence of acute tubulointerstitial nephritis (ATIN) related to drugs has dramatically increased over recent years. A new subtype of ATIN, apparently different from classical drug-related ATIN, has emerged that has been related to the administration of immune checkpoint inhibitors (ICIs). We investigated these differences between ICI-related ATIN (ICI ATIN) and non-ICI-related ATIN in terms of clinical features, response to treatment with steroids and the evolution of kidney function. METHODS: A total of 47 patients diagnosed with ATIN from two centres were recruited. Of these, 13 patients presented with ATIN during ICI treatment and 34 were diagnosed with ATIN attributed to other drugs. The main demographic, clinical and analytical variables such as gender, age and current medication were recorded. The type of malignancy, oncological treatment, ICI dose and presence of extrarenal immune-related adverse events were also reviewed. Renal biopsy diagnosis, time to drug withdrawal and ATIN-specific treatment, as well as laboratory data during follow-up, were also studied. RESULTS: Patients diagnosed with ICI ATIN presented with lower creatinine (ICI ATIN 3.8 ± 1.03 versus classical ATIN 5.98 ± 4.15 mg/dL, P = 0.007) at diagnosis and higher urinary leucocyte counts (ICI ATIN 263.2 ± 418.04 versus classical ATIN 133.55 ± 284.62, P = 0.048) compared with patients with non-ICI-related ATIN. Time from initiation of the culprit drug to ATIN diagnosis was longer in patients with ICI ATIN than in those with classical ATIN (197.07 ± 184.99 versus 114.4 ± 352.16 days, P = 0.006). In addition, during follow-up, the slope of decreasing creatinine over time was lower for ICI ATIN compared with non-ICI-related ATIN. CONCLUSIONS: In this study, we analysed differences between ICI ATIN and classical ATIN. We found that patients with ICI ATIN presented with a larger latency period after culprit drug initiation, milder acute kidney injury and slower creatinine amelioration compared with those with classical ATIN. These results may, in part, be ascribed to potential differences in the pathological mechanisms involved in ATIN development, suggesting that ICI and classical ATIN may be different diseases with similar renal histologies.

Acute Tubulointerstitial Nephritis in Clinical Oncology: A Comprehensive Review.

Acute kidney injury in patients who suffer a malignancy is a common complication. Due to its high prevalence and effective treatment, one of the most frequent causes that both oncologists and nephrologists must be aware of is acute tubulointerstitial nephritis (ATIN). ATIN is an immunomediated condition and the hallmark of the disease, with the presence of a tubulointerstitial inflammatory infiltrate in the renal parenchyma. This infiltrate is composed mainly of T lymphocytes that can be accompanied by macrophages, neutrophils, or eosinophils among other cells. One of the major causes is drug-related ATIN, and some antineoplastic treatments have been related to this condition. Worthy of note are the novel immunotherapy treatments aimed at enhancing natural immunity in order to defeat cancer cells. In the context of the immunosuppression status affecting ATIN patients, some pathogen antigens can trigger the development of the disease. Finally, hematological malignancies can also manifest in the kidney leading to ATIN, even at the debut of the disease. In this review, we aim to comprehensively examine differential diagnosis of ATIN in the setting of a neoplastic patient.

Predictors of outcome in a Spanish cohort of patients with Fabry disease on enzyme replacement therapy.

Fabry disease may be treated by enzyme replacement therapy (ERT), but the impact of chronic kidney disease (CKD) on the response to therapy remains unclear. The aim of the present study was to analyse the incidence and predictors of clinical events in patients on ERT. STUDY DESIGN: Multicentre retrospective observational analysis of patients diagnosed and treated with ERT for Fabry disease. The primary outcome was the first renal, neurological or cardiological events or death during a follow-up of 60 months (24-120). RESULTS: In 69 patients (42 males, 27 females, mean age 44.6±13.7 years), at the end of follow-up, eGFR and the left ventricular septum thickness remained stable and the urinary albumin: creatinine ratio tended to decrease, but this decrease only approached significance in patients on agalsidase-beta (242-128mg/g (p=0.05). At the end of follow-up, 21 (30%) patients had suffered an incident clinical event: 6 renal, 2 neurological and 13 cardiological (including 3 deaths). Events were more frequent in patients with baseline eGFR≤60ml/min/1.73m2 (log Rank 12.423, p=0.001), and this remained significant even after excluding incident renal events (log Rank 4.086, p=0.043) and in males and in females. Lower baseline eGFR was associated with a 3- to 7-fold increase the risk of clinical events in different Cox models. CONCLUSIONS: GFR at the initiation of ERT is the main predictor of clinical events, both in males and in females, suggesting that start of ERT prior to the development of CKD is associated with better outcomes.

