Background:
The Microbiology Division will switch to a different molecular platform for CMV viral load testing. The detection and quantitation of CMV DNA is intended for use as an aid in the management of immunocompromised patients with CMV infection undergoing antiviral therapy.
Effective date: Dec. 18, 2018
Methodology and reporting:
The test is FDA approved real-time PCR for plasma and has also been validated at UCI Health for bronchoalveolar lavage (BAL)/wash specimens. The assay targets two short sequences within the UL34 and UL80.5 genes of the CMV genome. The dual target is designed to provide robust, accurate, and sensitive amplification of CMV DNA. For a period of 30 days (Dec. 18, 2018 to Jan. 18, 2019), the laboratory will have both assays available to re-baseline patient’s viral load.
Plasma
- Reportable linear range of 50 - 156 million IU/mL (1.70 – 8.19 log IU/mL).
- Lower limit of quantification of 50 IU/mL (1.70 log IU/mL) with a lower limit of detection of 31.2 IU/mL (1.49 log IU/mL).
- During clinical validation testing, plasma samples were compared over a range of 3.5 to 6.1 log IU/mL. The Abbott Real-Time assay showed a mean bias of – 0.44 log IU/mL, (- 1.68 to + 0.59 log IU/mL).
Bronchoalveolar lavage/wash
- Reportable linear range of 100 - 4,000,000 IU/mL (2.0 log IU/mL – 6.6 log IU/mL).
- Lower limit of quantification of 100 IU/mL with a lower limit of detection of 31.2 IU/mL (1.49 log IU/mL).
Test code: SCMVQT
Discontinued in-house testing:
- SCMVQL: Cytomegalovirus (CMV) DNA by PCR, Qualitative
- Cytomegalovirus (CMV) DNA by PCR, Quantitative for spinal fluid, ocular fluid, amniotic fluid, urine, tissue biopsy
Specimen Required:
- Blood: Collect 10.0 mL whole blood in PPT (pearl-top EDTA tubes) or lavender EDTA tubes. Separate plasma from cells within 6 hours of collection. Transfer 2.0 mL plasma to sterile, plastic, transport tube and store refrigerated or frozen. Collect separate tubes dedicated for use on this test only.
- BAL/ Wash: 3.0 mL in a screw-capped, sterile container.
Stability: Plasma (after separation from cells) and BAL/ Wash: Ambient: 24h; Refrigerated: 5 days; Frozen: 3 months
Turnaround time (TAT): 2-10 days
Rejection criteria: Specimens that exceed stated stability, unlabeled/mislabeled/mismatched specimens, specimens submitted in leaking containers, non-sterile containers, and heparinized specimens. Any blood specimens shared with other test requests.
A summary of all tests offered by our laboratory services can be found here: http://www.pathology.uci.edu/services/index.asp
Sincerely,
Cassiana Bittencourt, MD
Director
Division of Medical Microbiology
Edwin S. Monuki, MD, PhD
Chair
Department of Pathology & Laboratory Medicine |
