Bk polyoma virus

BACKGROUND: BK polyoma virus (BKPyV) associated nephropathy (BKPyVAN) is a major cause of kidney graft loss in renal transplant patients. Interferons (IFNs) are an important innate immune response against viral infections and genetic polymorphisms of the IFN-pathways can affect susceptibility and mortality during viral infection. Here, we investigated whether the dinucleotide polymorphism rs368234815 (ΔG/TT) in the IFNL4 gene contributed to BKPyV reactivation or BKPyVAN after living-donor kidney transplantation...

BACKGROUND: Improved short- and long-term outcomes of kidney transplantation have been achieved over the past decades due to improved immunosuppression. This may have increased the risk for infections and, particularly, for the viral infections: cytomegalovirus (CMV), Epstein-Barr virus (EBV), and polyoma BK virus (BKV). METHODS: A retrospective review of viremic CMV, EBV, and BKV infections in pediatric renal transplant recipients treated and followed by a national referral center over a 10-year period...

Progressive multifocal leukoencephalopathy (PML) is a progressive and generally fatal demyelinating neurologic disease that occurs in profoundly immunocompromised patients due to infection with the human polyomavirus JC virus (JCPyV). Treatment options are limited and are largely focused on restoring T cell immunity, and outcomes are historically poor. Control of JCPyV in the setting of an immunocompromised patient by adoptive transfer of third-party virus specific T cells (VSTs) has been described in a small number of cases...

BACKGROUND: The objective of this study was to describe the most common medical complications in simultaneous pancreas-kidney recipients in our center. METHODS: Retrospective and descriptive study of complications observed in a series of 73 simultaneous pancreas-kidney transplant recipients, which included 54 men and 19 women with an average age of 40.6 years, between February 2009 and April 2019. The study assessed the incidence of cytopenia, viral infections, tumors, and graft rejection...

Kidney transplantation (KT) from deceased donors with hepatitis C virus (HCV) into HCV-negative recipients has become more common. However, the risk of complications such as BK polyomavirus (BKPyV) remains unknown. We assembled a retrospective cohort at four centers. We matched recipients of HCV-viremic kidneys to highly similar recipients of HCV-aviremic kidneys on established risk factors for BKPyV. To limit bias, matches were within the same center. The primary outcome was BKPyV viremia ≥1000 copies/ml or biopsy-proven BKPyV nephropathy; a secondary outcome was BKPyV viremia ≥10 000 copies/ml or nephropathy...

BACKGROUND: BK nephropathy (BKN) in kidney transplants diagnosed by histology is challenging because it involves damage from both virus activity and cognate T cell-mediated inflammation, directed against alloantigens (rejection) or viral antigens. The present study of indication biopsies from the Integrated Diagnostic System in the International Collaborative Microarray Study Extension study measured major capsid viral protein 2 (VP2) mRNA to assess virus activity and a T cell-mediated rejection (TCMR) classifier to assess cognate T cell-mediated inflammation...

Polyomavirus BK virus (BKPyV) infection is an important complication of kidney transplantation and allograft failure. The prevalence of viremia is 10%-15%, compared with BK-associated nephropathy (BKPyVAN) at 3%-5%. Given that there are no effective antiviral prophylaxis or treatment strategies for BKPyVAN, active screening to detect BKPyV viremia is recommended, particularly during the early posttransplant period. Immunosuppression reduction to allow viral clearance may avoid progression to severe and irreversible allograft damage...

Reactivations of BK polyoma virus (BKPyV) and human cytomegalovirus (HCMV) frequently cause life- and graft-threatening complications after renal transplantation. Both viruses are dependent on the mTOR pathway for replication. In this study we investigated the association of viral replication with mTOR activity in peripheral lymphocytes of renal transplant recipients. A flow-cytometry based assay for the measurement of Thr389 p70S6k phosphorylation, a surrogate marker of the mTOR pathway was established. Forty-eight adult renal transplant recipients were recruited to measure p70S6k activity in their peripheral blood mononuclear cells...

BK polyomavirus-associated nephropathy is a common complication after kidney transplantation leading to reduced graft function or loss. The molecular pathogenesis of BK polyomavirus-induced nephropathy is not well understood. A recent study had described a protective effect of the activating natural killer cell receptor KIR3DS1 in BK polyomavirus-associated nephropathy, suggesting a role of NK cells in modulating disease progression. Using an in vitro cell culture model of human BK polyomavirus infection and kidney biopsy samples from patients with BK polyomavirus-associated nephropathy, we observed significantly increased surface expression of the ligand for KIR3DS1, HLA-F, on BK polyomavirus-infected kidney tubular cells...

Differential diagnosis between Polyoma virus associated-nephropathy (PVAN) and T-cell mediated rejection (TCMR) might be challenging, as respective treatment approaches are totally opposite. Here we report the illustrative case of a kidney transplant recipient with PVAN who developed a persistent acute TCMR after full abrogation of viral infection through immunosuppression modulation. By simultaneous functional immune monitoring of BKV and donor-specific T-cell responses using IFN-γELISPOT assay, we retrospectively demonstrated the predominant effector mechanisms responsible of allograft injury and thus, potential guidance for treatment decision-making...

