A randomized, placebo-controlled, dose-escalation phase I/II multicenter trial of low-dose cidofovir for BK polyomavirus nephropathy.

BACKGROUND: BK polyomavirus-associated nephropathy (BKPyVAN) is an important cause of allograft dysfunction and failure in kidney transplant recipients (KTRs) and there are no proven effective treatments. Case reports and in vitro data support the potential activity of cidofovir against BK polyomavirus (BKPyV). METHODS: We report the results of a phase I/II, double-blind, placebo-controlled randomized dose-escalation trial of cidofovir in KTRs with biopsy-confirmed BKPyVAN and estimated glomerular filtration rate ≥30 mL/min. Intravenous cidofovir (0.25 mg/kg/dose or 0.5 mg/kg/dose) or placebo was administered on days 0, 7, 21, and 35, with final follow-up through day 49. RESULTS: The trial was prematurely discontinued due to slow accrual after 22 KTRs had completed the study. Cidofovir was safe and tolerated at the doses and duration studied. The proportion of subjects with any adverse event (AE) was similar between groups (9/14 [64%] in the combined cidofovir dose groups and 6/8 [75%] in the placebo group); 84% of AEs were mild. BKPyV DNAemia reduction by day 49 was similar between groups (>1 log10 reduction in (2/9 [22.2%] of 0.25 mg/kg group, 1/5 [20%] of 0.5 mg/kg group, and 2/8 [25%] of placebo group). CONCLUSIONS: These preliminary results indicate that low-dose cidofovir was safe and tolerated but had no significant BKPyV-specific antiviral effect in KTRs with BKPyVAN.

Renal Considerations in COVID-19: Biology, Pathology, and Pathophysiology.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemic of epic proportion. Beyond pulmonary involvement in coronavirus disease 2019 (COVID-19), a significant subset of patients experiences acute kidney injury. Patients who die from severe disease most notably show diffuse acute tubular injury on postmortem examination with a possible contribution of focal macro- and microvascular thrombi. Renal biopsies in patients with proteinuria and hematuria have demonstrated a glomerular dominant pattern of injury, most notably a collapsing glomerulopathy reminiscent of findings seen in human immunodeficiency virus (HIV) in individuals with apolipoprotein L-1 (APOL1) risk allele variants. Although various mechanisms have been proposed for the pathogenesis of acute kidney injury in SARS-CoV-2 infection, direct renal cell infection has not been definitively demonstrated and our understanding of the spectrum of renal involvement remains incomplete. Herein we discuss the biology, pathology, and pathogenesis of SARS-CoV-2 infection and associated renal involvement. We discuss the molecular biology, risk factors, and pathophysiology of renal injury associated with SARS-CoV-2 infection. We highlight the characteristics of specific renal pathologies based on native kidney biopsy and autopsy. Additionally, a brief discussion on ancillary studies and challenges in the diagnosis of SARS-CoV-2 is presented.

Survey of US Living Kidney Donation and Transplantation Practices in the COVID-19 Era.

INTRODUCTION: The scope of the impact of the coronavirus disease 2019 (COVID-19) pandemic on living donor kidney transplantation (LDKT) practices is not well defined. METHODS: We surveyed US transplant programs to assess practices, strategies, and barriers to living LDKT during the COVID-19 pandemic. After institutional review board approval, the survey was distributed from 9 May 2020 to 30 May 2020 by e-mail and postings to professional society list-servs. Responses were stratified based on state COVID-19 cumulative incidence levels. RESULTS: Staff at 118 unique centers responded, representing 61% of US living donor recovery programs and 75% of LKDT volume in the prepandemic year. Overall, 66% reported that LDKT surgery was on hold (81% in "high" vs. 49% in "low" COVID-19 cumulative incidence states). A total of 36% reported that evaluation of new donor candidates had paused, 27% reported that evaluations were very much decreased (>0% to <25% typical), and 23% reported that evaluations were moderately decreased (25% to <50% typical). Barriers to LDKT surgery included program concerns for donor (85%) and recipient (75%) safety, patient concerns (56%), elective case restrictions (47%), and hospital administrative restrictions (48%). Programs with higher local COVID-19 cumulative incidence reported more barriers related to staff and resource diversion. Most centers continuing donor evaluations used remote strategies (video, 82%; telephone, 43%). As LDKT resumes, all programs will screen for COVID-19, although timeframe and modalities will vary. Recommendations for presurgical self-quarantine are also variable. CONCLUSION: The COVID-19 pandemic has had broad impacts on LDKT practice. Ongoing research and consensus building are needed to reduce barriers, to guide optimal practices, and to support safe restoration of LDKT across centers.

