From the Guidelines
A positive cytomegalovirus (CMV) IgG test result indicates past exposure to CMV, which is a common virus that affects most people at some point in their lives, and generally does not require specific treatment in healthy individuals. This result means that your immune system has developed antibodies against the virus, providing lifelong immunity [ 1 ]. According to the 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM), the presence of IgG antibodies alone indicates past exposure to CMV [ 1 ].
Key Considerations
- In healthy individuals, a positive CMV IgG result is typically not a cause for concern and does not require treatment.
- For pregnant women, a positive CMV IgG result usually indicates protection against primary CMV infection during pregnancy, which is reassuring since primary infections pose the greatest risk to the developing fetus [ 1 ].
- For immunocompromised individuals, such as transplant recipients or HIV patients, a positive CMV IgG result may indicate a potential risk for viral reactivation when immunity is suppressed, and prophylactic antiviral medications like valganciclovir may be considered in certain situations [ 1 ].
- CMV remains dormant in the body after initial infection, and while most people never experience symptoms from this latent infection, it is essential to maintain good hygiene practices to prevent transmission to others through bodily fluids.
Clinical Implications
- The diagnosis and management of CMV infection should be guided by clinical presentation, laboratory results, and individual patient factors, such as immune status and pregnancy [ 1 ].
- Healthcare providers should be aware of the potential for CMV reactivation in immunocompromised individuals and consider prophylactic antiviral therapy as needed [ 1 ].
- Patients with positive CMV IgG results should be educated on the risks and benefits of CMV infection, as well as strategies for preventing transmission to others [ 1 ].
From the Research
Cytomegalovirus (CMV) Infection and IgG Positive Status
- CMV infection is a significant concern in immunocompromised patients, such as solid organ transplant recipients 2, 3, 4, 5, 6.
- The presence of CMV IgG antibodies indicates past exposure to the virus, but does not necessarily provide immunity against future infections 4.
- CMV IgG-positive status can influence the management of CMV infection in transplant recipients, with some studies suggesting that CMV IgG-negative recipients are at higher risk of developing ganciclovir-resistant CMV infections 4.
Ganciclovir Resistance and Treatment Options
- Ganciclovir resistance is a major challenge in the management of CMV infections, particularly in solid organ transplant recipients 2, 4, 6.
- Mutations in the UL97 or UL54 genes can confer ganciclovir resistance, with UL97 mutations being more common 4, 6.
- Treatment options for ganciclovir-resistant CMV infections include foscarnet, cidofovir, and CMV immunoglobulin (CMVIG) 2, 4, 5, 6.
- CMVIG may be considered as an adjunctive or alternative therapy in certain cases, such as ganciclovir intolerance or antiviral-resistant CMV infection 5.
Clinical Implications and Management
- The management of CMV infections in transplant recipients requires careful monitoring and prompt treatment to prevent complications and resistance 2, 3, 4, 5, 6.
- The use of valganciclovir as prophylaxis against CMV infection and disease in high-risk solid organ transplant recipients can reduce the risk of viral resistance 3.
- In cases of ganciclovir-resistant CMV infection, reduction of immunosuppression and treatment with alternative antiviral agents, such as foscarnet, may be necessary 4, 6.