BK viral load
BK virus by PCR
BK virus DNA quant
BKV by PCR
BKV DNA quant
BKV viral load
BK Virus PCR, Qnt, Plasma
Detection and serial monitoring of BV virus-associated nephropathy in kidney transplant recipients using plasma specimens
Detection and serial monitoring of BV virus-associated hemorrhagic cystitis in organ transplant recipients
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 renal function and eventual renal failure. The assay is calibrated to the First World Health Organization International Standard for BKV DNA.
1. Centrifuge blood collection tube per manufacturer's instructions (eg, centrifuge within 2 hours of collection for BD Vacutainer tubes).
2. Aliquot plasma into plastic vial.
ON AVERAGE, QUANTITATIVE BK VIRUS (BKV) DNA RESULTS IN PLASMA TESTED WITH THIS ASSAY CAN BE UP TO 1.4-FOLD (ABOUT 0.15 LOG IU/ML) HIGHER THAN THOSE GENERATED FROM THE PREVIOUS LABORATORY-DEVELOPED BKV DNA QUANTIFICATION ASSAY PERFORMED AT MAYO CLINIC LABORATORIES, DUE TO DIFFERENCES IN THE SPECIMEN EXTRACTION METHOD AND DESIGN IN THE AMPLIFICATION PRIMERS AND PROBES FOR THE VIRAL TARGET SEQUENCES.
A single "Undetected" test result does not necessarily rule out the presence BKV infection or reactivation. Serial measurement (eg, once weekly) of BKV DNA in plasma is recommended to determine the BKV replication status in a given transplant recipient.
The quantification range of this assay is 22 to 100,000,000 IU/mL (1.34 log to 8.00 log IU/mL), with a limit of detection (95% detection rate) at 22 IU/mL.
An "Undetected" test result indicates the absence of BK virus (BKV) DNA in the plasma.
A test result of "<22 IU/mL (<1.34 log IU/mL)" indicates that BKV DNA is detected in the plasma, but the assay cannot accurately quantify the BKV DNA present below this level.
A quantitative value (reported in IU/mL and log IU/mL) indicates the level of BKV DNA (ie, viral load) present in the plasma.
A test result of ">100,000,000 IU/mL (>8.00 log IU/mL)" indicates that BKV DNA level present in plasma is above 100,000,000 IU/mL (8.00 log IU/mL), and the assay cannot accurately quantify BKV DNA present above this level.
An "Inconclusive" result indicates that the presence or absence of BKV DNA in the plasma specimen could not be determined with certainty after repeat testing in the laboratory, possibly due to polymerase chain reaction inhibition or presence of interfering substance. Submission of a new specimen for testing is recommended if clinically indicated.