BK polyomavirus—pathogen, paradigm and puzzle

Abstract

BK virus is a polyomavirus with seroprevalence rates of 80% in adults. Infection is usually acquired during childhood, and the virus is benign or pathologic depending on immune status. The virus reactivates in immunodeficiency states, mostly among transplant (either kidney or bone marrow) recipients. There are approximately 15 000 renal transplants every year in the USA, of which 5–10% develop BK polyomavirus nephropathy; 50–80% of patients who develop nephropathy go on to develop graft failure. BK virus is associated with BK polyomavirus nephropathy, ureteral stenosis, late-onset hemorrhagic cystitis, bladder cancer and other nonlytic large T-expressing carcinomas. The renal spectrum begins with viruria and can end with graft failure. The clinical spectrum and outcomes vary among transplant patients. New noninvasive diagnostic methods, such as urinary polyomavirus Haufen detected by electron microscopy, are currently under study. Treatment is primarily directed at decreasing immunosuppression but may be associated with graft rejection. Repeat transplantation is encouraged as long as viral clearance in plasma prior to transplant is accomplished. There remain no definitive data regarding the utility of transplant nephrectomy.

Total nephroureterocystectomy and urethrectomy due to urothelial carcinoma associated with the BK polyomavirus infection after kidney transplantation: a case report with literature review

“…BKPyV primary infection commonly occurred as an asymptomatic, upper respiratory tract infection, or flulike infection at childhood, and approximately 65-90% of the general population may reach a seroprevalence state [5,[16][17][18][19][20]; thereafter, the virus is considered to remain mainly in the urinary tract. BKPyV infection in KTx recipient develops not only renal dysfunction due to nephropathy but also ureteral stenosis and hemorrhagic cystitis [21].…”

“…In particular, BK polyomavirus (BKPyV) is an important cause of nephropathy and graft failure for KTx recipients. BKPyV infection may cause nephropathy in 2-10% of KTx recipients [1][2][3][4][5] and lead to graft loss in approximately 15-80% [1,[5][6][7][8][9]. Furthermore, BKPyV has been known to have a tropism for the genitourinary tract and causes clinical disease.…”

Seroprevalence of BKV-Antibodies among Cancer Patients and Healthy Individuals

“…Reports show that positive serology for BKPyV infections in adults ranged between 60% and 100% [18,20,21] .…”

Human genes with relative synonymous codon usage analogous to that of polyomaviruses are involved in the mechanism of polyomavirus nephropathy

“…The infection of kidney tissues by HPyVs is associated with complications such as PVAN and allograft rejection. BKPyV can simultaneously induce inflammatory and fibrotic responses, immunosuppression, and tubular injury in kidney transplants, thereby causing kidney transplant rejection in 40–70% of infected grafts ( Babel et al., 2011 ; Ambalathingal et al., 2017 ; Raupp et al., 2020 ; Kotla et al., 2021 ; Shen et al., 2021 ). JCPyV-associated PVAN occurs in <3% of PVAN cases after renal transplantation ( Kantarci et al., 2011 ; Yang et al., 2017 ; Höcker et al., 2018 ).…”