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The COVID‐19 pandemic has brought unprecedented challenges to the transplant community. The reduction in transplantation volume during this time is partly due to concerns over potentially increased susceptibility and worsened outcomes of COVID‐19 in immunosuppressed recipients. The consequences of COVID‐19 on patients waitlisted for kidney transplantation, however, have not previously been characterized. We studied 56 waitlisted patients and 80 kidney transplant recipients diagnosed with COVID‐19 between March 13 and May 20, 2020. Despite similar demographics and burden of comorbidities between waitlisted and transplant patients, waitlisted patients were more likely to require hospitalization (82% vs. 65%, P = .03) and were at a higher risk of mortality (34% vs. 16%, P = .02). Intubation was required in one third of hospitalized patients in each group, and portended a very poor prognosis. The vast majority of patients who died were male (84% waitlist, 100% transplant). Multivariate analysis demonstrated waitlist status, age, and male sex were independently associated with mortality. COVID‐19 has had a dramatic impact on waitlisted patients, decreasing their opportunities for transplantation and posing significant mortality risk. Understanding the impact of COVID‐19 on waitlist patients in comparison to transplant recipients may aid centers in weighing the risks and benefits of transplantation in the setting of ongoing COVID‐19.

Chronic active T cell-mediated rejection, demonstrated by the presence of inflammation in areas of fibrosis, is associated with long-term allograft loss. Kung et al., in this issue of Kidney International, describe a series of cases of CA TCMR and analyze their clinical, molecular, and pathologic features as well as their response to therapy. Their translational study aids in understanding this diverse phenotype and provides future direction for managing these patients.

The response of the immune system to COVID-19 in end stage kidney disease patients who undergo kidney transplantation has yet to be described. We report data on 72 patients who underwent SARS-CoV-2 antibody testing both before and after kidney transplantation and were followed for a median of 186 days (range 83, 277). Of the 25 patients with a positive antibody test at the time of transplant, 17 (68%) remained positive after transplantation. Patients were significantly more likely to have a persistently positive test if they reported a symptomatic COVID-19 infection prior to transplant (p=0.01). SARS-CoV-2 IgG index values were measured in a subset of kidney transplant recipients and compared to wait -listed dialysis patients. These assays demonstrated a more significant decline in IgG (58% versus 14% p = 0.008) in transplant recipients when compared to dialysis patients tested during the same time period. Additional analysis of the quality of the immune response measuring the binding of SARS-CoV-2 antibodies to the receptor-binding domain (RBD binding), the antibody neutralizing capability, and the antibody avidity demonstrated a more pronounced effect when comparing pre-transplant values to post-induction therapy/post transplant values. The attenuated IgG response seen in transplant patients compared to dialysis patients after induction therapy requires further study. These data have important implications for post-transplant management of vaccinated dialysis patients.

Posttransplant diarrhea is associated with kidney allograft failure and death, but its etiology remains unknown in the majority of cases. Because altered gut microbial ecology is a potential basis for diarrhea, we investigated whether posttransplant diarrhea is associated with gut dysbiosis. We enrolled 71 kidney allograft recipients for serial fecal specimen collections in the first 3 months of transplantation and profiled the gut microbiota using 16S ribosomal RNA (rRNA) gene V4-V5 deep sequencing. The Shannon diversity index was significantly lower in 28 diarrheal fecal specimens from 25 recipients with posttransplant diarrhea than in 112 fecal specimens from 46 recipients without posttransplant diarrhea. We found a lower relative abundance of 13 commensal genera (Benjamini-Hochberg adjusted P ≤ .15) in the diarrheal fecal specimens including the same 4 genera identified in our prior study. The 28 diarrheal fecal specimens were also evaluated by a multiplexed polymerase chain reaction (PCR) assay for 22 bacterial, viral, and protozoan gastrointestinal pathogens, and 26 specimens were negative for infectious etiologies. Using PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) to predict metagenomic functions, we found that diarrheal fecal specimens had a lower abundance of metabolic genes. Our findings suggest that posttransplant diarrhea is not associated with common infectious diarrheal pathogens but with a gut dysbiosis.

We tested the hypothesis that single-cell RNA-sequencing (scRNA-seq) analysis of human kidney allograft biopsies will reveal distinct cell types and states and yield insights to decipher the complex heterogeneity of alloimmune injury. We selected 3 biopsies of kidney cortex from 3 individuals for scRNA-seq and processed them fresh using an identical protocol on the 10x Chromium platform; (i) HK: native kidney biopsy from a living donor, (ii) AK1: allograft kidney with transplant glomerulopathy, tubulointerstitial fibrosis, and worsening graft function, and (iii) AK2: allograft kidney after successful treatment of active antibody-mediated rejection. We did not study T-cell-mediated rejections. We generated 7217 high-quality single cell transcriptomes. Taking advantage of the recipient-donor sex mismatches revealed by X and Y chromosome autosomal gene expression, we determined that in AK1 with fibrosis, 42 months after transplantation, more than half of the kidney allograft fibroblasts were recipient-derived and therefore likely migratory and graft infiltrative, whereas in AK2 without fibrosis, 84 months after transplantation, most fibroblasts were donor-organ-derived. Furthermore, AK1 was enriched for tubular progenitor cells overexpressing profibrotic extracellular matrix genes. AK2, eight months after successful treatment of rejection, contained plasmablast cells with high expression of immunoglobulins, endothelial cell elaboration of T cell chemoattractant cytokines, and persistent presence of cytotoxic T cells. In addition to these key findings, our analysis revealed unique cell types and states in the kidney. Altogether, single-cell transcriptomics yielded novel mechanistic insights, which could pave the way for individualizing the care of transplant recipients.

Immune monitoring of kidney allograft recipients and personalized therapeutics may help reach the aspirational goal of "one transplant for life." The invasive kidney biopsy procedure, the diagnostic tool of choice, has become safer and the biopsy classification more refined. Nevertheless, biopsy-associated complications, interobserver variability in biopsy specimen scoring, and costs continue to be significant concerns. The dynamics of the immune repertoire make frequent assessments of allograft status necessary, but repeat biopsies of the kidney are neither practical nor safe. To address the existing challenges, we developed urinary cell mRNA profiling and investigated the diagnostic, prognostic, and predictive accuracy of absolute levels of a hypothesis-based panel of mRNAs encoding immunoregulatory proteins. Enabled by our refinements of the PCR assay and by investigating mechanistic hypotheses, our single-center studies identified urinary cell mRNAs associated with T cell-mediated rejection, antibody-mediated rejection, interstitial fibrosis and tubular atrophy, and BK virus nephropathy. In the multicenter National Institutes of Health Clinical Trials in Organ Transplantation-04, we discovered and validated a urinary cell three-gene signature of T-cell CD3 e chain mRNA, interferon gamma inducible protein 10 (IP-10) mRNA, and 18s ribosomal RNA that is diagnostic of subclinical acute cellular rejection and acute cellular rejection and prognostic of acute cellular rejection and graft function. The trajectory of the signature score remained flat and below the diagnostic threshold for acute cellular rejection in the patients with no rejection biopsy specimens, whereas a sharp rise was observed during the weeks before the biopsy specimen that showed acute cellular rejection. Our RNA sequencing and bioinformatics identified kidney allograft biopsy specimen gene signatures of acute rejection to be enriched in urinary cells matched to acute rejection biopsy specimens. The urinary cellular landscape was more diverse and more enriched for immune cell types compared with kidney allograft biopsy specimens. Urinary cell mRNA profile-guided clinical trials are needed to evaluate their value compared with current standard of care.

