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HelpTEST ID PBKQN BK Virus DNA Detection and Quantification, Plasma
Reporting Name
BKV DNA Detect/Quant, PSpecimen Type
Plasma EDTAShipping Instructions
1. Ship specimen frozen on dry ice only.
2. If shipment will be delayed for more than 24 hours, freeze plasma at -20 to -80° C (up to 84 days) before shipment and then transport on dry ice.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL Plasma
Collection Instructions: Within 2 hours of collection, centrifuge and aliquot plasma into a plastic vial.
Specimen Minimum Volume
Plasma: 0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma EDTA | Frozen (preferred) | 84 days |
| Refrigerated | 6 days |
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
Undetected
Day(s) Performed
Monday through Saturday
Report Available
1 to 3 daysSpecimen Retention Time
30 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
87799
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Microbiology Test Request (T244)
-Renal Diagnostics Test Request (T830)
Useful For
Detection and serial monitoring of BK virus-associated nephropathy in kidney transplant recipients using plasma specimens
Detection and serial monitoring of BK virus-associated hemorrhagic cystitis in organ transplant recipients
Highlights
This assay detects and quantifies the level of BK virus (BKV) DNA present in the plasma of kidney transplant recipients who are at risk of developing BKV-associated nephropathy leading to decreasing kidney function and eventual kidney failure. The assay is calibrated to the First World Health Organization International Standard for BKV DNA.
Clinical Information
BK virus (BKV) is a circular, double-stranded DNA polyomavirus with genome of approximately 5 kilobases. The polyomavirus family includes 13 known members, including the JC virus (JCV) and SV40. BKV shares about 75% of its DNA sequence with JCV. Nearly 80% of adults worldwide have antibodies to both viruses, indicating prior infection or exposure.
Initial infection with BKV is usually acquired in childhood, mostly asymptomatic or manifesting as a mild flu-like illness. After primary infection, BKV establishes latency in the kidney and bladder of the infected individual. In the setting of immunosuppression, the virus reactivates and begins to replicate, triggering renal tubular cell lysis and viruria. As the reactivation progresses, the virus multiplies and crosses into the bloodstream, causing viremia and invading the kidney graft. In patients with kidney transplants, reactivation of BKV typically reaches peak incidence at 3 months posttransplantation with BK viral replication in the kidney graft, causing BKV-associated nephropathy (BKVAN), which manifests as kidney dysfunction that may result in eventual loss of the transplanted kidney. Reactivation of BKV in the bladder can lead to hemorrhagic cystitis. Currently, there are no US Food and Drug Administration-approved antiviral agents or treatments for BKVAN or BKV-associated hemorrhagic cystitis. The main treatment is to decrease immunosuppression, with risk of acute rejection of the kidney graft.
After BK reactivation, the virus is first detectable in the urine, with viremia developing several weeks later. Quantitative BKV DNA in the plasma is the most widely used and preferred test for the laboratory diagnosis of BKVAN and BKV-associated hemorrhagic cystitis, as BKV viremia has higher positive predictive value (50%-60%) than BKV viruria for the diagnosis of BKVAN. Serial monitoring of BKV DNA level in plasma is recommended to guide optimal immunosuppressant dosing regimen. In those with BKVAN, clearance of BK viremia is a sign of resolution of the nephropathy.