Range and Consistency of Outcomes Reported in Randomized Trials Conducted in Kidney Transplant Recipients: A Systematic Review.

BACKGROUND: The potential for clinical trials to impact patient care may be limited if the outcomes reported vary by trial and lack direct relevance to patients. Despite the many trials conducted in kidney transplantation, premature death due to cardiovascular disease, infection, and malignancy remains high. We aimed to assess the range and consistency of outcomes reported in trials in kidney transplantation. METHODS: We searched for randomized trials conducted in kidney transplantation. We extracted the outcome measures, classified them into outcome domains, and into categories (clinical, surrogate or patient-reported outcome [PRO]). We assessed the measures used for the top 4 domains. RESULTS: Overall, 397 trials reported 12 047 outcomes measures and time points (median, 19 per trial; interquartile range, 9-42) across 106 different domains, of which 55 (52%) were surrogate, 35 (33%) clinical, and 16 (15%) PRO. The 4 most frequently reported were graft function (322 [81%] trials, 118 outcome measures), acute rejection (234 [59%], 93 measures), graft loss (215 [54%], 48 measures), and mortality (204 [51%], 51 measures). The remaining 102 domains were reported in less than 50% of trials. CONCLUSIONS: Mortality- and graft-related outcome domains were frequently reported and assessed with a multiplicity of measures. Most outcome domains were surrogate outcomes, and the reporting of relevant life-threatening complications and PRO were uncommon. Establishing core outcomes based on the shared priorities of patients/caregivers and health professionals in kidney transplantation may improve the relevance and consistency of outcome reporting in trials to better inform clinical decision making.

Bowman capsulitis predicts poor kidney allograft outcome in T cell-mediated rejection.

Acute T cell-mediated rejection (TCMR) is an important cause of renal allograft loss. The Banff classification for tubulointerstitial (type I) rejection is based on the extent of both interstitial inflammation and tubulitis. Lymphocytes may also be present between parietal epithelial cells and Bowman capsules in this setting, which we have termed "capsulitis." We conducted this study to determine the clinical significance of capsulitis. We identified 42 patients from the pathology archives at The University of Chicago with isolated Banff type I TCMR from 2010 to 2015. Patient demographic data, Banff classification, and graft outcome measurements were compared between capsulitis and noncapsulitis groups using Mann-Whitney U test. Capsulitis was present in 26 (62%) and was more frequently seen in Banff IB than in IA TCMR (88% versus 44%, P = .01). Patients with capsulitis had a higher serum creatinine at biopsy (4.6 versus 2.9 mg/dL, P = .04) and were more likely to progress to dialysis (42% versus 13%, P = .06), with fewer recovering their baseline serum creatinine (12% versus 38%, P = .08). Patients with both Banff IA TCMR and capsulitis have clinical outcomes similar to or possibly worse than Banff IB TCMR compared with those with Banff IA and an absence of capsulitis. Capsulitis is an important pathologic parameter in the evaluation of kidney transplant biopsies with potential diagnostic, prognostic, and therapeutic implications in the setting of TCMR.

Developing Consensus-Based Priority Outcome Domains for Trials in Kidney Transplantation: A Multinational Delphi Survey With Patients, Caregivers, and Health Professionals.