The return to dialysis after allograft failure is associated with increased morbidity and mortality. This transition is made more complex by the rising numbers of patients who seek repeat transplantation and therefore may have indications for remaining on low levels of immunosuppression, despite the potential increased morbidity. Management strategies vary across providers, driven by limited data on how to transition off immunosuppression as the allograft fails and a paucity of randomized controlled trials to support one approach over another. In this review, we summarize the current data available for management and care of the failing allograft. Additionally, we discuss a suggested plan for immunosuppression weaning based upon the availability of re-transplantation and residual allograft function. We propose a shared-care model in which there is improved coordination between transplant providers and general nephrologists so that immunosuppression management and preparation for renal replacement therapy and/or repeat transplantation can be conducted with the goal of improved outcomes and decreased morbidity in this vulnerable patient group.

Post-transplant diarrhea is a common complication after solid organ transplantation and is frequently attributed to the widely prescribed immunosuppressant mycophenolate mofetil (MMF). Given recent work identifying the relationship between MMF toxicity and gut bacterial β-glucuronidase activity, we evaluated the relationship between gut microbiota composition, fecal β-glucuronidase activity, and post-transplant diarrhea. We recruited 97 kidney transplant recipients and profiled the gut microbiota in 273 fecal specimens using 16S rRNA gene sequencing. We further characterized fecal β-glucuronidase activity in a subset of this cohort. Kidney transplant recipients with post-transplant diarrhea had decreased gut microbial diversity and decreased relative gut abundances of 12 genera when compared to those without post-transplant diarrhea (adjusted p value < .15, Wilcoxon rank sum test). Among the kidney transplant recipients with post-transplant diarrhea, those with higher fecal β-glucuronidase activity had a more prolonged course of diarrhea (≥7 days) compared to patients with lower fecal β-glucuronidase activity (91% vs 40%, p = .02, Fisher's exact test). Our data reveal post-transplant diarrhea as a complex phenomenon with decreased gut microbial diversity and commensal gut organisms. This study further links commensal bacterial metabolism with an important clinical outcome measure, suggesting fecal β-glucuronidase activity could be a novel biomarker for gastrointestinal-related MMF toxicity.

Kidney allograft failure and return to dialysis carry a high risk of morbidity. A practice survey was developed by the AST Kidney Pancreas Community of Practice workgroup and distributed electronically to the AST members. There were 104 respondents who represented 92 kidney transplant centers. Most survey respondents were transplant nephrologists at academic centers. The most common approach to immunosuppression management was to withdraw the antimetabolite first (73%), while only 12% responded they would withdraw calcineurin inhibitor (CNI) first. More than 60% reported that the availability of a living donor is the most important factor in their decision to taper immunosuppression, followed by risk of infection, risk of sensitization, frailty, and side effects of medications. More than half of respondents reported that embolization was either not available or offered to less than 10% as an option for surgical intervention. Majority reported that ≤50% of failed allograft patients were re-listed before dialysis, and less than a quarter of transplant nephrologists performed frequent visits with their patients with failed kidney allograft after they return to dialysis. This survey demonstrates heterogeneity in the care of patients with a failing allograft and the need for more evidence to guide improvements in clinical practice related to transition of care.

Urinary tract infection (UTI) is a common complication in kidney transplant recipients and can lead to significant morbidity and mortality. Recent evidence supports a role for the gut as a source for UTIs but little is known about the relationship between gut commensal bacteria and UTI development. We hypothesized that the abundance of gut commensal bacteria is associated with a lower risk of developing bacteriuria and UTIs. We performed gut microbiome profiling using 16S rRNA gene sequencing of the V4-V5 hypervariable region on 510 fecal specimens in 168 kidney transplant recipients. Fifty-one kidney transplant recipients (30%) developed Enterobacteriaceae bacteriuria within the first 6 months after transplantation (Enterobacteriaceae Bacteriuria Group) and 117 did not (No Enterobacteriaceae Bacteriuria Group). The relative abundances of Faecalibacterium and Romboutsia were significantly higher in the fecal specimens from the No Enterobacteriaceae Bacteriuria Group than those from the Enterobacteriaceae Bacteriuria Group (Adjusted P value

AKI is a recognized complication of coronavirus disease 2019 (COVID-19) (1). In this study, we characterized the AKI incidence and outcomes in patients with COVID-19 and AKI. We conducted a retrospective cohort study of 1002 patients admitted from March 1 to April 19, 2020 through the Emergency

We tested the hypothesis that single-cell RNA-sequencing (scRNA-seq) analysis of human kidney allograft biopsies will reveal distinct cell types and states and yield insights to decipher the complex heterogeneity of alloimmune injury. We selected 3 biopsies of kidney cortex from 3 individuals for scRNA-seq and processed them fresh using an identical protocol on the 10x Chromium platform; (i) HK: native kidney biopsy from a living donor, (ii) AK1: allograft kidney with transplant glomerulopathy, tubulointerstitial fibrosis, and worsening graft function, and (iii) AK2: allograft kidney after successful treatment of active antibody-mediated rejection. We did not study T-cell-mediated rejections. We generated 7217 high-quality single cell transcriptomes. Taking advantage of the recipient-donor sex mismatches revealed by X and Y chromosome autosomal gene expression, we determined that in AK1 with fibrosis, 42 months after transplantation, more than half of the kidney allograft fibroblasts were recipient-derived and therefore likely migratory and graft infiltrative, whereas in AK2 without fibrosis, 84 months after transplantation, most fibroblasts were donor-organ-derived. Furthermore, AK1 was enriched for tubular progenitor cells overexpressing profibrotic extracellular matrix genes. AK2, eight months after successful treatment of rejection, contained endothelial cells that expressed T-cell chemoattractant cytokines. In addition to these key findings, our analysis revealed unique cell types and states in the kidney. Altogether, single-cell transcriptomics yielded novel mechanistic insights, which could pave the way for individualizing the care of transplant recipients.

