Diagnosis of acute infection with cytomegalovirus (CMV)
This test should not be used for screening blood or plasma donors
Specimen Type
Serum
Specimen Requirements
Preferred: Serum Gel
Acceptable: Red Top
Minimum Sample Volume
0.4 mL
Stability
Refrigerated (preferred): 14 days
Frozen: 14 days
Unacceptable Specimen Conditions
Gross hemolysis
Gross lipemia
Gross icterus
Heat-inactivated specimen
Limitations
Sera drawn very early during the acute stage of infection may have undetectable levels of cytomegalovirus (CMV) IgM
Immunocompromised patients may have impaired immune responses and nonreactive IgM results may be due to delayed seroconversion and do not rule-out current infection
CMV IgM results 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 sample for testing in 10 to 14 days
The performance characteristics of these assays have not been evaluated in immunosuppressed 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 samples may cause increased nonspecific binding and produce false-positive results
Potential cross-reactivity for CMV IgM may occur with specimens positive for Epstein-Barr virus viral capsid antigen IgM and parvovirus B19 IgM.
