What is IgG avidity?

What is IgG avidity?

IgG avidity assays measure the binding strength between IgG antibodies and virus that can help distinguish a primary CMV infection from a past infection. Following primary CMV infection, IgG antibodies have low binding strength (low avidity) then over 2-4 months mature to high binding strength (high avidity).

What does high IgG avidity mean?

IgG produced early in infection is less avid and binds to T gondii antigens more weakly than do antibodies produced later in the course of infection. High antibody avidity indicates an older, earlier infection. This test may be helpful in the setting of pregnancy, as the timing of infection has prognostic value.

What does high avidity mean?

High or intermediate avidity indicates a low risk of congenital infection, whereas low avidity indicates an increased risk.

What has higher avidity IgG or IgM?

Avidity (functional affinity) is the accumulated strength of multiple affinities. For example, IgM is said to have low affinity but high avidity because it has 10 weak binding sites for antigen as opposed to the 2 stronger binding sites of IgG, IgE and IgD with higher single binding affinities.

What is the normal range of IgG?

Reference range/units Normal Ranges Adult: IgG 6.0 - 16.0g/L. IgA 0.8 - 3.0g/L.

What is the normal range of Toxoplasma IgG?

Depending on the test value, positive results are defined as a value of ≥5 IU/ml, equivocal results range from 3 to 5 IU/ml, and negative results are defined as a value of