Mycophenolic acid interferes the transcriptional regulation and protein trafficking of maturation surface markers in dendritic cells.

BACKGROUND: The ability of dendritic cells (DCs) to regulate adaptive immunity makes them interesting cells to be used as therapeutic targets modulating alloimmune responses. Mycophenolic acid (MPA) is an immunosuppressor commonly used in transplantation, and its effect on DCs has not been fully investigated. METHODS: Monocyte-derived DCs were obtained from healthy volunteers and cultured for 7 days. Cells were treated with MPA on day 2 and matured by lipopolysaccharide (LPS) stimulation. Functionality of mature DC (mDCs) was evaluated by allogeneic mixed lymphocytes reaction. Surface expression of maturation markers (CD40, CD83, CD86, and ICAM-1) was analyzed in both immature DCs (iDCs) and mDCs by flow cytometry. To assess transcriptional regulation and protein subcellular location, RT-PCR and confocal microscopy were used, respectively. RESULTS: MPA decreased surface expression of all maturation markers in mDCs and significantly abrogated DCs-induced allogeneic T-cell proliferation after MPA pre-treatment. In iDCs, the reduced surface protein expression after MPA paralleled with mRNA downregulation of their genes. In mDCs, the mRNA levels of ICAM-1, CD40 and CD83 were enhanced in MPA-treated mDCs with an increase in the expression of CD83 and ICAM-1 near the Golgi compared to non-treated mDCs. In contrast, mRNA levels of CD86 were diminished after MPA treatment. CONCLUSIONS: The reduced surface markers expression in mDCs exerted by MPA produced a decline in their capacity to activate immune responses. Moreover, the inhibition of guanosine-derived nucleotide biosynthesis by MPA treatment leads to DC maturation interference by two mechanisms depending on the marker, transcriptional downregulation or disrupted intracellular protein trafficking.

Chronic Kidney Disease-Associated Inflammation Increases the Risks of Acute Kidney Injury and Mortality after Cardiac Surgery.

Cardiovascular mortality increases with decreasing renal function although the cause is yet unknown. Here, we have investigated whether low chronic inflammation in chronic kidney diseases (CKD) could contribute to increased risk for coronary artery diseases (CAD). Thus, a prospective case-control study was conducted in patients with CAD and CKD undergoing coronary artery bypass graft surgery with the aim of detecting differences in cardiovascular outcomes, epicardial adipose tissue volume, and inflammatory marker activity associated with renal dysfunction. Expression of membrane CD14 and CD16, inflammatory cytokines and chemokines, mitogen-activated protein (MAP) kinases and hsa-miR-30a-5p were analyzed in peripheral blood mononuclear cells (PBMCs). Epicardial fat volume and tissue inflammation in perivascular adipose tissue and in the aorta were also studied. In the present study, 151 patients were included, 110 with CAD (51 with CKD) and 41 nonCAD controls (15 with CKD). CKD increased the risk of cardiac surgery-associated acute kidney injury (CSA-AKI) as well as the 30-day mortality after cardiac surgery. Higher counts of CD14++CD16+ monocytes were associated with vascular inflammation, with an increased expression of IL1ß, and with CKD in CAD patients. Expression of hsa-miR-30a-5p was correlated with hypertension. We conclude that CKD patients show an increased risk of CSA-AKI and mortality after cardiovascular surgery, associated with the expansion of the CD14++CD16+ subset of proinflammatory monocytes and with IL1ß expression. We propose that inflammation associated with CKD may contribute to atherosclerosis (ATH) pathogenesis.

A Comprehensive Phenotypic and Functional Immune Analysis Unravels Circulating Anti-Phospholipase A2 Receptor Antibody Secreting Cells in Membranous Nephropathy Patients.