Background Kidney graft recipients receiving immunosuppressive therapy may be at heightened risk for coronavirus disease 2019 (Covid-19) and adverse outcomes. It is therefore important to characterize the clinical course and outcome of Covid-19 in this population and identify safe therapeutic strategies. Methods We performed a retrospective chart review of 73 adult kidney graft recipients evaluated for Covid-19 from 13 March to 20 April 2020. Primary outcomes included recovery from symptoms, acute kidney injury, graft failure and case fatality rate. Results Of the 73 patients screened, 54 tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—39 with moderate to severe symptoms requiring hospital admission and 15 with mild symptoms managed in the ambulatory setting. Hospitalized patients were more likely to be male, of Hispanic ethnicity and to have cardiovascular disease. In the hospitalized group, tacrolimus dosage was reduced in 46% of patients and mycophenolate mofetil (MMF) therapy was stopped in 61% of patients. None of the ambulatory patients had tacrolimus reduction or discontinuation of MMF. Azithromycin or doxycycline was prescribed at a similar rate among hospitalized and ambulatory patients (38% versus 40%). Hydroxychloroquine was prescribed in 79% of hospitalized patients. Graft failure requiring hemodialysis occurred in 3 of 39 hospitalized patients (8%) and 7 patients died, resulting in a case fatality rate of 13% among Covid-19-positive patients and 18% among hospitalized Covid-19-positive patients. Conclusions Data from our study suggest that a strategy of systematic triage to outpatient or inpatient care, early management of concurrent bacterial infections and judicious adjustment of immunosuppressive drugs rather than cessation is feasible in kidney transplant recipients with Covid-19.

BackgroundOrgan graft recipients receiving immunosuppressive therapy are likely to be at heightened risk for the Coronavirus Disease 2019 (Covid-19) and adverse outcomes including death. It is therefore important to characterize the clinical course and outcome of Covid-19 in this vulnerable population and identify therapeutic strategies that are safe.MethodsWe performed a retrospective chart review of 54 adult kidney transplant patients diagnosed with Covid-19 and all managed in New York State, the epicenter of Covid-19 pandemic. All 54 patients were evaluated by video visits, or phone interviews, and referred to our Fever Clinic or Emergency Room for respiratory illness symptoms consistent with Covid-19 and admitted if deemed necessary from March 13, 2020 to April 20, 2020. Characteristics of the patients were stratified by hospitalization status and disease severity. Clinical course including alterations in immunosuppressive therapy were retrieved from their electronic medical records. Primary outcomes included recovery from Covid-19 symptoms, acute kidney injury, graft failure, and case fatality rate.ResultsOf the 54 SARS-Cov-2 positive kidney transplant recipients, 39 with moderate to severe symptoms were admitted and 15 with mild symptoms were managed at home. Hospitalized patients compared to non-hospitalized patients were more likely to be male, of Hispanic ethnicity, and to have cardiovascular disease. At baseline, all but 2 were receiving tacrolimus, mycophenolate mofetil (MMF) and 32 were on a steroid free immunosuppression regimen. Tacrolimus dosage was reduced in 46% of hospitalized patients and maintained at baseline level in the non-hospitalized cohort. Mycophenolate mofetil (MMF) dosage was maintained at the baseline dosage in 11% of hospitalized patients and 64% of non-hospitalized patients and was stopped in 61% hospitalized patients and 0% in the non-hospitalized cohort. Azithromycin or doxycycline were prescribed at a similar rate among hospitalized and non-hospitalized patients (38% vs. 40%). In addition, 50% of hospitalized patients were treated for concurrent bacterial infections including pneumonia, urinary tract infections and sepsis. Hydroxychloroquine was prescribed in 79% of hospitalized patients and only one of 15 non-hospitalized patients. Acute kidney injury occurred in 51% of hospitalized patients. Patients with severe disease were more likely to have elevations in inflammatory biomarkers at presentation. At a median of 21 days follow up, 67% of patients have had their symptoms resolved or improved and 33% have persistent symptoms. Graft failure requiring hemodialysis occurred in 3 of 39 hospitalized patients (8%). Three of 39 (8%) hospitalized patients expired and none of the 15 non-hospitalized patients expired.ConclusionsClinical presentation of Covid-19 in kidney transplant recipients was similar to what has been described in the general population. The case fatality rate in our entire cohort of 54 kidney transplant recipients was reassuringly low and patients with mild symptomology could be successfully managed at home. Data from the our study suggest that a strategy of systematic screening and triage to outpatient or inpatient care, close monitoring, early management of concurrent bacterial infections and judicious use of immunosuppressive drugs rather than cessation is beneficial.

Background and objectivesT cell mediated rejection (TCMR) is the most frequent type of acute rejection and is associated with kidney allograft failure. Almost 40% of TCMR episodes fail to respond to anti-rejection therapy. FOXP3 is a specification factor for regulatory T cells and our single center study of 83 kidney allograft recipients showed that urinary cell FOXP3 mRNA level is diagnostic of TCMR and predicts TCMR reversibility and allograft survival. The objective of the current study is to determine whether our original findings could be replicated in an independent cohort of 480 kidney allograft recipients enrolled in the multicenter Clinical Trials of Organ Transplantation (CTOT)-04.Design, setting, participants, and measurementsWe measured levels of FOXP3 mRNA and levels of mRNA for CD25, CD3E, and perforin, and 18S rRNA in 3559 urines from 480 kidney allograft recipients prospectively enrolled in CTOT-04. RNA was isolated from the urinary cells and preamplification-enhanced real-time quantitative PCR assays were used to measure mRNAs.Results18S rRNA normalized levels of mRNA for FOXP3 (P=0.01, Kruskal-Wallis test), CD25 (P=0.01), CD3E (PPP=0.008). Multivariable logistic regression analysis showed that FOXP3 mRNA level remains predictive after adjustment for potential cofounders. Kaplan-Meier survival curve analysis showed that FOXP3 mRNA level (P=0.0306) but not the levels of mRNA for CD25, CD3E, or perforin, is associated with kidney allograft survival.ConclusionIn the independent CTOT-04 cohort, we demonstrate that urinary cell level of FOXP3 mRNA is diagnostic of TCMR, predicts its reversibility, and is prognostic of kidney allograft survival following an episode of TCMR.

BACKGROUND: RNA sequencing (RNA-Seq) is a molecular tool to analyze global transcriptional changes, deduce pathogenic mechanisms, and discover biomarkers. We performed RNA-Seq to investigate gene expression and biological pathways in urinary cells and kidney allograft biopsies during an acute rejection episode and to determine whether urinary cell gene expression patterns are enriched for biopsy transcriptional profiles. METHODS: We performed RNA-Seq of 57 urine samples collected from 53 kidney allograft recipients (patients) with biopsies classified as acute T cell–mediated rejection (TCMR; n = 22), antibody-mediated rejection (AMR; n = 8), or normal/nonspecific changes (No Rejection; n = 27). We also performed RNA-Seq of 49 kidney allograft biopsies from 49 recipients with biopsies classified as TCMR (n = 12), AMR (n = 17), or No Rejection (n = 20). We analyzed RNA-Seq data for differential gene expression, biological pathways, and gene set enrichment across diagnoses and across biospecimens. RESULTS: We identified unique and shared gene signatures associated with biological pathways during an episode of TCMR or AMR compared with No Rejection. Gene Set Enrichment Analysis demonstrated enrichment for TCMR biopsy signature and AMR biopsy signature in TCMR urine and AMR urine, irrespective of whether the biopsy and urine were from the same or different patients. Cell type enrichment analysis revealed a diverse cellular landscape with an enrichment of immune cell types in urinary cells compared with biopsies. CONCLUSIONS: RNA-Seq of urinary cells and biopsies, in addition to identifying enriched gene signatures and pathways associated with TCMR or AMR, revealed genomic changes between TCMR and AMR, as well as between allograft biopsies and urinary cells.

