Clinical Background
BK virus is a polyoma virus in the same family of viruses as human papilloma and JC virus.
Epidemiology
- Prevalence
- Primary BK infection generally occurs in childhood (without specific symptoms)
- Most are seropositive by 5 years
- Transmission
- The virus is transmitted via respiratory secretions
- Organism
- Double-stranded DNA virus
- Genetically similar to JC virus
Clinical Presentation
- Clinical disease is rare in immunocompetent adults
- BK virus infections are a cause of morbidity and mortality for patients with hematologic malignancies and transplants
- Illnesses caused by BK virus include:
- Nephropathy and graft loss in renal transplant patients
- BK virus allograft nephropathy (BKVAN) is present in up to 8% of kidney transplant patients
- Tubulointerstitial nephritis is the most common manifestation
- New immunosuppressive regimens may increase the risk of BKVAN
- Hemorrhagic cystitis and renal impairment in patients with hematologic malignancy and bone marrow transplant
Treatment
- Bone marrow/hematologic malignancies
- Supportive in hemorrhagic cystitis; most patients recover
- Refractory cystitis may be catastrophic
- Poor response to antiviral therapy
- Renal transplant
- If no active rejection present, judicious reduction of immune suppression is acceptable and usually decreases viral load
See Also
Diagnosis
Diagnosis
- Gold standard in BKVAN is renal biopsy
- Demonstration of BK virus inclusions in renal cells
- PCR assay
- More sensitive than urine cytology measurements
- Provides objective estimate of viral load
Differential Diagnosis
- Other viral infections
- Acute or chronic rejection
- Malignancy
Tests generally appear in the order most useful for common clinical situations
| Test name: BK Virus, Quantitative by PCR
|
| ARUP #: 0090067 |
| Methodology: Polymerase Chain Reaction
|
| Use: Exclude diagnosis of BKVAN
Monitor patient response to treatment
|
| Limitations: A negative result does not rule out the presence of PCR inhibitors in the patient specimen or BK virus DNA concentrations below the level of detection by the assay
Inhibition may also lead to underestimation of viral quantitation |
| Follow-up: A renal allograft biopsy is required to make a definitive diagnosis of BKVAN |
| Test name: BK Virus, Qualitative by PCR
|
| ARUP #: 0099176 |
| Methodology: Polymerase Chain Reaction
|
| Use: Exclude diagnosis of BKVAN |
| Limitations: A negative result does not rule out the presence of PCR inhibitors in the patient specimen or BK virus DNA concentrations below the level of detection by the assay |
| Follow-up: A renal allograft biopsy is required to make a definitive diagnosis of BKVAN |
| Test name: Immunohistochemistry Stain Offering
|
| ARUP #: arup005 |
| Methodology: Immunohistochemistry
|
| Use: For fixed tissue samples, consultative services as well as immunohistochemical staining for the presence of BK virus are available |
References
General References
Boeckh M, Erard V, Zerr D, Englund J. Emerging viral infections after hematopoietic cell transplantation. Pediatr Transplant.
2005;
9 Suppl 7:
48-54.
Bohl DL, Brennan DC. BK virus nephropathy and kidney transplantation. Clin J Am Soc Nephrol.
2007;
2 Suppl 1:
S36-S46.
Braun WE. BK polyomavirus: a newly recognized threat to transplanted kidneys. Cleve Clin J Med.
2003;
70(
12):
1056, 1059-1060, 1062.
Drachenberg CB, Papadimitriou JC, Ramos E. Histologic versus molecular diagnosis of BK polyomavirus-associated nephropathy: a shifting paradigm?. Clin J Am Soc Nephrol.
2006;
1(
3):
374-379.
Liptak P, Kemeny E, Ivanyi B. Primer: histopathology of polyomavirus-associated nephropathy in renal allografts. Nat Clin Pract Nephrol.
2006;
2(
11):
631-636.
Randhawa P, Brennan DC. BK virus infection in transplant recipients: an overview and update. Am J Transplant.
2006;
6(
9):
2000-2005.
Wade JC. Viral infections in patients with hematological malignancies. Hematology Am Soc Hematol Educ Program.
2006;
:
368-374.
BK virus. Am J Transplant.
2004;
4 Suppl 10:
89-91.
Medical Reviewers
Hillyard, David R., M.D. Medical Director, Molecular Infectious Diseases at ARUP Laboratories; Associate Professor, Pathology, University of Utah
Comprehensive Review: January 2008
Last Update: May 2008
