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HelpEpic Test Code LAB467 Cytomegalovirus (CMV) Antibodies, IgG, Serum
Additional Codes
MML Code: CMVG
NY State Approved
YesPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Reporting Name
Cytomegalovirus Ab, IgG, SMethod Name
Multiplex Flow Immunoassay (MFI)
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days |
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Blood Tube Draw Volume
Min 50% draw volume
Specimen Type
SerumSpecimen Minimum Volume
0.4 mL
Reference Values
Negative (reported as positive, negative, or equivocal)
Report Available
Same day/1 to 3 daysDay(s) Performed
Monday through Saturday
CPT Code Information
86644
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
| Heat-inactivated specimen | Reject |
Useful For
Determining whether a patient (especially transplant recipients and organ and blood donors) has had a recent infection or previous exposure to cytomegalovirus
Clinical Information
Cytomegalovirus (CMV) is a member of the Herpesviridae family of viruses and usually causes asymptomatic infection after which it remains latent in patients, primarily within bone marrow-derived cells.(1) Primary CMV infection in immunocompetent individuals may also manifest as a mononucleosis-type syndrome, similar to primary Epstein-Barr virus infection, with fever, malaise, and lymphadenopathy.
CMV is a significant cause of morbidity and mortality among bone marrow or solid organ transplant recipients, individuals with AIDS, and other immunosuppressed patients due to virus reactivation or from a newly acquired infection.(2,3) Infection in these patient populations can affect almost any organ and lead to multiorgan failure. CMV is also responsible for congenital disease among newborns and is one of the TORCH infections (toxoplasmosis, other infections including syphilis, rubella, CMV, and herpes simplex virus).
CMV seroprevalence increases with age. In the United States the prevalence of CMV specific antibodies increases from approximately 36% in children from 6 to 11 years old to over 91% in adults over 80 years old.(4)
Interpretation
Positive cytomegalovirus (CMV) IgG results indicate past or recent CMV infection. These individuals may transmit CMV to susceptible individuals through blood and tissue products.
Equivocal CMV IgG results may occur during acute infection or may be due to nonspecific binding reactions. Submit an additional sample for testing if clinically indicated.
Individuals with negative CMV IgG results are presumed to not have had prior exposure or infection with CMV and are, therefore, considered susceptible to primary infection.
Cautions
Sera collected very early during the acute stage of infection may have undetectable levels of cytomegalovirus (CMV) IgG. The CMV IgG assay should not be used alone to diagnose CMV infection. Results should be considered in conjunction with clinical presentation, patient history, and other laboratory findings. In cases of suspected disease, submit a second specimen for testing in 10 to 14 days.
The performance characteristics of this assay have not been evaluated in immunosuppressed patients or organ transplant recipients and have not been established for cord blood or for testing of neonates.
Immune complexes or other immunoglobulin aggregates present in patient specimens may cause increased nonspecific binding and produce false-positive results.
Potential cross-reactivity for CMV with human chorionic gonadotropin, HIV IgG, multiple myeloma IgG, rheumatoid factor IgM, and Toxoplasma gondii IgG have not be ruled out.
Supportive Data
To evaluate the accuracy of the BioPlex cytomegalovirus (CMV) IgG multiplex flow immunoassay, 598 prospective serum samples submitted for routine CMV IgG testing by the VIDAS enzyme-linked fluorescence immunoassay (ELFA; bioMerieux) were also analyzed in a blinded fashion by the BioPlex assay within a 24-hour period. Samples with discordant results after initial testing were repeated by both assays during the same freeze/thaw cycle. Further resolution of discrepant results was performed by using the Diamedix CMV IgG enzyme immunoassay. The results are summarized in the table below:
Table. CMV IgG Comparison
|
|
CMV IgG (VIDAS ELFA) |
|||
|
BioPlex CMV IgG |
|
Positive |
Negative |
Equivocal |
|
Positive |
336 |
2(a) |
0 |
|
|
Negative |
3(b) |
254 |
3 |
|
|
Equivocal |
0 |
0 |
0 |
|
a) Both serum samples were negative by the Diamedix CMV IgG EIA
b) All three serum samples were negative by the Diamedix CMB IgG EIA
Sensitivity: 99.1% (336/339); 95% CI: 97.3%-99.8%
Specificity: 99.2% (254/256); 95% CI: 97.0%-100%)
Overall Percent Agreement: 98.7% (590/598); 95% CI: 97.3%-99.4%
Specimen Retention Time
14 daysForms
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.