In order to evaluate whether distinct cell types and states may be identified in human kidney allograft rejection compared to normal kidney, we sequenced 3 kidney biopsies using the 10x Chromium platform and generated 7,217 high-quality single-cell transcriptomes. Taking advantage of the recipient-donor sex mismatches in the allograft biopsies, we unexpectedly observed that in the biopsy with fibrosis, more than half of the kidney allograft fibroblasts were recipient-derived and therefore likely migratory and graft infiltrative, whereas in the biopsy without fibrosis, all the fibroblasts were donor-derived. Furthermore, tubular progenitor cells that overexpress profibrotic extracellular matrix genes potentially contributing to fibrosis, were enriched in the biopsy with fibrosis. In addition, our analysis revealed unique cell types and states in the kidney. Single-cell transcriptomics complemented histopathology and yielded promising mechanistic insights for individualizing the care of transplant recipients and revealed a new approach to study cell migratory contributions in allograft fibrosis.

Advances in bioinformatics allow identification of single nucleotide polymorphisms (variants) from RNA sequence data. In an allograft biopsy, 2 genomes contribute to the RNA pool, 1 from the donor organ and the other from the infiltrating recipient's cells. We hypothesize that imbalances in genetic variants of RNA sequence data of kidney allograft biopsies provide an objective measure of cellular infiltration of the allograft. We performed mRNA sequencing of 40 kidney allograft biopsies, selected to represent a comprehensive range of diagnostic categories. We analyzed the sequencing reads of these biopsies and of 462 lymphoblastoid cell lines from the 1000 Genomes Project, for RNA variants. The ratio of heterozygous to nonreference genome homozygous variants (Het/Hom ratio) on all autosomes was determined for each sample, and the estimation of stromal and immune cells in malignant tumors using expression data (ESTIMATE) score was computed as a complementary estimate of the degree of cellular infiltration into biopsies. The Het/Hom ratios (P = .02) and the ESTIMATE scores (P < .001) were associated with the biopsy diagnosis. Both measures correlated significantly (r = .67, P < .0001), even though the Het/Hom ratio is based on mRNA sequence variation, while the ESTIMATE score uses mRNA expression. Het/Hom ratio and the ESTIMATE score may offer unbiased and quantitative parameters for characterizing cellular traffic into human kidney allografts.

The origin of most bacterial infections in the urinary tract is often presumed to be the gut. Herein, we investigate the relationship between the gut microbiota and future development of bacteriuria and urinary tract infection (UTI). We perform gut microbial profiling using 16S rRNA gene deep sequencing on 510 fecal specimens from 168 kidney transplant recipients and metagenomic sequencing on a subset of fecal specimens and urine supernatant specimens. We report that a 1% relative gut abundance of Escherichia is an independent risk factor for Escherichia bacteriuria and UTI and a 1% relative gut abundance of Enterococcus is an independent risk factor for Enterococcus bacteriuria. Strain analysis establishes a close strain level alignment between species found in the gut and in the urine in the same subjects. Our results support a gut microbiota–UTI axis, suggesting that modulating the gut microbiota may be a potential novel strategy to prevent UTIs., Urinary tract infections (UTIs) are associated with changes in the gut microbiome. Here, the authors evaluate the relationship between the gut microbiome and development of UTI in kidney transplant patients and show that uropathogenic gut abundance might represent a risk factor for development of bacteriuria and UTI.

Posttransplant lymphoproliferative disorder (PTLD) is a malignancy caused by the immunosuppression that occurs after transplantation. It is primarily a nodal lesion but frequently it involves extranodal masses. Treatment is usually by reducing immunosuppressive therapy. Testicular lymphoma as PTLD is notably rare in documented literature and there is limited evidence of definitive treatment guidelines. This manuscript describes a patient who developed diffuse large B-cell lymphoma of his right testis one year following kidney transplantation. A diagnosis of PTLD was made and treatment with rituximab, locoregional radiotherapy, and intrathecal methotrexate in addition to the standard reduction of immunosuppression resulted in complete remission until now. We submit this case along with literature review of similar cases in the past and a review of specific peculiarities of our case with emphasis on our treatment plan to further the understanding of this diversiform disease.

We aimed to investigate the impact of the new kidney allocation system (KAS) on the rate of transplantation of sensitized patients at our center. Pre-KAS and post-KAS intervals were Jan 1st to Dec 3rd 2014 and Jan 1st 2015 to Dec 3rd 2015, respectively. The number of deceased-donor crossmatches performed by flow cytometry increased from 715 pre-KAS to 1188 post-KAS. The percent of crossmatches performed for sensitized patients with calculated panel reactive antibody (cPRA)0% increased from 19% pre-KAS to 26% post-KAS (p0.0001). The number of deceased-donor kidney transplants performed at our center increased from 115 pre-KAS to 125 post-KAS (9% increase). There was a significant increase in the percentage of deceased-donor kidney transplants received by sensitized candidates (from 14% to 26% pre- and post-KAS, respectively; p0.0001). The highest increase was seen in the patients with cPRA98%, from 0% to 9%, followed by the group with cPRA 50-79%, from 5% to 8%. This increase was balanced by a decrease of 12% in the percentage of non-sensitized recipients, and a modest decrease of 1% in the group with cPRA 1-49%. In conclusion, transplant rate has increased in sensitized patients after KAS. The highest increase was observed among highly sensitized patients (cPRA98%).

Background The gut microbiome is being associated increasingly with development of infections besides Clostridium difficile infection. A recent study found an association between butyrate‐producing gut (BPG) bacteria and less frequent development of lower respiratory viral infections in allogeneic hematopoietic stem cell transplant recipients (Haak et al, Blood 131(26): 2978, 2018). In this investigation, we examine the relationship between the abundance of BPG bacteria and the development of viral infections in a cohort of kidney transplant recipients. Methods We recruited 168 kidney transplant recipients who provided 510 fecal specimens in the first 3 months after transplantation and profiled the gut microbiota using 16S rRNA gene sequencing of the V4‐V5 hypervariable region. We classified the kidney transplant recipients into higher BPG Bacteria Group and lower BPG Bacteria Group using the same criteria of 1% relative gut abundance of BPG bacteria as the Haak et al study. Results Administration of antibiotics against anaerobes was associated with a significant decrease in the relative gut abundance of BPG bacteria. The higher BPG Bacteria Group was associated with less development of respiratory viral infections (Hazard Ratio [HR]: 0.28, P = .01) but not with less development of CMV viremia (HR: 0.38, P = .13) or BK viremia (HR: 1.02, P = .98) at 2 years post transplantation. Conclusion Our pilot investigation supports future validation of the relationship between high relative gut abundance of BPG bacteria and decreased risk for development of respiratory viral infections.

