Polyomaviruses and disease: is there more to know than viremia and viruria?
OBJECTIVE
Polyomavirus nephropathy (PVN) mainly caused by BK virus (BKV) remains the most common productive viral infection of the kidney. Over the past decade, clinical interest often focused on BK viremia and viruria as the diagnostic mainstays of patient management. The purpose of this review is to discuss viral nephropathy in the context of BK viremia and viruria and new strategies to optimize diagnostic accuracy and patient management. The emerging roles of polyomaviruses in oncogenesis, salivary gland disease, and post-bone marrow transplantation as well as novel Polyomavirus strains are highlighted.


RESULTS
Areas of investigation include proposals by the Banff working group on the classification of PVN and studies on PVN progression and resolution, including the role cellular immune responses may play during reconstitution injury. New noninvasive strategies to optimize the diagnosis of PVN, that is, the urinary 'polyomavirus-haufen' test and mRNA expression levels for BKV in the urine, hold great promise to accurately identify patients with viral nephropathy. Tools are now available to separate 'presumptive' from 'definitive' disease in various patient cohorts including individuals post-bone marrow transplantation. Recent observations also point to a currently underrecognized role of polyomaviruses in oncogenesis post-transplantation and salivary gland disease in patients with HIV-AIDS.


CONCLUSIONS
This review summarizes recent studies on PVN and the significance of the BKV strain in disease. Current paradigms for patient management post-(renal) transplantation are discussed in the setting of new observations. Issues that still require clarification and further validation are highlighted.
Division of Nephropathology, Department of Pathology and Laboratory Medicine, The University of North Carolina, Chapel Hill, North Carolina, USA.
Volker
V
Nickeleit
Harsharan K
HK
Singh
D000818:Animals; D001739:BK Virus; D006801:Humans; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D016030:Kidney Transplantation / Q000009:adverse effects; D027601:Polyomavirus Infections / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D014766:Viremia