BACKGROUND: Reducing immunosuppression can effectively treat BK viremia (BKV) and BK nephropathy, but has been associated with increased risks for acute rejection and development of donor-specific antibodies (DSA). To date there have been no systematic evaluations of re-escalating immunosuppression in transplant patients with resolving BKV. Importantly, the safety of this approach and impact on graft survival is unclear. METHODS: We performed a single-center retrospective review of kidney transplant recipients between July 2011 and June 2013 who had immunosuppression reduction after developing BKV (plasma PCR ≥ 1000 copies/ml)...

Human BK polyomavirus (BKPyV) prevalence has been increasing due to the introduction of more potent immunosuppressive agents in transplant recipients, and its clinical interest. BKPyV has been linked mostly to polyomavirus-associated hemorrhagic cystitis, in allogenic hematopoietic stem cell transplant, and polyomavirus-associated nephropathy in kidney transplant patients. BKPyV is a circular double-stranded DNA virus that encodes for seven proteins, of which Viral Protein 1 (VP1), the major structural protein, has been extensively used for genotyping...

The high morbidity and mortality of COVID-19 in immunocompetent patients raises significant concern for immunosuppressed kidney transplant recipients (KTRs). This level of concern, both on the part of the KTRs and transplant professionals, is heightened by a lack of prior knowledge on how Severe Acute Respiratory Syndrome 2 virus (SARS-CoV-2) may manifest differently in immunosuppressed patients. Characterizing how KTRs may present differently than the general population would allow for more targeted and timely evaluation and treatment of KTRs with COVID-19 infection...

INTRODUCTION: BK virus (BKPyV) nephropathy occurs in 1%-10% of kidney transplant recipients, with suboptimal therapeutic options. CASE: A 54-year-old woman received a transplant in March 2017. BKPyV was detected at 1.5 × 102  copies/mL within a month, necessitating halving of mycophenolate and addition of leflunomide. Allograft histology in December showed polyomavirus nephropathy treated with intravenous immunoglobulin and cessation of mycophenolate. In February 2018, cidofovir and ciprofloxacin were commenced...

Palatine tonsils have been observed to harbor several distinct respiratory and herpesviruses in separate studies. In this study, the presence of these viruses in palatine tonsils was comprehensively studied in both children and adults. A cross-sectional analysis of 181 patients (median age 22 years; range, 2.6-66) operated for a benign tonsillar disease was conducted. Real-time polymerase chain reaction was performed to detect 27 distinct viruses in all: eight human herpesviruses, 16 respiratory viruses, parvo B19, and polyoma BK/JC viruses...

There is no specific therapy for polyoma BK virus nephropathy (BKVN) in kidney transplant recipients, a condition associated with poor outcomes. Everolimus showed promising antiviral effects, but data from prospective studies are limited. Therefore, we converted ten consecutive kidney transplant recipients with biopsy-proven BKVN from standard exposure Calcineurin inhibitors and Mycophenolate to Everolimus and reduced exposure Calcineurin inhibitors. Ten patients not administered Everolimus, on reduced exposure Calcineurin inhibitor and halved MPA doses served as controls...

There is minimal literature describing the clinical workup of patients with persistent BKPyV-DNAemia despite aggressive immunosuppressive reduction. We present a case herein of persistent BKPyV-DNAemia with significant discordance of BK viruria level in a kidney transplant recipient found to have bladder carcinoma. Based on our findings, we recommend evaluating the urine of patients with persistent BKPyV-DNAemia for BK viruria. If there is significant discordance in the level of BKPyV-DNAemia and viruria, cystoscopy should be pursued to rule out bladder or uroepithelial malignancies...

BACKGROUND: Human polyoma virus-associated nephropathy frequently refers to allograft failure after kidney transplant. Thus, the early detection of viral activation is extremely important for these immunocompromised patients. METHODS: Previously, urine polyoma virus-infected cells (decoy cells) were indicated as the virus action, usually screened by the routine papanicolaou cytology in renal biopsy, but these methods are complex and the positive rate is low. In this article, the direct microscopy observation method, Wright-Giemsa staining, and Sternheimer-Malbin (SM) staining were all used to screen the decoy cells in urine samples of 213 kidney transplant patients who had used immunosuppressive drugs...

The risk of subsequent cytomegalovirus infection (CMV) in kidney transplant recipients (KTR) after diagnosis of BK polyomavirus viremia (BKV) is unclear, and current evidence is conflicting. We reviewed all KTR transplanted at our institution between 1/1/2005 and 12/31/2015. Follow-up began 3 months after transplantation to avoid confounding effects of prophylaxis. Clinically significant BKV, defined as detectable BK viremia >1000 copies/mL via molecular diagnostic testing (PCR), was treated as a time-varying exposure with 1-year follow-up...

The approach to transplantation in human immunodeficiency virus (HIV)-positive patients has been conservative due to fear of exacerbating an immunocompromised condition. As a result, HIV-positive patients with diabetes were initially excluded from beta cell replacement therapy. Early reports of pancreas transplant in patients with HIV described high rates of early graft loss with limited follow up. We report long-term follow up of islet or pancreas transplantation in HIV-positive Type I diabetic patients who received a kidney transplant concurrently, or had previously undergone kidney transplantation...