INTRODUCTION: Primary membranous nephropathy (MN) is characterized by the presence of antipodocyte antibodies, but studies describing phenotypic and functional abnormalities in circulating lymphocytes are limited. METHODS: We analyzed 68 different B- and T-cell subsets using flow cytometry in 30 MN patients (before initiating immunosuppression) compared with 31 patients with non-immune-mediated chronic kidney disease (CKD) and 12 healthy individuals. We also measured 19 serum cytokines in MN patients and in healthy controls. Lastly, we quantified the ex vivo production of phospholipase A2 receptor (PLA2R)-specific IgG by plasmablasts (measuring antibodies in culture supernatants and by the newly developed FluoroSpot assay [AutoImmun Diagnostika, Strasberg, Germany]) and assessed the circulating antibody repertoire by phage immunoprecipitation sequencing (PhIP-Seq). RESULTS: After adjusting for multiple testing, plasma cells and regulatory B cells (BREG) were significantly higher (P < 0.05) in MN patients compared with both control groups. The percentages of circulating plasma cells correlated with serum anti-PLA2R antibody levels (P = 0.042) and were associated with disease activity. Ex vivo-expanded PLA2R-specific IgG-producing plasmablasts generated from circulating PLA2R-specific memory B cells (mBCs) correlated with serum anti-PLA2R IgG antibodies (P < 0.001) in MN patients. Tumor necrosis factor-α (TNF-α) was the only significantly increased cytokine in MN patients (P < 0.05), whereas there was no significant difference across study groups in the autoantibody and antiviral antibody repertoire. CONCLUSION: This extensive phenotypic and functional immune characterization shows that autoreactive plasma cells are present in the circulation of MN patients, providing a new therapeutic target and a candidate biomarker of disease activity.

Integrated miRNA/mRNA Counter-Expression Analysis Highlights Oxidative Stress-Related Genes CCR7 and FOXO1 as Blood Markers of Coronary Arterial Disease.

Our interest in the mechanisms of atherosclerosis progression (ATHp) has led to the recent identification of 13 miRNAs and 1285 mRNAs whose expression was altered during ATHp. Here, we deepen the functional relationship among these 13 miRNAs and genes associated to oxidative stress, a crucial step in the onset and progression of vascular disease. We first compiled a list of genes associated to the response to oxidative stress (Oxstress genes) by performing a reverse Gene Ontology analysis (rGO, from the GO terms to the genes) with the GO terms GO0006979, GO1902882, GO1902883 and GO1902884, which included a total of 417 unique Oxstress genes. Next, we identified 108 putative targets of the 13 miRNAs among these unique Oxstress genes, which were validated by an integrated miRNA/mRNA counter-expression analysis with the 1285 mRNAs that yielded 14 genes, Map2k1, Mapk1, Mapk9, Dapk1, Atp2a2, Gata4, Fos, Egfr, Foxo1, Ccr7, Vkorc1l1, Rnf7, Kcnh3, and Mgat3. GO enrichment analysis and a protein-protein-interaction network analysis (PPI) identified most of the validated Oxstress transcripts as components of signaling pathways, highlighting a role for MAP signaling in ATHp. Lastly, expression of these Oxstress transcripts was measured in PBMCs from patients suffering severe coronary artery disease, a serious consequence of ATHp. This allowed the identification of FOXO1 and CCR7 as blood markers downregulated in CAD. These results are discussed in the context of the interaction of the Oxstress transcripts with the ATHp-associated miRNAs.

Treatment of multiple myeloma with renal involvement: the nephrologist's view.

Renal injury is a common complication in multiple myeloma (MM). In fact, as many as 10% of patients with MM develop dialysis-dependent acute kidney injury related to increased free light chain (FLC) production by a plasma cell clone. Myeloma cast nephropathy (MCN) is the most prevalent pathologic diagnosis associated with renal injury, followed by light chain deposition disease and light chain amyloidosis. Several FLC removal techniques have been explored to improve kidney disease in MM but their impact on renal clinical outcomes remains unclear. According to the evidence, high cut-off haemodialysis should be restricted to MM patients on chemotherapy with histological diagnosis of MCN and haemodialysis requirements. From our perspective, more efforts are needed to improve kidney outcomes in patients with MM and renal failure.

Macrophage Overexpressing NGAL Ameliorated Kidney Fibrosis in the UUO Mice Model.

