Overview: Cytomegalovirus IgG (CMV IgG) TestIntroduction: The Cytomegalovirus IgG Test detects IgG antibodies to cytomegalovirus, indicating past infection that may cause fatigue or fever in immunocompromised individuals. Aligned with 2023 IDSA guidelines, it uses an immunoassay for high sensitivity, aiding in infectious disease screening. This test is critical for guiding diagnosis, treatment, and improving outcomes in virology for patients with suspected CMV infections.
Other Names: CMV IgG Assay, Cytomegalovirus Antibody Test.
FDA Status: Laboratory-developed test (LDT), meeting virology standards for diagnostic accuracy.
Historical Milestone: CMV antibody testing began in the 1970s with viral research. Immunoassays emerged in the 1980s, and by the 2000s, high-sensitivity assays improved accuracy.
Purpose: Diagnoses past CMV infection, guides management in immunocompromised patients, and monitors antibody presence.
Test Parameters: 1. Cytomegalovirus IgG
Pretest Condition: No fasting required. Collect serum or saliva at any time. Report symptoms like fatigue or fever, and list immunocompromising conditions.
Specimen: 2-5 mL serum (SST) or 1-2 mL saliva (sterile container). Centrifuge serum within 1 hour. Transport in a biohazard bag within 8 hours.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 7 days
Sample Stability at Frozen: 6 months
Medical History: Document fatigue, fever, or immunocompromised states (e.g., HIV, transplant). Include current medications, especially antivirals.
Consent: Written consent required, detailing the tests purpose, diagnostic implications, and potential need for antiviral therapy.
Procedural Considerations: Uses an immunoassay to detect CMV IgG antibodies. Results are available in 1-2 days, enabling rapid clinical decisions.
Factors Affecting Result Accuracy: Cross-reactivity with other viruses may cause false positives. Early infection may cause false negatives.
Clinical Significance: Positive IgG results indicate past CMV infection, guiding monitoring in immunocompromised patients. Negative results may require IgM or PCR testing.
Specialist Consultation: Consult an infectious disease specialist for result interpretation. A transplant specialist referral is advised for high-risk cases.
Additional Supporting Tests: CMV IgM, CMV PCR, or viral culture to confirm infection status.
Test Limitations: False positives may occur with related viruses. Results require clinical correlation.
References: IDSA CMV Guidelines, 2023; Clinical Infectious Diseases, Ljungman P, 2022.
