What it measures
The total amount of IgA antibodies in the blood. IgA is the antibody class found mainly in the lining of the gut, airways and other mucous membranes. Low IgA on its own is fairly common and is often found by chance.
Why people test it
- Measured alongside the tTG-IgA coeliac test, as low IgA can make that test read falsely negative.
- Investigating frequent infections, usually together with IgG and IgM.
- Measured when another blood test suggests myeloma or a related condition.
Typical range
Gloucestershire Hospitals' laboratory gives an adult range (ages 16 to 60) of 0.70 to 4.00 g/L. Ranges vary by lab, method, age and sex, and your report shows the lab's own range. Source: Gloucestershire Hospitals NHS Foundation Trust, Pathology: Immunoglobulins and electrophoresis.
Finger-prick or vein?
A finger-prick sample is usually fine for this test, and some providers offer a home kit. Others take blood from a vein, at a clinic or with a visiting nurse.