BACKGROUND/AIMS: Alternatively activated macrophages (AAM) have regenerative and anti-inflammatory characteristics. Here, we sought to evaluate whether AAM cell therapy reduces renal inflammation and fibrosis in the unilateral ureteral obstruction (UUO) mice model. METHODS: We stabilized macrophages by adenoviral vector NGAL (Neutrophil gelatinase-associated lipocalin-2) and infused them into UUO mice. To ascertain whether macrophages were capable of reaching the obstructed kidney, macrophages were stained and detected by in vivo cell tracking. RESULTS: We demonstrated that some infused macrophages reached the obstructed kidney and that infusion of macrophages overexpressing NGAL was associated with reduced kidney interstitial fibrosis and inflammation. This therapeutic effect was mainly associated with the phenotype and function preservation of the transferred macrophages isolated from the obstructed kidney Conclusions: Macrophage plasticity is a major hurdle for achieving macrophage therapy success in chronic nephropathies and could be overcome by transferring lipocalin-2.

Paradigm Shift for Preparing Versatile M2+-Free Gels from Unmodified Sodium Alginate.

This manuscript describes a new route to prepare rapidly Ca2+-free hydrogels from unmodified sodium alginate by simply mixing with small organic molecules such as poly(carboxylic acid) compounds as cross-linker agents instead of classical divalent metal salts such as CaCl2. Dimethyl sulfoxide (DMSO) was also found to induce the rapid gelation of aqueous alginate solutions. The gelation process takes place at room temperature, and depending on the composition, gels with good thermal (90-100 °C) and mechanical properties compared to classical metal-containing analogs are obtained. DMSO-based gels showed remarkable self-supporting and thixotropic properties, which can be tuned by the biopolymer concentration. Furthermore, oxalic acid-based gels show superior elasticity than HCl, CaCl2 and DMSO-based gels. The possibility to prepare monoliths, beads, and films of these gels provide them with significant versatility. In particular, films made of alginate and oxalic acid show good potential as synergistic anticancer drug delivery carrier. Computational studies using both quantum mechanical and classical force-field methodologies reveal that hydrogen bonding networks between water and DMSO molecules located close to the alginate chains are responsible for the stability of DMSO-based gels. In contrast, the cohesion of oxalic acid-based gels is a consequence of the coexistence of multiple ionic associations involving oxalate, alginate, and Na+ counterions, which stabilize the system and keep all the interacting species grouped.

The value of repeat biopsy in lupus nephritis flares.

Whether a repeat renal biopsy is helpful during lupus nephritis (LN) flares remains debatable. In order to analyze the clinical utility of repeat renal biopsy in this complex situation, we retrospectively reviewed our series of 54 LN patients who had one or more repeat biopsies performed only on clinical indications. Additionally, we reviewed 686 well-documented similar cases previously reported (PubMed 1990-2015).The analysis of all patients reviewed showed that histological transformations are common during a LN flare, ranging from 40% to 76% of cases. However, the prevalence of transformations and the clinical value of repeat biopsy vary when they are analyzed according to proliferative or nonproliferative lesions.The great majority of patients with class II (78% in our series and 77.5% in the literature review) progressed to a higher grade of nephritis (classes III, IV, or V), resulting in worse renal prognosis. The frequency of pathological conversion in class V is lower (33% and 43%, respectively) but equally clinically relevant, since almost all cases switched to a proliferative class. Therefore, repeat biopsy is highly advisable in patients with nonproliferative LN at baseline biopsy, because these patients have a reasonable likelihood of switch to a proliferative LN that may require more aggressive immunosuppression.In contrast, the majority of patients (82% and 73%) with proliferative classes in the reference biopsy (III, IV or mixed III/IV + V), remained into proliferative classes on repeat biopsy. Although rebiopsy in this group does not seem as necessary, it is still advisable since it will allow us to identify the 18% to 20% of patients that switch to a nonproliferative class. In addition, consistent with the reported clinical experience, repeat biopsy might also be helpful to identify selected cases with clear progression of proliferative lesions despite the initial treatment, for whom it is advisable to intensify inmunosuppression. Thus, our experience and the literature data support that repeat biopsy also brings more advantges than threats in this group.The results of the repeat biopsy led to a change in the immunosuppresive treatment in more than half of the patients on average, intensifying it in the majority of the cases, but also reducing it in 5% to 30%.

Effector Antitumor and Regulatory T Cell Responses Influence the Development of Nonmelanoma Skin Cancer in Kidney Transplant Patients.