Acute rejection of human allografts has been viewed mostly through the lens of adaptive immunity, and the intragraft landscape of innate immunity genes has not been characterized in an unbiased fashion. We performed RNA sequencing of 34 kidney allograft biopsy specimens from 34 adult recipients; 16 were categorized as Banff acute T cell-mediated rejection (TCMR) and 18 as normal. Computational analysis of intragraft mRNA transcriptome identified significantly higher abundance of mRNA for pattern recognition receptors in TCMR compared with normal biopsies, as well as increased expression of mRNAs for cytokines, chemokines, interferons, and caspases. Intragraft levels of calcineurin mRNA were higher in TCMR biopsies, suggesting underimmunosuppression compared with normal biopsies. Cell-type-enrichment analysis revealed higher abundance of dendritic cells and macrophages in TCMR biopsies. Damage-associated molecular patterns, the endogenous ligands for pattern recognition receptors, as well markers of DNA damage were higher in TCMR. mRNA expression patterns supported increased calcium flux and indices of endoplasmic, cellular oxidative, and mitochondrial stress were higher in TCMR. Expression of mRNAs in major metabolic pathways was decreased in TCMR. Our global and unbiased transcriptome profiling identified heightened expression of innate immune system genes during an episode of TCMR in human kidney allografts.

BACKGROUND. In kidney transplant recipients, gastrointestinal (GI) pathogens in feces are only evaluated during diarrheal episodes. Little is known about the prevalence of GI pathogens in asymptomatic individuals in this population. METHODS. We recruited 142 kidney transplant recipients who provided a non-diarrheal fecal sample within the first 10 days after transplantation. The specimens were evaluated for GI pathogens using the BioFire® FilmArray® GI Panel (BioFire® Diagnostics, LLC; Salt Lake City, UT), which tests for 22 pathogens. The fecal microbiome was also characterized using 16S rRNA gene sequencing of the V4-V5 hypervariable region. We evaluated whether detection of Clostridioides difficile and other GI pathogens was associated with post-transplant diarrhea within the first 3 months after transplantation. RESULTS. Among the 142 subjects, a potential pathogen was detected in 43 (30%) using the GI Panel. The most common organisms detected were C. difficile (n=24, 17%), enteropathogenic Escherichia coli (n=8, 6%), and norovirus (n=5, 4%). Detection of a pathogen on the GI panel or detection of C. difficile alone was not associated with future post-transplant diarrhea (P > 0.05). The estimated number of gut bacterial species was significantly lower in subjects colonized with C. difficile than those not colonized with a GI pathogen (P = 0.01) CONCLUSION. Colonization with GI pathogens, particularly C. difficile, is common at the time of kidney transplantation but does not predict subsequent diarrhea. Detection of C. difficile carriage was associated with decreased microbial diversity and may be a biomarker of gut dysbiosis.

Kidney transplantation (KT) is the optimal therapy for end-stage kidney disease (ESKD), resulting in significant improvement in survival as well as quality of life when compared with maintenance dialysis. The burden of cardiovascular disease (CVD) in ESKD is reduced after KT; however, it still remains the leading cause of premature patient and allograft loss, as well as a source of significant morbidity and healthcare costs. All major phenotypes of CVD including coronary artery disease, heart failure, valvular heart disease, arrhythmias and pulmonary hypertension are represented in the KT recipient population. Pre-existing risk factors for CVD in the KT recipient are amplified by superimposed cardio-metabolic derangements after transplantation such as the metabolic effects of immunosuppressive regimens, obesity, posttransplant diabetes, hypertension, dyslipidemia and allograft dysfunction. This review summarizes the major risk factors for CVD in KT recipients and describes the individual phenotypes of overt CVD in this population. It highlights gaps in the existing literature to emphasize the need for future studies in those areas and optimize cardiovascular outcomes after KT. Finally, it outlines the need for a joint 'cardio-nephrology' clinical care model to ensure continuity, multidisciplinary collaboration and implementation of best clinical practices toward reducing CVD after KT.

We developed urinary cell messenger RNA (mRNA) profiling to monitor in vivo status of human kidney allografts based on our conceptualization that the kidney allograft may function as an in vivo flow cell sorter allowing access of graft infiltrating cells to the glomerular ultrafiltrate and that interrogation of urinary cells is informative of allograft status. For the profiling urinary cells, we developed a two-step preamplification enhanced real-time quantitative PCR (RT-QPCR) assays with a customized amplicon; preamplification compensating for the low RNA yield from urine and the customized amplicon facilitating absolute quantification of mRNA and overcoming the inherent limitations of relative quantification widely used in RT-QPCR assays. Herein, we review our discovery and validation of urinary cell mRNAs as noninvasive biomarkers prognostic and diagnostic of acute cellular rejection (ACR) in kidney allografts. We summarize our results reflecting the utility of urinary cell mRNA profiling for predicting reversal of ACR with anti-rejection therapy; differential diagnosis of kidney allograft dysfunction; and noninvasive diagnosis and prognosis of BK virus nephropathy. Messenger RNA profiles associated with human kidney allograft tolerance are also summarized in this review. Altogether, data supporting the idea that urinary cell mRNA profiles are informative of kidney allograft status and tolerance are reviewed in this report.

Background Deceased-donor kidneys are often exposed to ischemic events from donor instability, as evidenced by acute kidney injury (AKI). Clinicians may be reluctant to transplant kidneys with AKI that also have prolonged cold ischemia time (CIT) for fear of an additional deleterious effect. Study Design We evaluated national data between 1998 and 2013 of adult first-time kidney-only recipients of paired kidneys from donors with AKI (terminal serum creatinine ≥ 2 mg/dL), in which the CIT difference between recipients was ≥1, 5, 10, or 15 hours. Results On multivariate analysis of AKI kidney recipients, overall death-censored graft survival (DCGS) was comparable between recipients with higher CIT relative to paired donor recipients with lower CIT when the CIT difference was at least 1 hour (adjusted hazard ratio [aHR] 0.98, 95% CI 0.85 to 1.13, n = 4,458), 5 hours (aHR 0.97, 95% CI 0.79 to 1.18, n = 2,412), 10 hours (aHR 0.82, 95% CI 0.59 to 1.15, n = 922), or 15 hours (aHR 0.94, 95% CI 0.57 to 1.58, n = 442). Overall patient survival of the longer CIT groups was comparable or protective with delta CIT of ≥1 (aHR 0.94, 95% CI 0.83 to 1.06), 5 (aHR 0.80, 95% CI 0.68 to 0.94), 10 (aHR 0.70, 95% CI 0.53 to 0.91), and 15 (aHR 0.64, 95%CI 0.43 to 0.95) hours. Between each of the 4 delta-CIT levels of shorter and longer CIT, there were no statistically significant differences in the proportion of acute rejection at delta ≥1, 5, 10, or 15 hours. Conclusions These results suggest that in the setting of a previous ischemic donor event, prolonged CIT has limited bearing on long-term outcomes. This may be important evidence that despite the occurrence of other ischemic events, kidneys with prolonged CIT offer acceptable outcomes to recipients and are a potential source to expand the donor pool.

