What is an IgA blood test?

IgA tests measure the blood level of the antibody immunoglobulin A, explains Kids Health. An IgA test diagnoses immune system, kidney and intestine issues, and observes autoimmune conditions, such as celiac disease, rheumatoid arthritis and lupus. Blood is drawn from the vein, and results typically arrive within two days.

Low levels of IgA increase the risk of developing allergies, an autoimmune condition, asthma or infection, explains Kids Health. IgA tests are used when a patient has recurring infections. Immunoglobulin A is found in its highest concentration in the gastrointestinal tract, respiratory passages, tears and saliva, states Kids Health. An IgA test is mostly painless, but feeling lightheaded, pain at the puncture site or a hematoma could occur.