BACKGROUND: Chronic immunosuppression promotes nonmelanocytic squamous cell carcinoma (SCC) after kidney transplantation. Adaptive and innate immunity play a key role controlling tumor growth and are influenced by different immunosuppressive agents. We hypothesized that functional impairment of tumor-specific T cell responses due to calcineurin inhibitors (CNI) could contribute to SCC development, whereas conversion to mammalian target of rapamycin inhibitors (mTOR-i) could recover this protective immune response. METHODS: Peripheral tumor-specific T cell responses against main SCC-derived antigens using the IFN-γ enzyme-linked immunospot assay and intratumor (IT) and circulating immune phenotypes (CD4 + T, CD8 + T, CD20 + B, CD56 + NK, FOXP3 + regulatory T [Treg] cells) were explored in a cross-sectional analysis in 59 kidney transplant patients with SCC on CNI (KT-CNI-SCC) or mTOR-i (KT-mTORi-SCC), 25 nontransplants developing SCC (NoKT-SCC) and 6 healthy controls. Moreover, 25 KT-CNI-SCC were switched to mTOR-i and evaluated after 12 months. RESULTS: Kidney transplant patients showed lower IT infiltrates and tumor-specific T cell responses than NoKT-SCC, and intratumoral and circulating FOXP3 + Treg cells were higher in KT-mTORi-SCC (P < 0.05). Tumor-specific T cell responses were significantly lower in KT-CNI-SCC than KT-mTORi-SCC and NoKT-SCC and predicted SCC relapses (area under the curve = 0.837; P < 0.05). One-year after mTOR-i conversion, a significant increase in FOXP3 + Treg cell numbers and tumor-specific T cell responses were observed, reaching similar levels than KT-mTORi-SCC and NoKT-SCC patients. CONCLUSIONS: Tumor-specific T cell responses are strongly impaired in CNI-treated patients but recover after mTOR-i conversion, reducing SCC relapses.

Silencing of CD40 in vivo reduces progression of experimental atherogenesis through an NF-κB/miR-125b axis and reveals new potential mediators in the pathogenesis of atherosclerosis.

BACKGROUND AND AIMS: CD40/CD40L signaling exerts a critical role in the development of atherosclerosis, and microRNAs (miRNAs) are key regulators in vascular inflammation and plaque formation. In this work, we investigated mRNA/miRNA expression during progression of atherosclerotic lesions through CD40 silencing. METHODS: We silenced CD40 with a specific siRNA in ApoE-/- mice and compared expression of mRNA/miRNA in ascending aorta with scrambled treated mice. RESULTS: siRNA-CD40 treated mice significantly reduced the extension and severity of atherosclerotic lesions, as well as the number of F4/80+, galectin-3+ macrophages and NF-κB+ cells in the intima. Genome-wide mRNA/miRNA profiling allowed the identification of transcripts, which were significantly upregulated during atherosclerosis; among them, miR-125b and miR-30a, Xpr1, a regulator of macrophage differentiation, Taf3, a core transcription factor and the NF-κB activator Ikkß, whereas, the NF-κB inhibitor Ikbα was downregulated during disease progression. All those changes were reversed upon CD40 silencing. Interestingly, TAF3, XPR1 and miR-125b were also overexpressed in human atherosclerotic plaques. Murine Taf3 and Xpr1 were detected in the perivascular adipose tissue (PVAT), and Taf3 also in intimal foam cells. Finally, expression of miR-125b was regulated by the CD40-NF-κB signaling axis in RAW264.7 macrophages. CONCLUSIONS: CD40 silencing with a specific siRNA ameliorates progression of experimental atherosclerosis in ApoE-/- mice, and evidences a role for NF-κB, Taf3, Xpr1, and miR-125b in the pathogenesis of atherosclerosis.

Intragraft Antiviral-Specific Gene Expression as a Distinctive Transcriptional Signature for Studies in Polyomavirus-Associated Nephropathy.

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.

A Randomized Study Comparing Parathyroidectomy with Cinacalcet for Treating Hypercalcemia in Kidney Allograft Recipients with Hyperparathyroidism.

