Bloodstream Test: Immunoglobulin A What It Is The bloodstream is measured by An IgA test degree of immunoglobulin A, probably the most common antibodies in your body sildenafil citrate 100mg . Antibodies are proteins created by the disease fighting capability to fight bacteria, infections, and toxins. IgA is situated in high concentrations in your body’s mucous membranes, specially the respiratory passages and gastrointestinal system, in addition to in tears and saliva. IgA also is important in allergic reactions. IgA levels could be high in autoimmune circumstances also, disorders where the body makes antibodies against healthy tissues mistakenly. Why It’s Done An IgA test might help doctors diagnose issues with the disease fighting capability, intestines, and kidneys.