What is a highly positive igg 491 convalescent phase?

Out of context: Your question is missing the reason or the specific antibody test you are requesting us to interpret. It is not complete here. It is more appropriate to get your test results interpreted by the physician that ordered the test since they will have the clinical context and reason for the test already.

Immunoglobulin: IgG or immunoglobulin G is a protein secreted by B cells and is part of your immune system (lymphocytes) trying to eradicate a virus, bacteria or fungus that may have caused an infection. Frankly, I do not think a level of 491 is that high. Ask your physician who obtained this immune function test to explain.