Is it necessary to test for IgG if IgM is negative?
Disease description:
“I’m not afraid of anything—except falling ill, especially with a chronic disease.” Question: If the IgM test result is negative, is it still necessary to perform an IgG test?
Doctor's answer (2)
Dr. Chen Tansheng
Testing for immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies is clinically indicated in all relevant cases. Even if IgM testing yields a negative result, IgG testing remains necessary, as these are two distinct assays with different clinical implications. A positive IgM result suggests a recent infection, whereas a positive IgG result indicates a past infection. Together, these tests help determine whether treatment is required. If only past infection is confirmed and the patient is currently asymptomatic, no intervention may be needed.