BACKGROUND: Inconsistencies in outcome reporting and frequent omission of patient-centered outcomes can diminish the value of trials in treatment decision making. We identified critically important outcome domains in kidney transplantation based on the shared priorities of patients/caregivers and health professionals. METHODS: In a 3-round Delphi survey, patients/caregivers and health professionals rated the importance of outcome domains for trials in kidney transplantation on a 9-point Likert scale and provided comments. During rounds 2 and 3, participants rerated the outcomes after reviewing their own score, the distribution of the respondents' scores, and comments. We calculated the median, mean, and proportion rating 7 to 9 (critically important), and analyzed comments thematically. RESULTS: One thousand eighteen participants (461 [45%] patients/caregivers and 557 [55%] health professionals) from 79 countries completed round 1, and 779 (77%) completed round 3. The top 8 outcomes that met the consensus criteria in round 3 (mean, ≥7.5; median, ≥8; proportion, >85%) in both groups were graft loss, graft function, chronic rejection, acute rejection, mortality, infection, cancer (excluding skin), and cardiovascular disease. Compared with health professionals, patients/caregivers gave higher priority to 6 outcomes (mean difference of 0.5 or more): skin cancer, surgical complications, cognition, blood pressure, depression, and ability to work. We identified 5 themes: capacity to control and inevitability, personal relevance, debilitating repercussions, gaining awareness of risks, and addressing knowledge gaps. CONCLUSIONS: Graft complications and severe comorbidities were critically important for both stakeholder groups. These stakeholder-prioritized outcomes will inform the core outcome set to improve the consistency and relevance of trials in kidney transplantation.

Toward Establishing Core Outcome Domains For Trials in Kidney Transplantation: Report of the Standardized Outcomes in Nephrology-Kidney Transplantation Consensus Workshops.

BACKGROUND: Treatment decisions in kidney transplantation requires patients and clinicians to weigh the benefits and harms of a broad range of medical and surgical interventions, but the heterogeneity and lack of patient-relevant outcomes across trials in transplantation makes these trade-offs uncertain, thus, the need for a core outcome set that reflects stakeholder priorities. METHODS: We convened 2 international Standardized Outcomes in Nephrology-Kidney Transplantation stakeholder consensus workshops in Boston (17 patients/caregivers; 52 health professionals) and Hong Kong (10 patients/caregivers; 45 health professionals). In facilitated breakout groups, participants discussed the development and implementation of core outcome domains for trials in kidney transplantation. RESULTS: Seven themes were identified. Reinforcing the paramount importance of graft outcomes encompassed the prevailing dread of dialysis, distilling the meaning of graft function, and acknowledging the terrifying and ambiguous terminology of rejection. Reflecting critical trade-offs between graft health and medical comorbidities was fundamental. Contextualizing mortality explained discrepancies in the prioritization of death among stakeholders-inevitability of death (patients), preventing premature death (clinicians), and ensuring safety (regulators). Imperative to capture patient-reported outcomes was driven by making explicit patient priorities, fulfilling regulatory requirements, and addressing life participation. Specificity to transplant; feasibility and pragmatism (long-term impacts and responsiveness to interventions); and recognizing gradients of severity within outcome domains were raised as considerations. CONCLUSIONS: Stakeholders support the inclusion of graft health, mortality, cardiovascular disease, infection, cancer, and patient-reported outcomes (ie, life participation) in a core outcomes set. Addressing ambiguous terminology and feasibility is needed in establishing these core outcome domains for trials in kidney transplantation.

Variability in assessing for BK viremia: whole blood is not reliable and plasma is not above reproach - a retrospective analysis.

Polyomavirus nephropathy (PVN) is a major complication of kidney transplantation. Most reports describe polyomavirus viremia either precedes or is detectable at the time of diagnosis of PVN. This association is the basis of current screening recommendations. We retrospectively reviewed the PCR results of blood and urine samples from 29 kidney transplant recipients with biopsy-proven PVN. Biopsies were performed for a rise in serum creatinine or persistent high-level BK viruria. All biopsies showed polyoma virus large T-antigen expression in tubular epithelium using immunohistochemistry. All had viruria preceding or at the time of biopsy (range, 5.2 × 104 to >25 × 106 BKV DNA copies/ml). Twenty (69%) had viremia ranging from 2.5 × 103 to 4.3 × 106 copies/ml at the time of the biopsy. Via blood BK PCR assay, nine (31%) had no BK viremia detected either preceding or at the time of the biopsy. In five recipients where sufficient specimen permitted, additional plasma BK assessment revealed positive detection of viremia. A comparative analysis of assays from two centres was performed with spiked samples. BK DNA may not be detected in the blood of some kidney transplant recipients with histologically confirmed PVN. This may reflect limitation of whole blood as opposed to plasma-based BK DNA assessment.