Background Severe systemic hypertension (HTN) is a risk factor for perioperative cardiovascular complications; however, its impact at the time of kidney transplantation (KTX) is not well defined. Methods A retrospective cohort study of adult kidney-only transplant recipients between October 2009 and December 2012 was performed to examine outcomes between patients with (n = 111) and without (n = 98) severe preoperative HTN defined as SBP >180 or DBP> 110 mmHg. Results Recipients with severe HTN were older (56.7 ± 13.0 vs. 53.5 ± 12.4 yr, p = 0.07) and significantly more likely to receive an expanded criteria donor kidney (32.7% vs. 12.2%, p = 0.02). No patients developed hypertensive crisis, intracranial hemorrhage, or life threatening ventricular arrhythmias within 30 d post-transplantation; however, three patients with severe HTN had cardiac events: two with demand ischemia and one with decompensate heart failure. Two patients in the control group had decompensated heart failure. There were no differences between the groups in terms of cardiac event (2.7% vs. 2.0%, p = 0.75), one-yr patient survival (98.2% vs. 98.0%, p = 0.90) or graft survival (90.1% vs. 92.9%, p = 0.48), nadir creatinine >2 mg/dL (4.6% vs. 6.2%, p = 0.62), length of stay>6 d (37.8% vs. 35.7%, p = 0.75), and DGF (52.3% vs. 63.3%, p = 0.11). Conclusions Our results suggest that severe preoperative HTN should not be considered an absolute contraindication to kidney transplant in patients who are otherwise clinically stable.

Affymetrix Human Gene 1.0-ST arrays were used to assess the gene expression profiles of kidney transplant patients who presented with donor-specific antibodies (DSAs) but showed normal biopsy histopathology and did not develop antibody-mediated rejection (AMR). Biopsy and whole-blood profiles for these DSA-positive, AMR-negative (DSA+/AMR−) patients were compared to both DSA-positive, AMR-positive (DSA+/AMR+) patients as well as DSA-negative (DSA−) controls. While individual gene expression changes across sample groups were relatively subtle, gene-set enrichment analysis using previously identified pathogenesis-based transcripts (PBTs) identified a clear molecular signature involving increased rejection-associated transcripts in AMR− patients. Results from this study have been published in Kidney International (Hayde et al., 2014 [1]) and the associated data have been deposited in the GEO archive and are accessible via the following link: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE50084

Background. Clinicians may be reluctant to transplant small pediatric kidneys that have prolonged cold ischemia time (CIT) for fear of an additional deleterious effect because pediatric grafts are thought to be more sensitive to ischemia. We aimed to assess the risks associated with transplantation of small pediatric kidneys with prolonged CIT. Methods. We performed a retrospective cohort study examining US registry data between 1998 and 2013 of adult first-time kidney-only recipients of small pediatric kidneys from donors weighing 10 to 20 kg, stratified by CIT levels of 0 to 18 (n = 1413), 19 to 30 (n = 1116), and longer than 30 (n = 338) hours. Results. All-cause graft survival by CIT groups at 1-year was 92%, 88%, and 89%, respectively. 1-year risk-adjusted graft survival hazard ratios were significantly higher with CIT of 19 to 30 hours (adjusted hazard ratios, 1.37; 95% confidence interval, 1.04-1.81) and somewhat higher with CIT greater than 30 hours (adjusted hazard ratios, 1.24; 95% confidence interval, 0.82-1.88) relative to recipients with CIT 0 to 18 hours. There was little variation in the effect of CIT on graft survival when restricted to single kidney transplants only and no significant interaction of CIT category and single kidney transplantation (P = 0.93). Conclusions. Although prolonged CIT is associated with lower early graft survival in small pediatric donor kidney transplants, absolute decreases in 1-year graft survival rates were 3% to 4%.

Background. Deceased-donor kidneys are exposed to ischemic events from donor instability during the process of donation after circulatory death (DCD). Clinicians may be reluctant to transplant DCD kidneys with prolonged cold ischemia time (CIT) for fear of an additional deleterious effect. Methods. We performed a retrospective cohort study examining US registry data between 1998 and 2013 of adult first-time kidney-only recipients of paired kidneys (derived from the same donor transplanted into different recipients) from DCD donors. Results. On multivariable analysis, death-censored graft survival (DCGS) was comparable between recipients of kidneys with higher CIT relative to paired donor recipients with lower CIT when the CIT difference was 1 hour or longer (adjusted hazard ratio, [aHR], 1.02; 95% confidence interval [CI], 0.88-1.17; n = 6276), 5 hours or longer (aHR, 0.98; 95% CI, 0.80-1.19; n = 3130), 10 hours or longer (aHR, 1.15; 95% CI, 0.82-1.60; n = 1124) or 15 hours (aHR, 1.15; 95% CI, 0.66-1.99; n = 498). There was a higher rate of primary non function in the long CIT groups for delta 1 hour or longer (0.89% vs 1.63%; P = 0.006), 5 hours (1.09% vs 1.67%, P = 0.13); 10 hours (0.53% vs 1.78%; P = 0.03), and 15 hours (0.40% vs 1.61%; P = 0.18), respectively. Between each of the 4 delta CIT levels of shorter and longer CIT, there was a significantly and incrementally higher rate of delayed graft function in the long CIT groups for delta 1 hour or longer (37.3% vs 41.7%; P < 0.001), 5 hours (35.9% vs 42.7%; P < 0.001), 10 hours (29.4% vs 44.2%, P < 0.001), and 15 hours (29.6% vs 46.1%, P < 0.001), respectively. Overall patient survival was comparable with delta CITs of 1 hour or longer (aHR, 0.96; 95% CI, 0.84-1.08), 5 hours (aHR, 1.01; 95% CI, 0.85-1.20), and 15 hours (aHR, 1.27; 95% CI, 0.79-2.06) but not 10 hours (aHR, 1.47; 95% CI, 1.09-1.98). Conclusions. These results suggest that in the setting of a prior ischemic donor event, prolonged CIT has limited bearing on long-term outcomes.

