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BK virus, DNA, Quantitative, plasma

Item Value
Approval req'd? No
Available Stat? No. However, if the patient needs the result rapidly, contact the Virology lab at 415-353-4730 to make sure the sample is included in the next available run.
Test code BKV
Test group BK virus
Performed by Microbiology
In House Availability Test performed 3x per week.
Method Quantitative Real-Time PCR
Collection Instructions DO NOT draw from heparin containing line.
Container type Lavender top (6 mL)
Amount to Collect 6 mL blood
Sample type EDTA plasma
Preferred volume 3 mL EDTA Plasma
Min. Volume
< 3 years old 0.5 mL plasma
≥ 3 years old 1.5 mL plasma
UCSF Rejection Criteria Heparinized sample, grossly hemolyzed samples, repeat sample from a patient within 5 days unless the patient has a prior positive result in which case 2 samples may be submitted within one week.
Processing notes Separate plasma from cells and freeze at -70C within 6 hours of collection. Transport to China Basin on dry ice.
Units copies/mL
Normal range Not detected
Synonyms BKV; Polyoma virus
Stability Whole blood is stable at room temperature for 1 day. Plasma frozen at -70C 1 month
Turn around times 2-5 days.
Additional information BK virus is linked to the development of polyomavirus-associated nephropathy in kidney transplant recipients and hemorrhagic cystitis in bone marrow transplant recipients. Quantitative viral load thresholds of 10e4 copies/mL for plasma and 10e7 copies/mL for urine have been proposed as indicative of presumptive disease. PCR has been found to have excellent sensitivity and specificity for predicting disease, making measurements of BK viral load in urine and plasma useful for clinical monitoring and treatment of kidney transplant and bone marrow transplant recipients.

BKV copy number is determined by real-time PCR amplification of total plasma or urine DNA using primers to a segment of the VP2 gene on capsid protein of BK virus.

This assay is capable of accurate quantification from 1000 copies/mL to 1 x 10e10 copies/ml. Samples with DNA detected outside the linear range will be reported as "Detected, < 1000 copies/mL" or "Detected, > 1 x 10e10 copies/mL"..

Change in virus DNA level over time is a better indicator of clinical significance than absolute copy number.

The assay can reliably detect BKV DNA down to a lower limit of approximately 660 copies/ml.

This test was developed and its performance characteristics determined by the UCSF Clinical Laboratories. It has not been cleared or approved by the U.S. Food and Drug Administration.
CPT coding 87799
LOINC code 42587-6
LDT or Mod FDA? Yes
Last Updated 2/19/2015 1:56:18 PM
Entry Number 1041
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