High-level viruria as a screening tool for BK virus nephropathy in renal transplant recipients.

BACKGROUND: Although early monitoring of BK virus infection in renal transplant patients has led to improved outcomes over the past decade, it remains unclear whether monitoring for viremia is the best screening tool for BK virus nephropathy (BKVN). METHODS: We conducted a retrospective review of the medical records of 368 renal transplant recipients who had a minimum of 18 months of posttransplantation follow-up. The relationship between the presence of BK viruria and a composite end point of BK viremia/BKVN was established, and the predictive value of high-grade BK viruria for development of viremia/BKVN was determined. RESULTS: High grade of BK viruria was present in 110 (30.1%) of the renal transplant recipients. BK viremia/BKVN was present in 64 (17.4%) patients and was 50 times more likely to be present in patients with high-grade BK viruria. The risk of developing BK viremia/BKVN was 3 times higher in high-grade viruria patients, and viruria preceded viremia by nearly 7 weeks. CONCLUSION: The presence of high-grade viruria is an early marker for developing BK viremia/BKVN. Detection of high-grade viruria should prompt early allograft biopsy and/or preemptive reduction in immunosuppression.

Standardized Outcomes in Nephrology-Transplantation: A Global Initiative to Develop a Core Outcome Set for Trials in Kidney Transplantation.

BACKGROUND: Although advances in treatment have dramatically improved short-term graft survival and acute rejection in kidney transplant recipients, long-term graft outcomes have not substantially improved. Transplant recipients also have a considerably increased risk of cancer, cardiovascular disease, diabetes, and infection, which all contribute to appreciable morbidity and premature mortality. Many trials in kidney transplantation are short-term, frequently use unvalidated surrogate endpoints, outcomes of uncertain relevance to patients and clinicians, and do not consistently measure and report key outcomes like death, graft loss, graft function, and adverse effects of therapy. This diminishes the value of trials in supporting treatment decisions that require individual-level multiple tradeoffs between graft survival and the risk of side effects, adverse events, and mortality. The Standardized Outcomes in Nephrology-Transplantation initiative aims to develop a core outcome set for trials in kidney transplantation that is based on the shared priorities of all stakeholders. METHODS: This will include a systematic review to identify outcomes reported in randomized trials, a Delphi survey with an international multistakeholder panel (patients, caregivers, clinicians, researchers, policy makers, members from industry) to develop a consensus-based prioritized list of outcome domains and a consensus workshop to review and finalize the core outcome set for trials in kidney transplantation. CONCLUSIONS: Developing and implementing a core outcome set to be reported, at a minimum, in all kidney transplantation trials will improve the transparency, quality, and relevance of research; to enable kidney transplant recipients and their clinicians to make better-informed treatment decisions for improved patient outcomes.

Impact of Maintenance Steroids versus Rapid Steroid Withdrawal in African-American Kidney Transplant Recipients: Comparison of Two Urban Centers.

BACKGROUND: Rapid steroid withdrawal (RSW) is used increasingly in kidney transplantation but long-term outcomes in African-American (AA) recipients are not well known. We compared 1 and 5 year transplant outcomes in a large cohort of AA patients who were maintained on continued steroid therapy (CST) to those who underwent RSW. METHODS: Post-transplant courses of A as receiving kidney allografts from 2003-2011 at two urban transplant centers in Chicago were followed. Prior to outcome analysis, we used Inverse Probability of Treatment Weights (IPTW) to match the two groups on a set of baseline risk factors. Graft and patient survival, GFR at 1 and 5 years, incidence and type of rejection, incidence of post-transplant diabetes mellitus (PTDM), delayed graft function, CMV and BK viremia were compared. RESULTS: There were 150 AA recipients in the CST analytic group and 157 in the RSW analytic group. Graft and patient survival was similar between the two groups. Rates of CMV viremia were higher in the RSW compared to the CST analytic group at 1 year. Biopsy-proven acute rejection and PTDM were similar between the RSW and CST groups. CONCLUSIONS: In AA recipients, RSW has similar long-term outcomes to CST.

