OBJECTIVE We investigated the expression of early and late phase BK virus (BKV) proteins and their interactions with host cell proteins in renal allografts, with ongoing polyomavirus associated nephropathy (PVAN), and correlated this with the nuclear and cell morphology. METHODS Frozen sections from three patients with renal allografts (two biopsies, one explant) with PVAN were analysed by in...

Reactivation of the polyomavirus BK (BKV) causes polyomavirus nephropathy (PVN) in kidney transplant (KTx) recipients and may lead to loss of the renal allograft. We have identified two HLA-A*0201-restricted nine-amino-acid cytotoxic T lymphocyte (CTL) epitopes of the BKV major capsid protein VP1, VP1(p44), and VP1(p108). Using tetramer staining assays, we showed that these epitopes were recogn...

REFERENCES 1. Hirsch HH, Steiger J. Polyomavirus BK. Lancet Infect Dis 2003;3:611-23. 2. Friedman DP, Flanders AE. MR Imaging of BK virus encephalitis. AJNR Am J Neuroradiol 2006;27:1016-8. 3. Lopes da Silva R, Ferreira I, Teixeira G, et al. BK virus encephalitis with thrombotic microangiopathy in an allogeneic hematopoietic stem cell transplant recipient. Transpl Infect Dis 2011;13:161-7. 4. B...

BACKGROUND Methods for determining the origin of BK virus (BKV)-infected cells (decoy cells) in clinical urine samples have not been established although they could enhance the diagnosis of BKV infection in immunocompromised patients. METHODS We performed simultaneous immunostaining with anti-S100P (a urothelial marker) and anti-SV40 antibodies in 66 clinical urine samples exhibiting SV40 pos...

BK virus-associated hemorrhagic cystitis (HC) is frequent in patients undergoing bone marrow transplantation, but it rarely occurs among other immunosuppressed patients particularly in those who are receiving chemotherapy for hematologic malignancies. Herein, we report three children with malignancies suffering from hemorrhagic cystitis due to BK virus infection who were successfully improved. ...

Most research providing evidence for the role of oncogenic viruses in head and neck squamous cell carcinoma (SCC) development is focused on one type of virus without analyzing possible interactions between two or more types of viruses. The aim of this study was to analyse the prevalence of co-infection with human papillomavirus (HPV), Epstein-Barr virus (EBV) and polyoma BK virus (BKPyV) in ora...

BACKGROUND Reactivation of polyomavirus BK (BKV) after renal transplantation can lead to allograft dysfunction or loss with early detection improving outcomes. Current guidelines recommend quantitative polymerase chain reaction for surveillance; however, urinary decoy cell detection is a potentially cost-effective alternative. We present the outcomes from an early intensive BKV surveillance pro...

BK virus (BKV) genotyping has been historically based on nucleotides 1744 to 1812 in the VP1 gene. We reevaluated this practice by making BKV whole-genome and gene-specific phylogenetic trees as well as performing single nucleotide polymorphism (SNP) analysis of 162 sequences available in the public domain. It was found that currently known BKV subtypes and subgroups can no longer be reliably d...

Impaired BK virus (BKV)-specific immunity is a key risk factor of polyomavirus-associated nephropathy. We hypothesized that BKV agnoprotein might constitute an important immune target, as it is highly expressed after infection in vitro. We demonstrate abundant expression of BKV agnoprotein in vivo by immunostaining of kidney transplant (KT) biopsy specimens. Antibody responses to the recombinan...