We investigated why some donor-specific antibody-positive patients do not develop antibody-mediated rejection. Of 71 donor-specific antibody-positive patients, 46 had diagnosis of antibody-mediated rejection and 25 had normal biopsies. Fifty donor-specific antibody-negative patients with normal biopsies were used as a control group. A subgroup of 61 patients with available biopsy and 64 with blood samples were analyzed by microarrays. Both donor-specific antibody-positive/antibody-mediated rejection-positive and negative biopsies showed increased expression of gene transcripts associated with cytotoxic T cells, natural killer cells, macrophages, interferon-gamma, and rejection compared to donor-specific antibody-negative biopsies. Regulatory T-cell transcripts were upregulated in donor-specific antibody-positive/antibody-mediated rejection-positive and B-cell transcripts in donor-specific antibody-positive/antibody-mediated rejection-negative biopsies. Whole-blood gene expression analysis showed increased immune activity in only donor-specific antibody-positive/antibody-mediated rejection-positive but not negative patients. During a median follow-up of 36 months, 4 donor-specific antibody-positive/antibody-mediated rejection-negative patients developed antibody-mediated rejection, 12 continued to have donor-specific antibody, but 9 lost their donor-specific antibody. Gene expression profiles did not predict the development of antibody-mediated rejection or the persistence of donor-specific antibody. Thus, donor-specific antibody-positive/antibody-mediated rejection-negative patients had increased rejection-associated gene transcripts in their allografts despite no histologic findings of rejection but not in their blood. This was found in both biopsy and blood samples of donor-specific antibody-positive/antibody-mediated rejection-positive patients.

Background This study aimed to investigate global gene expression profiles of BK viremia and nephropathy (BKVN) samples using microarrays to investigate the immunologic response to BK virus. Methods Patients were monitored for BK viremia in the blood monthly for 6 months, then at 9 and 12 months after kidney transplantation. BKVN and normal transplant kidney biopsy samples, and whole blood samples of patients with and without BK viremia were analyzed by Affymetrix Human Gene 1.0 ST Arrays. Results During a mean follow-up of 917±325 days, 61 of the 289 patients (21%) developed BK viremia at a median 149 (27, 1,113) days after transplantation with a median peak PCR titers of 35,900 (1,000, 2,677,000). The only significant risk factor for development of BK viremia was induction with anti-thymocyte globulin (P=0.03). Only four patients developed BKVN (1.3%). Pathogenesis-based transcript analysis revealed a significant increased expression of interferon-gamma and rejection induced (GRIT), quantitative cytotoxic T-cell (QCAT), quantitative constitutive and alternate macrophage, B-cell and natural killer cell-associated transcripts (NKAT), indicating an active inflammatory immune response in BKVN biopsies (n=3) compared to normal transplant kidney biopsies with (n=3) and without BK viremia (n=11). The whole blood gene expression profiles of 19 BK viremia patients revealed significant increased expression of GRIT, QCAT, and NKAT compared to 14 patients without viremia. Conclusions The results showed increased activity of cytotoxic T cells and natural killer cells in BKVN and viremia samples resembling acute rejection and suggested the involvement of both adaptive and innate immunity.

BACKGROUND With the development of all oral, interferon-free directly acting antiviral (DAA) medications, treatment of hepatitis C virus (HCV) infection in renal transplant recipients is possible, but limited data exists on its safety and efficacy. METHODS We performed a retrospective cohort analysis of patients transplanted at our center with HCV who have been started on DAAs. Primary endpoints included sustained virologic response as defined as negative viral load at 12 weeks postcompletion of therapy and allograft function. RESULTS A total of 31 patients met inclusion criteria. The most commonly used regimen was sofosbuvir and ledipasvir (n = 21). Of the treated patients, 100% had undetectable viral load at the completion of therapy. Of the 31 patients treated, 30 (97%) achieved sustained virologic response. Both graft and patient survivals at most recent follow-up was 100%. There was no significant change in glomerular filtration rate (GFR) before or after therapy (64.2 ± 16.5 mL/min per body surface area before vs. 58.9 ± 17.5 mL/min per body surface area after therapy; P = 0.22); however, 3 patients now have GFR less than 20. A total of 6 (19.3%) of 31 patients had worsening proteinuria during or shortly after therapy. Patients with more than 500 mg/g of proteinuria at the start of treatment were significantly more likely to develop worsening proteinuria than those with less than 500 mg/g of proteinuria at the start of therapy (P < 0.001). Retrospective review of 20 untreated HCV patients did not demonstrate worsening allograft function and proteinuria during a median follow-up time of 1386 days (range, 332-6254). CONCLUSIONS Our preliminary data demonstrate that DAAs can be used safely and effectively in patients after kidney transplantation. Patients with proteinuria or lower GFR should be monitored more closely.

Supplemental Digital Content is available in the text., Background. Tacrolimus trough variability is an important risk factor for kidney allograft outcomes. Recent evidence suggests that the gut microbiota is associated with tacrolimus dosing requirements and direct metabolism of tacrolimus. We hypothesize that administration of antibiotics, which are known to alter the gut microbiota, is associated with tacrolimus trough variability. Methods. We conducted a retrospective chart review of subjects who received kidney transplants at our institution from 2012 to 2013 and evaluated subjects who received antibiotics during the first month of transplantation (Abx Group, N = 60) and subjects who did not (No Abx Group, N = 200). We evaluated whether antibiotic administration in the Abx Group had increased tacrolimus trough concentrations and concentration over tacrolimus dosage (C/D) after antibiotic administration. We also evaluated tacrolimus variability as measured by standard deviation (SD) and coefficient of variation between the Abx Group and No Abx Group. Results. In the Abx Group, tacrolimus trough concentration over tacrolimus dosage (C/D) increased 7 and 15 days after antibiotic administration (P = 0.001, P = 0.07, respectively, Wilcoxon signed-rank test). From postoperative day 31–45, the variability in tacrolimus trough levels in the Abx Group as measured by SD and coefficient of variation was significantly higher than the variability in the No Abx Group (P = 0.03, P = 0.02, Wilcoxon rank sum test, respectively). Conclusions. Our identification of antibiotic administration as a potentially new risk factor for tacrolimus trough variability suggests the need to carefully follow tacrolimus trough levels after antibiotic administration.

Background We investigated clinical outcomes and molecular signatures of transplant glomerulopathy (TG) stratified by microvascular inflammation (MVI) and donor-specific antibody (DSA) status. Methods We performed a retrospective review of 749 kidney transplant patients who received a for-cause kidney biopsy from 2009 to 2014. We classified TG as MVI positive (MVI+) or MVI negative (MVI-), and with or without DSA. We obtained gene expression profiles for 44 biopsies by Affymetrix HuGene 1.0 ST expression arrays. Results A total of 100 patients had TG; 49 were MVI+, and 51 were MVI-. After a median post-biopsy follow-up of 2.08 years (range 0.43-4.59), Kaplan-Meier survival analysis demonstrated worse allograft survival in MVI+ TG patients compared with MVI- TG patients (P = 0.01), and time to graft failure was significantly shorter in MVI+ patients (1.08 ± 1.01 years vs 2.3 ± 1.8 years; P = 0.002). DSA status did not affect graft survival within MVI+ or MVI- groups. Analysis of pathogenesis-based transcripts (PBT) showed that MVI+ TG biopsies had increased expression of gamma interferon and rejection (GRIT) and DSA-associated transcripts (DSAST), as observed in antibody-mediated rejection. MVI- TG biopsies had increased expression of cytotoxic and regulatory T cell- and B cell-associated transcripts but not GRIT or DSAST. DSA status had no effect on expression of any PBTs studied in MVI- TG biopsies. Conclusions Graft survival in TG is significantly worse in the presence of MVI. Gene expression profiles of MVI+ TG resemble antibody-mediated rejection while gene expression profiles of MVI- TG resemble cell-mediated rejection regardless of DSA status.