Late kidney dysfunction in a kidney transplant recipient.

Late kidney transplant dysfunction may be a harbinger of graft failure. For many years, calcineurin inhibitor toxicity was felt to be the main cause for graft dysfunction with fibrosis and transplant loss. Recently this idea has come into question. With the observation that peritubular capillary C4d staining in kidney allografts may indicate antibody-mediated injury in conjunction with biopsy study findings, an appreciation for antibody-mediated rejection as a major cause of late graft dysfunction and loss has emerged. Twenty percent to 30% of patients develop de novo donor-specific antibodies after kidney transplantation. There are no US Food and Drug Administration-approved treatments for antibody-mediated rejection, nor have any randomized controlled trials assessed efficacy. Off-label treatment strategies include some combination of plasma exchange, intravenous immunoglobulin, and rituximab. Other approaches, including splenectomy, bortezomib, and eculizumab, have also been tried.

AA amyloidosis in the renal allograft: a report of two cases and review of the literature.

AA amyloidosis is a disorder characterized by the abnormal formation, accumulation and systemic deposition of fibrillary material that frequently involves the kidney. Recurrent AA amyloidosis in the renal allograft has been documented in patients with tuberculosis, familial Mediterranean fever, ankylosing spondylitis, chronic pyelonephritis and rheumatoid arthritis. De novo AA amyloidosis is rarely described. We report two cases of AA amyloidosis in the renal allograft. Our first case is a 47-year-old male with a history of ankylosing spondylitis who developed end-stage renal disease reportedly from tubulointerstitial nephritis from non-steroidal anti-inflammatory agent use. A biopsy was never performed. One year after transplantation, AA amyloidosis was identified in the femoral head and 8 years post-transplantation, AA amyloidosis was identified in the renal allograft. He was treated with colchicine and adalimumab and has stable renal function at 1 year-follow-up. Our second case is a 57-year-old male with a long history of intravenous drug use and hepatitis C infection who developed end-stage kidney disease due to AA amyloidosis. Our second patient's course was complicated by renal adenovirus, pulmonary aspergillosis and hepatitis C with AA amyloidosis subsequently being identified in the allograft 2.5 years post-transplantation. Renal allograft function remains stable 4-years post-transplantation. These reports describe clinical and pathologic features of two cases of AA amyloidosis presenting with proteinuria and focal involvement of the renal allograft.

Plasma cell densities and glomerular filtration rates predict renal allograft outcomes following acute rejection.

The contribution of T cells and graft-reactive antibodies to acute allograft rejection is widely accepted, but the role of graft-infiltrating B and plasma cells is controversial. We examined 56 consecutive human renal transplant biopsies classified by Banff schema into T-cell-mediated (N = 21), antibody-mediated (N = 18), and mixed (N = 17) acute rejection, using standard immunohistochemistry for CD3, CD20, CD138, and CD45. In a predominantly African-American population (75%), neither Banff classification nor C4d deposition predicted the return to dialysis. Immunohistochemical analysis revealed CD3(+) T cells as the dominant cell type, followed by CD20(+) B cells and CD138(+) plasma cells in all acute rejection types. Using univariate Cox Proportional Hazard analysis, plasma cell density significantly predicted graft failure while B-cell density trended toward significance. Surprisingly T-cell density did not predict graft failure. The estimated glomerular filtration rate (eGFR) at diagnosis of acute rejection also predicted graft failure, while baseline eGFR ≥6 months prior to biopsy did not. Using multivariate analysis, a model including eGFR at biopsy and plasma cell density was most predictive of graft loss. These observations suggest that plasma cells may be a critical mediator and/or an independently sensitive marker of steroid-resistant acute rejection.

Monitoring and managing graft health in the kidney transplant recipient.

