From the Guidelines
Elevated IgG and low IgM antibody levels for Parvovirus B19, with a VP2 level of 22.1 and a VP1/VP2 co-capsid level of 20.9, indicate a past infection and are not directly relevant to the diagnosis of Tickborne diseases, such as Lyme disease, as described in the guidelines for the diagnosis of tick-borne bacterial diseases in Europe 1. The presence of elevated IgG antibodies suggests that the individual has developed long-term immunity to Parvovirus B19, which is a common virus that can cause Fifth disease in children and joint pain in adults.
- The lower IgM values indicate that this is not an active infection, as IgM antibodies typically rise during acute infection and then decline.
- The antibody patterns observed are normal after infection and represent the body's successful immune response to Parvovirus B19.
- It is essential to note that the diagnosis of Tickborne diseases, such as Lyme disease, relies on a combination of clinical criteria and laboratory evidence, including the detection of specific antibodies against the causative agent, Borrelia burgdorferi, as outlined in the guidelines 1.
- The use of IgG and IgM serology tests for the diagnosis of past viral infections should be interpreted with caution, particularly in patients who have received intravenous immunoglobin (IVIG) treatment, which may impact the results 1.
- In the context of Tickborne diseases, the focus should be on the clinical presentation and laboratory evidence specific to the suspected disease, rather than the presence of antibodies to other viruses, such as Parvovirus B19.
From the Research
Significance of Elevated IgG and Low IgM Antibody Levels
- Elevated IgG and low IgM antibody levels for Parvovirus B19 may indicate a past infection, as IgG antibodies typically persist for longer periods than IgM antibodies 2.
- The VP2 level of 22.1 and the VP1/VP2 co-capsid level of 20.9 may suggest that the individual has developed a immune response to the virus, but the low IgM level could indicate that the infection is not recent 3.
- It is essential to consider the analytical performance of the enzyme immunoassays (EIAs) used for serology testing, as different commercial assays may have varying sensitivity and specificity for detecting Parvovirus B19 IgM and IgG antibodies 4, 5, 6.
Implications for Tickborne Disease Laboratory Test
- The presence of elevated IgG and low IgM antibody levels for Parvovirus B19 in the context of a Tickborne disease laboratory test may not be directly related to the Tickborne illness, as Parvovirus B19 is a distinct virus that is not typically transmitted by ticks 2.
- However, it is crucial to consider the possibility of co-infections or cross-reactivity between different viruses, which may affect the interpretation of laboratory test results 3, 6.
- Further testing and clinical evaluation may be necessary to determine the significance of the Parvovirus B19 antibody levels in the context of the Tickborne disease laboratory test 4, 5.