Home
HelpEpic Test Code CMVLR Cytomegalovirus (CMV) Molecular Detection, PCR, Lower Respiratory
Ordering Guidance
For plasma specimens, order CMVQN / Cytomegalovirus (CMV) DNA Detection and Quantification by Real-Time PCR, Plasma.
Necessary Information
Specimen source is required.
Specimen Required
Specimen Type: Lower respiratory
Source: Bronchial washing, bronchoalveolar lavage, fluid/washings from lung, sputum, tracheal secretions, tracheal aspirates
Container/Tube:
Preferred: Sterile, screwcap, 5-mL aliquot tube
Acceptable: Sterile container
Specimen Volume: 1 mL
Collection Instructions: Do not centrifuge.
Useful For
Rapid qualitative detection of cytomegalovirus (CMV) DNA in lower respiratory specimens
This test is not intended for the monitoring of CMV disease progression or response to therapy.
Method Name
Real-Time Polymerase Chain Reaction (PCR)/DNA Probe Hybridization
Reporting Name
Cytomegalovirus, PCR, Lower RespSpecimen Type
VariesSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Refrigerated (preferred) | 7 days |
| Frozen | 7 days |
Reject Due To
| Lower respiratory swab Calcium alginate-tipped swab Wood swab Transport swab containing gel Feces Paraffin blocks Tissue specimens Tissue biopsy Bronchial brushings Heat-inactivated specimens Lower respiratory in transport media |
Reject |
Clinical Information
Cytomegalovirus (CMV) is a double-stranded DNA virus of the Herpesviridae family. CMV is transmitted through infected body fluids, as well as through sexual contact, organ transplantation, and intrauterine transmission during pregnancy. CMV infection may be asymptomatic but can cause a wide range of symptoms in immunocompromised individuals. Detection of CMV DNA in lower respiratory specimens may support the clinical diagnosis of CMV pneumonitis. Infection with CMV is a significant cause of morbidity and mortality in transplant recipients and other immunocompromised hosts.
Reference Values
Negative
Reference values apply to all ages.
Interpretation
A positive result indicates the presence of cytomegalovirus (CMV) DNA in the patient specimen.
A negative result indicates the absence of CMV DNA in the patient specimen but does not rule out possible infection with CMV.
An invalid result indicates the inability to conclusively determine presence or absence of CMV DNA in the patient specimen.
Cautions
This test is not validated for lung tissue or biopsy specimens; it is only validated for the lower respiratory specimens indicated in Specimen Required.
Negative results do not preclude cytomegalovirus (CMV) infection and should not be used as the sole basis for treatment or other patient management decisions.
False-negative results may occur if the viral nucleic acid is present at a level below the analytical sensitivity of the assay, if the virus has genomic mutations, insertions, deletions, or rearrangements, or if the assay is performed very early in the course of illness.
The performance of this test has not been established for monitoring treatment of CMV infection.
Supportive Data
The following validation data support the use of this assay for clinical testing.
Accuracy:
A total of 107 previously tested (n=78) and prospective (n=29) lower respiratory clinical specimens submitted to our reference laboratory for routine cytomegalovirus (CMV) real-time polymerase chain reaction (PCR) (CMVPV / Cytomegalovirus (CMV) Molecular Detection, PCR, Varies) were tested by this test.
The overall qualitative positive percent agreement was 96% (48/50). The overall qualitative negative percent agreement was 82% (47/57).
Additional CMV testing on 8 of the 12 discrepant specimens suggests these are true CMV positive specimens, which increased the overall percent agreement to 96% (103/107). Result discrepancies were notable for specimens retrospectively collected that were subjected to extended frozen storage prior to concurrent testing by routine CMV real-time PCR and the new CMV lower respiratory assay (Diasorin Simplexa CMV). Results suggest increased assay sensitivity over the routine CMV real-time PCR assay for lower respiratory specimens, especially for those undergoing extended frozen storage (≤-70° C).
Analytical Sensitivity/Limit of Detection:
To evaluate the analytical sensitivity, whole virus control (ZeptoMetrix) was spiked into residual analyte-negative lower respiratory fluid specimens between 0.1 and 1000 copies/mL and tested in six replicates per dilution. The lowest concentration detected in all six replicates was confirmed by spiking 20 unique residual analyte-negative lower respiratory fluid specimens. A positive result was obtained in 19/20 (95%) replicates, and the analytical sensitivity (limit of detection) was determined to be 90 copies/mL.
Analytical Specificity:
The Simplexa Congenital CMV Direct assay is not US Food and Drug Administration-authorized for lower respiratory specimens. However, the kit instructions for use (Simplexa Congenital CMV Direct, IFUK.US.MOL2255, Rev. 01, 11/2022) indicate no cross-reactivity was observed with a panel of 41 organisms spiked into an upper-respiratory matrix. Inclusivity was confirmed with CMV strains AD-169, Merlin, Towne and Toledo. Additionally, in silico BLAST analysis demonstrated that the assay should detect at least 327 CMV sequences available in the NCBI database, including the 4 CMV genotypes gB1, gB2, gB3 and gB4.
Additionally, a panel of 7 organisms commonly found in the lower respiratory tract were tested by this method as part of this validation, and no was signal detected.
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 to 2 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
87496