Ongoing monitoring of kidney transplants is a widely accepted and practiced part of posttransplantation management. One reason to monitor is to evaluate whether the transplant is stable. The transplant community evaluates stability by checking kidney function. Despite problems with sensitivity and specificity, obtaining serial serum creatinine levels is the most common approach to assessing kidney function. Some programs supplement serial serum creatinine levels with surveillance kidney biopsies. Although not uniformly accepted as beneficial, surveillance biopsies are useful in select subsets of patients such as highly sensitized recipients. Recent biopsy studies shed light on which histopathology findings portend poor prognoses. The Long-Term Deterioration of Kidney Allograft Function Study (DeKAF) and similar studies that will prospectively evaluate therapeutic interventions should help the transplant community better define how to monitor and manage the kidney transplant optimally. In the meantime, Kidney Diseases: Improving Global Outcomes (KDIGO) provides an evidence-based approach toward monitoring and managing the kidney transplant.

KDIGO clinical practice guideline for the care of kidney transplant recipients: a summary.

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression and graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research. This summary includes a brief description of methodology and the complete guideline recommendations but does not include the rationale and references for each recommendation, which are published elsewhere.

BK virus infection is associated with hematuria and renal impairment in recipients of allogeneic hematopoetic stem cell transplants.

BK virus (BKV) is an important pathogen and cause of nephropathy in renal transplant recipients, but its significance following hematopoetic stem cell transplantation (HSCT) is less well described. We measured blood and urine BKV in 124 allogeneic HSCT patients (67 had undergone prior HSCT [surveillance cohort]; 57 were monitored from transplant day 0 [prospective cohort]). BK viruria was manifest in 64.8% of the patients; 16.9% developed viremia. In the prospective cohort, the median time from transplantation to BK viremia development (128 days) was longer than for viruria (24 days; P < .0001). Among clinical factors (sex, disease, transplant type, alemtuzumab use, cytomegalovirus [CMV] viremia, graft-versus-host disease [GVHD], donor HLA C7 allele), only CMV viremia was more common in patients with BKV infection (P < or = .04). There was a direct relationship between blood and urine BKV levels and the occurrence, and degree, of hematuria (P < or = .03). Finally, BKV infection was analyzed along with other clinical factors in relation to the development of post-HSCT renal impairment. On multivariate analysis, only BK viremia (P=.000002) and alternative-donor transplantation (P=.002) were independent predictors of development of post-HSCT renal impairment, with BK viremia associated with a median 1.62mg/dL rise in creatinine from the pretransplant baseline. Among 8 patients in the surveillance cohort with BK viremia, 2 developed biopsy-proven BKV nephropathy requiring hemodialysis. Investigation of whether prophylaxis against, or treatment of, BKV in the post-HSCT setting mitigates the associated morbidities, especially kidney injury, warrants prospective evaluation.

Treatment of renal allograft polyoma BK virus infection with leflunomide.

BACKGROUND: Polyoma BK virus produces an aggressively destructive nephropathy in approximately 3% to 8% of renal allografts, is associated with graft loss within one year in 35% to 67% of those infected and there is no therapy of proven efficacy. Leflunomide is an immune suppressive drug with anti viral activity in vitro and in animals. METHODS: We treated twenty-six patients with biopsy proven NK virus nephropathy (BKN) with either leflunomide alone (n=17) or leflunomide plus a course of cidofovir (n=9) and followed them for six to forty months. Leflunomide was dosed to a targeted blood level of active metabolite, A77 1726, of 50 microg/ml to 100 microg/ml (150 microM to 300 microM). Response to treatment was gauged by serial determinations of viral load in blood and urine (PCR), serum creatinine, and repeat allograft biopsy. RESULTS: In the 22 patients consistently sustaining the targeted blood levels of active drug, blood and urine viral load levels uniformly decreased over time (P<.001). Mean serum creatinine levels stabilized over the first six months of treatment, and with 12 months or more of follow-up in 16 patients the mean serum creatinine has not changed significantly from base line. Four patients who did not consistently have blood levels of active drug (A77 1726) above 40 microg/ml did not clear the virus until these levels were attained or cidofovir was added. CONCLUSIONS: Leflunomide inhibits Polyoma virus replication in vitro and closely monitored leflunomide therapy with specifically targeted blood levels appears to be a safe and effective treatment for Polyoma BK nephropathy.