Early rehospitalization after kidney transplantation (KTx) is common and is considered a quality metric. Recipient and donor risk factors for early readmission after KTx are well studied. Little data exist on discharge-level factors associated with readmission.We performed a single-center, retrospective cohort study between 2011 and 2015 of adult KTx recipients to examine readmission indication, risk factors, and opportunities for reduction.Of 462 KTxs, 145 (31.4%) were readmitted within 30 days of discharge. The primary reason for readmission was surgery-site specific in 30 cases (20.7%). Of 115 recipients with nonsurgical indications for readmission 25 (21.7%) were related to infection, 24 (20.9%) graft dysfunction, 25 (21.7%) gastrointestinal, 25 (21.7%) metabolic, and 16 (13.9%) other reasons. On multivariate analysis significant independent predictors of early readmission were electrolyte abnormalities on the day of discharge (odds ratio [OR], 1.77; 95% confidence interval [95% CI], 1.17-2.69), 3 or more comorbidities (OR, 2.01; 95% CI, 1.04-3.86), delayed graft function at the time of discharge (OR, 1.65; 95% CI, 1.00-2.70), and post-KTx hospitalization complication (OR, 1.70; 95% CI, 1.10-2.61). Among 11.7% of patients, readmission may have been attenuated by addressing the medical issue before discharge from index hospitalization. In 28.3% of patients, readmission rates may have been reduced with continued management as an outpatient or provision of observational or same-day diagnostic resources.Specific discharge level factors correlate with readmission irrespective of comorbidities and transplant complications. These findings may have important implications on discharge practice by aiding to identify which KTx recipients could be targeted for enhanced care transitions. Overall, potential opportunities for readmission reduction exist on multiple process levels.

Background Combined deficits in arginine vasopressin secretion (AVP) and thirst sensation can result in life threatening hyperosmolality and hypernatremia. Complications include seizures, profound volume contraction and renal failure. Fortunately, this is an uncommon clinical condition, with approximately 70 cases reported in the literature over the past 47 years [1]. Defects in AVP secretion and/or synthesis produce central diabetes insipidus (DI), polyuria with polydipsia, hypernatremia and hyperosmolality. Most awake and alert patients with an intact thirst stimulus will "drink" themselves back to a normal serum sodium and osmolality. However, if there is concomitant destruction of the osmoreceptors that regulate thirst, osmolal and volume homeostasis cannot be maintained. The relationships between urine osmolarity and serum osmolarity and plasma vasopressin levels are vital for distinguishing a reset osmostat from central DI. Methods After obtaining approval from our institutional review board, we retrospectively reviewed the medical record of a 37-year-old patient who presented to our institution with a serum sodium of 176 mEq/l. Results Admission laboratory examination revealed: hemoglobin 12.8 g/dl; white blood cell count 4.7 × 103/µl, with a normal differential; random serum glucose 91 mg/dl ; sodium 176 mEq/l; plasma osmolality 366 mOsm/kg; BUN 33 mg/dl; serum creatinine 1 mg/dl; calcium 9.5 mg/dl; urine specific gravity 1.032; and urine osmolality 1,172 mOsm/kg. An MRI with contrast of the sella/ pituitary revealed an enhancing mass centered within the suprasellar cistern and anterior third ventricle, measuring 3.0 × 3.9 × 3.4 cm. The lesion appeared to involve the hypothalamus and displaced the optic chiasm inferiorly. Evaluation of pituitary function revealed normal serum levels of thyroid stimulating hormone, AM cortisol, luteinizing hormone, follicle stimulating hormone and prolactin. Figure 1 illustrates the relationship between measured serum AVP levels and serum osmolality. Figure 2 shows the relationship between measured urine and serum osmolality. If the serum AVP levels were not available, it would appear as though the patient had a reset osmostat. The kidneys appear to appropriately generate maximally concentrated urine at a serum osmolality above 348 but are unable to below this value. Conclusions When compared with the normal curve, our patient's AVP levels were lower than expected for the corresponding osmolality. This pattern is consistent with a partial central DI. She does not have a reset osmostat. In the presence of significant volume contraction and a reduced GFR, her kidneys produced more concentrated urine despite markedly decreased central vasopressin production. As the volume contraction abated and the GFR improved, polyuria recurred, despite persistent hyperosmolarity and hypernatremia.

BACKGROUND The benefits of kidney transplantation in diabetic patients with peripheral vascular disease (PVD) are unclear. While patients may have improved survival compared to dialysis, the burden of care after transplant has not been assessed. METHODS We performed a retrospective review of adult diabetic kidney-only transplant recipients with and without PVD transplanted from January 2012 until June 30, 2015. RESULTS Of 203 diabetic kidney transplant recipients, 56 (27.6%) had PVD and 147 (72.4%) had no PVD. At a median of 3.14 years follow-up, there were no significant differences in 30-, 90-, or 1-year readmission rates. At 1 year after transplant, PVD patients were significantly more likely to have a greater sum of unplanned inpatient days (44.6% vs 27.9% with ≥10 inpatient days, P = .03) and at least 1 reoperation (28.6% vs. 8.7%, P

The diagnostic criteria for antibody-mediated rejection (AMR) are continuously evolving. Here we investigated the clinical and molecular significance of different Banff microvascular inflammation (MVI) scores in transplant kidney biopsies. A total of 356 patients with clinically indicated kidney transplant biopsies were classified into three groups based on MVI scores of 0, 1, 2, or more for Groups 1–3, respectively. Gene expression profiles were assessed using arrays on a representative subset of 93 patients. The incidence of donor-specific anti-HLA antibodies was increased from 25% in Group 1 to 36% in Group 2 and to 54% in Group 3. Acute and chronic AMR were significantly more frequent in Group 3 (15% and 35%) compared with the Group 2 (3% and 15%) and Group 1 (0% and 5%), respectively. Gene expression profiles showed increased interferon-γ and rejection-induced, cytotoxic and regulatory T-cell, natural killer cell–associated and donor-specific antibody (DSA)–selective transcripts in Group 3 compared with Groups 1 and 2. There was no significant difference in gene expression profiles between the Groups 1 and 2. Increased intragraft expression of DSA–selective transcripts was found in the biopsies of C4d− Group 3 patients. Thus, an MVI score of 2 or more was significantly associated with a histological diagnosis of acute and chronic antibody-mediated rejection. Hence, increased intragraft DSA–selective gene transcripts may be used as molecular markers for AMR, especially in C4d− biopsies.