Cytomegalovirus (CMV) DNA, Quantitative PCR, Plasma
Test Mnemonic
CMVQNT
CPT Codes
- 87497 - QTY (1)
LOINC ®
30247-1
Aliases
- CMV DNA
- CMVQNT
- SQCMVQNT
- viral load
- CMVDNA
Includes
- CMV DNA
- CMV DNA (IU/mL)
- CMV DNA (log IU/mL)
Performing Laboratory
Cleveland Clinic Laboratories
FDA Category
In Vitro Diagnostic
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Plasma | EDTA PPT (White) | Centrifuge and refrigerate. | Collect EDTA plasma according to standard protocol. Plasma must be separated from whole blood within 36 hours of collection by centrifugation (at 1,100 RCF for a minimum of 10 minutes) for samples stored at 2-25 degrees Celsius. Specimen stability is increased to 6 days if plasma is separated from whole blood within 24 hours and stored at 2-8 degrees Celsius. Plasma must be aliquoted first if sample is to be frozen. Sample cannot be shared with a test performed outside of Molecular Microbiology. Sample can only be shared with CMVQNT, HCQPCR, HIVRNA, HBVDNU, EBVQNT, or BKQUAN. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 2 mL | Plasma | EDTA (Lavender) | Centrifuge, aliquot and refrigerate ASAP. | Collect EDTA plasma according to standard protocol. Centrifuge (at >1300 RCF for a minimum of 10 minutes), aliquot into a sterile secondary tube, and test within 36 hours of collection. Specimen stability is increased to 6 days if plasma is separated from whole blood within 24 hours and stored at 2-8 degrees Celsius. Plasma must be aliquoted first if sample is to be frozen. Sample cannot be shared with a test performed outside of Molecular Microbiology. Sample can only be shared with CMVQNT, HCQPCR, HIVRNA, HBVDNU, EBVQNT, or BKQUAN. | |
| 2 mL | Plasma | Pink KEDTA | Centrifuge and refrigerate. | Collect EDTA plasma according to standard protocol. Centrifuge (at >1300 RCF for a minimum of 10 minutes) and aliquot into a sterile secondary tube within 24 hours of collection. Plasma must be aliquoted first if sample is to be frozen. Sample cannot be shared with a test performed outside of Molecular Microbiology. Sample can only be shared with CMVQNT, HCQPCR, HIVRNA, HBVDNU, EBVQNT, or BKQUAN. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Minimum volume for testing is 1.0 mL of plasma. Aliquots must be made from specimen prior to testing in any lab outside of Molecular Microbiology, and must be placed in a sterile aliquot tube. |
Stability
| Environmental Condition | Description |
|---|---|
| Refrigerated | 6 days for plasma separated from whole blood within 24 hours; 36 hours for whole blood unspun/unseparated |
| Frozen | 12 weeks for plasma if separated from whole blood and aliquoted into a secondary tube within 24 hours (plasma cannot be frozen in PPT tubes) |
| Ambient | 36 hours for plasma or for whole blood unspun/unseparated |
Days Performed
7 days a week
Turnaround Time
1 - 3 days
Methodology
| Name | Description |
|---|---|
| Polymerase Chain Reaction (PCR), Quant |
Reference Range
| CMV DNA | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Normal | Not detected |
Special Info
CMVQNT should only be utilized for EDTA plasma. For saliva and urine, utilize CMVQL. For amniotic fluid, utilize CMVAMF. For all other specimen types (CSF, BAL, fluids, tissue, bone marrow), utilize CMVCSF.
Clinical Info
Cytomegalovirus (CMV) is a common viral pathogen that can cause severe disease in immunocompromised patients, and lead to a range of presentations in congenitally-exposed infants. cobas CMV is an FDA-approved in vitro nucleic acid amplification test for the quantitation of cytomegalovirus (CMV) DNA in human EDTA plasma, and is intended for use as an aid in the management of CMV in solid organ transplant patients and in hematopoietic stem cell transplant patients. In patients receiving anti-CMV therapy, serial DNA measurements can be used to assess viral response to treatment. The results from cobas CMV must be interpreted within the context of all relevant clinical and laboratory findings. This test is not intended for use as a screening test for blood or blood products. The assay is a quantitative PCR assay that targets highly-conserved regions of the CMV DNA polymerase (UL54) gene, and is reported out in international units (IU/mL). The linear range of the assay is 34.5 to 10,000,000 IU/mL (1.54 - 7.00 log IU/mL). The lower limit of detection of the assay is 34.5 IU/mL.
Clinical Limitation
For full limitations, refer to the assay instructions for use available on the manufacturer's website. The most important limitations are summarized as follows. Mutations within the highly-conserved regions of the CMV DNA polymerase (UL54) gene covered by cobas CMV may affect primers and/or probe binding resulting in the under-quantitation of virus or failure to detect the presence of virus. The cobas CMV mitigates this risk through the use of redundant amplification primers. Negative test results do not preclude CMV infection or tissue-invasive CMV disease, and test results should therefore not be the sole basis for patient management decisions. Due to potential variability from measurements with different CMV assays, it is recommended that the same device (or assay) be used for the measurement of CMV viral load when managing CMV infection in individual patients. Current guidelines based on the precision of PCR tests suggest that the changes in serial viral load measurements should be at least 3-fold (0.5 log10) to represent biologically important changes.
Clinical Reference
1. Kotton CN, Kumar D, Caliendo AM, Huprikar S, Chou S, Danziger-Isakov L, Humar A; The Transplantation Society International CMV Consensus Group. The Third International Consensus Guidelines on the Management of Cytomegalovirus in Solid-organ Transplantation. Transplantation. 2018 Jun;102(6):900-931. doi: 10.1097/TP.0000000000002191. PMID: 29596116. 2. U.S. Food and Drug Administration (FDA). Premarket Approval Summary of Safety and Effectiveness Data P160041. Accessed July 5, 2024. https://www.accessdata.fda.gov/cdrh_docs/pdf16/P160041B.pdf.