Kidney nontumor
Infection
BK virus / polyomavirus
Author: Nikhil Sangle, M.D.
Topic Completed: 3 September 2012
Minor changes: 18 February 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: BK virus polyomavirus [title] kidney pathology
Table of Contents
Definition / general | Clinical features | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Electron microscopy images | Differential diagnosisCite this page: Sangle N. BK virus / polyomavirus. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/kidneybkvirus.html. Accessed January 22nd, 2021.
Definition / general
- Polyomaviruses are nonenveloped DNA viruses, 45 nm in diameter; members of papovavirus family, which also contain papillomavirus
- Polyomavirus BK is widely present in healthy individuals, but latent in kidneys, central nervous system and B cells
- Other polyoma viruses are JC (causes progressive multifocal leukencephalopathy) and SV40 (causes subclinical infections)
- JC and BK virus infection is very prevalent in the first 2 years after kidney transplant (J Res Med Sci 2011;16:916)
- Immunosuppression promotes reactivation of latent polyoma virus, leading to viral replication in renal tubular epithelial cells
Clinical features
- BKV strain of polyoma virus may cause renal failure in AIDS patients, is reactivated in < 8% of renal transplant patients with heavy immunosuppression or rarely in other immunosuppressed patients
- Rarely occurs in nonrenal solid organ transplantation (Am J Transplant 2010;10:2324)
- Diagnose by PCR (but variant strains may affect quantitation of viral load, J Clin Microbiol 2011;49:4072); urinary decoy cell detection (Transplantation 2011;92:1018) and immunostains (SV40 immunostain crossreacts with JCV)
- Increased risk with ureteral stenting (Transplant Proc 2011;43:2641)
- Associated with interstitial nephritis, infection of glomerular epithelial cells and crescents (minority of cases)
- JC virus strain of polyoma virus usually not associated with renal damage (Hum Pathol 2001;32:656), but present in renal tissue in 6% of AIDS patients (Mod Pathol 2003;16:35)
Case reports
- 14 year old boy with AIDS and BK viral infection of lung and kidney causing diffuse alveolar damage and death (Am J Surg Pathol 2000;24:145)
- 31 year old IV drug user with AIDS and BK virus related renal failure (Arch Pathol Lab Med 1999;123:807)
- 53 year old with triple immunosuppressive therapy for transplant (Hum Pathol 2001;32:656)
- 62 year old man post transplant for SLE induced renal disease (Arch Pathol Lab Med 2001;125:973)
Microscopic (histologic) description
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In non transplanted kidney:
- Interstitial inflammation, atrophic tubules with large and eosinophilic nuclei
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In allograft kidney:
- Viral cytopathic effect with large, homogenous and purple intranuclear inclusions, primarily in tubular epithelium (Hum Pathol 2004;35:367)
- No necrosis (as seen in HSV), no perinuclear halo (as seen in CMV)
- Also ischemic glomerulopathy (62%), aneurysmal dilation of glomerular capillaries (28%) and mild increase in mesangial matrix (23%)
- Viral cytopathic effect in parietal Bowman capsule (29%, including using BK immunostains), crescents (12%) and glomerulonephritis (3%)
Microscopic (histologic) images
Images hosted on other servers:
Various images
Figure 1: tubulointerstitial nephritis with lymphocytes and enlarged tubular epithelial cells
Figure 2: tubular cells have large smudged nuclei and basophilic chromatin
Figure 3: EM shows distinct intranuclear inclusion
Figure 4: inclusion consists of crystalline arrays of nonenveloped, round, electron dense particles, mean 45 nm in diameter, in loose crystalline lattices
Electron microscopy images
Images hosted on other servers:
numerous viral
particles (inset:
anti SV40 antibody)
Differential diagnosis
- Other infection
- Rejection