Tertiary hyperparathyroidism is a common cause of hypercalcemia after kidney transplant. We designed this 12-month, prospective, multicenter, open-label, randomized study to evaluate whether subtotal parathyroidectomy is more effective than cinacalcet for controlling hypercalcemia caused by persistent hyperparathyroidism after kidney transplant. Kidney allograft recipients with hypercalcemia and elevated intact parathyroid hormone (iPTH) concentration were eligible if they had received a transplant ≥6 months before the study and had an eGFR>30 ml/min per 1.73 m(2) The primary end point was the proportion of patients with normocalcemia at 12 months. Secondary end points were serum iPTH concentration, serum phosphate concentration, bone mineral density, vascular calcification, renal function, patient and graft survival, and economic cost. In total, 30 patients were randomized to receive cinacalcet (n=15) or subtotal parathyroidectomy (n=15). At 12 months, ten of 15 patients in the cinacalcet group and 15 of 15 patients in the parathyroidectomy group (P=0.04) achieved normocalcemia. Normalization of serum phosphate concentration occurred in almost all patients. Subtotal parathyroidectomy induced greater reduction of iPTH and associated with a significant increase in femoral neck bone mineral density; vascular calcification remained unchanged in both groups. The most frequent adverse events were digestive intolerance in the cinacalcet group and hypocalcemia in the parathyroidectomy group. Surgery would be more cost effective than cinacalcet if cinacalcet duration reached 14 months. All patients were alive with a functioning graft at the end of follow-up. In conclusion, subtotal parathyroidectomy was superior to cinacalcet in controlling hypercalcemia in these patients with kidney transplants and persistent hyperparathyroidism.

Residual urinary volume is a risk factor for primary nonfunction in kidney transplantation.

Primary nonfunction is a severe complication after kidney transplantation. Residual renal function could be a risk factor for this complication in the current era of kidney transplantation from extended criteria donors (ECD). This is a single-center case-control study. Between 2000 and 2012, 1112 patients received a kidney transplant from a deceased donor. We identified 56 cases of early graft loss (kidney that never recover renal function and/or graft thrombosis <48 h after kidney transplantation). As controls we used patients receiving the contralateral kidney. Donor age was 55 ± 17 years with 57% fulfilling ECD criteria. Among the 56 cases, 14 were due to vascular rejection and 42 to primary nonfunction. Risk factors for early graft loss due to vascular rejection were previous transplant, time on dialysis, and HLA sensitization. Risk factors for primary nonfunction were first transplant, short period on dialysis, mainly peritoneal dialysis, and a residual urinary volume ≥500 ml/24 h. Conditional logistic regression analysis showed that residual urinary volume (OR = 20.01) rather than the dialysis modality was a major risk factor for primary nonfunction. In conclusion, residual urinary volume seems to be a risk factor for primary nonfunction in the current era of kidney transplantation.

Prognostic value of non-specific ST-T changes and left ventricular hypertrophy electrocardiographic criteria in hypertensive patients: 16-year follow-up results from the MINACOR cohort.

BACKGROUND: Non-specific electrocardiographic ST-T wave changes and voltage criteria for left ventricular hypertrophy (LVH) have been associated with cardiovascular morbidity and mortality. The aim of the cohort study was to evaluate the prognostic value of non-specific ST-T changes and LVH electrocardiographic criteria on cardiovascular events and mortality in hypertensive patients. METHODS: A cohort study of 352 non-diabetic hypertensive patients, without associated cardiovascular disease, randomly selected from 1,780 hypertensive patients attended in a primary care center. An electrocardiogram was performed at the baseline visit (classified according to the Minnesota Code). Cardiovascular events and death from any cause during the follow-up period were evaluated. A multivariate analysis adjusted for gender, age and cardiovascular risk factors was performed. RESULTS: Data of 273 patients were analyzed: 58.2% women, age 44.1 (7.9) years, 27.8% smokers, blood pressure at baseline 142.7 (15.3)/89.3 (9.6) mmHg. During the 197.5 (59.24) month follow-up, 62 patients (22.7%) had a cardiovascular event. On multivariate analysis, age, systolic blood pressure, incidence of diabetes, smoking and electrocardiographic LVH criteria (HR 2.66 [CI 95% 1.39 - 5.10]), were significantly associated with cardiovascular events, but the presence of non-specific ST-T abnormalities (HR 0.97 [CI 95% 0.49 -1.90]) was not significantly associated with cardiovascular morbidity and mortality. CONCLUSIONS: Hypertensive patients with LVH electrocardiographic criteria have significantly higher cardiovascular mortality and morbidity, but non-specific electrocardiographic ST-T changes are not associated with cardiovascular morbidity and mortality.